Fix some bugs when testing opensds ansible

[stor4nfv.git] / src / ceph / src / pybind / mgr / dashboard / static / AdminLTE-2.3.7 / plugins / fullcalendar / fullcalendar.js

/*!
 * FullCalendar v2.2.5
 * Docs & License: http://arshaw.com/fullcalendar/
 * (c) 2013 Adam Shaw
 */

(function(factory) {
        if (typeof define === 'function' && define.amd) {
                define([ 'jquery', 'moment' ], factory);
        }
        else {
                factory(jQuery, moment);
        }
})(function($, moment) {

    var defaults = {

        titleRangeSeparator: ' \u2014 ', // emphasized dash
        monthYearFormat: 'MMMM YYYY', // required for en. other languages rely on datepicker computable option

        defaultTimedEventDuration: '02:00:00',
        defaultAllDayEventDuration: { days: 1 },
        forceEventDuration: false,
        nextDayThreshold: '09:00:00', // 9am

        // display
        defaultView: 'month',
        aspectRatio: 1.35,
        header: {
                left: 'title',
                center: '',
                right: 'today prev,next'
        },
        weekends: true,
        weekNumbers: false,

        weekNumberTitle: 'W',
        weekNumberCalculation: 'local',
        
        //editable: false,
        
        // event ajax
        lazyFetching: true,
        startParam: 'start',
        endParam: 'end',
        timezoneParam: 'timezone',

        timezone: false,

        //allDayDefault: undefined,

        // locale
        isRTL: false,
        defaultButtonText: {
                prev: "prev",
                next: "next",
                prevYear: "prev year",
                nextYear: "next year",
                today: 'today',
                month: 'month',
                week: 'week',
                day: 'day'
        },

        buttonIcons: {
                prev: 'left-single-arrow',
                next: 'right-single-arrow',
                prevYear: 'left-double-arrow',
                nextYear: 'right-double-arrow'
        },
        
        // jquery-ui theming
        theme: false,
        themeButtonIcons: {
                prev: 'circle-triangle-w',
                next: 'circle-triangle-e',
                prevYear: 'seek-prev',
                nextYear: 'seek-next'
        },

        dragOpacity: .75,
        dragRevertDuration: 500,
        dragScroll: true,
        
        //selectable: false,
        unselectAuto: true,
        
        dropAccept: '*',

        eventLimit: false,
        eventLimitText: 'more',
        eventLimitClick: 'popover',
        dayPopoverFormat: 'LL',
        
        handleWindowResize: true,
        windowResizeDelay: 200 // milliseconds before an updateSize happens
        
};


var englishDefaults = {
        dayPopoverFormat: 'dddd, MMMM D'
};


// right-to-left defaults
var rtlDefaults = {
        header: {
                left: 'next,prev today',
                center: '',
                right: 'title'
        },
        buttonIcons: {
                prev: 'right-single-arrow',
                next: 'left-single-arrow',
                prevYear: 'right-double-arrow',
                nextYear: 'left-double-arrow'
        },
        themeButtonIcons: {
                prev: 'circle-triangle-e',
                next: 'circle-triangle-w',
                nextYear: 'seek-prev',
                prevYear: 'seek-next'
        }
};

    var fc = $.fullCalendar = { version: "2.2.5" };
var fcViews = fc.views = {};


$.fn.fullCalendar = function(options) {
        var args = Array.prototype.slice.call(arguments, 1); // for a possible method call
        var res = this; // what this function will return (this jQuery object by default)

        this.each(function(i, _element) { // loop each DOM element involved
                var element = $(_element);
                var calendar = element.data('fullCalendar'); // get the existing calendar object (if any)
                var singleRes; // the returned value of this single method call

                // a method call
                if (typeof options === 'string') {
                        if (calendar && $.isFunction(calendar[options])) {
                                singleRes = calendar[options].apply(calendar, args);
                                if (!i) {
                                        res = singleRes; // record the first method call result
                                }
                                if (options === 'destroy') { // for the destroy method, must remove Calendar object data
                                        element.removeData('fullCalendar');
                                }
                        }
                }
                // a new calendar initialization
                else if (!calendar) { // don't initialize twice
                        calendar = new Calendar(element, options);
                        element.data('fullCalendar', calendar);
                        calendar.render();
                }
        });
        
        return res;
};


// function for adding/overriding defaults
function setDefaults(d) {
        mergeOptions(defaults, d);
}


// Recursively combines option hash-objects.
// Better than `$.extend(true, ...)` because arrays are not traversed/copied.
//
// called like:
//     mergeOptions(target, obj1, obj2, ...)
//
function mergeOptions(target) {

        function mergeIntoTarget(name, value) {
                if ($.isPlainObject(value) && $.isPlainObject(target[name]) && !isForcedAtomicOption(name)) {
                        // merge into a new object to avoid destruction
                        target[name] = mergeOptions({}, target[name], value); // combine. `value` object takes precedence
                }
                else if (value !== undefined) { // only use values that are set and not undefined
                        target[name] = value;
                }
        }

        for (var i=1; i<arguments.length; i++) {
                $.each(arguments[i], mergeIntoTarget);
        }

        return target;
}


// overcome sucky view-option-hash and option-merging behavior messing with options it shouldn't
function isForcedAtomicOption(name) {
        // Any option that ends in "Time" or "Duration" is probably a Duration,
        // and these will commonly be specified as plain objects, which we don't want to mess up.
        return /(Time|Duration)$/.test(name);
}
// FIX: find a different solution for view-option-hashes and have a whitelist
// for options that can be recursively merged.

    var langOptionHash = fc.langs = {}; // initialize and expose


// TODO: document the structure and ordering of a FullCalendar lang file
// TODO: rename everything "lang" to "locale", like what the moment project did


// Initialize jQuery UI datepicker translations while using some of the translations
// Will set this as the default language for datepicker.
fc.datepickerLang = function(langCode, dpLangCode, dpOptions) {

        // get the FullCalendar internal option hash for this language. create if necessary
        var fcOptions = langOptionHash[langCode] || (langOptionHash[langCode] = {});

        // transfer some simple options from datepicker to fc
        fcOptions.isRTL = dpOptions.isRTL;
        fcOptions.weekNumberTitle = dpOptions.weekHeader;

        // compute some more complex options from datepicker
        $.each(dpComputableOptions, function(name, func) {
                fcOptions[name] = func(dpOptions);
        });

        // is jQuery UI Datepicker is on the page?
        if ($.datepicker) {

                // Register the language data.
                // FullCalendar and MomentJS use language codes like "pt-br" but Datepicker
                // does it like "pt-BR" or if it doesn't have the language, maybe just "pt".
                // Make an alias so the language can be referenced either way.
                $.datepicker.regional[dpLangCode] =
                        $.datepicker.regional[langCode] = // alias
                                dpOptions;

                // Alias 'en' to the default language data. Do this every time.
                $.datepicker.regional.en = $.datepicker.regional[''];

                // Set as Datepicker's global defaults.
                $.datepicker.setDefaults(dpOptions);
        }
};


// Sets FullCalendar-specific translations. Will set the language as the global default.
fc.lang = function(langCode, newFcOptions) {
        var fcOptions;
        var momOptions;

        // get the FullCalendar internal option hash for this language. create if necessary
        fcOptions = langOptionHash[langCode] || (langOptionHash[langCode] = {});

        // provided new options for this language? merge them in
        if (newFcOptions) {
                mergeOptions(fcOptions, newFcOptions);
        }

        // compute language options that weren't defined.
        // always do this. newFcOptions can be undefined when initializing from i18n file,
        // so no way to tell if this is an initialization or a default-setting.
        momOptions = getMomentLocaleData(langCode); // will fall back to en
        $.each(momComputableOptions, function(name, func) {
                if (fcOptions[name] === undefined) {
                        fcOptions[name] = func(momOptions, fcOptions);
                }
        });

        // set it as the default language for FullCalendar
        defaults.lang = langCode;
};


// NOTE: can't guarantee any of these computations will run because not every language has datepicker
// configs, so make sure there are English fallbacks for these in the defaults file.
var dpComputableOptions = {

        defaultButtonText: function(dpOptions) {
                return {
                        // the translations sometimes wrongly contain HTML entities
                        prev: stripHtmlEntities(dpOptions.prevText),
                        next: stripHtmlEntities(dpOptions.nextText),
                        today: stripHtmlEntities(dpOptions.currentText)
                };
        },

        // Produces format strings like "MMMM YYYY" -> "September 2014"
        monthYearFormat: function(dpOptions) {
                return dpOptions.showMonthAfterYear ?
                        'YYYY[' + dpOptions.yearSuffix + '] MMMM' :
                        'MMMM YYYY[' + dpOptions.yearSuffix + ']';
        }

};

var momComputableOptions = {

        // Produces format strings like "ddd MM/DD" -> "Fri 12/10"
        dayOfMonthFormat: function(momOptions, fcOptions) {
                var format = momOptions.longDateFormat('l'); // for the format like "M/D/YYYY"

                // strip the year off the edge, as well as other misc non-whitespace chars
                format = format.replace(/^Y+[^\w\s]*|[^\w\s]*Y+$/g, '');

                if (fcOptions.isRTL) {
                        format += ' ddd'; // for RTL, add day-of-week to end
                }
                else {
                        format = 'ddd ' + format; // for LTR, add day-of-week to beginning
                }
                return format;
        },

        // Produces format strings like "H(:mm)a" -> "6pm" or "6:30pm"
        smallTimeFormat: function(momOptions) {
                return momOptions.longDateFormat('LT')
                        .replace(':mm', '(:mm)')
                        .replace(/(\Wmm)$/, '($1)') // like above, but for foreign langs
                        .replace(/\s*a$/i, 'a'); // convert AM/PM/am/pm to lowercase. remove any spaces beforehand
        },

        // Produces format strings like "H(:mm)t" -> "6p" or "6:30p"
        extraSmallTimeFormat: function(momOptions) {
                return momOptions.longDateFormat('LT')
                        .replace(':mm', '(:mm)')
                        .replace(/(\Wmm)$/, '($1)') // like above, but for foreign langs
                        .replace(/\s*a$/i, 't'); // convert to AM/PM/am/pm to lowercase one-letter. remove any spaces beforehand
        },

        // Produces format strings like "H:mm" -> "6:30" (with no AM/PM)
        noMeridiemTimeFormat: function(momOptions) {
                return momOptions.longDateFormat('LT')
                        .replace(/\s*a$/i, ''); // remove trailing AM/PM
        }

};


// Returns moment's internal locale data. If doesn't exist, returns English.
// Works with moment-pre-2.8
function getMomentLocaleData(langCode) {
        var func = moment.localeData || moment.langData;
        return func.call(moment, langCode) ||
                func.call(moment, 'en'); // the newer localData could return null, so fall back to en
}


// Initialize English by forcing computation of moment-derived options.
// Also, sets it as the default.
fc.lang('en', englishDefaults);

// exports
fc.intersectionToSeg = intersectionToSeg;
fc.applyAll = applyAll;
fc.debounce = debounce;


/* FullCalendar-specific DOM Utilities
----------------------------------------------------------------------------------------------------------------------*/


// Given the scrollbar widths of some other container, create borders/margins on rowEls in order to match the left
// and right space that was offset by the scrollbars. A 1-pixel border first, then margin beyond that.
function compensateScroll(rowEls, scrollbarWidths) {
        if (scrollbarWidths.left) {
                rowEls.css({
                        'border-left-width': 1,
                        'margin-left': scrollbarWidths.left - 1
                });
        }
        if (scrollbarWidths.right) {
                rowEls.css({
                        'border-right-width': 1,
                        'margin-right': scrollbarWidths.right - 1
                });
        }
}


// Undoes compensateScroll and restores all borders/margins
function uncompensateScroll(rowEls) {
        rowEls.css({
                'margin-left': '',
                'margin-right': '',
                'border-left-width': '',
                'border-right-width': ''
        });
}


// Make the mouse cursor express that an event is not allowed in the current area
function disableCursor() {
        $('body').addClass('fc-not-allowed');
}


// Returns the mouse cursor to its original look
function enableCursor() {
        $('body').removeClass('fc-not-allowed');
}


// Given a total available height to fill, have `els` (essentially child rows) expand to accomodate.
// By default, all elements that are shorter than the recommended height are expanded uniformly, not considering
// any other els that are already too tall. if `shouldRedistribute` is on, it considers these tall rows and 
// reduces the available height.
function distributeHeight(els, availableHeight, shouldRedistribute) {

        // *FLOORING NOTE*: we floor in certain places because zoom can give inaccurate floating-point dimensions,
        // and it is better to be shorter than taller, to avoid creating unnecessary scrollbars.

        var minOffset1 = Math.floor(availableHeight / els.length); // for non-last element
        var minOffset2 = Math.floor(availableHeight - minOffset1 * (els.length - 1)); // for last element *FLOORING NOTE*
        var flexEls = []; // elements that are allowed to expand. array of DOM nodes
        var flexOffsets = []; // amount of vertical space it takes up
        var flexHeights = []; // actual css height
        var usedHeight = 0;

        undistributeHeight(els); // give all elements their natural height

        // find elements that are below the recommended height (expandable).
        // important to query for heights in a single first pass (to avoid reflow oscillation).
        els.each(function(i, el) {
                var minOffset = i === els.length - 1 ? minOffset2 : minOffset1;
                var naturalOffset = $(el).outerHeight(true);

                if (naturalOffset < minOffset) {
                        flexEls.push(el);
                        flexOffsets.push(naturalOffset);
                        flexHeights.push($(el).height());
                }
                else {
                        // this element stretches past recommended height (non-expandable). mark the space as occupied.
                        usedHeight += naturalOffset;
                }
        });

        // readjust the recommended height to only consider the height available to non-maxed-out rows.
        if (shouldRedistribute) {
                availableHeight -= usedHeight;
                minOffset1 = Math.floor(availableHeight / flexEls.length);
                minOffset2 = Math.floor(availableHeight - minOffset1 * (flexEls.length - 1)); // *FLOORING NOTE*
        }

        // assign heights to all expandable elements
        $(flexEls).each(function(i, el) {
                var minOffset = i === flexEls.length - 1 ? minOffset2 : minOffset1;
                var naturalOffset = flexOffsets[i];
                var naturalHeight = flexHeights[i];
                var newHeight = minOffset - (naturalOffset - naturalHeight); // subtract the margin/padding

                if (naturalOffset < minOffset) { // we check this again because redistribution might have changed things
                        $(el).height(newHeight);
                }
        });
}


// Undoes distrubuteHeight, restoring all els to their natural height
function undistributeHeight(els) {
        els.height('');
}


// Given `els`, a jQuery set of <td> cells, find the cell with the largest natural width and set the widths of all the
// cells to be that width.
// PREREQUISITE: if you want a cell to take up width, it needs to have a single inner element w/ display:inline
function matchCellWidths(els) {
        var maxInnerWidth = 0;

        els.find('> *').each(function(i, innerEl) {
                var innerWidth = $(innerEl).outerWidth();
                if (innerWidth > maxInnerWidth) {
                        maxInnerWidth = innerWidth;
                }
        });

        maxInnerWidth++; // sometimes not accurate of width the text needs to stay on one line. insurance

        els.width(maxInnerWidth);

        return maxInnerWidth;
}


// Turns a container element into a scroller if its contents is taller than the allotted height.
// Returns true if the element is now a scroller, false otherwise.
// NOTE: this method is best because it takes weird zooming dimensions into account
function setPotentialScroller(containerEl, height) {
        containerEl.height(height).addClass('fc-scroller');

        // are scrollbars needed?
        if (containerEl[0].scrollHeight - 1 > containerEl[0].clientHeight) { // !!! -1 because IE is often off-by-one :(
                return true;
        }

        unsetScroller(containerEl); // undo
        return false;
}


// Takes an element that might have been a scroller, and turns it back into a normal element.
function unsetScroller(containerEl) {
        containerEl.height('').removeClass('fc-scroller');
}


/* General DOM Utilities
----------------------------------------------------------------------------------------------------------------------*/


// borrowed from https://github.com/jquery/jquery-ui/blob/1.11.0/ui/core.js#L51
function getScrollParent(el) {
        var position = el.css('position'),
                scrollParent = el.parents().filter(function() {
                        var parent = $(this);
                        return (/(auto|scroll)/).test(
                                parent.css('overflow') + parent.css('overflow-y') + parent.css('overflow-x')
                        );
                }).eq(0);

        return position === 'fixed' || !scrollParent.length ? $(el[0].ownerDocument || document) : scrollParent;
}


// Given a container element, return an object with the pixel values of the left/right scrollbars.
// Left scrollbars might occur on RTL browsers (IE maybe?) but I have not tested.
// PREREQUISITE: container element must have a single child with display:block
function getScrollbarWidths(container) {
        var containerLeft = container.offset().left;
        var containerRight = containerLeft + container.width();
        var inner = container.children();
        var innerLeft = inner.offset().left;
        var innerRight = innerLeft + inner.outerWidth();

        return {
                left: innerLeft - containerLeft,
                right: containerRight - innerRight
        };
}


// Returns a boolean whether this was a left mouse click and no ctrl key (which means right click on Mac)
function isPrimaryMouseButton(ev) {
        return ev.which == 1 && !ev.ctrlKey;
}


/* FullCalendar-specific Misc Utilities
----------------------------------------------------------------------------------------------------------------------*/


// Creates a basic segment with the intersection of the two ranges. Returns undefined if no intersection.
// Expects all dates to be normalized to the same timezone beforehand.
// TODO: move to date section?
function intersectionToSeg(subjectRange, constraintRange) {
        var subjectStart = subjectRange.start;
        var subjectEnd = subjectRange.end;
        var constraintStart = constraintRange.start;
        var constraintEnd = constraintRange.end;
        var segStart, segEnd;
        var isStart, isEnd;

        if (subjectEnd > constraintStart && subjectStart < constraintEnd) { // in bounds at all?

                if (subjectStart >= constraintStart) {
                        segStart = subjectStart.clone();
                        isStart = true;
                }
                else {
                        segStart = constraintStart.clone();
                        isStart =  false;
                }

                if (subjectEnd <= constraintEnd) {
                        segEnd = subjectEnd.clone();
                        isEnd = true;
                }
                else {
                        segEnd = constraintEnd.clone();
                        isEnd = false;
                }

                return {
                        start: segStart,
                        end: segEnd,
                        isStart: isStart,
                        isEnd: isEnd
                };
        }
}


function smartProperty(obj, name) { // get a camel-cased/namespaced property of an object
        obj = obj || {};
        if (obj[name] !== undefined) {
                return obj[name];
        }
        var parts = name.split(/(?=[A-Z])/),
                i = parts.length - 1, res;
        for (; i>=0; i--) {
                res = obj[parts[i].toLowerCase()];
                if (res !== undefined) {
                        return res;
                }
        }
        return obj['default'];
}


/* Date Utilities
----------------------------------------------------------------------------------------------------------------------*/

var dayIDs = [ 'sun', 'mon', 'tue', 'wed', 'thu', 'fri', 'sat' ];
var intervalUnits = [ 'year', 'month', 'week', 'day', 'hour', 'minute', 'second', 'millisecond' ];


// Diffs the two moments into a Duration where full-days are recorded first, then the remaining time.
// Moments will have their timezones normalized.
function diffDayTime(a, b) {
        return moment.duration({
                days: a.clone().stripTime().diff(b.clone().stripTime(), 'days'),
                ms: a.time() - b.time() // time-of-day from day start. disregards timezone
        });
}


// Diffs the two moments via their start-of-day (regardless of timezone). Produces whole-day durations.
function diffDay(a, b) {
        return moment.duration({
                days: a.clone().stripTime().diff(b.clone().stripTime(), 'days')
        });
}


// Computes the larges whole-unit period of time, as a duration object.
// For example, 48 hours will be {days:2} whereas 49 hours will be {hours:49}.
// Accepts start/end, a range object, or an original duration object.
/* (never used)
function computeIntervalDuration(start, end) {
        var durationInput = {};
        var i, unit;
        var val;

        for (i = 0; i < intervalUnits.length; i++) {
                unit = intervalUnits[i];
                val = computeIntervalAs(unit, start, end);
                if (val) {
                        break;
                }
        }

        durationInput[unit] = val;
        return moment.duration(durationInput);
}
*/


// Computes the unit name of the largest whole-unit period of time.
// For example, 48 hours will be "days" wherewas 49 hours will be "hours".
// Accepts start/end, a range object, or an original duration object.
function computeIntervalUnit(start, end) {
        var i, unit;

        for (i = 0; i < intervalUnits.length; i++) {
                unit = intervalUnits[i];
                if (computeIntervalAs(unit, start, end)) {
                        break;
                }
        }

        return unit; // will be "milliseconds" if nothing else matches
}


// Computes the number of units the interval is cleanly comprised of.
// If the given unit does not cleanly divide the interval a whole number of times, `false` is returned.
// Accepts start/end, a range object, or an original duration object.
function computeIntervalAs(unit, start, end) {
        var val;

        if (end != null) { // given start, end
                val = end.diff(start, unit, true);
        }
        else if (moment.isDuration(start)) { // given duration
                val = start.as(unit);
        }
        else { // given { start, end } range object
                val = start.end.diff(start.start, unit, true);
        }

        if (val >= 1 && isInt(val)) {
                return val;
        }

        return false;
}


function isNativeDate(input) {
        return  Object.prototype.toString.call(input) === '[object Date]' || input instanceof Date;
}


// Returns a boolean about whether the given input is a time string, like "06:40:00" or "06:00"
function isTimeString(str) {
        return /^\d+\:\d+(?:\:\d+\.?(?:\d{3})?)?$/.test(str);
}


/* General Utilities
----------------------------------------------------------------------------------------------------------------------*/

var hasOwnPropMethod = {}.hasOwnProperty;


// Create an object that has the given prototype. Just like Object.create
function createObject(proto) {
        var f = function() {};
        f.prototype = proto;
        return new f();
}


function copyOwnProps(src, dest) {
        for (var name in src) {
                if (hasOwnProp(src, name)) {
                        dest[name] = src[name];
                }
        }
}


function hasOwnProp(obj, name) {
        return hasOwnPropMethod.call(obj, name);
}


// Is the given value a non-object non-function value?
function isAtomic(val) {
        return /undefined|null|boolean|number|string/.test($.type(val));
}


function applyAll(functions, thisObj, args) {
        if ($.isFunction(functions)) {
                functions = [ functions ];
        }
        if (functions) {
                var i;
                var ret;
                for (i=0; i<functions.length; i++) {
                        ret = functions[i].apply(thisObj, args) || ret;
                }
                return ret;
        }
}


function firstDefined() {
        for (var i=0; i<arguments.length; i++) {
                if (arguments[i] !== undefined) {
                        return arguments[i];
                }
        }
}


function htmlEscape(s) {
        return (s + '').replace(/&/g, '&amp;')
                .replace(/</g, '&lt;')
                .replace(/>/g, '&gt;')
                .replace(/'/g, '&#039;')
                .replace(/"/g, '&quot;')
                .replace(/\n/g, '<br />');
}


function stripHtmlEntities(text) {
        return text.replace(/&.*?;/g, '');
}


function capitaliseFirstLetter(str) {
        return str.charAt(0).toUpperCase() + str.slice(1);
}


function compareNumbers(a, b) { // for .sort()
        return a - b;
}


function isInt(n) {
        return n % 1 === 0;
}


// Returns a function, that, as long as it continues to be invoked, will not
// be triggered. The function will be called after it stops being called for
// N milliseconds.
// https://github.com/jashkenas/underscore/blob/1.6.0/underscore.js#L714
function debounce(func, wait) {
        var timeoutId;
        var args;
        var context;
        var timestamp; // of most recent call
        var later = function() {
                var last = +new Date() - timestamp;
                if (last < wait && last > 0) {
                        timeoutId = setTimeout(later, wait - last);
                }
                else {
                        timeoutId = null;
                        func.apply(context, args);
                        if (!timeoutId) {
                                context = args = null;
                        }
                }
        };

        return function() {
                context = this;
                args = arguments;
                timestamp = +new Date();
                if (!timeoutId) {
                        timeoutId = setTimeout(later, wait);
                }
        };
}

    var ambigDateOfMonthRegex = /^\s*\d{4}-\d\d$/;
var ambigTimeOrZoneRegex =
        /^\s*\d{4}-(?:(\d\d-\d\d)|(W\d\d$)|(W\d\d-\d)|(\d\d\d))((T| )(\d\d(:\d\d(:\d\d(\.\d+)?)?)?)?)?$/;
var newMomentProto = moment.fn; // where we will attach our new methods
var oldMomentProto = $.extend({}, newMomentProto); // copy of original moment methods
var allowValueOptimization;
var setUTCValues; // function defined below
var setLocalValues; // function defined below


// Creating
// -------------------------------------------------------------------------------------------------

// Creates a new moment, similar to the vanilla moment(...) constructor, but with
// extra features (ambiguous time, enhanced formatting). When given an existing moment,
// it will function as a clone (and retain the zone of the moment). Anything else will
// result in a moment in the local zone.
fc.moment = function() {
        return makeMoment(arguments);
};

// Sames as fc.moment, but forces the resulting moment to be in the UTC timezone.
fc.moment.utc = function() {
        var mom = makeMoment(arguments, true);

        // Force it into UTC because makeMoment doesn't guarantee it
        // (if given a pre-existing moment for example)
        if (mom.hasTime()) { // don't give ambiguously-timed moments a UTC zone
                mom.utc();
        }

        return mom;
};

// Same as fc.moment, but when given an ISO8601 string, the timezone offset is preserved.
// ISO8601 strings with no timezone offset will become ambiguously zoned.
fc.moment.parseZone = function() {
        return makeMoment(arguments, true, true);
};

// Builds an enhanced moment from args. When given an existing moment, it clones. When given a
// native Date, or called with no arguments (the current time), the resulting moment will be local.
// Anything else needs to be "parsed" (a string or an array), and will be affected by:
//    parseAsUTC - if there is no zone information, should we parse the input in UTC?
//    parseZone - if there is zone information, should we force the zone of the moment?
function makeMoment(args, parseAsUTC, parseZone) {
        var input = args[0];
        var isSingleString = args.length == 1 && typeof input === 'string';
        var isAmbigTime;
        var isAmbigZone;
        var ambigMatch;
        var mom;

        if (moment.isMoment(input)) {
                mom = moment.apply(null, args); // clone it
                transferAmbigs(input, mom); // the ambig flags weren't transfered with the clone
        }
        else if (isNativeDate(input) || input === undefined) {
                mom = moment.apply(null, args); // will be local
        }
        else { // "parsing" is required
                isAmbigTime = false;
                isAmbigZone = false;

                if (isSingleString) {
                        if (ambigDateOfMonthRegex.test(input)) {
                                // accept strings like '2014-05', but convert to the first of the month
                                input += '-01';
                                args = [ input ]; // for when we pass it on to moment's constructor
                                isAmbigTime = true;
                                isAmbigZone = true;
                        }
                        else if ((ambigMatch = ambigTimeOrZoneRegex.exec(input))) {
                                isAmbigTime = !ambigMatch[5]; // no time part?
                                isAmbigZone = true;
                        }
                }
                else if ($.isArray(input)) {
                        // arrays have no timezone information, so assume ambiguous zone
                        isAmbigZone = true;
                }
                // otherwise, probably a string with a format

                if (parseAsUTC || isAmbigTime) {
                        mom = moment.utc.apply(moment, args);
                }
                else {
                        mom = moment.apply(null, args);
                }

                if (isAmbigTime) {
                        mom._ambigTime = true;
                        mom._ambigZone = true; // ambiguous time always means ambiguous zone
                }
                else if (parseZone) { // let's record the inputted zone somehow
                        if (isAmbigZone) {
                                mom._ambigZone = true;
                        }
                        else if (isSingleString) {
                                mom.zone(input); // if not a valid zone, will assign UTC
                        }
                }
        }

        mom._fullCalendar = true; // flag for extended functionality

        return mom;
}


// A clone method that works with the flags related to our enhanced functionality.
// In the future, use moment.momentProperties
newMomentProto.clone = function() {
        var mom = oldMomentProto.clone.apply(this, arguments);

        // these flags weren't transfered with the clone
        transferAmbigs(this, mom);
        if (this._fullCalendar) {
                mom._fullCalendar = true;
        }

        return mom;
};


// Time-of-day
// -------------------------------------------------------------------------------------------------

// GETTER
// Returns a Duration with the hours/minutes/seconds/ms values of the moment.
// If the moment has an ambiguous time, a duration of 00:00 will be returned.
//
// SETTER
// You can supply a Duration, a Moment, or a Duration-like argument.
// When setting the time, and the moment has an ambiguous time, it then becomes unambiguous.
newMomentProto.time = function(time) {

        // Fallback to the original method (if there is one) if this moment wasn't created via FullCalendar.
        // `time` is a generic enough method name where this precaution is necessary to avoid collisions w/ other plugins.
        if (!this._fullCalendar) {
                return oldMomentProto.time.apply(this, arguments);
        }

        if (time == null) { // getter
                return moment.duration({
                        hours: this.hours(),
                        minutes: this.minutes(),
                        seconds: this.seconds(),
                        milliseconds: this.milliseconds()
                });
        }
        else { // setter

                this._ambigTime = false; // mark that the moment now has a time

                if (!moment.isDuration(time) && !moment.isMoment(time)) {
                        time = moment.duration(time);
                }

                // The day value should cause overflow (so 24 hours becomes 00:00:00 of next day).
                // Only for Duration times, not Moment times.
                var dayHours = 0;
                if (moment.isDuration(time)) {
                        dayHours = Math.floor(time.asDays()) * 24;
                }

                // We need to set the individual fields.
                // Can't use startOf('day') then add duration. In case of DST at start of day.
                return this.hours(dayHours + time.hours())
                        .minutes(time.minutes())
                        .seconds(time.seconds())
                        .milliseconds(time.milliseconds());
        }
};

// Converts the moment to UTC, stripping out its time-of-day and timezone offset,
// but preserving its YMD. A moment with a stripped time will display no time
// nor timezone offset when .format() is called.
newMomentProto.stripTime = function() {
        var a;

        if (!this._ambigTime) {

                // get the values before any conversion happens
                a = this.toArray(); // array of y/m/d/h/m/s/ms

                this.utc(); // set the internal UTC flag (will clear the ambig flags)
                setUTCValues(this, a.slice(0, 3)); // set the year/month/date. time will be zero

                // Mark the time as ambiguous. This needs to happen after the .utc() call, which calls .zone(),
                // which clears all ambig flags. Same with setUTCValues with moment-timezone.
                this._ambigTime = true;
                this._ambigZone = true; // if ambiguous time, also ambiguous timezone offset
        }

        return this; // for chaining
};

// Returns if the moment has a non-ambiguous time (boolean)
newMomentProto.hasTime = function() {
        return !this._ambigTime;
};


// Timezone
// -------------------------------------------------------------------------------------------------

// Converts the moment to UTC, stripping out its timezone offset, but preserving its
// YMD and time-of-day. A moment with a stripped timezone offset will display no
// timezone offset when .format() is called.
newMomentProto.stripZone = function() {
        var a, wasAmbigTime;

        if (!this._ambigZone) {

                // get the values before any conversion happens
                a = this.toArray(); // array of y/m/d/h/m/s/ms
                wasAmbigTime = this._ambigTime;

                this.utc(); // set the internal UTC flag (will clear the ambig flags)
                setUTCValues(this, a); // will set the year/month/date/hours/minutes/seconds/ms

                if (wasAmbigTime) {
                        // the above call to .utc()/.zone() unfortunately clears the ambig flags, so reassign
                        this._ambigTime = true;
                }

                // Mark the zone as ambiguous. This needs to happen after the .utc() call, which calls .zone(),
                // which clears all ambig flags. Same with setUTCValues with moment-timezone.
                this._ambigZone = true;
        }

        return this; // for chaining
};

// Returns of the moment has a non-ambiguous timezone offset (boolean)
newMomentProto.hasZone = function() {
        return !this._ambigZone;
};

// this method implicitly marks a zone (will get called upon .utc() and .local())
newMomentProto.zone = function(tzo) {

        if (tzo != null) { // setter
                // these assignments needs to happen before the original zone method is called.
                // I forget why, something to do with a browser crash.
                this._ambigTime = false;
                this._ambigZone = false;
        }

        return oldMomentProto.zone.apply(this, arguments);
};

// this method implicitly marks a zone
newMomentProto.local = function() {
        var a = this.toArray(); // year,month,date,hours,minutes,seconds,ms as an array
        var wasAmbigZone = this._ambigZone;

        oldMomentProto.local.apply(this, arguments); // will clear ambig flags

        if (wasAmbigZone) {
                // If the moment was ambiguously zoned, the date fields were stored as UTC.
                // We want to preserve these, but in local time.
                setLocalValues(this, a);
        }

        return this; // for chaining
};


// Formatting
// -------------------------------------------------------------------------------------------------

newMomentProto.format = function() {
        if (this._fullCalendar && arguments[0]) { // an enhanced moment? and a format string provided?
                return formatDate(this, arguments[0]); // our extended formatting
        }
        if (this._ambigTime) {
                return oldMomentFormat(this, 'YYYY-MM-DD');
        }
        if (this._ambigZone) {
                return oldMomentFormat(this, 'YYYY-MM-DD[T]HH:mm:ss');
        }
        return oldMomentProto.format.apply(this, arguments);
};

newMomentProto.toISOString = function() {
        if (this._ambigTime) {
                return oldMomentFormat(this, 'YYYY-MM-DD');
        }
        if (this._ambigZone) {
                return oldMomentFormat(this, 'YYYY-MM-DD[T]HH:mm:ss');
        }
        return oldMomentProto.toISOString.apply(this, arguments);
};


// Querying
// -------------------------------------------------------------------------------------------------

// Is the moment within the specified range? `end` is exclusive.
// FYI, this method is not a standard Moment method, so always do our enhanced logic.
newMomentProto.isWithin = function(start, end) {
        var a = commonlyAmbiguate([ this, start, end ]);
        return a[0] >= a[1] && a[0] < a[2];
};

// When isSame is called with units, timezone ambiguity is normalized before the comparison happens.
// If no units specified, the two moments must be identically the same, with matching ambig flags.
newMomentProto.isSame = function(input, units) {
        var a;

        // only do custom logic if this is an enhanced moment
        if (!this._fullCalendar) {
                return oldMomentProto.isSame.apply(this, arguments);
        }

        if (units) {
                a = commonlyAmbiguate([ this, input ], true); // normalize timezones but don't erase times
                return oldMomentProto.isSame.call(a[0], a[1], units);
        }
        else {
                input = fc.moment.parseZone(input); // normalize input
                return oldMomentProto.isSame.call(this, input) &&
                        Boolean(this._ambigTime) === Boolean(input._ambigTime) &&
                        Boolean(this._ambigZone) === Boolean(input._ambigZone);
        }
};

// Make these query methods work with ambiguous moments
$.each([
        'isBefore',
        'isAfter'
], function(i, methodName) {
        newMomentProto[methodName] = function(input, units) {
                var a;

                // only do custom logic if this is an enhanced moment
                if (!this._fullCalendar) {
                        return oldMomentProto[methodName].apply(this, arguments);
                }

                a = commonlyAmbiguate([ this, input ]);
                return oldMomentProto[methodName].call(a[0], a[1], units);
        };
});


// Misc Internals
// -------------------------------------------------------------------------------------------------

// given an array of moment-like inputs, return a parallel array w/ moments similarly ambiguated.
// for example, of one moment has ambig time, but not others, all moments will have their time stripped.
// set `preserveTime` to `true` to keep times, but only normalize zone ambiguity.
// returns the original moments if no modifications are necessary.
function commonlyAmbiguate(inputs, preserveTime) {
        var anyAmbigTime = false;
        var anyAmbigZone = false;
        var len = inputs.length;
        var moms = [];
        var i, mom;

        // parse inputs into real moments and query their ambig flags
        for (i = 0; i < len; i++) {
                mom = inputs[i];
                if (!moment.isMoment(mom)) {
                        mom = fc.moment.parseZone(mom);
                }
                anyAmbigTime = anyAmbigTime || mom._ambigTime;
                anyAmbigZone = anyAmbigZone || mom._ambigZone;
                moms.push(mom);
        }

        // strip each moment down to lowest common ambiguity
        // use clones to avoid modifying the original moments
        for (i = 0; i < len; i++) {
                mom = moms[i];
                if (!preserveTime && anyAmbigTime && !mom._ambigTime) {
                        moms[i] = mom.clone().stripTime();
                }
                else if (anyAmbigZone && !mom._ambigZone) {
                        moms[i] = mom.clone().stripZone();
                }
        }

        return moms;
}

// Transfers all the flags related to ambiguous time/zone from the `src` moment to the `dest` moment
function transferAmbigs(src, dest) {
        if (src._ambigTime) {
                dest._ambigTime = true;
        }
        else if (dest._ambigTime) {
                dest._ambigTime = false;
        }

        if (src._ambigZone) {
                dest._ambigZone = true;
        }
        else if (dest._ambigZone) {
                dest._ambigZone = false;
        }
}


// Sets the year/month/date/etc values of the moment from the given array.
// Inefficient because it calls each individual setter.
function setMomentValues(mom, a) {
        mom.year(a[0] || 0)
                .month(a[1] || 0)
                .date(a[2] || 0)
                .hours(a[3] || 0)
                .minutes(a[4] || 0)
                .seconds(a[5] || 0)
                .milliseconds(a[6] || 0);
}

// Can we set the moment's internal date directly?
allowValueOptimization = '_d' in moment() && 'updateOffset' in moment;

// Utility function. Accepts a moment and an array of the UTC year/month/date/etc values to set.
// Assumes the given moment is already in UTC mode.
setUTCValues = allowValueOptimization ? function(mom, a) {
        // simlate what moment's accessors do
        mom._d.setTime(Date.UTC.apply(Date, a));
        moment.updateOffset(mom, false); // keepTime=false
} : setMomentValues;

// Utility function. Accepts a moment and an array of the local year/month/date/etc values to set.
// Assumes the given moment is already in local mode.
setLocalValues = allowValueOptimization ? function(mom, a) {
        // simlate what moment's accessors do
        mom._d.setTime(+new Date( // FYI, there is now way to apply an array of args to a constructor
                a[0] || 0,
                a[1] || 0,
                a[2] || 0,
                a[3] || 0,
                a[4] || 0,
                a[5] || 0,
                a[6] || 0
        ));
        moment.updateOffset(mom, false); // keepTime=false
} : setMomentValues;

// Single Date Formatting
// -------------------------------------------------------------------------------------------------


// call this if you want Moment's original format method to be used
function oldMomentFormat(mom, formatStr) {
        return oldMomentProto.format.call(mom, formatStr); // oldMomentProto defined in moment-ext.js
}


// Formats `date` with a Moment formatting string, but allow our non-zero areas and
// additional token.
function formatDate(date, formatStr) {
        return formatDateWithChunks(date, getFormatStringChunks(formatStr));
}


function formatDateWithChunks(date, chunks) {
        var s = '';
        var i;

        for (i=0; i<chunks.length; i++) {
                s += formatDateWithChunk(date, chunks[i]);
        }

        return s;
}


// addition formatting tokens we want recognized
var tokenOverrides = {
        t: function(date) { // "a" or "p"
                return oldMomentFormat(date, 'a').charAt(0);
        },
        T: function(date) { // "A" or "P"
                return oldMomentFormat(date, 'A').charAt(0);
        }
};


function formatDateWithChunk(date, chunk) {
        var token;
        var maybeStr;

        if (typeof chunk === 'string') { // a literal string
                return chunk;
        }
        else if ((token = chunk.token)) { // a token, like "YYYY"
                if (tokenOverrides[token]) {
                        return tokenOverrides[token](date); // use our custom token
                }
                return oldMomentFormat(date, token);
        }
        else if (chunk.maybe) { // a grouping of other chunks that must be non-zero
                maybeStr = formatDateWithChunks(date, chunk.maybe);
                if (maybeStr.match(/[1-9]/)) {
                        return maybeStr;
                }
        }

        return '';
}


// Date Range Formatting
// -------------------------------------------------------------------------------------------------
// TODO: make it work with timezone offset

// Using a formatting string meant for a single date, generate a range string, like
// "Sep 2 - 9 2013", that intelligently inserts a separator where the dates differ.
// If the dates are the same as far as the format string is concerned, just return a single
// rendering of one date, without any separator.
function formatRange(date1, date2, formatStr, separator, isRTL) {
        var localeData;

        date1 = fc.moment.parseZone(date1);
        date2 = fc.moment.parseZone(date2);

        localeData = (date1.localeData || date1.lang).call(date1); // works with moment-pre-2.8

        // Expand localized format strings, like "LL" -> "MMMM D YYYY"
        formatStr = localeData.longDateFormat(formatStr) || formatStr;
        // BTW, this is not important for `formatDate` because it is impossible to put custom tokens
        // or non-zero areas in Moment's localized format strings.

        separator = separator || ' - ';

        return formatRangeWithChunks(
                date1,
                date2,
                getFormatStringChunks(formatStr),
                separator,
                isRTL
        );
}
fc.formatRange = formatRange; // expose


function formatRangeWithChunks(date1, date2, chunks, separator, isRTL) {
        var chunkStr; // the rendering of the chunk
        var leftI;
        var leftStr = '';
        var rightI;
        var rightStr = '';
        var middleI;
        var middleStr1 = '';
        var middleStr2 = '';
        var middleStr = '';

        // Start at the leftmost side of the formatting string and continue until you hit a token
        // that is not the same between dates.
        for (leftI=0; leftI<chunks.length; leftI++) {
                chunkStr = formatSimilarChunk(date1, date2, chunks[leftI]);
                if (chunkStr === false) {
                        break;
                }
                leftStr += chunkStr;
        }

        // Similarly, start at the rightmost side of the formatting string and move left
        for (rightI=chunks.length-1; rightI>leftI; rightI--) {
                chunkStr = formatSimilarChunk(date1, date2, chunks[rightI]);
                if (chunkStr === false) {
                        break;
                }
                rightStr = chunkStr + rightStr;
        }

        // The area in the middle is different for both of the dates.
        // Collect them distinctly so we can jam them together later.
        for (middleI=leftI; middleI<=rightI; middleI++) {
                middleStr1 += formatDateWithChunk(date1, chunks[middleI]);
                middleStr2 += formatDateWithChunk(date2, chunks[middleI]);
        }

        if (middleStr1 || middleStr2) {
                if (isRTL) {
                        middleStr = middleStr2 + separator + middleStr1;
                }
                else {
                        middleStr = middleStr1 + separator + middleStr2;
                }
        }

        return leftStr + middleStr + rightStr;
}


var similarUnitMap = {
        Y: 'year',
        M: 'month',
        D: 'day', // day of month
        d: 'day', // day of week
        // prevents a separator between anything time-related...
        A: 'second', // AM/PM
        a: 'second', // am/pm
        T: 'second', // A/P
        t: 'second', // a/p
        H: 'second', // hour (24)
        h: 'second', // hour (12)
        m: 'second', // minute
        s: 'second' // second
};
// TODO: week maybe?


// Given a formatting chunk, and given that both dates are similar in the regard the
// formatting chunk is concerned, format date1 against `chunk`. Otherwise, return `false`.
function formatSimilarChunk(date1, date2, chunk) {
        var token;
        var unit;

        if (typeof chunk === 'string') { // a literal string
                return chunk;
        }
        else if ((token = chunk.token)) {
                unit = similarUnitMap[token.charAt(0)];
                // are the dates the same for this unit of measurement?
                if (unit && date1.isSame(date2, unit)) {
                        return oldMomentFormat(date1, token); // would be the same if we used `date2`
                        // BTW, don't support custom tokens
                }
        }

        return false; // the chunk is NOT the same for the two dates
        // BTW, don't support splitting on non-zero areas
}


// Chunking Utils
// -------------------------------------------------------------------------------------------------


var formatStringChunkCache = {};


function getFormatStringChunks(formatStr) {
        if (formatStr in formatStringChunkCache) {
                return formatStringChunkCache[formatStr];
        }
        return (formatStringChunkCache[formatStr] = chunkFormatString(formatStr));
}


// Break the formatting string into an array of chunks
function chunkFormatString(formatStr) {
        var chunks = [];
        var chunker = /\[([^\]]*)\]|\(([^\)]*)\)|(LT|(\w)\4*o?)|([^\w\[\(]+)/g; // TODO: more descrimination
        var match;

        while ((match = chunker.exec(formatStr))) {
                if (match[1]) { // a literal string inside [ ... ]
                        chunks.push(match[1]);
                }
                else if (match[2]) { // non-zero formatting inside ( ... )
                        chunks.push({ maybe: chunkFormatString(match[2]) });
                }
                else if (match[3]) { // a formatting token
                        chunks.push({ token: match[3] });
                }
                else if (match[5]) { // an unenclosed literal string
                        chunks.push(match[5]);
                }
        }

        return chunks;
}

    fc.Class = Class; // export

// class that all other classes will inherit from
function Class() { }

// called upon a class to create a subclass
Class.extend = function(members) {
        var superClass = this;
        var subClass;

        members = members || {};

        // ensure a constructor for the subclass, forwarding all arguments to the super-constructor if it doesn't exist
        if (hasOwnProp(members, 'constructor')) {
                subClass = members.constructor;
        }
        if (typeof subClass !== 'function') {
                subClass = members.constructor = function() {
                        superClass.apply(this, arguments);
                };
        }

        // build the base prototype for the subclass, which is an new object chained to the superclass's prototype
        subClass.prototype = createObject(superClass.prototype);

        // copy each member variable/method onto the the subclass's prototype
        copyOwnProps(members, subClass.prototype);

        // copy over all class variables/methods to the subclass, such as `extend` and `mixin`
        copyOwnProps(superClass, subClass);

        return subClass;
};

// adds new member variables/methods to the class's prototype.
// can be called with another class, or a plain object hash containing new members.
Class.mixin = function(members) {
        copyOwnProps(members.prototype || members, this.prototype);
};
    /* A rectangular panel that is absolutely positioned over other content
------------------------------------------------------------------------------------------------------------------------
Options:
        - className (string)
        - content (HTML string or jQuery element set)
        - parentEl
        - top
        - left
        - right (the x coord of where the right edge should be. not a "CSS" right)
        - autoHide (boolean)
        - show (callback)
        - hide (callback)
*/

var Popover = Class.extend({

        isHidden: true,
        options: null,
        el: null, // the container element for the popover. generated by this object
        documentMousedownProxy: null, // document mousedown handler bound to `this`
        margin: 10, // the space required between the popover and the edges of the scroll container


        constructor: function(options) {
                this.options = options || {};
        },


        // Shows the popover on the specified position. Renders it if not already
        show: function() {
                if (this.isHidden) {
                        if (!this.el) {
                                this.render();
                        }
                        this.el.show();
                        this.position();
                        this.isHidden = false;
                        this.trigger('show');
                }
        },


        // Hides the popover, through CSS, but does not remove it from the DOM
        hide: function() {
                if (!this.isHidden) {
                        this.el.hide();
                        this.isHidden = true;
                        this.trigger('hide');
                }
        },


        // Creates `this.el` and renders content inside of it
        render: function() {
                var _this = this;
                var options = this.options;

                this.el = $('<div class="fc-popover"/>')
                        .addClass(options.className || '')
                        .css({
                                // position initially to the top left to avoid creating scrollbars
                                top: 0,
                                left: 0
                        })
                        .append(options.content)
                        .appendTo(options.parentEl);

                // when a click happens on anything inside with a 'fc-close' className, hide the popover
                this.el.on('click', '.fc-close', function() {
                        _this.hide();
                });

                if (options.autoHide) {
                        $(document).on('mousedown', this.documentMousedownProxy = $.proxy(this, 'documentMousedown'));
                }
        },


        // Triggered when the user clicks *anywhere* in the document, for the autoHide feature
        documentMousedown: function(ev) {
                // only hide the popover if the click happened outside the popover
                if (this.el && !$(ev.target).closest(this.el).length) {
                        this.hide();
                }
        },


        // Hides and unregisters any handlers
        destroy: function() {
                this.hide();

                if (this.el) {
                        this.el.remove();
                        this.el = null;
                }

                $(document).off('mousedown', this.documentMousedownProxy);
        },


        // Positions the popover optimally, using the top/left/right options
        position: function() {
                var options = this.options;
                var origin = this.el.offsetParent().offset();
                var width = this.el.outerWidth();
                var height = this.el.outerHeight();
                var windowEl = $(window);
                var viewportEl = getScrollParent(this.el);
                var viewportTop;
                var viewportLeft;
                var viewportOffset;
                var top; // the "position" (not "offset") values for the popover
                var left; //

                // compute top and left
                top = options.top || 0;
                if (options.left !== undefined) {
                        left = options.left;
                }
                else if (options.right !== undefined) {
                        left = options.right - width; // derive the left value from the right value
                }
                else {
                        left = 0;
                }

                if (viewportEl.is(window) || viewportEl.is(document)) { // normalize getScrollParent's result
                        viewportEl = windowEl;
                        viewportTop = 0; // the window is always at the top left
                        viewportLeft = 0; // (and .offset() won't work if called here)
                }
                else {
                        viewportOffset = viewportEl.offset();
                        viewportTop = viewportOffset.top;
                        viewportLeft = viewportOffset.left;
                }

                // if the window is scrolled, it causes the visible area to be further down
                viewportTop += windowEl.scrollTop();
                viewportLeft += windowEl.scrollLeft();

                // constrain to the view port. if constrained by two edges, give precedence to top/left
                if (options.viewportConstrain !== false) {
                        top = Math.min(top, viewportTop + viewportEl.outerHeight() - height - this.margin);
                        top = Math.max(top, viewportTop + this.margin);
                        left = Math.min(left, viewportLeft + viewportEl.outerWidth() - width - this.margin);
                        left = Math.max(left, viewportLeft + this.margin);
                }

                this.el.css({
                        top: top - origin.top,
                        left: left - origin.left
                });
        },


        // Triggers a callback. Calls a function in the option hash of the same name.
        // Arguments beyond the first `name` are forwarded on.
        // TODO: better code reuse for this. Repeat code
        trigger: function(name) {
                if (this.options[name]) {
                        this.options[name].apply(this, Array.prototype.slice.call(arguments, 1));
                }
        }

});

    /* A "coordinate map" converts pixel coordinates into an associated cell, which has an associated date
------------------------------------------------------------------------------------------------------------------------
Common interface:

        CoordMap.prototype = {
                build: function() {},
                getCell: function(x, y) {}
        };

*/

/* Coordinate map for a grid component
----------------------------------------------------------------------------------------------------------------------*/

var GridCoordMap = Class.extend({

        grid: null, // reference to the Grid
        rowCoords: null, // array of {top,bottom} objects
        colCoords: null, // array of {left,right} objects

        containerEl: null, // container element that all coordinates are constrained to. optionally assigned
        minX: null,
        maxX: null, // exclusive
        minY: null,
        maxY: null, // exclusive


        constructor: function(grid) {
                this.grid = grid;
        },


        // Queries the grid for the coordinates of all the cells
        build: function() {
                this.rowCoords = this.grid.computeRowCoords();
                this.colCoords = this.grid.computeColCoords();
                this.computeBounds();
        },


        // Clears the coordinates data to free up memory
        clear: function() {
                this.rowCoords = null;
                this.colCoords = null;
        },


        // Given a coordinate of the document, gets the associated cell. If no cell is underneath, returns null
        getCell: function(x, y) {
                var rowCoords = this.rowCoords;
                var colCoords = this.colCoords;
                var hitRow = null;
                var hitCol = null;
                var i, coords;
                var cell;

                if (this.inBounds(x, y)) {

                        for (i = 0; i < rowCoords.length; i++) {
                                coords = rowCoords[i];
                                if (y >= coords.top && y < coords.bottom) {
                                        hitRow = i;
                                        break;
                                }
                        }

                        for (i = 0; i < colCoords.length; i++) {
                                coords = colCoords[i];
                                if (x >= coords.left && x < coords.right) {
                                        hitCol = i;
                                        break;
                                }
                        }

                        if (hitRow !== null && hitCol !== null) {
                                cell = this.grid.getCell(hitRow, hitCol);
                                cell.grid = this.grid; // for DragListener's isCellsEqual. dragging between grids
                                return cell;
                        }
                }

                return null;
        },


        // If there is a containerEl, compute the bounds into min/max values
        computeBounds: function() {
                var containerOffset;

                if (this.containerEl) {
                        containerOffset = this.containerEl.offset();
                        this.minX = containerOffset.left;
                        this.maxX = containerOffset.left + this.containerEl.outerWidth();
                        this.minY = containerOffset.top;
                        this.maxY = containerOffset.top + this.containerEl.outerHeight();
                }
        },


        // Determines if the given coordinates are in bounds. If no `containerEl`, always true
        inBounds: function(x, y) {
                if (this.containerEl) {
                        return x >= this.minX && x < this.maxX && y >= this.minY && y < this.maxY;
                }
                return true;
        }

});


/* Coordinate map that is a combination of multiple other coordinate maps
----------------------------------------------------------------------------------------------------------------------*/

var ComboCoordMap = Class.extend({

        coordMaps: null, // an array of CoordMaps


        constructor: function(coordMaps) {
                this.coordMaps = coordMaps;
        },


        // Builds all coordMaps
        build: function() {
                var coordMaps = this.coordMaps;
                var i;

                for (i = 0; i < coordMaps.length; i++) {
                        coordMaps[i].build();
                }
        },


        // Queries all coordMaps for the cell underneath the given coordinates, returning the first result
        getCell: function(x, y) {
                var coordMaps = this.coordMaps;
                var cell = null;
                var i;

                for (i = 0; i < coordMaps.length && !cell; i++) {
                        cell = coordMaps[i].getCell(x, y);
                }

                return cell;
        },


        // Clears all coordMaps
        clear: function() {
                var coordMaps = this.coordMaps;
                var i;

                for (i = 0; i < coordMaps.length; i++) {
                        coordMaps[i].clear();
                }
        }

});

    /* Tracks mouse movements over a CoordMap and raises events about which cell the mouse is over.
----------------------------------------------------------------------------------------------------------------------*/
// TODO: very useful to have a handler that gets called upon cellOut OR when dragging stops (for cleanup)

var DragListener = Class.extend({

        coordMap: null,
        options: null,

        isListening: false,
        isDragging: false,

        // the cell the mouse was over when listening started
        origCell: null,

        // the cell the mouse is over
        cell: null,

        // coordinates of the initial mousedown
        mouseX0: null,
        mouseY0: null,

        // handler attached to the document, bound to the DragListener's `this`
        mousemoveProxy: null,
        mouseupProxy: null,

        scrollEl: null,
        scrollBounds: null, // { top, bottom, left, right }
        scrollTopVel: null, // pixels per second
        scrollLeftVel: null, // pixels per second
        scrollIntervalId: null, // ID of setTimeout for scrolling animation loop
        scrollHandlerProxy: null, // this-scoped function for handling when scrollEl is scrolled

        scrollSensitivity: 30, // pixels from edge for scrolling to start
        scrollSpeed: 200, // pixels per second, at maximum speed
        scrollIntervalMs: 50, // millisecond wait between scroll increment


        constructor: function(coordMap, options) {
                this.coordMap = coordMap;
                this.options = options || {};
        },


        // Call this when the user does a mousedown. Will probably lead to startListening
        mousedown: function(ev) {
                if (isPrimaryMouseButton(ev)) {

                        ev.preventDefault(); // prevents native selection in most browsers

                        this.startListening(ev);

                        // start the drag immediately if there is no minimum distance for a drag start
                        if (!this.options.distance) {
                                this.startDrag(ev);
                        }
                }
        },


        // Call this to start tracking mouse movements
        startListening: function(ev) {
                var scrollParent;
                var cell;

                if (!this.isListening) {

                        // grab scroll container and attach handler
                        if (ev && this.options.scroll) {
                                scrollParent = getScrollParent($(ev.target));
                                if (!scrollParent.is(window) && !scrollParent.is(document)) {
                                        this.scrollEl = scrollParent;

                                        // scope to `this`, and use `debounce` to make sure rapid calls don't happen
                                        this.scrollHandlerProxy = debounce($.proxy(this, 'scrollHandler'), 100);
                                        this.scrollEl.on('scroll', this.scrollHandlerProxy);
                                }
                        }

                        this.computeCoords(); // relies on `scrollEl`

                        // get info on the initial cell and its coordinates
                        if (ev) {
                                cell = this.getCell(ev);
                                this.origCell = cell;

                                this.mouseX0 = ev.pageX;
                                this.mouseY0 = ev.pageY;
                        }

                        $(document)
                                .on('mousemove', this.mousemoveProxy = $.proxy(this, 'mousemove'))
                                .on('mouseup', this.mouseupProxy = $.proxy(this, 'mouseup'))
                                .on('selectstart', this.preventDefault); // prevents native selection in IE<=8

                        this.isListening = true;
                        this.trigger('listenStart', ev);
                }
        },


        // Recomputes the drag-critical positions of elements
        computeCoords: function() {
                this.coordMap.build();
                this.computeScrollBounds();
        },


        // Called when the user moves the mouse
        mousemove: function(ev) {
                var minDistance;
                var distanceSq; // current distance from mouseX0/mouseY0, squared

                if (!this.isDragging) { // if not already dragging...
                        // then start the drag if the minimum distance criteria is met
                        minDistance = this.options.distance || 1;
                        distanceSq = Math.pow(ev.pageX - this.mouseX0, 2) + Math.pow(ev.pageY - this.mouseY0, 2);
                        if (distanceSq >= minDistance * minDistance) { // use pythagorean theorem
                                this.startDrag(ev);
                        }
                }

                if (this.isDragging) {
                        this.drag(ev); // report a drag, even if this mousemove initiated the drag
                }
        },


        // Call this to initiate a legitimate drag.
        // This function is called internally from this class, but can also be called explicitly from outside
        startDrag: function(ev) {
                var cell;

                if (!this.isListening) { // startDrag must have manually initiated
                        this.startListening();
                }

                if (!this.isDragging) {
                        this.isDragging = true;
                        this.trigger('dragStart', ev);

                        // report the initial cell the mouse is over
                        // especially important if no min-distance and drag starts immediately
                        cell = this.getCell(ev); // this might be different from this.origCell if the min-distance is large
                        if (cell) {
                                this.cellOver(cell);
                        }
                }
        },


        // Called while the mouse is being moved and when we know a legitimate drag is taking place
        drag: function(ev) {
                var cell;

                if (this.isDragging) {
                        cell = this.getCell(ev);

                        if (!isCellsEqual(cell, this.cell)) { // a different cell than before?
                                if (this.cell) {
                                        this.cellOut();
                                }
                                if (cell) {
                                        this.cellOver(cell);
                                }
                        }

                        this.dragScroll(ev); // will possibly cause scrolling
                }
        },


        // Called when a the mouse has just moved over a new cell
        cellOver: function(cell) {
                this.cell = cell;
                this.trigger('cellOver', cell, isCellsEqual(cell, this.origCell));
        },


        // Called when the mouse has just moved out of a cell
        cellOut: function() {
                if (this.cell) {
                        this.trigger('cellOut', this.cell);
                        this.cell = null;
                }
        },


        // Called when the user does a mouseup
        mouseup: function(ev) {
                this.stopDrag(ev);
                this.stopListening(ev);
        },


        // Called when the drag is over. Will not cause listening to stop however.
        // A concluding 'cellOut' event will NOT be triggered.
        stopDrag: function(ev) {
                if (this.isDragging) {
                        this.stopScrolling();
                        this.trigger('dragStop', ev);
                        this.isDragging = false;
                }
        },


        // Call this to stop listening to the user's mouse events
        stopListening: function(ev) {
                if (this.isListening) {

                        // remove the scroll handler if there is a scrollEl
                        if (this.scrollEl) {
                                this.scrollEl.off('scroll', this.scrollHandlerProxy);
                                this.scrollHandlerProxy = null;
                        }

                        $(document)
                                .off('mousemove', this.mousemoveProxy)
                                .off('mouseup', this.mouseupProxy)
                                .off('selectstart', this.preventDefault);

                        this.mousemoveProxy = null;
                        this.mouseupProxy = null;

                        this.isListening = false;
                        this.trigger('listenStop', ev);

                        this.origCell = this.cell = null;
                        this.coordMap.clear();
                }
        },


        // Gets the cell underneath the coordinates for the given mouse event
        getCell: function(ev) {
                return this.coordMap.getCell(ev.pageX, ev.pageY);
        },


        // Triggers a callback. Calls a function in the option hash of the same name.
        // Arguments beyond the first `name` are forwarded on.
        trigger: function(name) {
                if (this.options[name]) {
                        this.options[name].apply(this, Array.prototype.slice.call(arguments, 1));
                }
        },


        // Stops a given mouse event from doing it's native browser action. In our case, text selection.
        preventDefault: function(ev) {
                ev.preventDefault();
        },


        /* Scrolling
        ------------------------------------------------------------------------------------------------------------------*/


        // Computes and stores the bounding rectangle of scrollEl
        computeScrollBounds: function() {
                var el = this.scrollEl;
                var offset;

                if (el) {
                        offset = el.offset();
                        this.scrollBounds = {
                                top: offset.top,
                                left: offset.left,
                                bottom: offset.top + el.outerHeight(),
                                right: offset.left + el.outerWidth()
                        };
                }
        },


        // Called when the dragging is in progress and scrolling should be updated
        dragScroll: function(ev) {
                var sensitivity = this.scrollSensitivity;
                var bounds = this.scrollBounds;
                var topCloseness, bottomCloseness;
                var leftCloseness, rightCloseness;
                var topVel = 0;
                var leftVel = 0;

                if (bounds) { // only scroll if scrollEl exists

                        // compute closeness to edges. valid range is from 0.0 - 1.0
                        topCloseness = (sensitivity - (ev.pageY - bounds.top)) / sensitivity;
                        bottomCloseness = (sensitivity - (bounds.bottom - ev.pageY)) / sensitivity;
                        leftCloseness = (sensitivity - (ev.pageX - bounds.left)) / sensitivity;
                        rightCloseness = (sensitivity - (bounds.right - ev.pageX)) / sensitivity;

                        // translate vertical closeness into velocity.
                        // mouse must be completely in bounds for velocity to happen.
                        if (topCloseness >= 0 && topCloseness <= 1) {
                                topVel = topCloseness * this.scrollSpeed * -1; // negative. for scrolling up
                        }
                        else if (bottomCloseness >= 0 && bottomCloseness <= 1) {
                                topVel = bottomCloseness * this.scrollSpeed;
                        }

                        // translate horizontal closeness into velocity
                        if (leftCloseness >= 0 && leftCloseness <= 1) {
                                leftVel = leftCloseness * this.scrollSpeed * -1; // negative. for scrolling left
                        }
                        else if (rightCloseness >= 0 && rightCloseness <= 1) {
                                leftVel = rightCloseness * this.scrollSpeed;
                        }
                }

                this.setScrollVel(topVel, leftVel);
        },


        // Sets the speed-of-scrolling for the scrollEl
        setScrollVel: function(topVel, leftVel) {

                this.scrollTopVel = topVel;
                this.scrollLeftVel = leftVel;

                this.constrainScrollVel(); // massages into realistic values

                // if there is non-zero velocity, and an animation loop hasn't already started, then START
                if ((this.scrollTopVel || this.scrollLeftVel) && !this.scrollIntervalId) {
                        this.scrollIntervalId = setInterval(
                                $.proxy(this, 'scrollIntervalFunc'), // scope to `this`
                                this.scrollIntervalMs
                        );
                }
        },


        // Forces scrollTopVel and scrollLeftVel to be zero if scrolling has already gone all the way
        constrainScrollVel: function() {
                var el = this.scrollEl;

                if (this.scrollTopVel < 0) { // scrolling up?
                        if (el.scrollTop() <= 0) { // already scrolled all the way up?
                                this.scrollTopVel = 0;
                        }
                }
                else if (this.scrollTopVel > 0) { // scrolling down?
                        if (el.scrollTop() + el[0].clientHeight >= el[0].scrollHeight) { // already scrolled all the way down?
                                this.scrollTopVel = 0;
                        }
                }

                if (this.scrollLeftVel < 0) { // scrolling left?
                        if (el.scrollLeft() <= 0) { // already scrolled all the left?
                                this.scrollLeftVel = 0;
                        }
                }
                else if (this.scrollLeftVel > 0) { // scrolling right?
                        if (el.scrollLeft() + el[0].clientWidth >= el[0].scrollWidth) { // already scrolled all the way right?
                                this.scrollLeftVel = 0;
                        }
                }
        },


        // This function gets called during every iteration of the scrolling animation loop
        scrollIntervalFunc: function() {
                var el = this.scrollEl;
                var frac = this.scrollIntervalMs / 1000; // considering animation frequency, what the vel should be mult'd by

                // change the value of scrollEl's scroll
                if (this.scrollTopVel) {
                        el.scrollTop(el.scrollTop() + this.scrollTopVel * frac);
                }
                if (this.scrollLeftVel) {
                        el.scrollLeft(el.scrollLeft() + this.scrollLeftVel * frac);
                }

                this.constrainScrollVel(); // since the scroll values changed, recompute the velocities

                // if scrolled all the way, which causes the vels to be zero, stop the animation loop
                if (!this.scrollTopVel && !this.scrollLeftVel) {
                        this.stopScrolling();
                }
        },


        // Kills any existing scrolling animation loop
        stopScrolling: function() {
                if (this.scrollIntervalId) {
                        clearInterval(this.scrollIntervalId);
                        this.scrollIntervalId = null;

                        // when all done with scrolling, recompute positions since they probably changed
                        this.computeCoords();
                }
        },


        // Get called when the scrollEl is scrolled (NOTE: this is delayed via debounce)
        scrollHandler: function() {
                // recompute all coordinates, but *only* if this is *not* part of our scrolling animation
                if (!this.scrollIntervalId) {
                        this.computeCoords();
                }
        }

});


// Returns `true` if the cells are identically equal. `false` otherwise.
// They must have the same row, col, and be from the same grid.
// Two null values will be considered equal, as two "out of the grid" states are the same.
function isCellsEqual(cell1, cell2) {

        if (!cell1 && !cell2) {
                return true;
        }

        if (cell1 && cell2) {
                return cell1.grid === cell2.grid &&
                        cell1.row === cell2.row &&
                        cell1.col === cell2.col;
        }

        return false;
}

    /* Creates a clone of an element and lets it track the mouse as it moves
----------------------------------------------------------------------------------------------------------------------*/

var MouseFollower = Class.extend({

        options: null,

        sourceEl: null, // the element that will be cloned and made to look like it is dragging
        el: null, // the clone of `sourceEl` that will track the mouse
        parentEl: null, // the element that `el` (the clone) will be attached to

        // the initial position of el, relative to the offset parent. made to match the initial offset of sourceEl
        top0: null,
        left0: null,

        // the initial position of the mouse
        mouseY0: null,
        mouseX0: null,

        // the number of pixels the mouse has moved from its initial position
        topDelta: null,
        leftDelta: null,

        mousemoveProxy: null, // document mousemove handler, bound to the MouseFollower's `this`

        isFollowing: false,
        isHidden: false,
        isAnimating: false, // doing the revert animation?

        constructor: function(sourceEl, options) {
                this.options = options = options || {};
                this.sourceEl = sourceEl;
                this.parentEl = options.parentEl ? $(options.parentEl) : sourceEl.parent(); // default to sourceEl's parent
        },


        // Causes the element to start following the mouse
        start: function(ev) {
                if (!this.isFollowing) {
                        this.isFollowing = true;

                        this.mouseY0 = ev.pageY;
                        this.mouseX0 = ev.pageX;
                        this.topDelta = 0;
                        this.leftDelta = 0;

                        if (!this.isHidden) {
                                this.updatePosition();
                        }

                        $(document).on('mousemove', this.mousemoveProxy = $.proxy(this, 'mousemove'));
                }
        },


        // Causes the element to stop following the mouse. If shouldRevert is true, will animate back to original position.
        // `callback` gets invoked when the animation is complete. If no animation, it is invoked immediately.
        stop: function(shouldRevert, callback) {
                var _this = this;
                var revertDuration = this.options.revertDuration;

                function complete() {
                        this.isAnimating = false;
                        _this.destroyEl();

                        this.top0 = this.left0 = null; // reset state for future updatePosition calls

                        if (callback) {
                                callback();
                        }
                }

                if (this.isFollowing && !this.isAnimating) { // disallow more than one stop animation at a time
                        this.isFollowing = false;

                        $(document).off('mousemove', this.mousemoveProxy);

                        if (shouldRevert && revertDuration && !this.isHidden) { // do a revert animation?
                                this.isAnimating = true;
                                this.el.animate({
                                        top: this.top0,
                                        left: this.left0
                                }, {
                                        duration: revertDuration,
                                        complete: complete
                                });
                        }
                        else {
                                complete();
                        }
                }
        },


        // Gets the tracking element. Create it if necessary
        getEl: function() {
                var el = this.el;

                if (!el) {
                        this.sourceEl.width(); // hack to force IE8 to compute correct bounding box
                        el = this.el = this.sourceEl.clone()
                                .css({
                                        position: 'absolute',
                                        visibility: '', // in case original element was hidden (commonly through hideEvents())
                                        display: this.isHidden ? 'none' : '', // for when initially hidden
                                        margin: 0,
                                        right: 'auto', // erase and set width instead
                                        bottom: 'auto', // erase and set height instead
                                        width: this.sourceEl.width(), // explicit height in case there was a 'right' value
                                        height: this.sourceEl.height(), // explicit width in case there was a 'bottom' value
                                        opacity: this.options.opacity || '',
                                        zIndex: this.options.zIndex
                                })
                                .appendTo(this.parentEl);
                }

                return el;
        },


        // Removes the tracking element if it has already been created
        destroyEl: function() {
                if (this.el) {
                        this.el.remove();
                        this.el = null;
                }
        },


        // Update the CSS position of the tracking element
        updatePosition: function() {
                var sourceOffset;
                var origin;

                this.getEl(); // ensure this.el

                // make sure origin info was computed
                if (this.top0 === null) {
                        this.sourceEl.width(); // hack to force IE8 to compute correct bounding box
                        sourceOffset = this.sourceEl.offset();
                        origin = this.el.offsetParent().offset();
                        this.top0 = sourceOffset.top - origin.top;
                        this.left0 = sourceOffset.left - origin.left;
                }

                this.el.css({
                        top: this.top0 + this.topDelta,
                        left: this.left0 + this.leftDelta
                });
        },


        // Gets called when the user moves the mouse
        mousemove: function(ev) {
                this.topDelta = ev.pageY - this.mouseY0;
                this.leftDelta = ev.pageX - this.mouseX0;

                if (!this.isHidden) {
                        this.updatePosition();
                }
        },


        // Temporarily makes the tracking element invisible. Can be called before following starts
        hide: function() {
                if (!this.isHidden) {
                        this.isHidden = true;
                        if (this.el) {
                                this.el.hide();
                        }
                }
        },


        // Show the tracking element after it has been temporarily hidden
        show: function() {
                if (this.isHidden) {
                        this.isHidden = false;
                        this.updatePosition();
                        this.getEl().show();
                }
        }

});

    /* A utility class for rendering <tr> rows.
----------------------------------------------------------------------------------------------------------------------*/
// It leverages methods of the subclass and the View to determine custom rendering behavior for each row "type"
// (such as highlight rows, day rows, helper rows, etc).

var RowRenderer = Class.extend({

        view: null, // a View object
        isRTL: null, // shortcut to the view's isRTL option
        cellHtml: '<td/>', // plain default HTML used for a cell when no other is available


        constructor: function(view) {
                this.view = view;
                this.isRTL = view.opt('isRTL');
        },


        // Renders the HTML for a row, leveraging custom cell-HTML-renderers based on the `rowType`.
        // Also applies the "intro" and "outro" cells, which are specified by the subclass and views.
        // `row` is an optional row number.
        rowHtml: function(rowType, row) {
                var renderCell = this.getHtmlRenderer('cell', rowType);
                var rowCellHtml = '';
                var col;
                var cell;

                row = row || 0;

                for (col = 0; col < this.colCnt; col++) {
                        cell = this.getCell(row, col);
                        rowCellHtml += renderCell(cell);
                }

                rowCellHtml = this.bookendCells(rowCellHtml, rowType, row); // apply intro and outro

                return '<tr>' + rowCellHtml + '</tr>';
        },


        // Applies the "intro" and "outro" HTML to the given cells.
        // Intro means the leftmost cell when the calendar is LTR and the rightmost cell when RTL. Vice-versa for outro.
        // `cells` can be an HTML string of <td>'s or a jQuery <tr> element
        // `row` is an optional row number.
        bookendCells: function(cells, rowType, row) {
                var intro = this.getHtmlRenderer('intro', rowType)(row || 0);
                var outro = this.getHtmlRenderer('outro', rowType)(row || 0);
                var prependHtml = this.isRTL ? outro : intro;
                var appendHtml = this.isRTL ? intro : outro;

                if (typeof cells === 'string') {
                        return prependHtml + cells + appendHtml;
                }
                else { // a jQuery <tr> element
                        return cells.prepend(prependHtml).append(appendHtml);
                }
        },


        // Returns an HTML-rendering function given a specific `rendererName` (like cell, intro, or outro) and a specific
        // `rowType` (like day, eventSkeleton, helperSkeleton), which is optional.
        // If a renderer for the specific rowType doesn't exist, it will fall back to a generic renderer.
        // We will query the View object first for any custom rendering functions, then the methods of the subclass.
        getHtmlRenderer: function(rendererName, rowType) {
                var view = this.view;
                var generalName; // like "cellHtml"
                var specificName; // like "dayCellHtml". based on rowType
                var provider; // either the View or the RowRenderer subclass, whichever provided the method
                var renderer;

                generalName = rendererName + 'Html';
                if (rowType) {
                        specificName = rowType + capitaliseFirstLetter(rendererName) + 'Html';
                }

                if (specificName && (renderer = view[specificName])) {
                        provider = view;
                }
                else if (specificName && (renderer = this[specificName])) {
                        provider = this;
                }
                else if ((renderer = view[generalName])) {
                        provider = view;
                }
                else if ((renderer = this[generalName])) {
                        provider = this;
                }

                if (typeof renderer === 'function') {
                        return function() {
                                return renderer.apply(provider, arguments) || ''; // use correct `this` and always return a string
                        };
                }

                // the rendered can be a plain string as well. if not specified, always an empty string.
                return function() {
                        return renderer || '';
                };
        }

});

    /* An abstract class comprised of a "grid" of cells that each represent a specific datetime
----------------------------------------------------------------------------------------------------------------------*/

var Grid = fc.Grid = RowRenderer.extend({

        start: null, // the date of the first cell
        end: null, // the date after the last cell

        rowCnt: 0, // number of rows
        colCnt: 0, // number of cols
        rowData: null, // array of objects, holding misc data for each row
        colData: null, // array of objects, holding misc data for each column

        el: null, // the containing element
        coordMap: null, // a GridCoordMap that converts pixel values to datetimes
        elsByFill: null, // a hash of jQuery element sets used for rendering each fill. Keyed by fill name.

        documentDragStartProxy: null, // binds the Grid's scope to documentDragStart (in DayGrid.events)

        // derived from options
        colHeadFormat: null, // TODO: move to another class. not applicable to all Grids
        eventTimeFormat: null,
        displayEventEnd: null,


        constructor: function() {
                RowRenderer.apply(this, arguments); // call the super-constructor

                this.coordMap = new GridCoordMap(this);
                this.elsByFill = {};
                this.documentDragStartProxy = $.proxy(this, 'documentDragStart');
        },


        // Renders the grid into the `el` element.
        // Subclasses should override and call this super-method when done.
        render: function() {
                this.bindHandlers();
        },


        // Called when the grid's resources need to be cleaned up
        destroy: function() {
                this.unbindHandlers();
        },


        /* Options
        ------------------------------------------------------------------------------------------------------------------*/


        // Generates the format string used for the text in column headers, if not explicitly defined by 'columnFormat'
        // TODO: move to another class. not applicable to all Grids
        computeColHeadFormat: function() {
                // subclasses must implement if they want to use headHtml()
        },


        // Generates the format string used for event time text, if not explicitly defined by 'timeFormat'
        computeEventTimeFormat: function() {
                return this.view.opt('smallTimeFormat');
        },


        // Determines whether events should have their end times displayed, if not explicitly defined by 'displayEventEnd'
        computeDisplayEventEnd: function() {
                return false;
        },


        /* Dates
        ------------------------------------------------------------------------------------------------------------------*/


        // Tells the grid about what period of time to display. Grid will subsequently compute dates for cell system.
        setRange: function(range) {
                var view = this.view;

                this.start = range.start.clone();
                this.end = range.end.clone();

                this.rowData = [];
                this.colData = [];
                this.updateCells();

                // Populate option-derived settings. Look for override first, then compute if necessary.
                this.colHeadFormat = view.opt('columnFormat') || this.computeColHeadFormat();
                this.eventTimeFormat = view.opt('timeFormat') || this.computeEventTimeFormat();
                this.displayEventEnd = view.opt('displayEventEnd');
                if (this.displayEventEnd == null) {
                        this.displayEventEnd = this.computeDisplayEventEnd();
                }
        },


        // Responsible for setting rowCnt/colCnt and any other row/col data
        updateCells: function() {
                // subclasses must implement
        },


        // Converts a range with an inclusive `start` and an exclusive `end` into an array of segment objects
        rangeToSegs: function(range) {
                // subclasses must implement
        },


        /* Cells
        ------------------------------------------------------------------------------------------------------------------*/
        // NOTE: columns are ordered left-to-right


        // Gets an object containing row/col number, misc data, and range information about the cell.
        // Accepts row/col values, an object with row/col properties, or a single-number offset from the first cell.
        getCell: function(row, col) {
                var cell;

                if (col == null) {
                        if (typeof row === 'number') { // a single-number offset
                                col = row % this.colCnt;
                                row = Math.floor(row / this.colCnt);
                        }
                        else { // an object with row/col properties
                                col = row.col;
                                row = row.row;
                        }
                }

                cell = { row: row, col: col };

                $.extend(cell, this.getRowData(row), this.getColData(col));
                $.extend(cell, this.computeCellRange(cell));

                return cell;
        },


        // Given a cell object with index and misc data, generates a range object
        computeCellRange: function(cell) {
                // subclasses must implement
        },


        // Retrieves misc data about the given row
        getRowData: function(row) {
                return this.rowData[row] || {};
        },


        // Retrieves misc data baout the given column
        getColData: function(col) {
                return this.colData[col] || {};
        },


        // Retrieves the element representing the given row
        getRowEl: function(row) {
                // subclasses should implement if leveraging the default getCellDayEl() or computeRowCoords()
        },


        // Retrieves the element representing the given column
        getColEl: function(col) {
                // subclasses should implement if leveraging the default getCellDayEl() or computeColCoords()
        },


        // Given a cell object, returns the element that represents the cell's whole-day
        getCellDayEl: function(cell) {
                return this.getColEl(cell.col) || this.getRowEl(cell.row);
        },


        /* Cell Coordinates
        ------------------------------------------------------------------------------------------------------------------*/


        // Computes the top/bottom coordinates of all rows.
        // By default, queries the dimensions of the element provided by getRowEl().
        computeRowCoords: function() {
                var items = [];
                var i, el;
                var item;

                for (i = 0; i < this.rowCnt; i++) {
                        el = this.getRowEl(i);
                        item = {
                                top: el.offset().top
                        };
                        if (i > 0) {
                                items[i - 1].bottom = item.top;
                        }
                        items.push(item);
                }
                item.bottom = item.top + el.outerHeight();

                return items;
        },


        // Computes the left/right coordinates of all rows.
        // By default, queries the dimensions of the element provided by getColEl().
        computeColCoords: function() {
                var items = [];
                var i, el;
                var item;

                for (i = 0; i < this.colCnt; i++) {
                        el = this.getColEl(i);
                        item = {
                                left: el.offset().left
                        };
                        if (i > 0) {
                                items[i - 1].right = item.left;
                        }
                        items.push(item);
                }
                item.right = item.left + el.outerWidth();

                return items;
        },


        /* Handlers
        ------------------------------------------------------------------------------------------------------------------*/


        // Attaches handlers to DOM
        bindHandlers: function() {
                var _this = this;

                // attach a handler to the grid's root element.
                // we don't need to clean up in unbindHandlers or destroy, because when jQuery removes the element from the
                // DOM it automatically unregisters the handlers.
                this.el.on('mousedown', function(ev) {
                        if (
                                !$(ev.target).is('.fc-event-container *, .fc-more') && // not an an event element, or "more.." link
                                !$(ev.target).closest('.fc-popover').length // not on a popover (like the "more.." events one)
                        ) {
                                _this.dayMousedown(ev);
                        }
                });

                // attach event-element-related handlers. in Grid.events
                // same garbage collection note as above.
                this.bindSegHandlers();

                $(document).on('dragstart', this.documentDragStartProxy); // jqui drag
        },


        // Unattaches handlers from the DOM
        unbindHandlers: function() {
                $(document).off('dragstart', this.documentDragStartProxy); // jqui drag
        },


        // Process a mousedown on an element that represents a day. For day clicking and selecting.
        dayMousedown: function(ev) {
                var _this = this;
                var view = this.view;
                var isSelectable = view.opt('selectable');
                var dayClickCell; // null if invalid dayClick
                var selectionRange; // null if invalid selection

                // this listener tracks a mousedown on a day element, and a subsequent drag.
                // if the drag ends on the same day, it is a 'dayClick'.
                // if 'selectable' is enabled, this listener also detects selections.
                var dragListener = new DragListener(this.coordMap, {
                        //distance: 5, // needs more work if we want dayClick to fire correctly
                        scroll: view.opt('dragScroll'),
                        dragStart: function() {
                                view.unselect(); // since we could be rendering a new selection, we want to clear any old one
                        },
                        cellOver: function(cell, isOrig) {
                                var origCell = dragListener.origCell;
                                if (origCell) { // click needs to have started on a cell
                                        dayClickCell = isOrig ? cell : null; // single-cell selection is a day click
                                        if (isSelectable) {
                                                selectionRange = _this.computeSelection(origCell, cell);
                                                if (selectionRange) {
                                                        _this.renderSelection(selectionRange);
                                                }
                                                else {
                                                        disableCursor();
                                                }
                                        }
                                }
                        },
                        cellOut: function(cell) {
                                dayClickCell = null;
                                selectionRange = null;
                                _this.destroySelection();
                                enableCursor();
                        },
                        listenStop: function(ev) {
                                if (dayClickCell) {
                                        view.trigger('dayClick', _this.getCellDayEl(dayClickCell), dayClickCell.start, ev);
                                }
                                if (selectionRange) {
                                        // the selection will already have been rendered. just report it
                                        view.reportSelection(selectionRange, ev);
                                }
                                enableCursor();
                        }
                });

                dragListener.mousedown(ev); // start listening, which will eventually initiate a dragStart
        },


        /* Event Helper
        ------------------------------------------------------------------------------------------------------------------*/
        // TODO: should probably move this to Grid.events, like we did event dragging / resizing


        // Renders a mock event over the given range.
        // The range's end can be null, in which case the mock event that is rendered will have a null end time.
        // `sourceSeg` is the internal segment object involved in the drag. If null, something external is dragging.
        renderRangeHelper: function(range, sourceSeg) {
                var fakeEvent;

                fakeEvent = sourceSeg ? createObject(sourceSeg.event) : {}; // mask the original event object if possible
                fakeEvent.start = range.start.clone();
                fakeEvent.end = range.end ? range.end.clone() : null;
                fakeEvent.allDay = null; // force it to be freshly computed by normalizeEventDateProps
                this.view.calendar.normalizeEventDateProps(fakeEvent);

                // this extra className will be useful for differentiating real events from mock events in CSS
                fakeEvent.className = (fakeEvent.className || []).concat('fc-helper');

                // if something external is being dragged in, don't render a resizer
                if (!sourceSeg) {
                        fakeEvent.editable = false;
                }

                this.renderHelper(fakeEvent, sourceSeg); // do the actual rendering
        },


        // Renders a mock event
        renderHelper: function(event, sourceSeg) {
                // subclasses must implement
        },


        // Unrenders a mock event
        destroyHelper: function() {
                // subclasses must implement
        },


        /* Selection
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders a visual indication of a selection. Will highlight by default but can be overridden by subclasses.
        renderSelection: function(range) {
                this.renderHighlight(range);
        },


        // Unrenders any visual indications of a selection. Will unrender a highlight by default.
        destroySelection: function() {
                this.destroyHighlight();
        },


        // Given the first and last cells of a selection, returns a range object.
        // Will return something falsy if the selection is invalid (when outside of selectionConstraint for example).
        // Subclasses can override and provide additional data in the range object. Will be passed to renderSelection().
        computeSelection: function(firstCell, lastCell) {
                var dates = [
                        firstCell.start,
                        firstCell.end,
                        lastCell.start,
                        lastCell.end
                ];
                var range;

                dates.sort(compareNumbers); // sorts chronologically. works with Moments

                range = {
                        start: dates[0].clone(),
                        end: dates[3].clone()
                };

                if (!this.view.calendar.isSelectionRangeAllowed(range)) {
                        return null;
                }

                return range;
        },


        /* Highlight
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders an emphasis on the given date range. `start` is inclusive. `end` is exclusive.
        renderHighlight: function(range) {
                this.renderFill('highlight', this.rangeToSegs(range));
        },


        // Unrenders the emphasis on a date range
        destroyHighlight: function() {
                this.destroyFill('highlight');
        },


        // Generates an array of classNames for rendering the highlight. Used by the fill system.
        highlightSegClasses: function() {
                return [ 'fc-highlight' ];
        },


        /* Fill System (highlight, background events, business hours)
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders a set of rectangles over the given segments of time.
        // Returns a subset of segs, the segs that were actually rendered.
        // Responsible for populating this.elsByFill. TODO: better API for expressing this requirement
        renderFill: function(type, segs) {
                // subclasses must implement
        },


        // Unrenders a specific type of fill that is currently rendered on the grid
        destroyFill: function(type) {
                var el = this.elsByFill[type];

                if (el) {
                        el.remove();
                        delete this.elsByFill[type];
                }
        },


        // Renders and assigns an `el` property for each fill segment. Generic enough to work with different types.
        // Only returns segments that successfully rendered.
        // To be harnessed by renderFill (implemented by subclasses).
        // Analagous to renderFgSegEls.
        renderFillSegEls: function(type, segs) {
                var _this = this;
                var segElMethod = this[type + 'SegEl'];
                var html = '';
                var renderedSegs = [];
                var i;

                if (segs.length) {

                        // build a large concatenation of segment HTML
                        for (i = 0; i < segs.length; i++) {
                                html += this.fillSegHtml(type, segs[i]);
                        }

                        // Grab individual elements from the combined HTML string. Use each as the default rendering.
                        // Then, compute the 'el' for each segment.
                        $(html).each(function(i, node) {
                                var seg = segs[i];
                                var el = $(node);

                                // allow custom filter methods per-type
                                if (segElMethod) {
                                        el = segElMethod.call(_this, seg, el);
                                }

                                if (el) { // custom filters did not cancel the render
                                        el = $(el); // allow custom filter to return raw DOM node

                                        // correct element type? (would be bad if a non-TD were inserted into a table for example)
                                        if (el.is(_this.fillSegTag)) {
                                                seg.el = el;
                                                renderedSegs.push(seg);
                                        }
                                }
                        });
                }

                return renderedSegs;
        },


        fillSegTag: 'div', // subclasses can override


        // Builds the HTML needed for one fill segment. Generic enought o work with different types.
        fillSegHtml: function(type, seg) {
                var classesMethod = this[type + 'SegClasses']; // custom hooks per-type
                var stylesMethod = this[type + 'SegStyles']; //
                var classes = classesMethod ? classesMethod.call(this, seg) : [];
                var styles = stylesMethod ? stylesMethod.call(this, seg) : ''; // a semi-colon separated CSS property string

                return '<' + this.fillSegTag +
                        (classes.length ? ' class="' + classes.join(' ') + '"' : '') +
                        (styles ? ' style="' + styles + '"' : '') +
                        ' />';
        },


        /* Generic rendering utilities for subclasses
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders a day-of-week header row.
        // TODO: move to another class. not applicable to all Grids
        headHtml: function() {
                return '' +
                        '<div class="fc-row ' + this.view.widgetHeaderClass + '">' +
                                '<table>' +
                                        '<thead>' +
                                                this.rowHtml('head') + // leverages RowRenderer
                                        '</thead>' +
                                '</table>' +
                        '</div>';
        },


        // Used by the `headHtml` method, via RowRenderer, for rendering the HTML of a day-of-week header cell
        // TODO: move to another class. not applicable to all Grids
        headCellHtml: function(cell) {
                var view = this.view;
                var date = cell.start;

                return '' +
                        '<th class="fc-day-header ' + view.widgetHeaderClass + ' fc-' + dayIDs[date.day()] + '">' +
                                htmlEscape(date.format(this.colHeadFormat)) +
                        '</th>';
        },


        // Renders the HTML for a single-day background cell
        bgCellHtml: function(cell) {
                var view = this.view;
                var date = cell.start;
                var classes = this.getDayClasses(date);

                classes.unshift('fc-day', view.widgetContentClass);

                return '<td class="' + classes.join(' ') + '"' +
                        ' data-date="' + date.format('YYYY-MM-DD') + '"' + // if date has a time, won't format it
                        '></td>';
        },


        // Computes HTML classNames for a single-day cell
        getDayClasses: function(date) {
                var view = this.view;
                var today = view.calendar.getNow().stripTime();
                var classes = [ 'fc-' + dayIDs[date.day()] ];

                if (
                        view.name === 'month' &&
                        date.month() != view.intervalStart.month()
                ) {
                        classes.push('fc-other-month');
                }

                if (date.isSame(today, 'day')) {
                        classes.push(
                                'fc-today',
                                view.highlightStateClass
                        );
                }
                else if (date < today) {
                        classes.push('fc-past');
                }
                else {
                        classes.push('fc-future');
                }

                return classes;
        }

});

    /* Event-rendering and event-interaction methods for the abstract Grid class
----------------------------------------------------------------------------------------------------------------------*/

Grid.mixin({

        mousedOverSeg: null, // the segment object the user's mouse is over. null if over nothing
        isDraggingSeg: false, // is a segment being dragged? boolean
        isResizingSeg: false, // is a segment being resized? boolean
        segs: null, // the event segments currently rendered in the grid


        // Renders the given events onto the grid
        renderEvents: function(events) {
                var segs = this.eventsToSegs(events);
                var bgSegs = [];
                var fgSegs = [];
                var i, seg;

                for (i = 0; i < segs.length; i++) {
                        seg = segs[i];

                        if (isBgEvent(seg.event)) {
                                bgSegs.push(seg);
                        }
                        else {
                                fgSegs.push(seg);
                        }
                }

                // Render each different type of segment.
                // Each function may return a subset of the segs, segs that were actually rendered.
                bgSegs = this.renderBgSegs(bgSegs) || bgSegs;
                fgSegs = this.renderFgSegs(fgSegs) || fgSegs;

                this.segs = bgSegs.concat(fgSegs);
        },


        // Unrenders all events currently rendered on the grid
        destroyEvents: function() {
                this.triggerSegMouseout(); // trigger an eventMouseout if user's mouse is over an event

                this.destroyFgSegs();
                this.destroyBgSegs();

                this.segs = null;
        },


        // Retrieves all rendered segment objects currently rendered on the grid
        getEventSegs: function() {
                return this.segs || [];
        },


        /* Foreground Segment Rendering
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders foreground event segments onto the grid. May return a subset of segs that were rendered.
        renderFgSegs: function(segs) {
                // subclasses must implement
        },


        // Unrenders all currently rendered foreground segments
        destroyFgSegs: function() {
                // subclasses must implement
        },


        // Renders and assigns an `el` property for each foreground event segment.
        // Only returns segments that successfully rendered.
        // A utility that subclasses may use.
        renderFgSegEls: function(segs, disableResizing) {
                var view = this.view;
                var html = '';
                var renderedSegs = [];
                var i;

                if (segs.length) { // don't build an empty html string

                        // build a large concatenation of event segment HTML
                        for (i = 0; i < segs.length; i++) {
                                html += this.fgSegHtml(segs[i], disableResizing);
                        }

                        // Grab individual elements from the combined HTML string. Use each as the default rendering.
                        // Then, compute the 'el' for each segment. An el might be null if the eventRender callback returned false.
                        $(html).each(function(i, node) {
                                var seg = segs[i];
                                var el = view.resolveEventEl(seg.event, $(node));

                                if (el) {
                                        el.data('fc-seg', seg); // used by handlers
                                        seg.el = el;
                                        renderedSegs.push(seg);
                                }
                        });
                }

                return renderedSegs;
        },


        // Generates the HTML for the default rendering of a foreground event segment. Used by renderFgSegEls()
        fgSegHtml: function(seg, disableResizing) {
                // subclasses should implement
        },


        /* Background Segment Rendering
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders the given background event segments onto the grid.
        // Returns a subset of the segs that were actually rendered.
        renderBgSegs: function(segs) {
                return this.renderFill('bgEvent', segs);
        },


        // Unrenders all the currently rendered background event segments
        destroyBgSegs: function() {
                this.destroyFill('bgEvent');
        },


        // Renders a background event element, given the default rendering. Called by the fill system.
        bgEventSegEl: function(seg, el) {
                return this.view.resolveEventEl(seg.event, el); // will filter through eventRender
        },


        // Generates an array of classNames to be used for the default rendering of a background event.
        // Called by the fill system.
        bgEventSegClasses: function(seg) {
                var event = seg.event;
                var source = event.source || {};

                return [ 'fc-bgevent' ].concat(
                        event.className,
                        source.className || []
                );
        },


        // Generates a semicolon-separated CSS string to be used for the default rendering of a background event.
        // Called by the fill system.
        // TODO: consolidate with getEventSkinCss?
        bgEventSegStyles: function(seg) {
                var view = this.view;
                var event = seg.event;
                var source = event.source || {};
                var eventColor = event.color;
                var sourceColor = source.color;
                var optionColor = view.opt('eventColor');
                var backgroundColor =
                        event.backgroundColor ||
                        eventColor ||
                        source.backgroundColor ||
                        sourceColor ||
                        view.opt('eventBackgroundColor') ||
                        optionColor;

                if (backgroundColor) {
                        return 'background-color:' + backgroundColor;
                }

                return '';
        },


        // Generates an array of classNames to be used for the rendering business hours overlay. Called by the fill system.
        businessHoursSegClasses: function(seg) {
                return [ 'fc-nonbusiness', 'fc-bgevent' ];
        },


        /* Handlers
        ------------------------------------------------------------------------------------------------------------------*/


        // Attaches event-element-related handlers to the container element and leverage bubbling
        bindSegHandlers: function() {
                var _this = this;
                var view = this.view;

                $.each(
                        {
                                mouseenter: function(seg, ev) {
                                        _this.triggerSegMouseover(seg, ev);
                                },
                                mouseleave: function(seg, ev) {
                                        _this.triggerSegMouseout(seg, ev);
                                },
                                click: function(seg, ev) {
                                        return view.trigger('eventClick', this, seg.event, ev); // can return `false` to cancel
                                },
                                mousedown: function(seg, ev) {
                                        if ($(ev.target).is('.fc-resizer') && view.isEventResizable(seg.event)) {
                                                _this.segResizeMousedown(seg, ev);
                                        }
                                        else if (view.isEventDraggable(seg.event)) {
                                                _this.segDragMousedown(seg, ev);
                                        }
                                }
                        },
                        function(name, func) {
                                // attach the handler to the container element and only listen for real event elements via bubbling
                                _this.el.on(name, '.fc-event-container > *', function(ev) {
                                        var seg = $(this).data('fc-seg'); // grab segment data. put there by View::renderEvents

                                        // only call the handlers if there is not a drag/resize in progress
                                        if (seg && !_this.isDraggingSeg && !_this.isResizingSeg) {
                                                return func.call(this, seg, ev); // `this` will be the event element
                                        }
                                });
                        }
                );
        },


        // Updates internal state and triggers handlers for when an event element is moused over
        triggerSegMouseover: function(seg, ev) {
                if (!this.mousedOverSeg) {
                        this.mousedOverSeg = seg;
                        this.view.trigger('eventMouseover', seg.el[0], seg.event, ev);
                }
        },


        // Updates internal state and triggers handlers for when an event element is moused out.
        // Can be given no arguments, in which case it will mouseout the segment that was previously moused over.
        triggerSegMouseout: function(seg, ev) {
                ev = ev || {}; // if given no args, make a mock mouse event

                if (this.mousedOverSeg) {
                        seg = seg || this.mousedOverSeg; // if given no args, use the currently moused-over segment
                        this.mousedOverSeg = null;
                        this.view.trigger('eventMouseout', seg.el[0], seg.event, ev);
                }
        },


        /* Event Dragging
        ------------------------------------------------------------------------------------------------------------------*/


        // Called when the user does a mousedown on an event, which might lead to dragging.
        // Generic enough to work with any type of Grid.
        segDragMousedown: function(seg, ev) {
                var _this = this;
                var view = this.view;
                var el = seg.el;
                var event = seg.event;
                var dropLocation;

                // A clone of the original element that will move with the mouse
                var mouseFollower = new MouseFollower(seg.el, {
                        parentEl: view.el,
                        opacity: view.opt('dragOpacity'),
                        revertDuration: view.opt('dragRevertDuration'),
                        zIndex: 2 // one above the .fc-view
                });

                // Tracks mouse movement over the *view's* coordinate map. Allows dragging and dropping between subcomponents
                // of the view.
                var dragListener = new DragListener(view.coordMap, {
                        distance: 5,
                        scroll: view.opt('dragScroll'),
                        listenStart: function(ev) {
                                mouseFollower.hide(); // don't show until we know this is a real drag
                                mouseFollower.start(ev);
                        },
                        dragStart: function(ev) {
                                _this.triggerSegMouseout(seg, ev); // ensure a mouseout on the manipulated event has been reported
                                _this.isDraggingSeg = true;
                                view.hideEvent(event); // hide all event segments. our mouseFollower will take over
                                view.trigger('eventDragStart', el[0], event, ev, {}); // last argument is jqui dummy
                        },
                        cellOver: function(cell, isOrig) {
                                var origCell = seg.cell || dragListener.origCell; // starting cell could be forced (DayGrid.limit)

                                dropLocation = _this.computeEventDrop(origCell, cell, event);
                                if (dropLocation) {
                                        if (view.renderDrag(dropLocation, seg)) { // have the subclass render a visual indication
                                                mouseFollower.hide(); // if the subclass is already using a mock event "helper", hide our own
                                        }
                                        else {
                                                mouseFollower.show();
                                        }
                                        if (isOrig) {
                                                dropLocation = null; // needs to have moved cells to be a valid drop
                                        }
                                }
                                else {
                                        // have the helper follow the mouse (no snapping) with a warning-style cursor
                                        mouseFollower.show();
                                        disableCursor();
                                }
                        },
                        cellOut: function() { // called before mouse moves to a different cell OR moved out of all cells
                                dropLocation = null;
                                view.destroyDrag(); // unrender whatever was done in renderDrag
                                mouseFollower.show(); // show in case we are moving out of all cells
                                enableCursor();
                        },
                        dragStop: function(ev) {
                                // do revert animation if hasn't changed. calls a callback when finished (whether animation or not)
                                mouseFollower.stop(!dropLocation, function() {
                                        _this.isDraggingSeg = false;
                                        view.destroyDrag();
                                        view.showEvent(event);
                                        view.trigger('eventDragStop', el[0], event, ev, {}); // last argument is jqui dummy

                                        if (dropLocation) {
                                                view.reportEventDrop(event, dropLocation, el, ev);
                                        }
                                });
                                enableCursor();
                        },
                        listenStop: function() {
                                mouseFollower.stop(); // put in listenStop in case there was a mousedown but the drag never started
                        }
                });

                dragListener.mousedown(ev); // start listening, which will eventually lead to a dragStart
        },


        // Given the cell an event drag began, and the cell event was dropped, calculates the new start/end/allDay
        // values for the event. Subclasses may override and set additional properties to be used by renderDrag.
        // A falsy returned value indicates an invalid drop.
        computeEventDrop: function(startCell, endCell, event) {
                var dragStart = startCell.start;
                var dragEnd = endCell.start;
                var delta;
                var newStart;
                var newEnd;
                var newAllDay;
                var dropLocation;

                if (dragStart.hasTime() === dragEnd.hasTime()) {
                        delta = diffDayTime(dragEnd, dragStart);
                        newStart = event.start.clone().add(delta);
                        if (event.end === null) { // do we need to compute an end?
                                newEnd = null;
                        }
                        else {
                                newEnd = event.end.clone().add(delta);
                        }
                        newAllDay = event.allDay; // keep it the same
                }
                else {
                        // if switching from day <-> timed, start should be reset to the dropped date, and the end cleared
                        newStart = dragEnd.clone();
                        newEnd = null; // end should be cleared
                        newAllDay = !dragEnd.hasTime();
                }

                dropLocation = {
                        start: newStart,
                        end: newEnd,
                        allDay: newAllDay
                };

                if (!this.view.calendar.isEventRangeAllowed(dropLocation, event)) {
                        return null;
                }

                return dropLocation;
        },


        /* External Element Dragging
        ------------------------------------------------------------------------------------------------------------------*/


        // Called when a jQuery UI drag is initiated anywhere in the DOM
        documentDragStart: function(ev, ui) {
                var view = this.view;
                var el;
                var accept;

                if (view.opt('droppable')) { // only listen if this setting is on
                        el = $(ev.target);

                        // Test that the dragged element passes the dropAccept selector or filter function.
                        // FYI, the default is "*" (matches all)
                        accept = view.opt('dropAccept');
                        if ($.isFunction(accept) ? accept.call(el[0], el) : el.is(accept)) {

                                this.startExternalDrag(el, ev, ui);
                        }
                }
        },


        // Called when a jQuery UI drag starts and it needs to be monitored for cell dropping
        startExternalDrag: function(el, ev, ui) {
                var _this = this;
                var meta = getDraggedElMeta(el); // extra data about event drop, including possible event to create
                var dragListener;
                var dropLocation; // a null value signals an unsuccessful drag

                // listener that tracks mouse movement over date-associated pixel regions
                dragListener = new DragListener(this.coordMap, {
                        cellOver: function(cell) {
                                dropLocation = _this.computeExternalDrop(cell, meta);
                                if (dropLocation) {
                                        _this.renderDrag(dropLocation); // called without a seg parameter
                                }
                                else { // invalid drop cell
                                        disableCursor();
                                }
                        },
                        cellOut: function() {
                                dropLocation = null; // signal unsuccessful
                                _this.destroyDrag();
                                enableCursor();
                        }
                });

                // gets called, only once, when jqui drag is finished
                $(document).one('dragstop', function(ev, ui) {
                        _this.destroyDrag();
                        enableCursor();

                        if (dropLocation) { // element was dropped on a valid date/time cell
                                _this.view.reportExternalDrop(meta, dropLocation, el, ev, ui);
                        }
                });

                dragListener.startDrag(ev); // start listening immediately
        },


        // Given a cell to be dropped upon, and misc data associated with the jqui drag (guaranteed to be a plain object),
        // returns start/end dates for the event that would result from the hypothetical drop. end might be null.
        // Returning a null value signals an invalid drop cell.
        computeExternalDrop: function(cell, meta) {
                var dropLocation = {
                        start: cell.start.clone(),
                        end: null
                };

                // if dropped on an all-day cell, and element's metadata specified a time, set it
                if (meta.startTime && !dropLocation.start.hasTime()) {
                        dropLocation.start.time(meta.startTime);
                }

                if (meta.duration) {
                        dropLocation.end = dropLocation.start.clone().add(meta.duration);
                }

                if (!this.view.calendar.isExternalDropRangeAllowed(dropLocation, meta.eventProps)) {
                        return null;
                }

                return dropLocation;
        },



        /* Drag Rendering (for both events and an external elements)
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders a visual indication of an event or external element being dragged.
        // `dropLocation` contains hypothetical start/end/allDay values the event would have if dropped. end can be null.
        // `seg` is the internal segment object that is being dragged. If dragging an external element, `seg` is null.
        // A truthy returned value indicates this method has rendered a helper element.
        renderDrag: function(dropLocation, seg) {
                // subclasses must implement
        },


        // Unrenders a visual indication of an event or external element being dragged
        destroyDrag: function() {
                // subclasses must implement
        },


        /* Resizing
        ------------------------------------------------------------------------------------------------------------------*/


        // Called when the user does a mousedown on an event's resizer, which might lead to resizing.
        // Generic enough to work with any type of Grid.
        segResizeMousedown: function(seg, ev) {
                var _this = this;
                var view = this.view;
                var calendar = view.calendar;
                var el = seg.el;
                var event = seg.event;
                var start = event.start;
                var oldEnd = calendar.getEventEnd(event);
                var newEnd; // falsy if invalid resize
                var dragListener;

                function destroy() { // resets the rendering to show the original event
                        _this.destroyEventResize();
                        view.showEvent(event);
                        enableCursor();
                }

                // Tracks mouse movement over the *grid's* coordinate map
                dragListener = new DragListener(this.coordMap, {
                        distance: 5,
                        scroll: view.opt('dragScroll'),
                        dragStart: function(ev) {
                                _this.triggerSegMouseout(seg, ev); // ensure a mouseout on the manipulated event has been reported
                                _this.isResizingSeg = true;
                                view.trigger('eventResizeStart', el[0], event, ev, {}); // last argument is jqui dummy
                        },
                        cellOver: function(cell) {
                                newEnd = cell.end;

                                if (!newEnd.isAfter(start)) { // was end moved before start?
                                        newEnd = start.clone().add( // make the event span a single slot
                                                diffDayTime(cell.end, cell.start) // assumes all slot durations are the same
                                        );
                                }

                                if (newEnd.isSame(oldEnd)) {
                                        newEnd = null;
                                }
                                else if (!calendar.isEventRangeAllowed({ start: start, end: newEnd }, event)) {
                                        newEnd = null;
                                        disableCursor();
                                }
                                else {
                                        _this.renderEventResize({ start: start, end: newEnd }, seg);
                                        view.hideEvent(event);
                                }
                        },
                        cellOut: function() { // called before mouse moves to a different cell OR moved out of all cells
                                newEnd = null;
                                destroy();
                        },
                        dragStop: function(ev) {
                                _this.isResizingSeg = false;
                                destroy();
                                view.trigger('eventResizeStop', el[0], event, ev, {}); // last argument is jqui dummy

                                if (newEnd) { // valid date to resize to?
                                        view.reportEventResize(event, newEnd, el, ev);
                                }
                        }
                });

                dragListener.mousedown(ev); // start listening, which will eventually lead to a dragStart
        },


        // Renders a visual indication of an event being resized.
        // `range` has the updated dates of the event. `seg` is the original segment object involved in the drag.
        renderEventResize: function(range, seg) {
                // subclasses must implement
        },


        // Unrenders a visual indication of an event being resized.
        destroyEventResize: function() {
                // subclasses must implement
        },


        /* Rendering Utils
        ------------------------------------------------------------------------------------------------------------------*/


        // Compute the text that should be displayed on an event's element.
        // `range` can be the Event object itself, or something range-like, with at least a `start`.
        // The `timeFormat` options and the grid's default format is used, but `formatStr` can override.
        getEventTimeText: function(range, formatStr) {

                formatStr = formatStr || this.eventTimeFormat;

                if (range.end && this.displayEventEnd) {
                        return this.view.formatRange(range, formatStr);
                }
                else {
                        return range.start.format(formatStr);
                }
        },


        // Generic utility for generating the HTML classNames for an event segment's element
        getSegClasses: function(seg, isDraggable, isResizable) {
                var event = seg.event;
                var classes = [
                        'fc-event',
                        seg.isStart ? 'fc-start' : 'fc-not-start',
                        seg.isEnd ? 'fc-end' : 'fc-not-end'
                ].concat(
                        event.className,
                        event.source ? event.source.className : []
                );

                if (isDraggable) {
                        classes.push('fc-draggable');
                }
                if (isResizable) {
                        classes.push('fc-resizable');
                }

                return classes;
        },


        // Utility for generating a CSS string with all the event skin-related properties
        getEventSkinCss: function(event) {
                var view = this.view;
                var source = event.source || {};
                var eventColor = event.color;
                var sourceColor = source.color;
                var optionColor = view.opt('eventColor');
                var backgroundColor =
                        event.backgroundColor ||
                        eventColor ||
                        source.backgroundColor ||
                        sourceColor ||
                        view.opt('eventBackgroundColor') ||
                        optionColor;
                var borderColor =
                        event.borderColor ||
                        eventColor ||
                        source.borderColor ||
                        sourceColor ||
                        view.opt('eventBorderColor') ||
                        optionColor;
                var textColor =
                        event.textColor ||
                        source.textColor ||
                        view.opt('eventTextColor');
                var statements = [];
                if (backgroundColor) {
                        statements.push('background-color:' + backgroundColor);
                }
                if (borderColor) {
                        statements.push('border-color:' + borderColor);
                }
                if (textColor) {
                        statements.push('color:' + textColor);
                }
                return statements.join(';');
        },


        /* Converting events -> ranges -> segs
        ------------------------------------------------------------------------------------------------------------------*/


        // Converts an array of event objects into an array of event segment objects.
        // A custom `rangeToSegsFunc` may be given for arbitrarily slicing up events.
        eventsToSegs: function(events, rangeToSegsFunc) {
                var eventRanges = this.eventsToRanges(events);
                var segs = [];
                var i;

                for (i = 0; i < eventRanges.length; i++) {
                        segs.push.apply(
                                segs,
                                this.eventRangeToSegs(eventRanges[i], rangeToSegsFunc)
                        );
                }

                return segs;
        },


        // Converts an array of events into an array of "range" objects.
        // A "range" object is a plain object with start/end properties denoting the time it covers. Also an event property.
        // For "normal" events, this will be identical to the event's start/end, but for "inverse-background" events,
        // will create an array of ranges that span the time *not* covered by the given event.
        eventsToRanges: function(events) {
                var _this = this;
                var eventsById = groupEventsById(events);
                var ranges = [];

                // group by ID so that related inverse-background events can be rendered together
                $.each(eventsById, function(id, eventGroup) {
                        if (eventGroup.length) {
                                ranges.push.apply(
                                        ranges,
                                        isInverseBgEvent(eventGroup[0]) ?
                                                _this.eventsToInverseRanges(eventGroup) :
                                                _this.eventsToNormalRanges(eventGroup)
                                );
                        }
                });

                return ranges;
        },


        // Converts an array of "normal" events (not inverted rendering) into a parallel array of ranges
        eventsToNormalRanges: function(events) {
                var calendar = this.view.calendar;
                var ranges = [];
                var i, event;
                var eventStart, eventEnd;

                for (i = 0; i < events.length; i++) {
                        event = events[i];

                        // make copies and normalize by stripping timezone
                        eventStart = event.start.clone().stripZone();
                        eventEnd = calendar.getEventEnd(event).stripZone();

                        ranges.push({
                                event: event,
                                start: eventStart,
                                end: eventEnd,
                                eventStartMS: +eventStart,
                                eventDurationMS: eventEnd - eventStart
                        });
                }

                return ranges;
        },


        // Converts an array of events, with inverse-background rendering, into an array of range objects.
        // The range objects will cover all the time NOT covered by the events.
        eventsToInverseRanges: function(events) {
                var view = this.view;
                var viewStart = view.start.clone().stripZone(); // normalize timezone
                var viewEnd = view.end.clone().stripZone(); // normalize timezone
                var normalRanges = this.eventsToNormalRanges(events); // will give us normalized dates we can use w/o copies
                var inverseRanges = [];
                var event0 = events[0]; // assign this to each range's `.event`
                var start = viewStart; // the end of the previous range. the start of the new range
                var i, normalRange;

                // ranges need to be in order. required for our date-walking algorithm
                normalRanges.sort(compareNormalRanges);

                for (i = 0; i < normalRanges.length; i++) {
                        normalRange = normalRanges[i];

                        // add the span of time before the event (if there is any)
                        if (normalRange.start > start) { // compare millisecond time (skip any ambig logic)
                                inverseRanges.push({
                                        event: event0,
                                        start: start,
                                        end: normalRange.start
                                });
                        }

                        start = normalRange.end;
                }

                // add the span of time after the last event (if there is any)
                if (start < viewEnd) { // compare millisecond time (skip any ambig logic)
                        inverseRanges.push({
                                event: event0,
                                start: start,
                                end: viewEnd
                        });
                }

                return inverseRanges;
        },


        // Slices the given event range into one or more segment objects.
        // A `rangeToSegsFunc` custom slicing function can be given.
        eventRangeToSegs: function(eventRange, rangeToSegsFunc) {
                var segs;
                var i, seg;

                if (rangeToSegsFunc) {
                        segs = rangeToSegsFunc(eventRange);
                }
                else {
                        segs = this.rangeToSegs(eventRange); // defined by the subclass
                }

                for (i = 0; i < segs.length; i++) {
                        seg = segs[i];
                        seg.event = eventRange.event;
                        seg.eventStartMS = eventRange.eventStartMS;
                        seg.eventDurationMS = eventRange.eventDurationMS;
                }

                return segs;
        }

});


/* Utilities
----------------------------------------------------------------------------------------------------------------------*/


function isBgEvent(event) { // returns true if background OR inverse-background
        var rendering = getEventRendering(event);
        return rendering === 'background' || rendering === 'inverse-background';
}


function isInverseBgEvent(event) {
        return getEventRendering(event) === 'inverse-background';
}


function getEventRendering(event) {
        return firstDefined((event.source || {}).rendering, event.rendering);
}


function groupEventsById(events) {
        var eventsById = {};
        var i, event;

        for (i = 0; i < events.length; i++) {
                event = events[i];
                (eventsById[event._id] || (eventsById[event._id] = [])).push(event);
        }

        return eventsById;
}


// A cmp function for determining which non-inverted "ranges" (see above) happen earlier
function compareNormalRanges(range1, range2) {
        return range1.eventStartMS - range2.eventStartMS; // earlier ranges go first
}


// A cmp function for determining which segments should take visual priority
// DOES NOT WORK ON INVERTED BACKGROUND EVENTS because they have no eventStartMS/eventDurationMS
function compareSegs(seg1, seg2) {
        return seg1.eventStartMS - seg2.eventStartMS || // earlier events go first
                seg2.eventDurationMS - seg1.eventDurationMS || // tie? longer events go first
                seg2.event.allDay - seg1.event.allDay || // tie? put all-day events first (booleans cast to 0/1)
                (seg1.event.title || '').localeCompare(seg2.event.title); // tie? alphabetically by title
}

fc.compareSegs = compareSegs; // export


/* External-Dragging-Element Data
----------------------------------------------------------------------------------------------------------------------*/

// Require all HTML5 data-* attributes used by FullCalendar to have this prefix.
// A value of '' will query attributes like data-event. A value of 'fc' will query attributes like data-fc-event.
fc.dataAttrPrefix = '';

// Given a jQuery element that might represent a dragged FullCalendar event, returns an intermediate data structure
// to be used for Event Object creation.
// A defined `.eventProps`, even when empty, indicates that an event should be created.
function getDraggedElMeta(el) {
        var prefix = fc.dataAttrPrefix;
        var eventProps; // properties for creating the event, not related to date/time
        var startTime; // a Duration
        var duration;
        var stick;

        if (prefix) { prefix += '-'; }
        eventProps = el.data(prefix + 'event') || null;

        if (eventProps) {
                if (typeof eventProps === 'object') {
                        eventProps = $.extend({}, eventProps); // make a copy
                }
                else { // something like 1 or true. still signal event creation
                        eventProps = {};
                }

                // pluck special-cased date/time properties
                startTime = eventProps.start;
                if (startTime == null) { startTime = eventProps.time; } // accept 'time' as well
                duration = eventProps.duration;
                stick = eventProps.stick;
                delete eventProps.start;
                delete eventProps.time;
                delete eventProps.duration;
                delete eventProps.stick;
        }

        // fallback to standalone attribute values for each of the date/time properties
        if (startTime == null) { startTime = el.data(prefix + 'start'); }
        if (startTime == null) { startTime = el.data(prefix + 'time'); } // accept 'time' as well
        if (duration == null) { duration = el.data(prefix + 'duration'); }
        if (stick == null) { stick = el.data(prefix + 'stick'); }

        // massage into correct data types
        startTime = startTime != null ? moment.duration(startTime) : null;
        duration = duration != null ? moment.duration(duration) : null;
        stick = Boolean(stick);

        return { eventProps: eventProps, startTime: startTime, duration: duration, stick: stick };
}


    /* A component that renders a grid of whole-days that runs horizontally. There can be multiple rows, one per week.
----------------------------------------------------------------------------------------------------------------------*/

var DayGrid = Grid.extend({

        numbersVisible: false, // should render a row for day/week numbers? set by outside view. TODO: make internal
        bottomCoordPadding: 0, // hack for extending the hit area for the last row of the coordinate grid
        breakOnWeeks: null, // should create a new row for each week? set by outside view

        cellDates: null, // flat chronological array of each cell's dates
        dayToCellOffsets: null, // maps days offsets from grid's start date, to cell offsets

        rowEls: null, // set of fake row elements
        dayEls: null, // set of whole-day elements comprising the row's background
        helperEls: null, // set of cell skeleton elements for rendering the mock event "helper"


        // Renders the rows and columns into the component's `this.el`, which should already be assigned.
        // isRigid determins whether the individual rows should ignore the contents and be a constant height.
        // Relies on the view's colCnt and rowCnt. In the future, this component should probably be self-sufficient.
        render: function(isRigid) {
                var view = this.view;
                var rowCnt = this.rowCnt;
                var colCnt = this.colCnt;
                var cellCnt = rowCnt * colCnt;
                var html = '';
                var row;
                var i, cell;

                for (row = 0; row < rowCnt; row++) {
                        html += this.dayRowHtml(row, isRigid);
                }
                this.el.html(html);

                this.rowEls = this.el.find('.fc-row');
                this.dayEls = this.el.find('.fc-day');

                // trigger dayRender with each cell's element
                for (i = 0; i < cellCnt; i++) {
                        cell = this.getCell(i);
                        view.trigger('dayRender', null, cell.start, this.dayEls.eq(i));
                }

                Grid.prototype.render.call(this); // call the super-method
        },


        destroy: function() {
                this.destroySegPopover();
                Grid.prototype.destroy.call(this); // call the super-method
        },


        // Generates the HTML for a single row. `row` is the row number.
        dayRowHtml: function(row, isRigid) {
                var view = this.view;
                var classes = [ 'fc-row', 'fc-week', view.widgetContentClass ];

                if (isRigid) {
                        classes.push('fc-rigid');
                }

                return '' +
                        '<div class="' + classes.join(' ') + '">' +
                                '<div class="fc-bg">' +
                                        '<table>' +
                                                this.rowHtml('day', row) + // leverages RowRenderer. calls dayCellHtml()
                                        '</table>' +
                                '</div>' +
                                '<div class="fc-content-skeleton">' +
                                        '<table>' +
                                                (this.numbersVisible ?
                                                        '<thead>' +
                                                                this.rowHtml('number', row) + // leverages RowRenderer. View will define render method
                                                        '</thead>' :
                                                        ''
                                                        ) +
                                        '</table>' +
                                '</div>' +
                        '</div>';
        },


        // Renders the HTML for a whole-day cell. Will eventually end up in the day-row's background.
        // We go through a 'day' row type instead of just doing a 'bg' row type so that the View can do custom rendering
        // specifically for whole-day rows, whereas a 'bg' might also be used for other purposes (TimeGrid bg for example).
        dayCellHtml: function(cell) {
                return this.bgCellHtml(cell);
        },


        /* Options
        ------------------------------------------------------------------------------------------------------------------*/


        // Computes a default column header formatting string if `colFormat` is not explicitly defined
        computeColHeadFormat: function() {
                if (this.rowCnt > 1) { // more than one week row. day numbers will be in each cell
                        return 'ddd'; // "Sat"
                }
                else if (this.colCnt > 1) { // multiple days, so full single date string WON'T be in title text
                        return this.view.opt('dayOfMonthFormat'); // "Sat 12/10"
                }
                else { // single day, so full single date string will probably be in title text
                        return 'dddd'; // "Saturday"
                }
        },


        // Computes a default event time formatting string if `timeFormat` is not explicitly defined
        computeEventTimeFormat: function() {
                return this.view.opt('extraSmallTimeFormat'); // like "6p" or "6:30p"
        },


        // Computes a default `displayEventEnd` value if one is not expliclty defined
        computeDisplayEventEnd: function() {
                return this.colCnt == 1; // we'll likely have space if there's only one day
        },


        /* Cell System
        ------------------------------------------------------------------------------------------------------------------*/


        // Initializes row/col information
        updateCells: function() {
                var cellDates;
                var firstDay;
                var rowCnt;
                var colCnt;

                this.updateCellDates(); // populates cellDates and dayToCellOffsets
                cellDates = this.cellDates;

                if (this.breakOnWeeks) {
                        // count columns until the day-of-week repeats
                        firstDay = cellDates[0].day();
                        for (colCnt = 1; colCnt < cellDates.length; colCnt++) {
                                if (cellDates[colCnt].day() == firstDay) {
                                        break;
                                }
                        }
                        rowCnt = Math.ceil(cellDates.length / colCnt);
                }
                else {
                        rowCnt = 1;
                        colCnt = cellDates.length;
                }

                this.rowCnt = rowCnt;
                this.colCnt = colCnt;
        },


        // Populates cellDates and dayToCellOffsets
        updateCellDates: function() {
                var view = this.view;
                var date = this.start.clone();
                var dates = [];
                var offset = -1;
                var offsets = [];

                while (date.isBefore(this.end)) { // loop each day from start to end
                        if (view.isHiddenDay(date)) {
                                offsets.push(offset + 0.5); // mark that it's between offsets
                        }
                        else {
                                offset++;
                                offsets.push(offset);
                                dates.push(date.clone());
                        }
                        date.add(1, 'days');
                }

                this.cellDates = dates;
                this.dayToCellOffsets = offsets;
        },


        // Given a cell object, generates a range object
        computeCellRange: function(cell) {
                var colCnt = this.colCnt;
                var index = cell.row * colCnt + (this.isRTL ? colCnt - cell.col - 1 : cell.col);
                var start = this.cellDates[index].clone();
                var end = start.clone().add(1, 'day');

                return { start: start, end: end };
        },


        // Retrieves the element representing the given row
        getRowEl: function(row) {
                return this.rowEls.eq(row);
        },


        // Retrieves the element representing the given column
        getColEl: function(col) {
                return this.dayEls.eq(col);
        },


        // Gets the whole-day element associated with the cell
        getCellDayEl: function(cell) {
                return this.dayEls.eq(cell.row * this.colCnt + cell.col);
        },


        // Overrides Grid's method for when row coordinates are computed
        computeRowCoords: function() {
                var rowCoords = Grid.prototype.computeRowCoords.call(this); // call the super-method

                // hack for extending last row (used by AgendaView)
                rowCoords[rowCoords.length - 1].bottom += this.bottomCoordPadding;

                return rowCoords;
        },


        /* Dates
        ------------------------------------------------------------------------------------------------------------------*/


        // Slices up a date range by row into an array of segments
        rangeToSegs: function(range) {
                var isRTL = this.isRTL;
                var rowCnt = this.rowCnt;
                var colCnt = this.colCnt;
                var segs = [];
                var first, last; // inclusive cell-offset range for given range
                var row;
                var rowFirst, rowLast; // inclusive cell-offset range for current row
                var isStart, isEnd;
                var segFirst, segLast; // inclusive cell-offset range for segment
                var seg;

                range = this.view.computeDayRange(range); // make whole-day range, considering nextDayThreshold
                first = this.dateToCellOffset(range.start);
                last = this.dateToCellOffset(range.end.subtract(1, 'days')); // offset of inclusive end date

                for (row = 0; row < rowCnt; row++) {
                        rowFirst = row * colCnt;
                        rowLast = rowFirst + colCnt - 1;

                        // intersect segment's offset range with the row's
                        segFirst = Math.max(rowFirst, first);
                        segLast = Math.min(rowLast, last);

                        // deal with in-between indices
                        segFirst = Math.ceil(segFirst); // in-between starts round to next cell
                        segLast = Math.floor(segLast); // in-between ends round to prev cell

                        if (segFirst <= segLast) { // was there any intersection with the current row?

                                // must be matching integers to be the segment's start/end
                                isStart = segFirst === first;
                                isEnd = segLast === last;

                                // translate offsets to be relative to start-of-row
                                segFirst -= rowFirst;
                                segLast -= rowFirst;

                                seg = { row: row, isStart: isStart, isEnd: isEnd };
                                if (isRTL) {
                                        seg.leftCol = colCnt - segLast - 1;
                                        seg.rightCol = colCnt - segFirst - 1;
                                }
                                else {
                                        seg.leftCol = segFirst;
                                        seg.rightCol = segLast;
                                }
                                segs.push(seg);
                        }
                }

                return segs;
        },


        // Given a date, returns its chronolocial cell-offset from the first cell of the grid.
        // If the date lies between cells (because of hiddenDays), returns a floating-point value between offsets.
        // If before the first offset, returns a negative number.
        // If after the last offset, returns an offset past the last cell offset.
        // Only works for *start* dates of cells. Will not work for exclusive end dates for cells.
        dateToCellOffset: function(date) {
                var offsets = this.dayToCellOffsets;
                var day = date.diff(this.start, 'days');

                if (day < 0) {
                        return offsets[0] - 1;
                }
                else if (day >= offsets.length) {
                        return offsets[offsets.length - 1] + 1;
                }
                else {
                        return offsets[day];
                }
        },


        /* Event Drag Visualization
        ------------------------------------------------------------------------------------------------------------------*/
        // TODO: move to DayGrid.event, similar to what we did with Grid's drag methods


        // Renders a visual indication of an event or external element being dragged.
        // The dropLocation's end can be null. seg can be null. See Grid::renderDrag for more info.
        renderDrag: function(dropLocation, seg) {
                var opacity;

                // always render a highlight underneath
                this.renderHighlight(
                        this.view.calendar.ensureVisibleEventRange(dropLocation) // needs to be a proper range
                );

                // if a segment from the same calendar but another component is being dragged, render a helper event
                if (seg && !seg.el.closest(this.el).length) {

                        this.renderRangeHelper(dropLocation, seg);

                        opacity = this.view.opt('dragOpacity');
                        if (opacity !== undefined) {
                                this.helperEls.css('opacity', opacity);
                        }

                        return true; // a helper has been rendered
                }
        },


        // Unrenders any visual indication of a hovering event
        destroyDrag: function() {
                this.destroyHighlight();
                this.destroyHelper();
        },


        /* Event Resize Visualization
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders a visual indication of an event being resized
        renderEventResize: function(range, seg) {
                this.renderHighlight(range);
                this.renderRangeHelper(range, seg);
        },


        // Unrenders a visual indication of an event being resized
        destroyEventResize: function() {
                this.destroyHighlight();
                this.destroyHelper();
        },


        /* Event Helper
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders a mock "helper" event. `sourceSeg` is the associated internal segment object. It can be null.
        renderHelper: function(event, sourceSeg) {
                var helperNodes = [];
                var segs = this.eventsToSegs([ event ]);
                var rowStructs;

                segs = this.renderFgSegEls(segs); // assigns each seg's el and returns a subset of segs that were rendered
                rowStructs = this.renderSegRows(segs);

                // inject each new event skeleton into each associated row
                this.rowEls.each(function(row, rowNode) {
                        var rowEl = $(rowNode); // the .fc-row
                        var skeletonEl = $('<div class="fc-helper-skeleton"><table/></div>'); // will be absolutely positioned
                        var skeletonTop;

                        // If there is an original segment, match the top position. Otherwise, put it at the row's top level
                        if (sourceSeg && sourceSeg.row === row) {
                                skeletonTop = sourceSeg.el.position().top;
                        }
                        else {
                                skeletonTop = rowEl.find('.fc-content-skeleton tbody').position().top;
                        }

                        skeletonEl.css('top', skeletonTop)
                                .find('table')
                                        .append(rowStructs[row].tbodyEl);

                        rowEl.append(skeletonEl);
                        helperNodes.push(skeletonEl[0]);
                });

                this.helperEls = $(helperNodes); // array -> jQuery set
        },


        // Unrenders any visual indication of a mock helper event
        destroyHelper: function() {
                if (this.helperEls) {
                        this.helperEls.remove();
                        this.helperEls = null;
                }
        },


        /* Fill System (highlight, background events, business hours)
        ------------------------------------------------------------------------------------------------------------------*/


        fillSegTag: 'td', // override the default tag name


        // Renders a set of rectangles over the given segments of days.
        // Only returns segments that successfully rendered.
        renderFill: function(type, segs) {
                var nodes = [];
                var i, seg;
                var skeletonEl;

                segs = this.renderFillSegEls(type, segs); // assignes `.el` to each seg. returns successfully rendered segs

                for (i = 0; i < segs.length; i++) {
                        seg = segs[i];
                        skeletonEl = this.renderFillRow(type, seg);
                        this.rowEls.eq(seg.row).append(skeletonEl);
                        nodes.push(skeletonEl[0]);
                }

                this.elsByFill[type] = $(nodes);

                return segs;
        },


        // Generates the HTML needed for one row of a fill. Requires the seg's el to be rendered.
        renderFillRow: function(type, seg) {
                var colCnt = this.colCnt;
                var startCol = seg.leftCol;
                var endCol = seg.rightCol + 1;
                var skeletonEl;
                var trEl;

                skeletonEl = $(
                        '<div class="fc-' + type.toLowerCase() + '-skeleton">' +
                                '<table><tr/></table>' +
                        '</div>'
                );
                trEl = skeletonEl.find('tr');

                if (startCol > 0) {
                        trEl.append('<td colspan="' + startCol + '"/>');
                }

                trEl.append(
                        seg.el.attr('colspan', endCol - startCol)
                );

                if (endCol < colCnt) {
                        trEl.append('<td colspan="' + (colCnt - endCol) + '"/>');
                }

                this.bookendCells(trEl, type);

                return skeletonEl;
        }

});

    /* Event-rendering methods for the DayGrid class
----------------------------------------------------------------------------------------------------------------------*/

DayGrid.mixin({

        rowStructs: null, // an array of objects, each holding information about a row's foreground event-rendering


        // Unrenders all events currently rendered on the grid
        destroyEvents: function() {
                this.destroySegPopover(); // removes the "more.." events popover
                Grid.prototype.destroyEvents.apply(this, arguments); // calls the super-method
        },


        // Retrieves all rendered segment objects currently rendered on the grid
        getEventSegs: function() {
                return Grid.prototype.getEventSegs.call(this) // get the segments from the super-method
                        .concat(this.popoverSegs || []); // append the segments from the "more..." popover
        },


        // Renders the given background event segments onto the grid
        renderBgSegs: function(segs) {

                // don't render timed background events
                var allDaySegs = $.grep(segs, function(seg) {
                        return seg.event.allDay;
                });

                return Grid.prototype.renderBgSegs.call(this, allDaySegs); // call the super-method
        },


        // Renders the given foreground event segments onto the grid
        renderFgSegs: function(segs) {
                var rowStructs;

                // render an `.el` on each seg
                // returns a subset of the segs. segs that were actually rendered
                segs = this.renderFgSegEls(segs);

                rowStructs = this.rowStructs = this.renderSegRows(segs);

                // append to each row's content skeleton
                this.rowEls.each(function(i, rowNode) {
                        $(rowNode).find('.fc-content-skeleton > table').append(
                                rowStructs[i].tbodyEl
                        );
                });

                return segs; // return only the segs that were actually rendered
        },


        // Unrenders all currently rendered foreground event segments
        destroyFgSegs: function() {
                var rowStructs = this.rowStructs || [];
                var rowStruct;

                while ((rowStruct = rowStructs.pop())) {
                        rowStruct.tbodyEl.remove();
                }

                this.rowStructs = null;
        },


        // Uses the given events array to generate <tbody> elements that should be appended to each row's content skeleton.
        // Returns an array of rowStruct objects (see the bottom of `renderSegRow`).
        // PRECONDITION: each segment shoud already have a rendered and assigned `.el`
        renderSegRows: function(segs) {
                var rowStructs = [];
                var segRows;
                var row;

                segRows = this.groupSegRows(segs); // group into nested arrays

                // iterate each row of segment groupings
                for (row = 0; row < segRows.length; row++) {
                        rowStructs.push(
                                this.renderSegRow(row, segRows[row])
                        );
                }

                return rowStructs;
        },


        // Builds the HTML to be used for the default element for an individual segment
        fgSegHtml: function(seg, disableResizing) {
                var view = this.view;
                var event = seg.event;
                var isDraggable = view.isEventDraggable(event);
                var isResizable = !disableResizing && event.allDay && seg.isEnd && view.isEventResizable(event);
                var classes = this.getSegClasses(seg, isDraggable, isResizable);
                var skinCss = this.getEventSkinCss(event);
                var timeHtml = '';
                var titleHtml;

                classes.unshift('fc-day-grid-event');

                // Only display a timed events time if it is the starting segment
                if (!event.allDay && seg.isStart) {
                        timeHtml = '<span class="fc-time">' + htmlEscape(this.getEventTimeText(event)) + '</span>';
                }

                titleHtml =
                        '<span class="fc-title">' +
                                (htmlEscape(event.title || '') || '&nbsp;') + // we always want one line of height
                        '</span>';
                
                return '<a class="' + classes.join(' ') + '"' +
                                (event.url ?
                                        ' href="' + htmlEscape(event.url) + '"' :
                                        ''
                                        ) +
                                (skinCss ?
                                        ' style="' + skinCss + '"' :
                                        ''
                                        ) +
                        '>' +
                                '<div class="fc-content">' +
                                        (this.isRTL ?
                                                titleHtml + ' ' + timeHtml : // put a natural space in between
                                                timeHtml + ' ' + titleHtml   //
                                                ) +
                                '</div>' +
                                (isResizable ?
                                        '<div class="fc-resizer"/>' :
                                        ''
                                        ) +
                        '</a>';
        },


        // Given a row # and an array of segments all in the same row, render a <tbody> element, a skeleton that contains
        // the segments. Returns object with a bunch of internal data about how the render was calculated.
        renderSegRow: function(row, rowSegs) {
                var colCnt = this.colCnt;
                var segLevels = this.buildSegLevels(rowSegs); // group into sub-arrays of levels
                var levelCnt = Math.max(1, segLevels.length); // ensure at least one level
                var tbody = $('<tbody/>');
                var segMatrix = []; // lookup for which segments are rendered into which level+col cells
                var cellMatrix = []; // lookup for all <td> elements of the level+col matrix
                var loneCellMatrix = []; // lookup for <td> elements that only take up a single column
                var i, levelSegs;
                var col;
                var tr;
                var j, seg;
                var td;

                // populates empty cells from the current column (`col`) to `endCol`
                function emptyCellsUntil(endCol) {
                        while (col < endCol) {
                                // try to grab a cell from the level above and extend its rowspan. otherwise, create a fresh cell
                                td = (loneCellMatrix[i - 1] || [])[col];
                                if (td) {
                                        td.attr(
                                                'rowspan',
                                                parseInt(td.attr('rowspan') || 1, 10) + 1
                                        );
                                }
                                else {
                                        td = $('<td/>');
                                        tr.append(td);
                                }
                                cellMatrix[i][col] = td;
                                loneCellMatrix[i][col] = td;
                                col++;
                        }
                }

                for (i = 0; i < levelCnt; i++) { // iterate through all levels
                        levelSegs = segLevels[i];
                        col = 0;
                        tr = $('<tr/>');

                        segMatrix.push([]);
                        cellMatrix.push([]);
                        loneCellMatrix.push([]);

                        // levelCnt might be 1 even though there are no actual levels. protect against this.
                        // this single empty row is useful for styling.
                        if (levelSegs) {
                                for (j = 0; j < levelSegs.length; j++) { // iterate through segments in level
                                        seg = levelSegs[j];

                                        emptyCellsUntil(seg.leftCol);

                                        // create a container that occupies or more columns. append the event element.
                                        td = $('<td class="fc-event-container"/>').append(seg.el);
                                        if (seg.leftCol != seg.rightCol) {
                                                td.attr('colspan', seg.rightCol - seg.leftCol + 1);
                                        }
                                        else { // a single-column segment
                                                loneCellMatrix[i][col] = td;
                                        }

                                        while (col <= seg.rightCol) {
                                                cellMatrix[i][col] = td;
                                                segMatrix[i][col] = seg;
                                                col++;
                                        }

                                        tr.append(td);
                                }
                        }

                        emptyCellsUntil(colCnt); // finish off the row
                        this.bookendCells(tr, 'eventSkeleton');
                        tbody.append(tr);
                }

                return { // a "rowStruct"
                        row: row, // the row number
                        tbodyEl: tbody,
                        cellMatrix: cellMatrix,
                        segMatrix: segMatrix,
                        segLevels: segLevels,
                        segs: rowSegs
                };
        },


        // Stacks a flat array of segments, which are all assumed to be in the same row, into subarrays of vertical levels.
        buildSegLevels: function(segs) {
                var levels = [];
                var i, seg;
                var j;

                // Give preference to elements with certain criteria, so they have
                // a chance to be closer to the top.
                segs.sort(compareSegs);
                
                for (i = 0; i < segs.length; i++) {
                        seg = segs[i];

                        // loop through levels, starting with the topmost, until the segment doesn't collide with other segments
                        for (j = 0; j < levels.length; j++) {
                                if (!isDaySegCollision(seg, levels[j])) {
                                        break;
                                }
                        }
                        // `j` now holds the desired subrow index
                        seg.level = j;

                        // create new level array if needed and append segment
                        (levels[j] || (levels[j] = [])).push(seg);
                }

                // order segments left-to-right. very important if calendar is RTL
                for (j = 0; j < levels.length; j++) {
                        levels[j].sort(compareDaySegCols);
                }

                return levels;
        },


        // Given a flat array of segments, return an array of sub-arrays, grouped by each segment's row
        groupSegRows: function(segs) {
                var segRows = [];
                var i;

                for (i = 0; i < this.rowCnt; i++) {
                        segRows.push([]);
                }

                for (i = 0; i < segs.length; i++) {
                        segRows[segs[i].row].push(segs[i]);
                }

                return segRows;
        }

});


// Computes whether two segments' columns collide. They are assumed to be in the same row.
function isDaySegCollision(seg, otherSegs) {
        var i, otherSeg;

        for (i = 0; i < otherSegs.length; i++) {
                otherSeg = otherSegs[i];

                if (
                        otherSeg.leftCol <= seg.rightCol &&
                        otherSeg.rightCol >= seg.leftCol
                ) {
                        return true;
                }
        }

        return false;
}


// A cmp function for determining the leftmost event
function compareDaySegCols(a, b) {
        return a.leftCol - b.leftCol;
}

    /* Methods relate to limiting the number events for a given day on a DayGrid
----------------------------------------------------------------------------------------------------------------------*/
// NOTE: all the segs being passed around in here are foreground segs

DayGrid.mixin({

        segPopover: null, // the Popover that holds events that can't fit in a cell. null when not visible
        popoverSegs: null, // an array of segment objects that the segPopover holds. null when not visible


        destroySegPopover: function() {
                if (this.segPopover) {
                        this.segPopover.hide(); // will trigger destruction of `segPopover` and `popoverSegs`
                }
        },


        // Limits the number of "levels" (vertically stacking layers of events) for each row of the grid.
        // `levelLimit` can be false (don't limit), a number, or true (should be computed).
        limitRows: function(levelLimit) {
                var rowStructs = this.rowStructs || [];
                var row; // row #
                var rowLevelLimit;

                for (row = 0; row < rowStructs.length; row++) {
                        this.unlimitRow(row);

                        if (!levelLimit) {
                                rowLevelLimit = false;
                        }
                        else if (typeof levelLimit === 'number') {
                                rowLevelLimit = levelLimit;
                        }
                        else {
                                rowLevelLimit = this.computeRowLevelLimit(row);
                        }

                        if (rowLevelLimit !== false) {
                                this.limitRow(row, rowLevelLimit);
                        }
                }
        },


        // Computes the number of levels a row will accomodate without going outside its bounds.
        // Assumes the row is "rigid" (maintains a constant height regardless of what is inside).
        // `row` is the row number.
        computeRowLevelLimit: function(row) {
                var rowEl = this.rowEls.eq(row); // the containing "fake" row div
                var rowHeight = rowEl.height(); // TODO: cache somehow?
                var trEls = this.rowStructs[row].tbodyEl.children();
                var i, trEl;

                // Reveal one level <tr> at a time and stop when we find one out of bounds
                for (i = 0; i < trEls.length; i++) {
                        trEl = trEls.eq(i).removeClass('fc-limited'); // get and reveal
                        if (trEl.position().top + trEl.outerHeight() > rowHeight) {
                                return i;
                        }
                }

                return false; // should not limit at all
        },


        // Limits the given grid row to the maximum number of levels and injects "more" links if necessary.
        // `row` is the row number.
        // `levelLimit` is a number for the maximum (inclusive) number of levels allowed.
        limitRow: function(row, levelLimit) {
                var _this = this;
                var rowStruct = this.rowStructs[row];
                var moreNodes = []; // array of "more" <a> links and <td> DOM nodes
                var col = 0; // col #, left-to-right (not chronologically)
                var cell;
                var levelSegs; // array of segment objects in the last allowable level, ordered left-to-right
                var cellMatrix; // a matrix (by level, then column) of all <td> jQuery elements in the row
                var limitedNodes; // array of temporarily hidden level <tr> and segment <td> DOM nodes
                var i, seg;
                var segsBelow; // array of segment objects below `seg` in the current `col`
                var totalSegsBelow; // total number of segments below `seg` in any of the columns `seg` occupies
                var colSegsBelow; // array of segment arrays, below seg, one for each column (offset from segs's first column)
                var td, rowspan;
                var segMoreNodes; // array of "more" <td> cells that will stand-in for the current seg's cell
                var j;
                var moreTd, moreWrap, moreLink;

                // Iterates through empty level cells and places "more" links inside if need be
                function emptyCellsUntil(endCol) { // goes from current `col` to `endCol`
                        while (col < endCol) {
                                cell = _this.getCell(row, col);
                                segsBelow = _this.getCellSegs(cell, levelLimit);
                                if (segsBelow.length) {
                                        td = cellMatrix[levelLimit - 1][col];
                                        moreLink = _this.renderMoreLink(cell, segsBelow);
                                        moreWrap = $('<div/>').append(moreLink);
                                        td.append(moreWrap);
                                        moreNodes.push(moreWrap[0]);
                                }
                                col++;
                        }
                }

                if (levelLimit && levelLimit < rowStruct.segLevels.length) { // is it actually over the limit?
                        levelSegs = rowStruct.segLevels[levelLimit - 1];
                        cellMatrix = rowStruct.cellMatrix;

                        limitedNodes = rowStruct.tbodyEl.children().slice(levelLimit) // get level <tr> elements past the limit
                                .addClass('fc-limited').get(); // hide elements and get a simple DOM-nodes array

                        // iterate though segments in the last allowable level
                        for (i = 0; i < levelSegs.length; i++) {
                                seg = levelSegs[i];
                                emptyCellsUntil(seg.leftCol); // process empty cells before the segment

                                // determine *all* segments below `seg` that occupy the same columns
                                colSegsBelow = [];
                                totalSegsBelow = 0;
                                while (col <= seg.rightCol) {
                                        cell = this.getCell(row, col);
                                        segsBelow = this.getCellSegs(cell, levelLimit);
                                        colSegsBelow.push(segsBelow);
                                        totalSegsBelow += segsBelow.length;
                                        col++;
                                }

                                if (totalSegsBelow) { // do we need to replace this segment with one or many "more" links?
                                        td = cellMatrix[levelLimit - 1][seg.leftCol]; // the segment's parent cell
                                        rowspan = td.attr('rowspan') || 1;
                                        segMoreNodes = [];

                                        // make a replacement <td> for each column the segment occupies. will be one for each colspan
                                        for (j = 0; j < colSegsBelow.length; j++) {
                                                moreTd = $('<td class="fc-more-cell"/>').attr('rowspan', rowspan);
                                                segsBelow = colSegsBelow[j];
                                                cell = this.getCell(row, seg.leftCol + j);
                                                moreLink = this.renderMoreLink(cell, [ seg ].concat(segsBelow)); // count seg as hidden too
                                                moreWrap = $('<div/>').append(moreLink);
                                                moreTd.append(moreWrap);
                                                segMoreNodes.push(moreTd[0]);
                                                moreNodes.push(moreTd[0]);
                                        }

                                        td.addClass('fc-limited').after($(segMoreNodes)); // hide original <td> and inject replacements
                                        limitedNodes.push(td[0]);
                                }
                        }

                        emptyCellsUntil(this.colCnt); // finish off the level
                        rowStruct.moreEls = $(moreNodes); // for easy undoing later
                        rowStruct.limitedEls = $(limitedNodes); // for easy undoing later
                }
        },


        // Reveals all levels and removes all "more"-related elements for a grid's row.
        // `row` is a row number.
        unlimitRow: function(row) {
                var rowStruct = this.rowStructs[row];

                if (rowStruct.moreEls) {
                        rowStruct.moreEls.remove();
                        rowStruct.moreEls = null;
                }

                if (rowStruct.limitedEls) {
                        rowStruct.limitedEls.removeClass('fc-limited');
                        rowStruct.limitedEls = null;
                }
        },


        // Renders an <a> element that represents hidden event element for a cell.
        // Responsible for attaching click handler as well.
        renderMoreLink: function(cell, hiddenSegs) {
                var _this = this;
                var view = this.view;

                return $('<a class="fc-more"/>')
                        .text(
                                this.getMoreLinkText(hiddenSegs.length)
                        )
                        .on('click', function(ev) {
                                var clickOption = view.opt('eventLimitClick');
                                var date = cell.start;
                                var moreEl = $(this);
                                var dayEl = _this.getCellDayEl(cell);
                                var allSegs = _this.getCellSegs(cell);

                                // rescope the segments to be within the cell's date
                                var reslicedAllSegs = _this.resliceDaySegs(allSegs, date);
                                var reslicedHiddenSegs = _this.resliceDaySegs(hiddenSegs, date);

                                if (typeof clickOption === 'function') {
                                        // the returned value can be an atomic option
                                        clickOption = view.trigger('eventLimitClick', null, {
                                                date: date,
                                                dayEl: dayEl,
                                                moreEl: moreEl,
                                                segs: reslicedAllSegs,
                                                hiddenSegs: reslicedHiddenSegs
                                        }, ev);
                                }

                                if (clickOption === 'popover') {
                                        _this.showSegPopover(cell, moreEl, reslicedAllSegs);
                                }
                                else if (typeof clickOption === 'string') { // a view name
                                        view.calendar.zoomTo(date, clickOption);
                                }
                        });
        },


        // Reveals the popover that displays all events within a cell
        showSegPopover: function(cell, moreLink, segs) {
                var _this = this;
                var view = this.view;
                var moreWrap = moreLink.parent(); // the <div> wrapper around the <a>
                var topEl; // the element we want to match the top coordinate of
                var options;

                if (this.rowCnt == 1) {
                        topEl = view.el; // will cause the popover to cover any sort of header
                }
                else {
                        topEl = this.rowEls.eq(cell.row); // will align with top of row
                }

                options = {
                        className: 'fc-more-popover',
                        content: this.renderSegPopoverContent(cell, segs),
                        parentEl: this.el,
                        top: topEl.offset().top,
                        autoHide: true, // when the user clicks elsewhere, hide the popover
                        viewportConstrain: view.opt('popoverViewportConstrain'),
                        hide: function() {
                                // destroy everything when the popover is hidden
                                _this.segPopover.destroy();
                                _this.segPopover = null;
                                _this.popoverSegs = null;
                        }
                };

                // Determine horizontal coordinate.
                // We use the moreWrap instead of the <td> to avoid border confusion.
                if (this.isRTL) {
                        options.right = moreWrap.offset().left + moreWrap.outerWidth() + 1; // +1 to be over cell border
                }
                else {
                        options.left = moreWrap.offset().left - 1; // -1 to be over cell border
                }

                this.segPopover = new Popover(options);
                this.segPopover.show();
        },


        // Builds the inner DOM contents of the segment popover
        renderSegPopoverContent: function(cell, segs) {
                var view = this.view;
                var isTheme = view.opt('theme');
                var title = cell.start.format(view.opt('dayPopoverFormat'));
                var content = $(
                        '<div class="fc-header ' + view.widgetHeaderClass + '">' +
                                '<span class="fc-close ' +
                                        (isTheme ? 'ui-icon ui-icon-closethick' : 'fc-icon fc-icon-x') +
                                '"></span>' +
                                '<span class="fc-title">' +
                                        htmlEscape(title) +
                                '</span>' +
                                '<div class="fc-clear"/>' +
                        '</div>' +
                        '<div class="fc-body ' + view.widgetContentClass + '">' +
                                '<div class="fc-event-container"></div>' +
                        '</div>'
                );
                var segContainer = content.find('.fc-event-container');
                var i;

                // render each seg's `el` and only return the visible segs
                segs = this.renderFgSegEls(segs, true); // disableResizing=true
                this.popoverSegs = segs;

                for (i = 0; i < segs.length; i++) {

                        // because segments in the popover are not part of a grid coordinate system, provide a hint to any
                        // grids that want to do drag-n-drop about which cell it came from
                        segs[i].cell = cell;

                        segContainer.append(segs[i].el);
                }

                return content;
        },


        // Given the events within an array of segment objects, reslice them to be in a single day
        resliceDaySegs: function(segs, dayDate) {

                // build an array of the original events
                var events = $.map(segs, function(seg) {
                        return seg.event;
                });

                var dayStart = dayDate.clone().stripTime();
                var dayEnd = dayStart.clone().add(1, 'days');
                var dayRange = { start: dayStart, end: dayEnd };

                // slice the events with a custom slicing function
                return this.eventsToSegs(
                        events,
                        function(range) {
                                var seg = intersectionToSeg(range, dayRange); // undefind if no intersection
                                return seg ? [ seg ] : []; // must return an array of segments
                        }
                );
        },


        // Generates the text that should be inside a "more" link, given the number of events it represents
        getMoreLinkText: function(num) {
                var opt = this.view.opt('eventLimitText');

                if (typeof opt === 'function') {
                        return opt(num);
                }
                else {
                        return '+' + num + ' ' + opt;
                }
        },


        // Returns segments within a given cell.
        // If `startLevel` is specified, returns only events including and below that level. Otherwise returns all segs.
        getCellSegs: function(cell, startLevel) {
                var segMatrix = this.rowStructs[cell.row].segMatrix;
                var level = startLevel || 0;
                var segs = [];
                var seg;

                while (level < segMatrix.length) {
                        seg = segMatrix[level][cell.col];
                        if (seg) {
                                segs.push(seg);
                        }
                        level++;
                }

                return segs;
        }

});

    /* A component that renders one or more columns of vertical time slots
----------------------------------------------------------------------------------------------------------------------*/

var TimeGrid = Grid.extend({

        slotDuration: null, // duration of a "slot", a distinct time segment on given day, visualized by lines
        snapDuration: null, // granularity of time for dragging and selecting

        minTime: null, // Duration object that denotes the first visible time of any given day
        maxTime: null, // Duration object that denotes the exclusive visible end time of any given day

        axisFormat: null, // formatting string for times running along vertical axis

        dayEls: null, // cells elements in the day-row background
        slatEls: null, // elements running horizontally across all columns

        slatTops: null, // an array of top positions, relative to the container. last item holds bottom of last slot

        helperEl: null, // cell skeleton element for rendering the mock event "helper"

        businessHourSegs: null,


        constructor: function() {
                Grid.apply(this, arguments); // call the super-constructor
                this.processOptions();
        },


        // Renders the time grid into `this.el`, which should already be assigned.
        // Relies on the view's colCnt. In the future, this component should probably be self-sufficient.
        render: function() {
                this.el.html(this.renderHtml());
                this.dayEls = this.el.find('.fc-day');
                this.slatEls = this.el.find('.fc-slats tr');

                this.computeSlatTops();
                this.renderBusinessHours();
                Grid.prototype.render.call(this); // call the super-method
        },


        renderBusinessHours: function() {
                var events = this.view.calendar.getBusinessHoursEvents();
                this.businessHourSegs = this.renderFill('businessHours', this.eventsToSegs(events), 'bgevent');
        },


        // Renders the basic HTML skeleton for the grid
        renderHtml: function() {
                return '' +
                        '<div class="fc-bg">' +
                                '<table>' +
                                        this.rowHtml('slotBg') + // leverages RowRenderer, which will call slotBgCellHtml
                                '</table>' +
                        '</div>' +
                        '<div class="fc-slats">' +
                                '<table>' +
                                        this.slatRowHtml() +
                                '</table>' +
                        '</div>';
        },


        // Renders the HTML for a vertical background cell behind the slots.
        // This method is distinct from 'bg' because we wanted a new `rowType` so the View could customize the rendering.
        slotBgCellHtml: function(cell) {
                return this.bgCellHtml(cell);
        },


        // Generates the HTML for the horizontal "slats" that run width-wise. Has a time axis on a side. Depends on RTL.
        slatRowHtml: function() {
                var view = this.view;
                var isRTL = this.isRTL;
                var html = '';
                var slotNormal = this.slotDuration.asMinutes() % 15 === 0;
                var slotTime = moment.duration(+this.minTime); // wish there was .clone() for durations
                var slotDate; // will be on the view's first day, but we only care about its time
                var minutes;
                var axisHtml;

                // Calculate the time for each slot
                while (slotTime < this.maxTime) {
                        slotDate = this.start.clone().time(slotTime); // will be in UTC but that's good. to avoid DST issues
                        minutes = slotDate.minutes();

                        axisHtml =
                                '<td class="fc-axis fc-time ' + view.widgetContentClass + '" ' + view.axisStyleAttr() + '>' +
                                        ((!slotNormal || !minutes) ? // if irregular slot duration, or on the hour, then display the time
                                                '<span>' + // for matchCellWidths
                                                        htmlEscape(slotDate.format(this.axisFormat)) +
                                                '</span>' :
                                                ''
                                                ) +
                                '</td>';

                        html +=
                                '<tr ' + (!minutes ? '' : 'class="fc-minor"') + '>' +
                                        (!isRTL ? axisHtml : '') +
                                        '<td class="' + view.widgetContentClass + '"/>' +
                                        (isRTL ? axisHtml : '') +
                                "</tr>";

                        slotTime.add(this.slotDuration);
                }

                return html;
        },


        /* Options
        ------------------------------------------------------------------------------------------------------------------*/


        // Parses various options into properties of this object
        processOptions: function() {
                var view = this.view;
                var slotDuration = view.opt('slotDuration');
                var snapDuration = view.opt('snapDuration');

                slotDuration = moment.duration(slotDuration);
                snapDuration = snapDuration ? moment.duration(snapDuration) : slotDuration;

                this.slotDuration = slotDuration;
                this.snapDuration = snapDuration;

                this.minTime = moment.duration(view.opt('minTime'));
                this.maxTime = moment.duration(view.opt('maxTime'));

                this.axisFormat = view.opt('axisFormat') || view.opt('smallTimeFormat');
        },


        // Computes a default column header formatting string if `colFormat` is not explicitly defined
        computeColHeadFormat: function() {
                if (this.colCnt > 1) { // multiple days, so full single date string WON'T be in title text
                        return this.view.opt('dayOfMonthFormat'); // "Sat 12/10"
                }
                else { // single day, so full single date string will probably be in title text
                        return 'dddd'; // "Saturday"
                }
        },


        // Computes a default event time formatting string if `timeFormat` is not explicitly defined
        computeEventTimeFormat: function() {
                return this.view.opt('noMeridiemTimeFormat'); // like "6:30" (no AM/PM)
        },


        // Computes a default `displayEventEnd` value if one is not expliclty defined
        computeDisplayEventEnd: function() {
                return true;
        },


        /* Cell System
        ------------------------------------------------------------------------------------------------------------------*/


        // Initializes row/col information
        updateCells: function() {
                var view = this.view;
                var colData = [];
                var date;

                date = this.start.clone();
                while (date.isBefore(this.end)) {
                        colData.push({
                                day: date.clone()
                        });
                        date.add(1, 'day');
                        date = view.skipHiddenDays(date);
                }

                if (this.isRTL) {
                        colData.reverse();
                }

                this.colData = colData;
                this.colCnt = colData.length;
                this.rowCnt = Math.ceil((this.maxTime - this.minTime) / this.snapDuration); // # of vertical snaps
        },


        // Given a cell object, generates a range object
        computeCellRange: function(cell) {
                var time = this.computeSnapTime(cell.row);
                var start = this.view.calendar.rezoneDate(cell.day).time(time);
                var end = start.clone().add(this.snapDuration);

                return { start: start, end: end };
        },


        // Retrieves the element representing the given column
        getColEl: function(col) {
                return this.dayEls.eq(col);
        },


        /* Dates
        ------------------------------------------------------------------------------------------------------------------*/


        // Given a row number of the grid, representing a "snap", returns a time (Duration) from its start-of-day
        computeSnapTime: function(row) {
                return moment.duration(this.minTime + this.snapDuration * row);
        },


        // Slices up a date range by column into an array of segments
        rangeToSegs: function(range) {
                var colCnt = this.colCnt;
                var segs = [];
                var seg;
                var col;
                var colDate;
                var colRange;

                // normalize :(
                range = {
                        start: range.start.clone().stripZone(),
                        end: range.end.clone().stripZone()
                };

                for (col = 0; col < colCnt; col++) {
                        colDate = this.colData[col].day; // will be ambig time/timezone
                        colRange = {
                                start: colDate.clone().time(this.minTime),
                                end: colDate.clone().time(this.maxTime)
                        };
                        seg = intersectionToSeg(range, colRange); // both will be ambig timezone
                        if (seg) {
                                seg.col = col;
                                segs.push(seg);
                        }
                }

                return segs;
        },


        /* Coordinates
        ------------------------------------------------------------------------------------------------------------------*/


        // Called when there is a window resize/zoom and we need to recalculate coordinates for the grid
        resize: function() {
                this.computeSlatTops();
                this.updateSegVerticals();
        },


        // Computes the top/bottom coordinates of each "snap" rows
        computeRowCoords: function() {
                var originTop = this.el.offset().top;
                var items = [];
                var i;
                var item;

                for (i = 0; i < this.rowCnt; i++) {
                        item = {
                                top: originTop + this.computeTimeTop(this.computeSnapTime(i))
                        };
                        if (i > 0) {
                                items[i - 1].bottom = item.top;
                        }
                        items.push(item);
                }
                item.bottom = item.top + this.computeTimeTop(this.computeSnapTime(i));

                return items;
        },


        // Computes the top coordinate, relative to the bounds of the grid, of the given date.
        // A `startOfDayDate` must be given for avoiding ambiguity over how to treat midnight.
        computeDateTop: function(date, startOfDayDate) {
                return this.computeTimeTop(
                        moment.duration(
                                date.clone().stripZone() - startOfDayDate.clone().stripTime()
                        )
                );
        },


        // Computes the top coordinate, relative to the bounds of the grid, of the given time (a Duration).
        computeTimeTop: function(time) {
                var slatCoverage = (time - this.minTime) / this.slotDuration; // floating-point value of # of slots covered
                var slatIndex;
                var slatRemainder;
                var slatTop;
                var slatBottom;

                // constrain. because minTime/maxTime might be customized
                slatCoverage = Math.max(0, slatCoverage);
                slatCoverage = Math.min(this.slatEls.length, slatCoverage);

                slatIndex = Math.floor(slatCoverage); // an integer index of the furthest whole slot
                slatRemainder = slatCoverage - slatIndex;
                slatTop = this.slatTops[slatIndex]; // the top position of the furthest whole slot

                if (slatRemainder) { // time spans part-way into the slot
                        slatBottom = this.slatTops[slatIndex + 1];
                        return slatTop + (slatBottom - slatTop) * slatRemainder; // part-way between slots
                }
                else {
                        return slatTop;
                }
        },


        // Queries each `slatEl` for its position relative to the grid's container and stores it in `slatTops`.
        // Includes the the bottom of the last slat as the last item in the array.
        computeSlatTops: function() {
                var tops = [];
                var top;

                this.slatEls.each(function(i, node) {
                        top = $(node).position().top;
                        tops.push(top);
                });

                tops.push(top + this.slatEls.last().outerHeight()); // bottom of the last slat

                this.slatTops = tops;
        },


        /* Event Drag Visualization
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders a visual indication of an event being dragged over the specified date(s).
        // dropLocation's end might be null, as well as `seg`. See Grid::renderDrag for more info.
        // A returned value of `true` signals that a mock "helper" event has been rendered.
        renderDrag: function(dropLocation, seg) {
                var opacity;

                if (seg) { // if there is event information for this drag, render a helper event
                        this.renderRangeHelper(dropLocation, seg);

                        opacity = this.view.opt('dragOpacity');
                        if (opacity !== undefined) {
                                this.helperEl.css('opacity', opacity);
                        }

                        return true; // signal that a helper has been rendered
                }
                else {
                        // otherwise, just render a highlight
                        this.renderHighlight(
                                this.view.calendar.ensureVisibleEventRange(dropLocation) // needs to be a proper range
                        );
                }
        },


        // Unrenders any visual indication of an event being dragged
        destroyDrag: function() {
                this.destroyHelper();
                this.destroyHighlight();
        },


        /* Event Resize Visualization
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders a visual indication of an event being resized
        renderEventResize: function(range, seg) {
                this.renderRangeHelper(range, seg);
        },


        // Unrenders any visual indication of an event being resized
        destroyEventResize: function() {
                this.destroyHelper();
        },


        /* Event Helper
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders a mock "helper" event. `sourceSeg` is the original segment object and might be null (an external drag)
        renderHelper: function(event, sourceSeg) {
                var segs = this.eventsToSegs([ event ]);
                var tableEl;
                var i, seg;
                var sourceEl;

                segs = this.renderFgSegEls(segs); // assigns each seg's el and returns a subset of segs that were rendered
                tableEl = this.renderSegTable(segs);

                // Try to make the segment that is in the same row as sourceSeg look the same
                for (i = 0; i < segs.length; i++) {
                        seg = segs[i];
                        if (sourceSeg && sourceSeg.col === seg.col) {
                                sourceEl = sourceSeg.el;
                                seg.el.css({
                                        left: sourceEl.css('left'),
                                        right: sourceEl.css('right'),
                                        'margin-left': sourceEl.css('margin-left'),
                                        'margin-right': sourceEl.css('margin-right')
                                });
                        }
                }

                this.helperEl = $('<div class="fc-helper-skeleton"/>')
                        .append(tableEl)
                                .appendTo(this.el);
        },


        // Unrenders any mock helper event
        destroyHelper: function() {
                if (this.helperEl) {
                        this.helperEl.remove();
                        this.helperEl = null;
                }
        },


        /* Selection
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders a visual indication of a selection. Overrides the default, which was to simply render a highlight.
        renderSelection: function(range) {
                if (this.view.opt('selectHelper')) { // this setting signals that a mock helper event should be rendered
                        this.renderRangeHelper(range);
                }
                else {
                        this.renderHighlight(range);
                }
        },


        // Unrenders any visual indication of a selection
        destroySelection: function() {
                this.destroyHelper();
                this.destroyHighlight();
        },


        /* Fill System (highlight, background events, business hours)
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders a set of rectangles over the given time segments.
        // Only returns segments that successfully rendered.
        renderFill: function(type, segs, className) {
                var segCols;
                var skeletonEl;
                var trEl;
                var col, colSegs;
                var tdEl;
                var containerEl;
                var dayDate;
                var i, seg;

                if (segs.length) {

                        segs = this.renderFillSegEls(type, segs); // assignes `.el` to each seg. returns successfully rendered segs
                        segCols = this.groupSegCols(segs); // group into sub-arrays, and assigns 'col' to each seg

                        className = className || type.toLowerCase();
                        skeletonEl = $(
                                '<div class="fc-' + className + '-skeleton">' +
                                        '<table><tr/></table>' +
                                '</div>'
                        );
                        trEl = skeletonEl.find('tr');

                        for (col = 0; col < segCols.length; col++) {
                                colSegs = segCols[col];
                                tdEl = $('<td/>').appendTo(trEl);

                                if (colSegs.length) {
                                        containerEl = $('<div class="fc-' + className + '-container"/>').appendTo(tdEl);
                                        dayDate = this.colData[col].day;

                                        for (i = 0; i < colSegs.length; i++) {
                                                seg = colSegs[i];
                                                containerEl.append(
                                                        seg.el.css({
                                                                top: this.computeDateTop(seg.start, dayDate),
                                                                bottom: -this.computeDateTop(seg.end, dayDate) // the y position of the bottom edge
                                                        })
                                                );
                                        }
                                }
                        }

                        this.bookendCells(trEl, type);

                        this.el.append(skeletonEl);
                        this.elsByFill[type] = skeletonEl;
                }

                return segs;
        }

});

    /* Event-rendering methods for the TimeGrid class
----------------------------------------------------------------------------------------------------------------------*/

TimeGrid.mixin({

        eventSkeletonEl: null, // has cells with event-containers, which contain absolutely positioned event elements


        // Renders the given foreground event segments onto the grid
        renderFgSegs: function(segs) {
                segs = this.renderFgSegEls(segs); // returns a subset of the segs. segs that were actually rendered

                this.el.append(
                        this.eventSkeletonEl = $('<div class="fc-content-skeleton"/>')
                                .append(this.renderSegTable(segs))
                );

                return segs; // return only the segs that were actually rendered
        },


        // Unrenders all currently rendered foreground event segments
        destroyFgSegs: function(segs) {
                if (this.eventSkeletonEl) {
                        this.eventSkeletonEl.remove();
                        this.eventSkeletonEl = null;
                }
        },


        // Renders and returns the <table> portion of the event-skeleton.
        // Returns an object with properties 'tbodyEl' and 'segs'.
        renderSegTable: function(segs) {
                var tableEl = $('<table><tr/></table>');
                var trEl = tableEl.find('tr');
                var segCols;
                var i, seg;
                var col, colSegs;
                var containerEl;

                segCols = this.groupSegCols(segs); // group into sub-arrays, and assigns 'col' to each seg

                this.computeSegVerticals(segs); // compute and assign top/bottom

                for (col = 0; col < segCols.length; col++) { // iterate each column grouping
                        colSegs = segCols[col];
                        placeSlotSegs(colSegs); // compute horizontal coordinates, z-index's, and reorder the array

                        containerEl = $('<div class="fc-event-container"/>');

                        // assign positioning CSS and insert into container
                        for (i = 0; i < colSegs.length; i++) {
                                seg = colSegs[i];
                                seg.el.css(this.generateSegPositionCss(seg));

                                // if the height is short, add a className for alternate styling
                                if (seg.bottom - seg.top < 30) {
                                        seg.el.addClass('fc-short');
                                }

                                containerEl.append(seg.el);
                        }

                        trEl.append($('<td/>').append(containerEl));
                }

                this.bookendCells(trEl, 'eventSkeleton');

                return tableEl;
        },


        // Refreshes the CSS top/bottom coordinates for each segment element. Probably after a window resize/zoom.
        // Repositions business hours segs too, so not just for events. Maybe shouldn't be here.
        updateSegVerticals: function() {
                var allSegs = (this.segs || []).concat(this.businessHourSegs || []);
                var i;

                this.computeSegVerticals(allSegs);

                for (i = 0; i < allSegs.length; i++) {
                        allSegs[i].el.css(
                                this.generateSegVerticalCss(allSegs[i])
                        );
                }
        },


        // For each segment in an array, computes and assigns its top and bottom properties
        computeSegVerticals: function(segs) {
                var i, seg;

                for (i = 0; i < segs.length; i++) {
                        seg = segs[i];
                        seg.top = this.computeDateTop(seg.start, seg.start);
                        seg.bottom = this.computeDateTop(seg.end, seg.start);
                }
        },


        // Renders the HTML for a single event segment's default rendering
        fgSegHtml: function(seg, disableResizing) {
                var view = this.view;
                var event = seg.event;
                var isDraggable = view.isEventDraggable(event);
                var isResizable = !disableResizing && seg.isEnd && view.isEventResizable(event);
                var classes = this.getSegClasses(seg, isDraggable, isResizable);
                var skinCss = this.getEventSkinCss(event);
                var timeText;
                var fullTimeText; // more verbose time text. for the print stylesheet
                var startTimeText; // just the start time text

                classes.unshift('fc-time-grid-event');

                if (view.isMultiDayEvent(event)) { // if the event appears to span more than one day...
                        // Don't display time text on segments that run entirely through a day.
                        // That would appear as midnight-midnight and would look dumb.
                        // Otherwise, display the time text for the *segment's* times (like 6pm-midnight or midnight-10am)
                        if (seg.isStart || seg.isEnd) {
                                timeText = this.getEventTimeText(seg);
                                fullTimeText = this.getEventTimeText(seg, 'LT');
                                startTimeText = this.getEventTimeText({ start: seg.start });
                        }
                } else {
                        // Display the normal time text for the *event's* times
                        timeText = this.getEventTimeText(event);
                        fullTimeText = this.getEventTimeText(event, 'LT');
                        startTimeText = this.getEventTimeText({ start: event.start });
                }

                return '<a class="' + classes.join(' ') + '"' +
                        (event.url ?
                                ' href="' + htmlEscape(event.url) + '"' :
                                ''
                                ) +
                        (skinCss ?
                                ' style="' + skinCss + '"' :
                                ''
                                ) +
                        '>' +
                                '<div class="fc-content">' +
                                        (timeText ?
                                                '<div class="fc-time"' +
                                                ' data-start="' + htmlEscape(startTimeText) + '"' +
                                                ' data-full="' + htmlEscape(fullTimeText) + '"' +
                                                '>' +
                                                        '<span>' + htmlEscape(timeText) + '</span>' +
                                                '</div>' :
                                                ''
                                                ) +
                                        (event.title ?
                                                '<div class="fc-title">' +
                                                        htmlEscape(event.title) +
                                                '</div>' :
                                                ''
                                                ) +
                                '</div>' +
                                '<div class="fc-bg"/>' +
                                (isResizable ?
                                        '<div class="fc-resizer"/>' :
                                        ''
                                        ) +
                        '</a>';
        },


        // Generates an object with CSS properties/values that should be applied to an event segment element.
        // Contains important positioning-related properties that should be applied to any event element, customized or not.
        generateSegPositionCss: function(seg) {
                var shouldOverlap = this.view.opt('slotEventOverlap');
                var backwardCoord = seg.backwardCoord; // the left side if LTR. the right side if RTL. floating-point
                var forwardCoord = seg.forwardCoord; // the right side if LTR. the left side if RTL. floating-point
                var props = this.generateSegVerticalCss(seg); // get top/bottom first
                var left; // amount of space from left edge, a fraction of the total width
                var right; // amount of space from right edge, a fraction of the total width

                if (shouldOverlap) {
                        // double the width, but don't go beyond the maximum forward coordinate (1.0)
                        forwardCoord = Math.min(1, backwardCoord + (forwardCoord - backwardCoord) * 2);
                }

                if (this.isRTL) {
                        left = 1 - forwardCoord;
                        right = backwardCoord;
                }
                else {
                        left = backwardCoord;
                        right = 1 - forwardCoord;
                }

                props.zIndex = seg.level + 1; // convert from 0-base to 1-based
                props.left = left * 100 + '%';
                props.right = right * 100 + '%';

                if (shouldOverlap && seg.forwardPressure) {
                        // add padding to the edge so that forward stacked events don't cover the resizer's icon
                        props[this.isRTL ? 'marginLeft' : 'marginRight'] = 10 * 2; // 10 is a guesstimate of the icon's width
                }

                return props;
        },


        // Generates an object with CSS properties for the top/bottom coordinates of a segment element
        generateSegVerticalCss: function(seg) {
                return {
                        top: seg.top,
                        bottom: -seg.bottom // flipped because needs to be space beyond bottom edge of event container
                };
        },


        // Given a flat array of segments, return an array of sub-arrays, grouped by each segment's col
        groupSegCols: function(segs) {
                var segCols = [];
                var i;

                for (i = 0; i < this.colCnt; i++) {
                        segCols.push([]);
                }

                for (i = 0; i < segs.length; i++) {
                        segCols[segs[i].col].push(segs[i]);
                }

                return segCols;
        }

});


// Given an array of segments that are all in the same column, sets the backwardCoord and forwardCoord on each.
// Also reorders the given array by date!
function placeSlotSegs(segs) {
        var levels;
        var level0;
        var i;

        segs.sort(compareSegs); // order by date
        levels = buildSlotSegLevels(segs);
        computeForwardSlotSegs(levels);

        if ((level0 = levels[0])) {

                for (i = 0; i < level0.length; i++) {
                        computeSlotSegPressures(level0[i]);
                }

                for (i = 0; i < level0.length; i++) {
                        computeSlotSegCoords(level0[i], 0, 0);
                }
        }
}


// Builds an array of segments "levels". The first level will be the leftmost tier of segments if the calendar is
// left-to-right, or the rightmost if the calendar is right-to-left. Assumes the segments are already ordered by date.
function buildSlotSegLevels(segs) {
        var levels = [];
        var i, seg;
        var j;

        for (i=0; i<segs.length; i++) {
                seg = segs[i];

                // go through all the levels and stop on the first level where there are no collisions
                for (j=0; j<levels.length; j++) {
                        if (!computeSlotSegCollisions(seg, levels[j]).length) {
                                break;
                        }
                }

                seg.level = j;

                (levels[j] || (levels[j] = [])).push(seg);
        }

        return levels;
}


// For every segment, figure out the other segments that are in subsequent
// levels that also occupy the same vertical space. Accumulate in seg.forwardSegs
function computeForwardSlotSegs(levels) {
        var i, level;
        var j, seg;
        var k;

        for (i=0; i<levels.length; i++) {
                level = levels[i];

                for (j=0; j<level.length; j++) {
                        seg = level[j];

                        seg.forwardSegs = [];
                        for (k=i+1; k<levels.length; k++) {
                                computeSlotSegCollisions(seg, levels[k], seg.forwardSegs);
                        }
                }
        }
}


// Figure out which path forward (via seg.forwardSegs) results in the longest path until
// the furthest edge is reached. The number of segments in this path will be seg.forwardPressure
function computeSlotSegPressures(seg) {
        var forwardSegs = seg.forwardSegs;
        var forwardPressure = 0;
        var i, forwardSeg;

        if (seg.forwardPressure === undefined) { // not already computed

                for (i=0; i<forwardSegs.length; i++) {
                        forwardSeg = forwardSegs[i];

                        // figure out the child's maximum forward path
                        computeSlotSegPressures(forwardSeg);

                        // either use the existing maximum, or use the child's forward pressure
                        // plus one (for the forwardSeg itself)
                        forwardPressure = Math.max(
                                forwardPressure,
                                1 + forwardSeg.forwardPressure
                        );
                }

                seg.forwardPressure = forwardPressure;
        }
}


// Calculate seg.forwardCoord and seg.backwardCoord for the segment, where both values range
// from 0 to 1. If the calendar is left-to-right, the seg.backwardCoord maps to "left" and
// seg.forwardCoord maps to "right" (via percentage). Vice-versa if the calendar is right-to-left.
//
// The segment might be part of a "series", which means consecutive segments with the same pressure
// who's width is unknown until an edge has been hit. `seriesBackwardPressure` is the number of
// segments behind this one in the current series, and `seriesBackwardCoord` is the starting
// coordinate of the first segment in the series.
function computeSlotSegCoords(seg, seriesBackwardPressure, seriesBackwardCoord) {
        var forwardSegs = seg.forwardSegs;
        var i;

        if (seg.forwardCoord === undefined) { // not already computed

                if (!forwardSegs.length) {

                        // if there are no forward segments, this segment should butt up against the edge
                        seg.forwardCoord = 1;
                }
                else {

                        // sort highest pressure first
                        forwardSegs.sort(compareForwardSlotSegs);

                        // this segment's forwardCoord will be calculated from the backwardCoord of the
                        // highest-pressure forward segment.
                        computeSlotSegCoords(forwardSegs[0], seriesBackwardPressure + 1, seriesBackwardCoord);
                        seg.forwardCoord = forwardSegs[0].backwardCoord;
                }

                // calculate the backwardCoord from the forwardCoord. consider the series
                seg.backwardCoord = seg.forwardCoord -
                        (seg.forwardCoord - seriesBackwardCoord) / // available width for series
                        (seriesBackwardPressure + 1); // # of segments in the series

                // use this segment's coordinates to computed the coordinates of the less-pressurized
                // forward segments
                for (i=0; i<forwardSegs.length; i++) {
                        computeSlotSegCoords(forwardSegs[i], 0, seg.forwardCoord);
                }
        }
}


// Find all the segments in `otherSegs` that vertically collide with `seg`.
// Append into an optionally-supplied `results` array and return.
function computeSlotSegCollisions(seg, otherSegs, results) {
        results = results || [];

        for (var i=0; i<otherSegs.length; i++) {
                if (isSlotSegCollision(seg, otherSegs[i])) {
                        results.push(otherSegs[i]);
                }
        }

        return results;
}


// Do these segments occupy the same vertical space?
function isSlotSegCollision(seg1, seg2) {
        return seg1.bottom > seg2.top && seg1.top < seg2.bottom;
}


// A cmp function for determining which forward segment to rely on more when computing coordinates.
function compareForwardSlotSegs(seg1, seg2) {
        // put higher-pressure first
        return seg2.forwardPressure - seg1.forwardPressure ||
                // put segments that are closer to initial edge first (and favor ones with no coords yet)
                (seg1.backwardCoord || 0) - (seg2.backwardCoord || 0) ||
                // do normal sorting...
                compareSegs(seg1, seg2);
}

    /* An abstract class from which other views inherit from
----------------------------------------------------------------------------------------------------------------------*/

var View = fc.View = Class.extend({

        type: null, // subclass' view name (string)
        name: null, // deprecated. use `type` instead

        calendar: null, // owner Calendar object
        options: null, // view-specific options
        coordMap: null, // a CoordMap object for converting pixel regions to dates
        el: null, // the view's containing element. set by Calendar

        // range the view is actually displaying (moments)
        start: null,
        end: null, // exclusive

        // range the view is formally responsible for (moments)
        // may be different from start/end. for example, a month view might have 1st-31st, excluding padded dates
        intervalStart: null,
        intervalEnd: null, // exclusive

        intervalDuration: null, // the whole-unit duration that is being displayed
        intervalUnit: null, // name of largest unit being displayed, like "month" or "week"

        isSelected: false, // boolean whether a range of time is user-selected or not

        // subclasses can optionally use a scroll container
        scrollerEl: null, // the element that will most likely scroll when content is too tall
        scrollTop: null, // cached vertical scroll value

        // classNames styled by jqui themes
        widgetHeaderClass: null,
        widgetContentClass: null,
        highlightStateClass: null,

        // for date utils, computed from options
        nextDayThreshold: null,
        isHiddenDayHash: null,

        // document handlers, bound to `this` object
        documentMousedownProxy: null, // TODO: doesn't work with touch


        constructor: function(calendar, viewOptions, viewType) {
                this.calendar = calendar;
                this.options = viewOptions;
                this.type = this.name = viewType; // .name is deprecated

                this.nextDayThreshold = moment.duration(this.opt('nextDayThreshold'));
                this.initTheming();
                this.initHiddenDays();

                this.documentMousedownProxy = $.proxy(this, 'documentMousedown');

                this.initialize();
        },


        // A good place for subclasses to initialize member variables
        initialize: function() {
                // subclasses can implement
        },


        // Retrieves an option with the given name
        opt: function(name) {
                var val;

                val = this.options[name]; // look at view-specific options first
                if (val !== undefined) {
                        return val;
                }

                val = this.calendar.options[name];
                if ($.isPlainObject(val) && !isForcedAtomicOption(name)) { // view-option-hashes are deprecated
                        return smartProperty(val, this.type);
                }

                return val;
        },


        // Triggers handlers that are view-related. Modifies args before passing to calendar.
        trigger: function(name, thisObj) { // arguments beyond thisObj are passed along
                var calendar = this.calendar;

                return calendar.trigger.apply(
                        calendar,
                        [name, thisObj || this].concat(
                                Array.prototype.slice.call(arguments, 2), // arguments beyond thisObj
                                [ this ] // always make the last argument a reference to the view. TODO: deprecate
                        )
                );
        },


        /* Dates
        ------------------------------------------------------------------------------------------------------------------*/


        // Updates all internal dates to center around the given current date
        setDate: function(date) {
                this.setRange(this.computeRange(date));
        },


        // Updates all internal dates for displaying the given range.
        // Expects all values to be normalized (like what computeRange does).
        setRange: function(range) {
                $.extend(this, range);
        },


        // Given a single current date, produce information about what range to display.
        // Subclasses can override. Must return all properties.
        computeRange: function(date) {
                var intervalDuration = moment.duration(this.opt('duration') || this.constructor.duration || { days: 1 });
                var intervalUnit = computeIntervalUnit(intervalDuration);
                var intervalStart = date.clone().startOf(intervalUnit);
                var intervalEnd = intervalStart.clone().add(intervalDuration);
                var start, end;

                // normalize the range's time-ambiguity
                if (computeIntervalAs('days', intervalDuration)) { // whole-days?
                        intervalStart.stripTime();
                        intervalEnd.stripTime();
                }
                else { // needs to have a time?
                        if (!intervalStart.hasTime()) {
                                intervalStart = this.calendar.rezoneDate(intervalStart); // convert to current timezone, with 00:00
                        }
                        if (!intervalEnd.hasTime()) {
                                intervalEnd = this.calendar.rezoneDate(intervalEnd); // convert to current timezone, with 00:00
                        }
                }

                start = intervalStart.clone();
                start = this.skipHiddenDays(start);
                end = intervalEnd.clone();
                end = this.skipHiddenDays(end, -1, true); // exclusively move backwards

                return {
                        intervalDuration: intervalDuration,
                        intervalUnit: intervalUnit,
                        intervalStart: intervalStart,
                        intervalEnd: intervalEnd,
                        start: start,
                        end: end
                };
        },


        // Computes the new date when the user hits the prev button, given the current date
        computePrevDate: function(date) {
                return this.skipHiddenDays(
                        date.clone().startOf(this.intervalUnit).subtract(this.intervalDuration), -1
                );
        },


        // Computes the new date when the user hits the next button, given the current date
        computeNextDate: function(date) {
                return this.skipHiddenDays(
                        date.clone().startOf(this.intervalUnit).add(this.intervalDuration)
                );
        },


        /* Title and Date Formatting
        ------------------------------------------------------------------------------------------------------------------*/


        // Computes what the title at the top of the calendar should be for this view
        computeTitle: function() {
                return this.formatRange(
                        { start: this.intervalStart, end: this.intervalEnd },
                        this.opt('titleFormat') || this.computeTitleFormat(),
                        this.opt('titleRangeSeparator')
                );
        },


        // Generates the format string that should be used to generate the title for the current date range.
        // Attempts to compute the most appropriate format if not explicitly specified with `titleFormat`.
        computeTitleFormat: function() {
                if (this.intervalUnit == 'year') {
                        return 'YYYY';
                }
                else if (this.intervalUnit == 'month') {
                        return this.opt('monthYearFormat'); // like "September 2014"
                }
                else if (this.intervalDuration.as('days') > 1) {
                        return 'll'; // multi-day range. shorter, like "Sep 9 - 10 2014"
                }
                else {
                        return 'LL'; // one day. longer, like "September 9 2014"
                }
        },


        // Utility for formatting a range. Accepts a range object, formatting string, and optional separator.
        // Displays all-day ranges naturally, with an inclusive end. Takes the current isRTL into account.
        formatRange: function(range, formatStr, separator) {
                var end = range.end;

                if (!end.hasTime()) { // all-day?
                        end = end.clone().subtract(1); // convert to inclusive. last ms of previous day
                }

                return formatRange(range.start, end, formatStr, separator, this.opt('isRTL'));
        },


        /* Rendering
        ------------------------------------------------------------------------------------------------------------------*/


        // Wraps the basic render() method with more View-specific logic. Called by the owner Calendar.
        renderView: function() {
                this.render();
                this.updateSize();
                this.initializeScroll();
                this.trigger('viewRender', this, this, this.el);

                // attach handlers to document. do it here to allow for destroy/rerender
                $(document).on('mousedown', this.documentMousedownProxy);
        },


        // Renders the view inside an already-defined `this.el`
        render: function() {
                // subclasses should implement
        },


        // Wraps the basic destroy() method with more View-specific logic. Called by the owner Calendar.
        destroyView: function() {
                this.unselect();
                this.destroyViewEvents();
                this.destroy();
                this.trigger('viewDestroy', this, this, this.el);

                $(document).off('mousedown', this.documentMousedownProxy);
        },


        // Clears the view's rendering
        destroy: function() {
                this.el.empty(); // removes inner contents but leaves the element intact
        },


        // Initializes internal variables related to theming
        initTheming: function() {
                var tm = this.opt('theme') ? 'ui' : 'fc';

                this.widgetHeaderClass = tm + '-widget-header';
                this.widgetContentClass = tm + '-widget-content';
                this.highlightStateClass = tm + '-state-highlight';
        },


        /* Dimensions
        ------------------------------------------------------------------------------------------------------------------*/


        // Refreshes anything dependant upon sizing of the container element of the grid
        updateSize: function(isResize) {
                if (isResize) {
                        this.recordScroll();
                }
                this.updateHeight();
                this.updateWidth();
        },


        // Refreshes the horizontal dimensions of the calendar
        updateWidth: function() {
                // subclasses should implement
        },


        // Refreshes the vertical dimensions of the calendar
        updateHeight: function() {
                var calendar = this.calendar; // we poll the calendar for height information

                this.setHeight(
                        calendar.getSuggestedViewHeight(),
                        calendar.isHeightAuto()
                );
        },


        // Updates the vertical dimensions of the calendar to the specified height.
        // if `isAuto` is set to true, height becomes merely a suggestion and the view should use its "natural" height.
        setHeight: function(height, isAuto) {
                // subclasses should implement
        },


        /* Scroller
        ------------------------------------------------------------------------------------------------------------------*/


        // Given the total height of the view, return the number of pixels that should be used for the scroller.
        // By default, uses this.scrollerEl, but can pass this in as well.
        // Utility for subclasses.
        computeScrollerHeight: function(totalHeight, scrollerEl) {
                var both;
                var otherHeight; // cumulative height of everything that is not the scrollerEl in the view (header+borders)

                scrollerEl = scrollerEl || this.scrollerEl;
                both = this.el.add(scrollerEl);

                // fuckin IE8/9/10/11 sometimes returns 0 for dimensions. this weird hack was the only thing that worked
                both.css({
                        position: 'relative', // cause a reflow, which will force fresh dimension recalculation
                        left: -1 // ensure reflow in case the el was already relative. negative is less likely to cause new scroll
                });
                otherHeight = this.el.outerHeight() - scrollerEl.height(); // grab the dimensions
                both.css({ position: '', left: '' }); // undo hack

                return totalHeight - otherHeight;
        },


        // Sets the scroll value of the scroller to the initial pre-configured state prior to allowing the user to change it
        initializeScroll: function() {
        },


        // Called for remembering the current scroll value of the scroller.
        // Should be called before there is a destructive operation (like removing DOM elements) that might inadvertently
        // change the scroll of the container.
        recordScroll: function() {
                if (this.scrollerEl) {
                        this.scrollTop = this.scrollerEl.scrollTop();
                }
        },


        // Set the scroll value of the scroller to the previously recorded value.
        // Should be called after we know the view's dimensions have been restored following some type of destructive
        // operation (like temporarily removing DOM elements).
        restoreScroll: function() {
                if (this.scrollTop !== null) {
                        this.scrollerEl.scrollTop(this.scrollTop);
                }
        },


        /* Event Elements / Segments
        ------------------------------------------------------------------------------------------------------------------*/


        // Wraps the basic renderEvents() method with more View-specific logic
        renderViewEvents: function(events) {
                this.renderEvents(events);

                this.eventSegEach(function(seg) {
                        this.trigger('eventAfterRender', seg.event, seg.event, seg.el);
                });
                this.trigger('eventAfterAllRender');
        },


        // Renders the events onto the view.
        renderEvents: function() {
                // subclasses should implement
        },


        // Wraps the basic destroyEvents() method with more View-specific logic
        destroyViewEvents: function() {
                this.eventSegEach(function(seg) {
                        this.trigger('eventDestroy', seg.event, seg.event, seg.el);
                });

                this.destroyEvents();
        },


        // Removes event elements from the view.
        destroyEvents: function() {
                // subclasses should implement
        },


        // Given an event and the default element used for rendering, returns the element that should actually be used.
        // Basically runs events and elements through the eventRender hook.
        resolveEventEl: function(event, el) {
                var custom = this.trigger('eventRender', event, event, el);

                if (custom === false) { // means don't render at all
                        el = null;
                }
                else if (custom && custom !== true) {
                        el = $(custom);
                }

                return el;
        },


        // Hides all rendered event segments linked to the given event
        showEvent: function(event) {
                this.eventSegEach(function(seg) {
                        seg.el.css('visibility', '');
                }, event);
        },


        // Shows all rendered event segments linked to the given event
        hideEvent: function(event) {
                this.eventSegEach(function(seg) {
                        seg.el.css('visibility', 'hidden');
                }, event);
        },


        // Iterates through event segments. Goes through all by default.
        // If the optional `event` argument is specified, only iterates through segments linked to that event.
        // The `this` value of the callback function will be the view.
        eventSegEach: function(func, event) {
                var segs = this.getEventSegs();
                var i;

                for (i = 0; i < segs.length; i++) {
                        if (!event || segs[i].event._id === event._id) {
                                func.call(this, segs[i]);
                        }
                }
        },


        // Retrieves all the rendered segment objects for the view
        getEventSegs: function() {
                // subclasses must implement
                return [];
        },


        /* Event Drag-n-Drop
        ------------------------------------------------------------------------------------------------------------------*/


        // Computes if the given event is allowed to be dragged by the user
        isEventDraggable: function(event) {
                var source = event.source || {};

                return firstDefined(
                        event.startEditable,
                        source.startEditable,
                        this.opt('eventStartEditable'),
                        event.editable,
                        source.editable,
                        this.opt('editable')
                );
        },


        // Must be called when an event in the view is dropped onto new location.
        // `dropLocation` is an object that contains the new start/end/allDay values for the event.
        reportEventDrop: function(event, dropLocation, el, ev) {
                var calendar = this.calendar;
                var mutateResult = calendar.mutateEvent(event, dropLocation);
                var undoFunc = function() {
                        mutateResult.undo();
                        calendar.reportEventChange();
                };

                this.triggerEventDrop(event, mutateResult.dateDelta, undoFunc, el, ev);
                calendar.reportEventChange(); // will rerender events
        },


        // Triggers event-drop handlers that have subscribed via the API
        triggerEventDrop: function(event, dateDelta, undoFunc, el, ev) {
                this.trigger('eventDrop', el[0], event, dateDelta, undoFunc, ev, {}); // {} = jqui dummy
        },


        /* External Element Drag-n-Drop
        ------------------------------------------------------------------------------------------------------------------*/


        // Must be called when an external element, via jQuery UI, has been dropped onto the calendar.
        // `meta` is the parsed data that has been embedded into the dragging event.
        // `dropLocation` is an object that contains the new start/end/allDay values for the event.
        reportExternalDrop: function(meta, dropLocation, el, ev, ui) {
                var eventProps = meta.eventProps;
                var eventInput;
                var event;

                // Try to build an event object and render it. TODO: decouple the two
                if (eventProps) {
                        eventInput = $.extend({}, eventProps, dropLocation);
                        event = this.calendar.renderEvent(eventInput, meta.stick)[0]; // renderEvent returns an array
                }

                this.triggerExternalDrop(event, dropLocation, el, ev, ui);
        },


        // Triggers external-drop handlers that have subscribed via the API
        triggerExternalDrop: function(event, dropLocation, el, ev, ui) {

                // trigger 'drop' regardless of whether element represents an event
                this.trigger('drop', el[0], dropLocation.start, ev, ui);

                if (event) {
                        this.trigger('eventReceive', null, event); // signal an external event landed
                }
        },


        /* Drag-n-Drop Rendering (for both events and external elements)
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders a visual indication of a event or external-element drag over the given drop zone.
        // If an external-element, seg will be `null`
        renderDrag: function(dropLocation, seg) {
                // subclasses must implement
        },


        // Unrenders a visual indication of an event or external-element being dragged.
        destroyDrag: function() {
                // subclasses must implement
        },


        /* Event Resizing
        ------------------------------------------------------------------------------------------------------------------*/


        // Computes if the given event is allowed to be resize by the user
        isEventResizable: function(event) {
                var source = event.source || {};

                return firstDefined(
                        event.durationEditable,
                        source.durationEditable,
                        this.opt('eventDurationEditable'),
                        event.editable,
                        source.editable,
                        this.opt('editable')
                );
        },


        // Must be called when an event in the view has been resized to a new length
        reportEventResize: function(event, newEnd, el, ev) {
                var calendar = this.calendar;
                var mutateResult = calendar.mutateEvent(event, { end: newEnd });
                var undoFunc = function() {
                        mutateResult.undo();
                        calendar.reportEventChange();
                };

                this.triggerEventResize(event, mutateResult.durationDelta, undoFunc, el, ev);
                calendar.reportEventChange(); // will rerender events
        },


        // Triggers event-resize handlers that have subscribed via the API
        triggerEventResize: function(event, durationDelta, undoFunc, el, ev) {
                this.trigger('eventResize', el[0], event, durationDelta, undoFunc, ev, {}); // {} = jqui dummy
        },


        /* Selection
        ------------------------------------------------------------------------------------------------------------------*/


        // Selects a date range on the view. `start` and `end` are both Moments.
        // `ev` is the native mouse event that begin the interaction.
        select: function(range, ev) {
                this.unselect(ev);
                this.renderSelection(range);
                this.reportSelection(range, ev);
        },


        // Renders a visual indication of the selection
        renderSelection: function(range) {
                // subclasses should implement
        },


        // Called when a new selection is made. Updates internal state and triggers handlers.
        reportSelection: function(range, ev) {
                this.isSelected = true;
                this.trigger('select', null, range.start, range.end, ev);
        },


        // Undoes a selection. updates in the internal state and triggers handlers.
        // `ev` is the native mouse event that began the interaction.
        unselect: function(ev) {
                if (this.isSelected) {
                        this.isSelected = false;
                        this.destroySelection();
                        this.trigger('unselect', null, ev);
                }
        },


        // Unrenders a visual indication of selection
        destroySelection: function() {
                // subclasses should implement
        },


        // Handler for unselecting when the user clicks something and the 'unselectAuto' setting is on
        documentMousedown: function(ev) {
                var ignore;

                // is there a selection, and has the user made a proper left click?
                if (this.isSelected && this.opt('unselectAuto') && isPrimaryMouseButton(ev)) {

                        // only unselect if the clicked element is not identical to or inside of an 'unselectCancel' element
                        ignore = this.opt('unselectCancel');
                        if (!ignore || !$(ev.target).closest(ignore).length) {
                                this.unselect(ev);
                        }
                }
        },


        /* Date Utils
        ------------------------------------------------------------------------------------------------------------------*/


        // Initializes internal variables related to calculating hidden days-of-week
        initHiddenDays: function() {
                var hiddenDays = this.opt('hiddenDays') || []; // array of day-of-week indices that are hidden
                var isHiddenDayHash = []; // is the day-of-week hidden? (hash with day-of-week-index -> bool)
                var dayCnt = 0;
                var i;

                if (this.opt('weekends') === false) {
                        hiddenDays.push(0, 6); // 0=sunday, 6=saturday
                }

                for (i = 0; i < 7; i++) {
                        if (
                                !(isHiddenDayHash[i] = $.inArray(i, hiddenDays) !== -1)
                        ) {
                                dayCnt++;
                        }
                }

                if (!dayCnt) {
                        throw 'invalid hiddenDays'; // all days were hidden? bad.
                }

                this.isHiddenDayHash = isHiddenDayHash;
        },


        // Is the current day hidden?
        // `day` is a day-of-week index (0-6), or a Moment
        isHiddenDay: function(day) {
                if (moment.isMoment(day)) {
                        day = day.day();
                }
                return this.isHiddenDayHash[day];
        },


        // Incrementing the current day until it is no longer a hidden day, returning a copy.
        // If the initial value of `date` is not a hidden day, don't do anything.
        // Pass `isExclusive` as `true` if you are dealing with an end date.
        // `inc` defaults to `1` (increment one day forward each time)
        skipHiddenDays: function(date, inc, isExclusive) {
                var out = date.clone();
                inc = inc || 1;
                while (
                        this.isHiddenDayHash[(out.day() + (isExclusive ? inc : 0) + 7) % 7]
                ) {
                        out.add(inc, 'days');
                }
                return out;
        },


        // Returns the date range of the full days the given range visually appears to occupy.
        // Returns a new range object.
        computeDayRange: function(range) {
                var startDay = range.start.clone().stripTime(); // the beginning of the day the range starts
                var end = range.end;
                var endDay = null;
                var endTimeMS;

                if (end) {
                        endDay = end.clone().stripTime(); // the beginning of the day the range exclusively ends
                        endTimeMS = +end.time(); // # of milliseconds into `endDay`

                        // If the end time is actually inclusively part of the next day and is equal to or
                        // beyond the next day threshold, adjust the end to be the exclusive end of `endDay`.
                        // Otherwise, leaving it as inclusive will cause it to exclude `endDay`.
                        if (endTimeMS && endTimeMS >= this.nextDayThreshold) {
                                endDay.add(1, 'days');
                        }
                }

                // If no end was specified, or if it is within `startDay` but not past nextDayThreshold,
                // assign the default duration of one day.
                if (!end || endDay <= startDay) {
                        endDay = startDay.clone().add(1, 'days');
                }

                return { start: startDay, end: endDay };
        },


        // Does the given event visually appear to occupy more than one day?
        isMultiDayEvent: function(event) {
                var range = this.computeDayRange(event); // event is range-ish

                return range.end.diff(range.start, 'days') > 1;
        }

});

    function Calendar(element, instanceOptions) {
        var t = this;



        // Build options object
        // -----------------------------------------------------------------------------------
        // Precedence (lowest to highest): defaults, rtlDefaults, langOptions, instanceOptions

        instanceOptions = instanceOptions || {};

        var options = mergeOptions({}, defaults, instanceOptions);
        var langOptions;

        // determine language options
        if (options.lang in langOptionHash) {
                langOptions = langOptionHash[options.lang];
        }
        else {
                langOptions = langOptionHash[defaults.lang];
        }

        if (langOptions) { // if language options exist, rebuild...
                options = mergeOptions({}, defaults, langOptions, instanceOptions);
        }

        if (options.isRTL) { // is isRTL, rebuild...
                options = mergeOptions({}, defaults, rtlDefaults, langOptions || {}, instanceOptions);
        }


        
        // Exports
        // -----------------------------------------------------------------------------------

        t.options = options;
        t.render = render;
        t.destroy = destroy;
        t.refetchEvents = refetchEvents;
        t.reportEvents = reportEvents;
        t.reportEventChange = reportEventChange;
        t.rerenderEvents = renderEvents; // `renderEvents` serves as a rerender. an API method
        t.changeView = changeView;
        t.select = select;
        t.unselect = unselect;
        t.prev = prev;
        t.next = next;
        t.prevYear = prevYear;
        t.nextYear = nextYear;
        t.today = today;
        t.gotoDate = gotoDate;
        t.incrementDate = incrementDate;
        t.zoomTo = zoomTo;
        t.getDate = getDate;
        t.getCalendar = getCalendar;
        t.getView = getView;
        t.option = option;
        t.trigger = trigger;
        t.isValidViewType = isValidViewType;
        t.getViewButtonText = getViewButtonText;



        // Language-data Internals
        // -----------------------------------------------------------------------------------
        // Apply overrides to the current language's data


        var localeData = createObject( // make a cheap copy
                getMomentLocaleData(options.lang) // will fall back to en
        );

        if (options.monthNames) {
                localeData._months = options.monthNames;
        }
        if (options.monthNamesShort) {
                localeData._monthsShort = options.monthNamesShort;
        }
        if (options.dayNames) {
                localeData._weekdays = options.dayNames;
        }
        if (options.dayNamesShort) {
                localeData._weekdaysShort = options.dayNamesShort;
        }
        if (options.firstDay != null) {
                var _week = createObject(localeData._week); // _week: { dow: # }
                _week.dow = options.firstDay;
                localeData._week = _week;
        }



        // Calendar-specific Date Utilities
        // -----------------------------------------------------------------------------------


        t.defaultAllDayEventDuration = moment.duration(options.defaultAllDayEventDuration);
        t.defaultTimedEventDuration = moment.duration(options.defaultTimedEventDuration);


        // Builds a moment using the settings of the current calendar: timezone and language.
        // Accepts anything the vanilla moment() constructor accepts.
        t.moment = function() {
                var mom;

                if (options.timezone === 'local') {
                        mom = fc.moment.apply(null, arguments);

                        // Force the moment to be local, because fc.moment doesn't guarantee it.
                        if (mom.hasTime()) { // don't give ambiguously-timed moments a local zone
                                mom.local();
                        }
                }
                else if (options.timezone === 'UTC') {
                        mom = fc.moment.utc.apply(null, arguments); // process as UTC
                }
                else {
                        mom = fc.moment.parseZone.apply(null, arguments); // let the input decide the zone
                }

                if ('_locale' in mom) { // moment 2.8 and above
                        mom._locale = localeData;
                }
                else { // pre-moment-2.8
                        mom._lang = localeData;
                }

                return mom;
        };


        // Returns a boolean about whether or not the calendar knows how to calculate
        // the timezone offset of arbitrary dates in the current timezone.
        t.getIsAmbigTimezone = function() {
                return options.timezone !== 'local' && options.timezone !== 'UTC';
        };


        // Returns a copy of the given date in the current timezone of it is ambiguously zoned.
        // This will also give the date an unambiguous time.
        t.rezoneDate = function(date) {
                return t.moment(date.toArray());
        };


        // Returns a moment for the current date, as defined by the client's computer,
        // or overridden by the `now` option.
        t.getNow = function() {
                var now = options.now;
                if (typeof now === 'function') {
                        now = now();
                }
                return t.moment(now);
        };


        // Calculates the week number for a moment according to the calendar's
        // `weekNumberCalculation` setting.
        t.calculateWeekNumber = function(mom) {
                var calc = options.weekNumberCalculation;

                if (typeof calc === 'function') {
                        return calc(mom);
                }
                else if (calc === 'local') {
                        return mom.week();
                }
                else if (calc.toUpperCase() === 'ISO') {
                        return mom.isoWeek();
                }
        };


        // Get an event's normalized end date. If not present, calculate it from the defaults.
        t.getEventEnd = function(event) {
                if (event.end) {
                        return event.end.clone();
                }
                else {
                        return t.getDefaultEventEnd(event.allDay, event.start);
                }
        };


        // Given an event's allDay status and start date, return swhat its fallback end date should be.
        t.getDefaultEventEnd = function(allDay, start) { // TODO: rename to computeDefaultEventEnd
                var end = start.clone();

                if (allDay) {
                        end.stripTime().add(t.defaultAllDayEventDuration);
                }
                else {
                        end.add(t.defaultTimedEventDuration);
                }

                if (t.getIsAmbigTimezone()) {
                        end.stripZone(); // we don't know what the tzo should be
                }

                return end;
        };


        // Produces a human-readable string for the given duration.
        // Side-effect: changes the locale of the given duration.
        function humanizeDuration(duration) {
                return (duration.locale || duration.lang).call(duration, options.lang) // works moment-pre-2.8
                        .humanize();
        }


        
        // Imports
        // -----------------------------------------------------------------------------------


        EventManager.call(t, options);
        var isFetchNeeded = t.isFetchNeeded;
        var fetchEvents = t.fetchEvents;



        // Locals
        // -----------------------------------------------------------------------------------


        var _element = element[0];
        var header;
        var headerElement;
        var content;
        var tm; // for making theme classes
        var viewSpecCache = {};
        var currentView;
        var suggestedViewHeight;
        var windowResizeProxy; // wraps the windowResize function
        var ignoreWindowResize = 0;
        var date;
        var events = [];
        
        
        
        // Main Rendering
        // -----------------------------------------------------------------------------------


        if (options.defaultDate != null) {
                date = t.moment(options.defaultDate);
        }
        else {
                date = t.getNow();
        }
        
        
        function render(inc) {
                if (!content) {
                        initialRender();
                }
                else if (elementVisible()) {
                        // mainly for the public API
                        calcSize();
                        renderView(inc);
                }
        }
        
        
        function initialRender() {
                tm = options.theme ? 'ui' : 'fc';
                element.addClass('fc');

                if (options.isRTL) {
                        element.addClass('fc-rtl');
                }
                else {
                        element.addClass('fc-ltr');
                }

                if (options.theme) {
                        element.addClass('ui-widget');
                }
                else {
                        element.addClass('fc-unthemed');
                }

                content = $("<div class='fc-view-container'/>").prependTo(element);

                header = new Header(t, options);
                headerElement = header.render();
                if (headerElement) {
                        element.prepend(headerElement);
                }

                changeView(options.defaultView);

                if (options.handleWindowResize) {
                        windowResizeProxy = debounce(windowResize, options.windowResizeDelay); // prevents rapid calls
                        $(window).resize(windowResizeProxy);
                }
        }
        
        
        function destroy() {

                if (currentView) {
                        currentView.destroyView();
                }

                header.destroy();
                content.remove();
                element.removeClass('fc fc-ltr fc-rtl fc-unthemed ui-widget');

                $(window).unbind('resize', windowResizeProxy);
        }
        
        
        function elementVisible() {
                return element.is(':visible');
        }
        
        

        // View Rendering
        // -----------------------------------------------------------------------------------


        function changeView(viewType) {
                renderView(0, viewType);
        }


        // Renders a view because of a date change, view-type change, or for the first time
        function renderView(delta, viewType) {
                ignoreWindowResize++;

                // if viewType is changing, destroy the old view
                if (currentView && viewType && currentView.type !== viewType) {
                        header.deactivateButton(currentView.type);
                        freezeContentHeight(); // prevent a scroll jump when view element is removed
                        if (currentView.start) { // rendered before?
                                currentView.destroyView();
                        }
                        currentView.el.remove();
                        currentView = null;
                }

                // if viewType changed, or the view was never created, create a fresh view
                if (!currentView && viewType) {
                        currentView = instantiateView(viewType);
                        currentView.el =  $("<div class='fc-view fc-" + viewType + "-view' />").appendTo(content);
                        header.activateButton(viewType);
                }

                if (currentView) {

                        // let the view determine what the delta means
                        if (delta < 0) {
                                date = currentView.computePrevDate(date);
                        }
                        else if (delta > 0) {
                                date = currentView.computeNextDate(date);
                        }

                        // render or rerender the view
                        if (
                                !currentView.start || // never rendered before
                                delta || // explicit date window change
                                !date.isWithin(currentView.intervalStart, currentView.intervalEnd) // implicit date window change
                        ) {
                                if (elementVisible()) {

                                        freezeContentHeight();
                                        if (currentView.start) { // rendered before?
                                                currentView.destroyView();
                                        }
                                        currentView.setDate(date);
                                        currentView.renderView();
                                        unfreezeContentHeight();

                                        // need to do this after View::render, so dates are calculated
                                        updateTitle();
                                        updateTodayButton();

                                        getAndRenderEvents();
                                }
                        }
                }

                unfreezeContentHeight(); // undo any lone freezeContentHeight calls
                ignoreWindowResize--;
        }



        // View Instantiation
        // -----------------------------------------------------------------------------------


        // Given a view name for a custom view or a standard view, creates a ready-to-go View object
        function instantiateView(viewType) {
                var spec = getViewSpec(viewType);

                return new spec['class'](t, spec.options, viewType);
        }


        // Gets information about how to create a view
        function getViewSpec(requestedViewType) {
                var allDefaultButtonText = options.defaultButtonText || {};
                var allButtonText = options.buttonText || {};
                var hash = options.views || {}; // the `views` option object
                var viewType = requestedViewType;
                var viewOptionsChain = [];
                var viewOptions;
                var viewClass;
                var duration, unit, unitIsSingle = false;
                var buttonText;

                if (viewSpecCache[requestedViewType]) {
                        return viewSpecCache[requestedViewType];
                }

                function processSpecInput(input) {
                        if (typeof input === 'function') {
                                viewClass = input;
                        }
                        else if (typeof input === 'object') {
                                $.extend(viewOptions, input);
                        }
                }

                // iterate up a view's spec ancestor chain util we find a class to instantiate
                while (viewType && !viewClass) {
                        viewOptions = {}; // only for this specific view in the ancestry
                        processSpecInput(fcViews[viewType]); // $.fullCalendar.views, lower precedence
                        processSpecInput(hash[viewType]); // options at initialization, higher precedence
                        viewOptionsChain.unshift(viewOptions); // record older ancestors first
                        viewType = viewOptions.type;
                }

                viewOptionsChain.unshift({}); // jQuery's extend needs at least one arg
                viewOptions = $.extend.apply($, viewOptionsChain); // combine all, newer ancestors overwritting old

                if (viewClass) {

                        duration = viewOptions.duration || viewClass.duration;
                        if (duration) {
                                duration = moment.duration(duration);
                                unit = computeIntervalUnit(duration);
                                unitIsSingle = computeIntervalAs(unit, duration) === 1;
                        }

                        // options that are specified per the view's duration, like "week" or "day"
                        if (unitIsSingle && hash[unit]) {
                                viewOptions = $.extend({}, hash[unit], viewOptions); // lowest priority
                        }

                        // compute the final text for the button representing this view
                        buttonText =
                                allButtonText[requestedViewType] || // init options, like "agendaWeek"
                                (unitIsSingle ? allButtonText[unit] : null) || // init options, like "week"
                                allDefaultButtonText[requestedViewType] || // lang data, like "agendaWeek"
                                (unitIsSingle ? allDefaultButtonText[unit] : null) || // lang data, like "week"
                                viewOptions.buttonText ||
                                viewClass.buttonText ||
                                (duration ? humanizeDuration(duration) : null) ||
                                requestedViewType;

                        return (viewSpecCache[requestedViewType] = {
                                'class': viewClass,
                                options: viewOptions,
                                buttonText: buttonText
                        });
                }
        }


        // Returns a boolean about whether the view is okay to instantiate at some point
        function isValidViewType(viewType) {
                return Boolean(getViewSpec(viewType));
        }


        // Gets the text that should be displayed on a view's button in the header
        function getViewButtonText(viewType) {
                var spec = getViewSpec(viewType);

                if (spec) {
                        return spec.buttonText;
                }
        }
        
        

        // Resizing
        // -----------------------------------------------------------------------------------


        t.getSuggestedViewHeight = function() {
                if (suggestedViewHeight === undefined) {
                        calcSize();
                }
                return suggestedViewHeight;
        };


        t.isHeightAuto = function() {
                return options.contentHeight === 'auto' || options.height === 'auto';
        };
        
        
        function updateSize(shouldRecalc) {
                if (elementVisible()) {

                        if (shouldRecalc) {
                                _calcSize();
                        }

                        ignoreWindowResize++;
                        currentView.updateSize(true); // isResize=true. will poll getSuggestedViewHeight() and isHeightAuto()
                        ignoreWindowResize--;

                        return true; // signal success
                }
        }


        function calcSize() {
                if (elementVisible()) {
                        _calcSize();
                }
        }
        
        
        function _calcSize() { // assumes elementVisible
                if (typeof options.contentHeight === 'number') { // exists and not 'auto'
                        suggestedViewHeight = options.contentHeight;
                }
                else if (typeof options.height === 'number') { // exists and not 'auto'
                        suggestedViewHeight = options.height - (headerElement ? headerElement.outerHeight(true) : 0);
                }
                else {
                        suggestedViewHeight = Math.round(content.width() / Math.max(options.aspectRatio, .5));
                }
        }
        
        
        function windowResize(ev) {
                if (
                        !ignoreWindowResize &&
                        ev.target === window && // so we don't process jqui "resize" events that have bubbled up
                        currentView.start // view has already been rendered
                ) {
                        if (updateSize(true)) {
                                currentView.trigger('windowResize', _element);
                        }
                }
        }
        
        
        
        /* Event Fetching/Rendering
        -----------------------------------------------------------------------------*/
        // TODO: going forward, most of this stuff should be directly handled by the view


        function refetchEvents() { // can be called as an API method
                destroyEvents(); // so that events are cleared before user starts waiting for AJAX
                fetchAndRenderEvents();
        }


        function renderEvents() { // destroys old events if previously rendered
                if (elementVisible()) {
                        freezeContentHeight();
                        currentView.destroyViewEvents(); // no performance cost if never rendered
                        currentView.renderViewEvents(events);
                        unfreezeContentHeight();
                }
        }


        function destroyEvents() {
                freezeContentHeight();
                currentView.destroyViewEvents();
                unfreezeContentHeight();
        }
        

        function getAndRenderEvents() {
                if (!options.lazyFetching || isFetchNeeded(currentView.start, currentView.end)) {
                        fetchAndRenderEvents();
                }
                else {
                        renderEvents();
                }
        }


        function fetchAndRenderEvents() {
                fetchEvents(currentView.start, currentView.end);
                        // ... will call reportEvents
                        // ... which will call renderEvents
        }

        
        // called when event data arrives
        function reportEvents(_events) {
                events = _events;
                renderEvents();
        }


        // called when a single event's data has been changed
        function reportEventChange() {
                renderEvents();
        }



        /* Header Updating
        -----------------------------------------------------------------------------*/


        function updateTitle() {
                header.updateTitle(currentView.computeTitle());
        }


        function updateTodayButton() {
                var now = t.getNow();
                if (now.isWithin(currentView.intervalStart, currentView.intervalEnd)) {
                        header.disableButton('today');
                }
                else {
                        header.enableButton('today');
                }
        }
        


        /* Selection
        -----------------------------------------------------------------------------*/
        

        function select(start, end) {

                start = t.moment(start);
                if (end) {
                        end = t.moment(end);
                }
                else if (start.hasTime()) {
                        end = start.clone().add(t.defaultTimedEventDuration);
                }
                else {
                        end = start.clone().add(t.defaultAllDayEventDuration);
                }

                currentView.select({ start: start, end: end }); // accepts a range
        }
        

        function unselect() { // safe to be called before renderView
                if (currentView) {
                        currentView.unselect();
                }
        }
        
        
        
        /* Date
        -----------------------------------------------------------------------------*/
        
        
        function prev() {
                renderView(-1);
        }
        
        
        function next() {
                renderView(1);
        }
        
        
        function prevYear() {
                date.add(-1, 'years');
                renderView();
        }
        
        
        function nextYear() {
                date.add(1, 'years');
                renderView();
        }
        
        
        function today() {
                date = t.getNow();
                renderView();
        }
        
        
        function gotoDate(dateInput) {
                date = t.moment(dateInput);
                renderView();
        }
        
        
        function incrementDate(delta) {
                date.add(moment.duration(delta));
                renderView();
        }


        // Forces navigation to a view for the given date.
        // `viewType` can be a specific view name or a generic one like "week" or "day".
        function zoomTo(newDate, viewType) {
                var viewStr;
                var match;

                if (!viewType || !isValidViewType(viewType)) { // a general view name, or "auto"
                        viewType = viewType || 'day';
                        viewStr = header.getViewsWithButtons().join(' '); // space-separated string of all the views in the header

                        // try to match a general view name, like "week", against a specific one, like "agendaWeek"
                        match = viewStr.match(new RegExp('\\w+' + capitaliseFirstLetter(viewType)));

                        // fall back to the day view being used in the header
                        if (!match) {
                                match = viewStr.match(/\w+Day/);
                        }

                        viewType = match ? match[0] : 'agendaDay'; // fall back to agendaDay
                }

                date = newDate;
                changeView(viewType);
        }
        
        
        function getDate() {
                return date.clone();
        }



        /* Height "Freezing"
        -----------------------------------------------------------------------------*/


        function freezeContentHeight() {
                content.css({
                        width: '100%',
                        height: content.height(),
                        overflow: 'hidden'
                });
        }


        function unfreezeContentHeight() {
                content.css({
                        width: '',
                        height: '',
                        overflow: ''
                });
        }
        
        
        
        /* Misc
        -----------------------------------------------------------------------------*/
        

        function getCalendar() {
                return t;
        }

        
        function getView() {
                return currentView;
        }
        
        
        function option(name, value) {
                if (value === undefined) {
                        return options[name];
                }
                if (name == 'height' || name == 'contentHeight' || name == 'aspectRatio') {
                        options[name] = value;
                        updateSize(true); // true = allow recalculation of height
                }
        }
        
        
        function trigger(name, thisObj) {
                if (options[name]) {
                        return options[name].apply(
                                thisObj || _element,
                                Array.prototype.slice.call(arguments, 2)
                        );
                }
        }

}

    /* Top toolbar area with buttons and title
----------------------------------------------------------------------------------------------------------------------*/
// TODO: rename all header-related things to "toolbar"

function Header(calendar, options) {
        var t = this;
        
        // exports
        t.render = render;
        t.destroy = destroy;
        t.updateTitle = updateTitle;
        t.activateButton = activateButton;
        t.deactivateButton = deactivateButton;
        t.disableButton = disableButton;
        t.enableButton = enableButton;
        t.getViewsWithButtons = getViewsWithButtons;
        
        // locals
        var el = $();
        var viewsWithButtons = [];
        var tm;


        function render() {
                var sections = options.header;

                tm = options.theme ? 'ui' : 'fc';

                if (sections) {
                        el = $("<div class='fc-toolbar'/>")
                                .append(renderSection('left'))
                                .append(renderSection('right'))
                                .append(renderSection('center'))
                                .append('<div class="fc-clear"/>');

                        return el;
                }
        }
        
        
        function destroy() {
                el.remove();
        }
        
        
        function renderSection(position) {
                var sectionEl = $('<div class="fc-' + position + '"/>');
                var buttonStr = options.header[position];

                if (buttonStr) {
                        $.each(buttonStr.split(' '), function(i) {
                                var groupChildren = $();
                                var isOnlyButtons = true;
                                var groupEl;

                                $.each(this.split(','), function(j, buttonName) {
                                        var buttonClick;
                                        var themeIcon;
                                        var normalIcon;
                                        var defaultText;
                                        var viewText; // highest priority
                                        var customText;
                                        var innerHtml;
                                        var classes;
                                        var button;

                                        if (buttonName == 'title') {
                                                groupChildren = groupChildren.add($('<h2>&nbsp;</h2>')); // we always want it to take up height
                                                isOnlyButtons = false;
                                        }
                                        else {
                                                if (calendar[buttonName]) { // a calendar method
                                                        buttonClick = function() {
                                                                calendar[buttonName]();
                                                        };
                                                }
                                                else if (calendar.isValidViewType(buttonName)) { // a view type
                                                        buttonClick = function() {
                                                                calendar.changeView(buttonName);
                                                        };
                                                        viewsWithButtons.push(buttonName);
                                                        viewText = calendar.getViewButtonText(buttonName);
                                                }
                                                if (buttonClick) {

                                                        // smartProperty allows different text per view button (ex: "Agenda Week" vs "Basic Week")
                                                        themeIcon = smartProperty(options.themeButtonIcons, buttonName);
                                                        normalIcon = smartProperty(options.buttonIcons, buttonName);
                                                        defaultText = smartProperty(options.defaultButtonText, buttonName); // from languages
                                                        customText = smartProperty(options.buttonText, buttonName);

                                                        if (viewText || customText) {
                                                                innerHtml = htmlEscape(viewText || customText);
                                                        }
                                                        else if (themeIcon && options.theme) {
                                                                innerHtml = "<span class='ui-icon ui-icon-" + themeIcon + "'></span>";
                                                        }
                                                        else if (normalIcon && !options.theme) {
                                                                innerHtml = "<span class='fc-icon fc-icon-" + normalIcon + "'></span>";
                                                        }
                                                        else {
                                                                innerHtml = htmlEscape(defaultText || buttonName);
                                                        }

                                                        classes = [
                                                                'fc-' + buttonName + '-button',
                                                                tm + '-button',
                                                                tm + '-state-default'
                                                        ];

                                                        button = $( // type="button" so that it doesn't submit a form
                                                                '<button type="button" class="' + classes.join(' ') + '">' +
                                                                        innerHtml +
                                                                '</button>'
                                                                )
                                                                .click(function() {
                                                                        // don't process clicks for disabled buttons
                                                                        if (!button.hasClass(tm + '-state-disabled')) {

                                                                                buttonClick();

                                                                                // after the click action, if the button becomes the "active" tab, or disabled,
                                                                                // it should never have a hover class, so remove it now.
                                                                                if (
                                                                                        button.hasClass(tm + '-state-active') ||
                                                                                        button.hasClass(tm + '-state-disabled')
                                                                                ) {
                                                                                        button.removeClass(tm + '-state-hover');
                                                                                }
                                                                        }
                                                                })
                                                                .mousedown(function() {
                                                                        // the *down* effect (mouse pressed in).
                                                                        // only on buttons that are not the "active" tab, or disabled
                                                                        button
                                                                                .not('.' + tm + '-state-active')
                                                                                .not('.' + tm + '-state-disabled')
                                                                                .addClass(tm + '-state-down');
                                                                })
                                                                .mouseup(function() {
                                                                        // undo the *down* effect
                                                                        button.removeClass(tm + '-state-down');
                                                                })
                                                                .hover(
                                                                        function() {
                                                                                // the *hover* effect.
                                                                                // only on buttons that are not the "active" tab, or disabled
                                                                                button
                                                                                        .not('.' + tm + '-state-active')
                                                                                        .not('.' + tm + '-state-disabled')
                                                                                        .addClass(tm + '-state-hover');
                                                                        },
                                                                        function() {
                                                                                // undo the *hover* effect
                                                                                button
                                                                                        .removeClass(tm + '-state-hover')
                                                                                        .removeClass(tm + '-state-down'); // if mouseleave happens before mouseup
                                                                        }
                                                                );

                                                        groupChildren = groupChildren.add(button);
                                                }
                                        }
                                });

                                if (isOnlyButtons) {
                                        groupChildren
                                                .first().addClass(tm + '-corner-left').end()
                                                .last().addClass(tm + '-corner-right').end();
                                }

                                if (groupChildren.length > 1) {
                                        groupEl = $('<div/>');
                                        if (isOnlyButtons) {
                                                groupEl.addClass('fc-button-group');
                                        }
                                        groupEl.append(groupChildren);
                                        sectionEl.append(groupEl);
                                }
                                else {
                                        sectionEl.append(groupChildren); // 1 or 0 children
                                }
                        });
                }

                return sectionEl;
        }
        
        
        function updateTitle(text) {
                el.find('h2').text(text);
        }
        
        
        function activateButton(buttonName) {
                el.find('.fc-' + buttonName + '-button')
                        .addClass(tm + '-state-active');
        }
        
        
        function deactivateButton(buttonName) {
                el.find('.fc-' + buttonName + '-button')
                        .removeClass(tm + '-state-active');
        }
        
        
        function disableButton(buttonName) {
                el.find('.fc-' + buttonName + '-button')
                        .attr('disabled', 'disabled')
                        .addClass(tm + '-state-disabled');
        }
        
        
        function enableButton(buttonName) {
                el.find('.fc-' + buttonName + '-button')
                        .removeAttr('disabled')
                        .removeClass(tm + '-state-disabled');
        }


        function getViewsWithButtons() {
                return viewsWithButtons;
        }

}

    fc.sourceNormalizers = [];
fc.sourceFetchers = [];

var ajaxDefaults = {
        dataType: 'json',
        cache: false
};

var eventGUID = 1;


function EventManager(options) { // assumed to be a calendar
        var t = this;
        
        
        // exports
        t.isFetchNeeded = isFetchNeeded;
        t.fetchEvents = fetchEvents;
        t.addEventSource = addEventSource;
        t.removeEventSource = removeEventSource;
        t.updateEvent = updateEvent;
        t.renderEvent = renderEvent;
        t.removeEvents = removeEvents;
        t.clientEvents = clientEvents;
        t.mutateEvent = mutateEvent;
        t.normalizeEventDateProps = normalizeEventDateProps;
        t.ensureVisibleEventRange = ensureVisibleEventRange;
        
        
        // imports
        var trigger = t.trigger;
        var getView = t.getView;
        var reportEvents = t.reportEvents;
        
        
        // locals
        var stickySource = { events: [] };
        var sources = [ stickySource ];
        var rangeStart, rangeEnd;
        var currentFetchID = 0;
        var pendingSourceCnt = 0;
        var loadingLevel = 0;
        var cache = []; // holds events that have already been expanded


        $.each(
                (options.events ? [ options.events ] : []).concat(options.eventSources || []),
                function(i, sourceInput) {
                        var source = buildEventSource(sourceInput);
                        if (source) {
                                sources.push(source);
                        }
                }
        );
        
        
        
        /* Fetching
        -----------------------------------------------------------------------------*/
        
        
        function isFetchNeeded(start, end) {
                return !rangeStart || // nothing has been fetched yet?
                        // or, a part of the new range is outside of the old range? (after normalizing)
                        start.clone().stripZone() < rangeStart.clone().stripZone() ||
                        end.clone().stripZone() > rangeEnd.clone().stripZone();
        }
        
        
        function fetchEvents(start, end) {
                rangeStart = start;
                rangeEnd = end;
                cache = [];
                var fetchID = ++currentFetchID;
                var len = sources.length;
                pendingSourceCnt = len;
                for (var i=0; i<len; i++) {
                        fetchEventSource(sources[i], fetchID);
                }
        }
        
        
        function fetchEventSource(source, fetchID) {
                _fetchEventSource(source, function(eventInputs) {
                        var isArraySource = $.isArray(source.events);
                        var i, eventInput;
                        var abstractEvent;

                        if (fetchID == currentFetchID) {

                                if (eventInputs) {
                                        for (i = 0; i < eventInputs.length; i++) {
                                                eventInput = eventInputs[i];

                                                if (isArraySource) { // array sources have already been convert to Event Objects
                                                        abstractEvent = eventInput;
                                                }
                                                else {
                                                        abstractEvent = buildEventFromInput(eventInput, source);
                                                }

                                                if (abstractEvent) { // not false (an invalid event)
                                                        cache.push.apply(
                                                                cache,
                                                                expandEvent(abstractEvent) // add individual expanded events to the cache
                                                        );
                                                }
                                        }
                                }

                                pendingSourceCnt--;
                                if (!pendingSourceCnt) {
                                        reportEvents(cache);
                                }
                        }
                });
        }
        
        
        function _fetchEventSource(source, callback) {
                var i;
                var fetchers = fc.sourceFetchers;
                var res;

                for (i=0; i<fetchers.length; i++) {
                        res = fetchers[i].call(
                                t, // this, the Calendar object
                                source,
                                rangeStart.clone(),
                                rangeEnd.clone(),
                                options.timezone,
                                callback
                        );

                        if (res === true) {
                                // the fetcher is in charge. made its own async request
                                return;
                        }
                        else if (typeof res == 'object') {
                                // the fetcher returned a new source. process it
                                _fetchEventSource(res, callback);
                                return;
                        }
                }

                var events = source.events;
                if (events) {
                        if ($.isFunction(events)) {
                                pushLoading();
                                events.call(
                                        t, // this, the Calendar object
                                        rangeStart.clone(),
                                        rangeEnd.clone(),
                                        options.timezone,
                                        function(events) {
                                                callback(events);
                                                popLoading();
                                        }
                                );
                        }
                        else if ($.isArray(events)) {
                                callback(events);
                        }
                        else {
                                callback();
                        }
                }else{
                        var url = source.url;
                        if (url) {
                                var success = source.success;
                                var error = source.error;
                                var complete = source.complete;

                                // retrieve any outbound GET/POST $.ajax data from the options
                                var customData;
                                if ($.isFunction(source.data)) {
                                        // supplied as a function that returns a key/value object
                                        customData = source.data();
                                }
                                else {
                                        // supplied as a straight key/value object
                                        customData = source.data;
                                }

                                // use a copy of the custom data so we can modify the parameters
                                // and not affect the passed-in object.
                                var data = $.extend({}, customData || {});

                                var startParam = firstDefined(source.startParam, options.startParam);
                                var endParam = firstDefined(source.endParam, options.endParam);
                                var timezoneParam = firstDefined(source.timezoneParam, options.timezoneParam);

                                if (startParam) {
                                        data[startParam] = rangeStart.format();
                                }
                                if (endParam) {
                                        data[endParam] = rangeEnd.format();
                                }
                                if (options.timezone && options.timezone != 'local') {
                                        data[timezoneParam] = options.timezone;
                                }

                                pushLoading();
                                $.ajax($.extend({}, ajaxDefaults, source, {
                                        data: data,
                                        success: function(events) {
                                                events = events || [];
                                                var res = applyAll(success, this, arguments);
                                                if ($.isArray(res)) {
                                                        events = res;
                                                }
                                                callback(events);
                                        },
                                        error: function() {
                                                applyAll(error, this, arguments);
                                                callback();
                                        },
                                        complete: function() {
                                                applyAll(complete, this, arguments);
                                                popLoading();
                                        }
                                }));
                        }else{
                                callback();
                        }
                }
        }
        
        
        
        /* Sources
        -----------------------------------------------------------------------------*/
        

        function addEventSource(sourceInput) {
                var source = buildEventSource(sourceInput);
                if (source) {
                        sources.push(source);
                        pendingSourceCnt++;
                        fetchEventSource(source, currentFetchID); // will eventually call reportEvents
                }
        }


        function buildEventSource(sourceInput) { // will return undefined if invalid source
                var normalizers = fc.sourceNormalizers;
                var source;
                var i;

                if ($.isFunction(sourceInput) || $.isArray(sourceInput)) {
                        source = { events: sourceInput };
                }
                else if (typeof sourceInput === 'string') {
                        source = { url: sourceInput };
                }
                else if (typeof sourceInput === 'object') {
                        source = $.extend({}, sourceInput); // shallow copy
                }

                if (source) {

                        // TODO: repeat code, same code for event classNames
                        if (source.className) {
                                if (typeof source.className === 'string') {
                                        source.className = source.className.split(/\s+/);
                                }
                                // otherwise, assumed to be an array
                        }
                        else {
                                source.className = [];
                        }

                        // for array sources, we convert to standard Event Objects up front
                        if ($.isArray(source.events)) {
                                source.origArray = source.events; // for removeEventSource
                                source.events = $.map(source.events, function(eventInput) {
                                        return buildEventFromInput(eventInput, source);
                                });
                        }

                        for (i=0; i<normalizers.length; i++) {
                                normalizers[i].call(t, source);
                        }

                        return source;
                }
        }


        function removeEventSource(source) {
                sources = $.grep(sources, function(src) {
                        return !isSourcesEqual(src, source);
                });
                // remove all client events from that source
                cache = $.grep(cache, function(e) {
                        return !isSourcesEqual(e.source, source);
                });
                reportEvents(cache);
        }


        function isSourcesEqual(source1, source2) {
                return source1 && source2 && getSourcePrimitive(source1) == getSourcePrimitive(source2);
        }


        function getSourcePrimitive(source) {
                return (
                        (typeof source === 'object') ? // a normalized event source?
                                (source.origArray || source.googleCalendarId || source.url || source.events) : // get the primitive
                                null
                ) ||
                source; // the given argument *is* the primitive
        }
        
        
        
        /* Manipulation
        -----------------------------------------------------------------------------*/


        // Only ever called from the externally-facing API
        function updateEvent(event) {

                // massage start/end values, even if date string values
                event.start = t.moment(event.start);
                if (event.end) {
                        event.end = t.moment(event.end);
                }
                else {
                        event.end = null;
                }

                mutateEvent(event, getMiscEventProps(event)); // will handle start/end/allDay normalization
                reportEvents(cache); // reports event modifications (so we can redraw)
        }


        // Returns a hash of misc event properties that should be copied over to related events.
        function getMiscEventProps(event) {
                var props = {};

                $.each(event, function(name, val) {
                        if (isMiscEventPropName(name)) {
                                if (val !== undefined && isAtomic(val)) { // a defined non-object
                                        props[name] = val;
                                }
                        }
                });

                return props;
        }

        // non-date-related, non-id-related, non-secret
        function isMiscEventPropName(name) {
                return !/^_|^(id|allDay|start|end)$/.test(name);
        }

        
        // returns the expanded events that were created
        function renderEvent(eventInput, stick) {
                var abstractEvent = buildEventFromInput(eventInput);
                var events;
                var i, event;

                if (abstractEvent) { // not false (a valid input)
                        events = expandEvent(abstractEvent);

                        for (i = 0; i < events.length; i++) {
                                event = events[i];

                                if (!event.source) {
                                        if (stick) {
                                                stickySource.events.push(event);
                                                event.source = stickySource;
                                        }
                                        cache.push(event);
                                }
                        }

                        reportEvents(cache);

                        return events;
                }

                return [];
        }
        
        
        function removeEvents(filter) {
                var eventID;
                var i;

                if (filter == null) { // null or undefined. remove all events
                        filter = function() { return true; }; // will always match
                }
                else if (!$.isFunction(filter)) { // an event ID
                        eventID = filter + '';
                        filter = function(event) {
                                return event._id == eventID;
                        };
                }

                // Purge event(s) from our local cache
                cache = $.grep(cache, filter, true); // inverse=true

                // Remove events from array sources.
                // This works because they have been converted to official Event Objects up front.
                // (and as a result, event._id has been calculated).
                for (i=0; i<sources.length; i++) {
                        if ($.isArray(sources[i].events)) {
                                sources[i].events = $.grep(sources[i].events, filter, true);
                        }
                }

                reportEvents(cache);
        }
        
        
        function clientEvents(filter) {
                if ($.isFunction(filter)) {
                        return $.grep(cache, filter);
                }
                else if (filter != null) { // not null, not undefined. an event ID
                        filter += '';
                        return $.grep(cache, function(e) {
                                return e._id == filter;
                        });
                }
                return cache; // else, return all
        }
        
        
        
        /* Loading State
        -----------------------------------------------------------------------------*/
        
        
        function pushLoading() {
                if (!(loadingLevel++)) {
                        trigger('loading', null, true, getView());
                }
        }
        
        
        function popLoading() {
                if (!(--loadingLevel)) {
                        trigger('loading', null, false, getView());
                }
        }
        
        
        
        /* Event Normalization
        -----------------------------------------------------------------------------*/


        // Given a raw object with key/value properties, returns an "abstract" Event object.
        // An "abstract" event is an event that, if recurring, will not have been expanded yet.
        // Will return `false` when input is invalid.
        // `source` is optional
        function buildEventFromInput(input, source) {
                var out = {};
                var start, end;
                var allDay;

                if (options.eventDataTransform) {
                        input = options.eventDataTransform(input);
                }
                if (source && source.eventDataTransform) {
                        input = source.eventDataTransform(input);
                }

                // Copy all properties over to the resulting object.
                // The special-case properties will be copied over afterwards.
                $.extend(out, input);

                if (source) {
                        out.source = source;
                }

                out._id = input._id || (input.id === undefined ? '_fc' + eventGUID++ : input.id + '');

                if (input.className) {
                        if (typeof input.className == 'string') {
                                out.className = input.className.split(/\s+/);
                        }
                        else { // assumed to be an array
                                out.className = input.className;
                        }
                }
                else {
                        out.className = [];
                }

                start = input.start || input.date; // "date" is an alias for "start"
                end = input.end;

                // parse as a time (Duration) if applicable
                if (isTimeString(start)) {
                        start = moment.duration(start);
                }
                if (isTimeString(end)) {
                        end = moment.duration(end);
                }

                if (input.dow || moment.isDuration(start) || moment.isDuration(end)) {

                        // the event is "abstract" (recurring) so don't calculate exact start/end dates just yet
                        out.start = start ? moment.duration(start) : null; // will be a Duration or null
                        out.end = end ? moment.duration(end) : null; // will be a Duration or null
                        out._recurring = true; // our internal marker
                }
                else {

                        if (start) {
                                start = t.moment(start);
                                if (!start.isValid()) {
                                        return false;
                                }
                        }

                        if (end) {
                                end = t.moment(end);
                                if (!end.isValid()) {
                                        end = null; // let defaults take over
                                }
                        }

                        allDay = input.allDay;
                        if (allDay === undefined) { // still undefined? fallback to default
                                allDay = firstDefined(
                                        source ? source.allDayDefault : undefined,
                                        options.allDayDefault
                                );
                                // still undefined? normalizeEventDateProps will calculate it
                        }

                        assignDatesToEvent(start, end, allDay, out);
                }

                return out;
        }


        // Normalizes and assigns the given dates to the given partially-formed event object.
        // NOTE: mutates the given start/end moments. does not make a copy.
        function assignDatesToEvent(start, end, allDay, event) {
                event.start = start;
                event.end = end;
                event.allDay = allDay;
                normalizeEventDateProps(event);
                backupEventDates(event);
        }


        // Ensures the allDay property exists.
        // Ensures the start/end dates are consistent with allDay and forceEventDuration.
        // Accepts an Event object, or a plain object with event-ish properties.
        // NOTE: Will modify the given object.
        function normalizeEventDateProps(props) {

                if (props.allDay == null) {
                        props.allDay = !(props.start.hasTime() || (props.end && props.end.hasTime()));
                }

                if (props.allDay) {
                        props.start.stripTime();
                        if (props.end) {
                                props.end.stripTime();
                        }
                }
                else {
                        if (!props.start.hasTime()) {
                                props.start = t.rezoneDate(props.start); // will also give it a 00:00 time
                        }
                        if (props.end && !props.end.hasTime()) {
                                props.end = t.rezoneDate(props.end); // will also give it a 00:00 time
                        }
                }

                if (props.end && !props.end.isAfter(props.start)) {
                        props.end = null;
                }

                if (!props.end) {
                        if (options.forceEventDuration) {
                                props.end = t.getDefaultEventEnd(props.allDay, props.start);
                        }
                        else {
                                props.end = null;
                        }
                }
        }


        // If `range` is a proper range with a start and end, returns the original object.
        // If missing an end, computes a new range with an end, computing it as if it were an event.
        // TODO: make this a part of the event -> eventRange system
        function ensureVisibleEventRange(range) {
                var allDay;

                if (!range.end) {

                        allDay = range.allDay; // range might be more event-ish than we think
                        if (allDay == null) {
                                allDay = !range.start.hasTime();
                        }

                        range = {
                                start: range.start,
                                end: t.getDefaultEventEnd(allDay, range.start)
                        };
                }
                return range;
        }


        // If the given event is a recurring event, break it down into an array of individual instances.
        // If not a recurring event, return an array with the single original event.
        // If given a falsy input (probably because of a failed buildEventFromInput call), returns an empty array.
        // HACK: can override the recurring window by providing custom rangeStart/rangeEnd (for businessHours).
        function expandEvent(abstractEvent, _rangeStart, _rangeEnd) {
                var events = [];
                var dowHash;
                var dow;
                var i;
                var date;
                var startTime, endTime;
                var start, end;
                var event;

                _rangeStart = _rangeStart || rangeStart;
                _rangeEnd = _rangeEnd || rangeEnd;

                if (abstractEvent) {
                        if (abstractEvent._recurring) {

                                // make a boolean hash as to whether the event occurs on each day-of-week
                                if ((dow = abstractEvent.dow)) {
                                        dowHash = {};
                                        for (i = 0; i < dow.length; i++) {
                                                dowHash[dow[i]] = true;
                                        }
                                }

                                // iterate through every day in the current range
                                date = _rangeStart.clone().stripTime(); // holds the date of the current day
                                while (date.isBefore(_rangeEnd)) {

                                        if (!dowHash || dowHash[date.day()]) { // if everyday, or this particular day-of-week

                                                startTime = abstractEvent.start; // the stored start and end properties are times (Durations)
                                                endTime = abstractEvent.end; // "
                                                start = date.clone();
                                                end = null;

                                                if (startTime) {
                                                        start = start.time(startTime);
                                                }
                                                if (endTime) {
                                                        end = date.clone().time(endTime);
                                                }

                                                event = $.extend({}, abstractEvent); // make a copy of the original
                                                assignDatesToEvent(
                                                        start, end,
                                                        !startTime && !endTime, // allDay?
                                                        event
                                                );
                                                events.push(event);
                                        }

                                        date.add(1, 'days');
                                }
                        }
                        else {
                                events.push(abstractEvent); // return the original event. will be a one-item array
                        }
                }

                return events;
        }



        /* Event Modification Math
        -----------------------------------------------------------------------------------------*/


        // Modifies an event and all related events by applying the given properties.
        // Special date-diffing logic is used for manipulation of dates.
        // If `props` does not contain start/end dates, the updated values are assumed to be the event's current start/end.
        // All date comparisons are done against the event's pristine _start and _end dates.
        // Returns an object with delta information and a function to undo all operations.
        //
        function mutateEvent(event, props) {
                var miscProps = {};
                var clearEnd;
                var dateDelta;
                var durationDelta;
                var undoFunc;

                props = props || {};

                // ensure new date-related values to compare against
                if (!props.start) {
                        props.start = event.start.clone();
                }
                if (props.end === undefined) {
                        props.end = event.end ? event.end.clone() : null;
                }
                if (props.allDay == null) { // is null or undefined?
                        props.allDay = event.allDay;
                }

                normalizeEventDateProps(props); // massages start/end/allDay

                // clear the end date if explicitly changed to null
                clearEnd = event._end !== null && props.end === null;

                // compute the delta for moving the start and end dates together
                if (props.allDay) {
                        dateDelta = diffDay(props.start, event._start); // whole-day diff from start-of-day
                }
                else {
                        dateDelta = diffDayTime(props.start, event._start);
                }

                // compute the delta for moving the end date (after applying dateDelta)
                if (!clearEnd && props.end) {
                        durationDelta = diffDayTime(
                                // new duration
                                props.end,
                                props.start
                        ).subtract(diffDayTime(
                                // subtract old duration
                                event._end || t.getDefaultEventEnd(event._allDay, event._start),
                                event._start
                        ));
                }

                // gather all non-date-related properties
                $.each(props, function(name, val) {
                        if (isMiscEventPropName(name)) {
                                if (val !== undefined) {
                                        miscProps[name] = val;
                                }
                        }
                });

                // apply the operations to the event and all related events
                undoFunc = mutateEvents(
                        clientEvents(event._id), // get events with this ID
                        clearEnd,
                        props.allDay,
                        dateDelta,
                        durationDelta,
                        miscProps
                );

                return {
                        dateDelta: dateDelta,
                        durationDelta: durationDelta,
                        undo: undoFunc
                };
        }


        // Modifies an array of events in the following ways (operations are in order):
        // - clear the event's `end`
        // - convert the event to allDay
        // - add `dateDelta` to the start and end
        // - add `durationDelta` to the event's duration
        // - assign `miscProps` to the event
        //
        // Returns a function that can be called to undo all the operations.
        //
        // TODO: don't use so many closures. possible memory issues when lots of events with same ID.
        //
        function mutateEvents(events, clearEnd, allDay, dateDelta, durationDelta, miscProps) {
                var isAmbigTimezone = t.getIsAmbigTimezone();
                var undoFunctions = [];

                // normalize zero-length deltas to be null
                if (dateDelta && !dateDelta.valueOf()) { dateDelta = null; }
                if (durationDelta && !durationDelta.valueOf()) { durationDelta = null; }

                $.each(events, function(i, event) {
                        var oldProps;
                        var newProps;

                        // build an object holding all the old values, both date-related and misc.
                        // for the undo function.
                        oldProps = {
                                start: event.start.clone(),
                                end: event.end ? event.end.clone() : null,
                                allDay: event.allDay
                        };
                        $.each(miscProps, function(name) {
                                oldProps[name] = event[name];
                        });

                        // new date-related properties. work off the original date snapshot.
                        // ok to use references because they will be thrown away when backupEventDates is called.
                        newProps = {
                                start: event._start,
                                end: event._end,
                                allDay: event._allDay
                        };

                        if (clearEnd) {
                                newProps.end = null;
                        }

                        newProps.allDay = allDay;

                        normalizeEventDateProps(newProps); // massages start/end/allDay

                        if (dateDelta) {
                                newProps.start.add(dateDelta);
                                if (newProps.end) {
                                        newProps.end.add(dateDelta);
                                }
                        }

                        if (durationDelta) {
                                if (!newProps.end) {
                                        newProps.end = t.getDefaultEventEnd(newProps.allDay, newProps.start);
                                }
                                newProps.end.add(durationDelta);
                        }

                        // if the dates have changed, and we know it is impossible to recompute the
                        // timezone offsets, strip the zone.
                        if (
                                isAmbigTimezone &&
                                !newProps.allDay &&
                                (dateDelta || durationDelta)
                        ) {
                                newProps.start.stripZone();
                                if (newProps.end) {
                                        newProps.end.stripZone();
                                }
                        }

                        $.extend(event, miscProps, newProps); // copy over misc props, then date-related props
                        backupEventDates(event); // regenerate internal _start/_end/_allDay

                        undoFunctions.push(function() {
                                $.extend(event, oldProps);
                                backupEventDates(event); // regenerate internal _start/_end/_allDay
                        });
                });

                return function() {
                        for (var i = 0; i < undoFunctions.length; i++) {
                                undoFunctions[i]();
                        }
                };
        }


        /* Business Hours
        -----------------------------------------------------------------------------------------*/

        t.getBusinessHoursEvents = getBusinessHoursEvents;


        // Returns an array of events as to when the business hours occur in the given view.
        // Abuse of our event system :(
        function getBusinessHoursEvents() {
                var optionVal = options.businessHours;
                var defaultVal = {
                        className: 'fc-nonbusiness',
                        start: '09:00',
                        end: '17:00',
                        dow: [ 1, 2, 3, 4, 5 ], // monday - friday
                        rendering: 'inverse-background'
                };
                var view = t.getView();
                var eventInput;

                if (optionVal) {
                        if (typeof optionVal === 'object') {
                                // option value is an object that can override the default business hours
                                eventInput = $.extend({}, defaultVal, optionVal);
                        }
                        else {
                                // option value is `true`. use default business hours
                                eventInput = defaultVal;
                        }
                }

                if (eventInput) {
                        return expandEvent(
                                buildEventFromInput(eventInput),
                                view.start,
                                view.end
                        );
                }

                return [];
        }


        /* Overlapping / Constraining
        -----------------------------------------------------------------------------------------*/

        t.isEventRangeAllowed = isEventRangeAllowed;
        t.isSelectionRangeAllowed = isSelectionRangeAllowed;
        t.isExternalDropRangeAllowed = isExternalDropRangeAllowed;


        function isEventRangeAllowed(range, event) {
                var source = event.source || {};
                var constraint = firstDefined(
                        event.constraint,
                        source.constraint,
                        options.eventConstraint
                );
                var overlap = firstDefined(
                        event.overlap,
                        source.overlap,
                        options.eventOverlap
                );

                range = ensureVisibleEventRange(range); // ensure a proper range with an end for isRangeAllowed

                return isRangeAllowed(range, constraint, overlap, event);
        }


        function isSelectionRangeAllowed(range) {
                return isRangeAllowed(range, options.selectConstraint, options.selectOverlap);
        }


        // when `eventProps` is defined, consider this an event.
        // `eventProps` can contain misc non-date-related info about the event.
        function isExternalDropRangeAllowed(range, eventProps) {
                var eventInput;
                var event;

                // note: very similar logic is in View's reportExternalDrop
                if (eventProps) {
                        eventInput = $.extend({}, eventProps, range);
                        event = expandEvent(buildEventFromInput(eventInput))[0];
                }

                if (event) {
                        return isEventRangeAllowed(range, event);
                }
                else { // treat it as a selection

                        range = ensureVisibleEventRange(range); // ensure a proper range with an end for isSelectionRangeAllowed

                        return isSelectionRangeAllowed(range);
                }
        }


        // Returns true if the given range (caused by an event drop/resize or a selection) is allowed to exist
        // according to the constraint/overlap settings.
        // `event` is not required if checking a selection.
        function isRangeAllowed(range, constraint, overlap, event) {
                var constraintEvents;
                var anyContainment;
                var i, otherEvent;
                var otherOverlap;

                // normalize. fyi, we're normalizing in too many places :(
                range = {
                        start: range.start.clone().stripZone(),
                        end: range.end.clone().stripZone()
                };

                // the range must be fully contained by at least one of produced constraint events
                if (constraint != null) {

                        // not treated as an event! intermediate data structure
                        // TODO: use ranges in the future
                        constraintEvents = constraintToEvents(constraint);

                        anyContainment = false;
                        for (i = 0; i < constraintEvents.length; i++) {
                                if (eventContainsRange(constraintEvents[i], range)) {
                                        anyContainment = true;
                                        break;
                                }
                        }

                        if (!anyContainment) {
                                return false;
                        }
                }

                for (i = 0; i < cache.length; i++) { // loop all events and detect overlap
                        otherEvent = cache[i];

                        // don't compare the event to itself or other related [repeating] events
                        if (event && event._id === otherEvent._id) {
                                continue;
                        }

                        // there needs to be an actual intersection before disallowing anything
                        if (eventIntersectsRange(otherEvent, range)) {

                                // evaluate overlap for the given range and short-circuit if necessary
                                if (overlap === false) {
                                        return false;
                                }
                                else if (typeof overlap === 'function' && !overlap(otherEvent, event)) {
                                        return false;
                                }

                                // if we are computing if the given range is allowable for an event, consider the other event's
                                // EventObject-specific or Source-specific `overlap` property
                                if (event) {
                                        otherOverlap = firstDefined(
                                                otherEvent.overlap,
                                                (otherEvent.source || {}).overlap
                                                // we already considered the global `eventOverlap`
                                        );
                                        if (otherOverlap === false) {
                                                return false;
                                        }
                                        if (typeof otherOverlap === 'function' && !otherOverlap(event, otherEvent)) {
                                                return false;
                                        }
                                }
                        }
                }

                return true;
        }


        // Given an event input from the API, produces an array of event objects. Possible event inputs:
        // 'businessHours'
        // An event ID (number or string)
        // An object with specific start/end dates or a recurring event (like what businessHours accepts)
        function constraintToEvents(constraintInput) {

                if (constraintInput === 'businessHours') {
                        return getBusinessHoursEvents();
                }

                if (typeof constraintInput === 'object') {
                        return expandEvent(buildEventFromInput(constraintInput));
                }

                return clientEvents(constraintInput); // probably an ID
        }


        // Does the event's date range fully contain the given range?
        // start/end already assumed to have stripped zones :(
        function eventContainsRange(event, range) {
                var eventStart = event.start.clone().stripZone();
                var eventEnd = t.getEventEnd(event).stripZone();

                return range.start >= eventStart && range.end <= eventEnd;
        }


        // Does the event's date range intersect with the given range?
        // start/end already assumed to have stripped zones :(
        function eventIntersectsRange(event, range) {
                var eventStart = event.start.clone().stripZone();
                var eventEnd = t.getEventEnd(event).stripZone();

                return range.start < eventEnd && range.end > eventStart;
        }

}


// updates the "backup" properties, which are preserved in order to compute diffs later on.
function backupEventDates(event) {
        event._allDay = event.allDay;
        event._start = event.start.clone();
        event._end = event.end ? event.end.clone() : null;
}

    /* An abstract class for the "basic" views, as well as month view. Renders one or more rows of day cells.
----------------------------------------------------------------------------------------------------------------------*/
// It is a manager for a DayGrid subcomponent, which does most of the heavy lifting.
// It is responsible for managing width/height.

var BasicView = fcViews.basic = View.extend({

        dayGrid: null, // the main subcomponent that does most of the heavy lifting

        dayNumbersVisible: false, // display day numbers on each day cell?
        weekNumbersVisible: false, // display week numbers along the side?

        weekNumberWidth: null, // width of all the week-number cells running down the side

        headRowEl: null, // the fake row element of the day-of-week header


        initialize: function() {
                this.dayGrid = new DayGrid(this);
                this.coordMap = this.dayGrid.coordMap; // the view's date-to-cell mapping is identical to the subcomponent's
        },


        // Sets the display range and computes all necessary dates
        setRange: function(range) {
                View.prototype.setRange.call(this, range); // call the super-method

                this.dayGrid.breakOnWeeks = /year|month|week/.test(this.intervalUnit); // do before setRange
                this.dayGrid.setRange(range);
        },


        // Compute the value to feed into setRange. Overrides superclass.
        computeRange: function(date) {
                var range = View.prototype.computeRange.call(this, date); // get value from the super-method

                // year and month views should be aligned with weeks. this is already done for week
                if (/year|month/.test(range.intervalUnit)) {
                        range.start.startOf('week');
                        range.start = this.skipHiddenDays(range.start);

                        // make end-of-week if not already
                        if (range.end.weekday()) {
                                range.end.add(1, 'week').startOf('week');
                                range.end = this.skipHiddenDays(range.end, -1, true); // exclusively move backwards
                        }
                }

                return range;
        },


        // Renders the view into `this.el`, which should already be assigned
        render: function() {

                this.dayNumbersVisible = this.dayGrid.rowCnt > 1; // TODO: make grid responsible
                this.weekNumbersVisible = this.opt('weekNumbers');
                this.dayGrid.numbersVisible = this.dayNumbersVisible || this.weekNumbersVisible;

                this.el.addClass('fc-basic-view').html(this.renderHtml());

                this.headRowEl = this.el.find('thead .fc-row');

                this.scrollerEl = this.el.find('.fc-day-grid-container');
                this.dayGrid.coordMap.containerEl = this.scrollerEl; // constrain clicks/etc to the dimensions of the scroller

                this.dayGrid.el = this.el.find('.fc-day-grid');
                this.dayGrid.render(this.hasRigidRows());
        },


        // Make subcomponents ready for cleanup
        destroy: function() {
                this.dayGrid.destroy();
                View.prototype.destroy.call(this); // call the super-method
        },


        // Builds the HTML skeleton for the view.
        // The day-grid component will render inside of a container defined by this HTML.
        renderHtml: function() {
                return '' +
                        '<table>' +
                                '<thead>' +
                                        '<tr>' +
                                                '<td class="' + this.widgetHeaderClass + '">' +
                                                        this.dayGrid.headHtml() + // render the day-of-week headers
                                                '</td>' +
                                        '</tr>' +
                                '</thead>' +
                                '<tbody>' +
                                        '<tr>' +
                                                '<td class="' + this.widgetContentClass + '">' +
                                                        '<div class="fc-day-grid-container">' +
                                                                '<div class="fc-day-grid"/>' +
                                                        '</div>' +
                                                '</td>' +
                                        '</tr>' +
                                '</tbody>' +
                        '</table>';
        },


        // Generates the HTML that will go before the day-of week header cells.
        // Queried by the DayGrid subcomponent when generating rows. Ordering depends on isRTL.
        headIntroHtml: function() {
                if (this.weekNumbersVisible) {
                        return '' +
                                '<th class="fc-week-number ' + this.widgetHeaderClass + '" ' + this.weekNumberStyleAttr() + '>' +
                                        '<span>' + // needed for matchCellWidths
                                                htmlEscape(this.opt('weekNumberTitle')) +
                                        '</span>' +
                                '</th>';
                }
        },


        // Generates the HTML that will go before content-skeleton cells that display the day/week numbers.
        // Queried by the DayGrid subcomponent. Ordering depends on isRTL.
        numberIntroHtml: function(row) {
                if (this.weekNumbersVisible) {
                        return '' +
                                '<td class="fc-week-number" ' + this.weekNumberStyleAttr() + '>' +
                                        '<span>' + // needed for matchCellWidths
                                                this.calendar.calculateWeekNumber(this.dayGrid.getCell(row, 0).start) +
                                        '</span>' +
                                '</td>';
                }
        },


        // Generates the HTML that goes before the day bg cells for each day-row.
        // Queried by the DayGrid subcomponent. Ordering depends on isRTL.
        dayIntroHtml: function() {
                if (this.weekNumbersVisible) {
                        return '<td class="fc-week-number ' + this.widgetContentClass + '" ' +
                                this.weekNumberStyleAttr() + '></td>';
                }
        },


        // Generates the HTML that goes before every other type of row generated by DayGrid. Ordering depends on isRTL.
        // Affects helper-skeleton and highlight-skeleton rows.
        introHtml: function() {
                if (this.weekNumbersVisible) {
                        return '<td class="fc-week-number" ' + this.weekNumberStyleAttr() + '></td>';
                }
        },


        // Generates the HTML for the <td>s of the "number" row in the DayGrid's content skeleton.
        // The number row will only exist if either day numbers or week numbers are turned on.
        numberCellHtml: function(cell) {
                var date = cell.start;
                var classes;

                if (!this.dayNumbersVisible) { // if there are week numbers but not day numbers
                        return '<td/>'; //  will create an empty space above events :(
                }

                classes = this.dayGrid.getDayClasses(date);
                classes.unshift('fc-day-number');

                return '' +
                        '<td class="' + classes.join(' ') + '" data-date="' + date.format() + '">' +
                                date.date() +
                        '</td>';
        },


        // Generates an HTML attribute string for setting the width of the week number column, if it is known
        weekNumberStyleAttr: function() {
                if (this.weekNumberWidth !== null) {
                        return 'style="width:' + this.weekNumberWidth + 'px"';
                }
                return '';
        },


        // Determines whether each row should have a constant height
        hasRigidRows: function() {
                var eventLimit = this.opt('eventLimit');
                return eventLimit && typeof eventLimit !== 'number';
        },


        /* Dimensions
        ------------------------------------------------------------------------------------------------------------------*/


        // Refreshes the horizontal dimensions of the view
        updateWidth: function() {
                if (this.weekNumbersVisible) {
                        // Make sure all week number cells running down the side have the same width.
                        // Record the width for cells created later.
                        this.weekNumberWidth = matchCellWidths(
                                this.el.find('.fc-week-number')
                        );
                }
        },


        // Adjusts the vertical dimensions of the view to the specified values
        setHeight: function(totalHeight, isAuto) {
                var eventLimit = this.opt('eventLimit');
                var scrollerHeight;

                // reset all heights to be natural
                unsetScroller(this.scrollerEl);
                uncompensateScroll(this.headRowEl);

                this.dayGrid.destroySegPopover(); // kill the "more" popover if displayed

                // is the event limit a constant level number?
                if (eventLimit && typeof eventLimit === 'number') {
                        this.dayGrid.limitRows(eventLimit); // limit the levels first so the height can redistribute after
                }

                scrollerHeight = this.computeScrollerHeight(totalHeight);
                this.setGridHeight(scrollerHeight, isAuto);

                // is the event limit dynamically calculated?
                if (eventLimit && typeof eventLimit !== 'number') {
                        this.dayGrid.limitRows(eventLimit); // limit the levels after the grid's row heights have been set
                }

                if (!isAuto && setPotentialScroller(this.scrollerEl, scrollerHeight)) { // using scrollbars?

                        compensateScroll(this.headRowEl, getScrollbarWidths(this.scrollerEl));

                        // doing the scrollbar compensation might have created text overflow which created more height. redo
                        scrollerHeight = this.computeScrollerHeight(totalHeight);
                        this.scrollerEl.height(scrollerHeight);

                        this.restoreScroll();
                }
        },


        // Sets the height of just the DayGrid component in this view
        setGridHeight: function(height, isAuto) {
                if (isAuto) {
                        undistributeHeight(this.dayGrid.rowEls); // let the rows be their natural height with no expanding
                }
                else {
                        distributeHeight(this.dayGrid.rowEls, height, true); // true = compensate for height-hogging rows
                }
        },


        /* Events
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders the given events onto the view and populates the segments array
        renderEvents: function(events) {
                this.dayGrid.renderEvents(events);

                this.updateHeight(); // must compensate for events that overflow the row
        },


        // Retrieves all segment objects that are rendered in the view
        getEventSegs: function() {
                return this.dayGrid.getEventSegs();
        },


        // Unrenders all event elements and clears internal segment data
        destroyEvents: function() {
                this.recordScroll(); // removing events will reduce height and mess with the scroll, so record beforehand
                this.dayGrid.destroyEvents();

                // we DON'T need to call updateHeight() because:
                // A) a renderEvents() call always happens after this, which will eventually call updateHeight()
                // B) in IE8, this causes a flash whenever events are rerendered
        },


        /* Dragging (for both events and external elements)
        ------------------------------------------------------------------------------------------------------------------*/


        // A returned value of `true` signals that a mock "helper" event has been rendered.
        renderDrag: function(dropLocation, seg) {
                return this.dayGrid.renderDrag(dropLocation, seg);
        },


        destroyDrag: function() {
                this.dayGrid.destroyDrag();
        },


        /* Selection
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders a visual indication of a selection
        renderSelection: function(range) {
                this.dayGrid.renderSelection(range);
        },


        // Unrenders a visual indications of a selection
        destroySelection: function() {
                this.dayGrid.destroySelection();
        }

});

    /* A month view with day cells running in rows (one-per-week) and columns
----------------------------------------------------------------------------------------------------------------------*/

setDefaults({
        fixedWeekCount: true
});

var MonthView = fcViews.month = BasicView.extend({

        // Produces information about what range to display
        computeRange: function(date) {
                var range = BasicView.prototype.computeRange.call(this, date); // get value from super-method

                if (this.isFixedWeeks()) {
                        // ensure 6 weeks
                        range.end.add(
                                6 - range.end.diff(range.start, 'weeks'),
                                'weeks'
                        );
                }

                return range;
        },


        // Overrides the default BasicView behavior to have special multi-week auto-height logic
        setGridHeight: function(height, isAuto) {

                isAuto = isAuto || this.opt('weekMode') === 'variable'; // LEGACY: weekMode is deprecated

                // if auto, make the height of each row the height that it would be if there were 6 weeks
                if (isAuto) {
                        height *= this.rowCnt / 6;
                }

                distributeHeight(this.dayGrid.rowEls, height, !isAuto); // if auto, don't compensate for height-hogging rows
        },


        isFixedWeeks: function() {
                var weekMode = this.opt('weekMode'); // LEGACY: weekMode is deprecated
                if (weekMode) {
                        return weekMode === 'fixed'; // if any other type of weekMode, assume NOT fixed
                }

                return this.opt('fixedWeekCount');
        }

});

MonthView.duration = { months: 1 };

    /* A week view with simple day cells running horizontally
----------------------------------------------------------------------------------------------------------------------*/

fcViews.basicWeek = {
        type: 'basic',
        duration: { weeks: 1 }
};
    /* A view with a single simple day cell
----------------------------------------------------------------------------------------------------------------------*/

fcViews.basicDay = {
        type: 'basic',
        duration: { days: 1 }
};
    /* An abstract class for all agenda-related views. Displays one more columns with time slots running vertically.
----------------------------------------------------------------------------------------------------------------------*/
// Is a manager for the TimeGrid subcomponent and possibly the DayGrid subcomponent (if allDaySlot is on).
// Responsible for managing width/height.

setDefaults({
        allDaySlot: true,
        allDayText: 'all-day',
        scrollTime: '06:00:00',
        slotDuration: '00:30:00',
        minTime: '00:00:00',
        maxTime: '24:00:00',
        slotEventOverlap: true
});

var AGENDA_ALL_DAY_EVENT_LIMIT = 5;

fcViews.agenda = View.extend({ // AgendaView

        timeGrid: null, // the main time-grid subcomponent of this view
        dayGrid: null, // the "all-day" subcomponent. if all-day is turned off, this will be null

        axisWidth: null, // the width of the time axis running down the side

        noScrollRowEls: null, // set of fake row elements that must compensate when scrollerEl has scrollbars

        // when the time-grid isn't tall enough to occupy the given height, we render an <hr> underneath
        bottomRuleEl: null,
        bottomRuleHeight: null,


        initialize: function() {
                this.timeGrid = new TimeGrid(this);

                if (this.opt('allDaySlot')) { // should we display the "all-day" area?
                        this.dayGrid = new DayGrid(this); // the all-day subcomponent of this view

                        // the coordinate grid will be a combination of both subcomponents' grids
                        this.coordMap = new ComboCoordMap([
                                this.dayGrid.coordMap,
                                this.timeGrid.coordMap
                        ]);
                }
                else {
                        this.coordMap = this.timeGrid.coordMap;
                }
        },


        /* Rendering
        ------------------------------------------------------------------------------------------------------------------*/


        // Sets the display range and computes all necessary dates
        setRange: function(range) {
                View.prototype.setRange.call(this, range); // call the super-method

                this.timeGrid.setRange(range);
                if (this.dayGrid) {
                        this.dayGrid.setRange(range);
                }
        },


        // Renders the view into `this.el`, which has already been assigned
        render: function() {

                this.el.addClass('fc-agenda-view').html(this.renderHtml());

                // the element that wraps the time-grid that will probably scroll
                this.scrollerEl = this.el.find('.fc-time-grid-container');
                this.timeGrid.coordMap.containerEl = this.scrollerEl; // don't accept clicks/etc outside of this

                this.timeGrid.el = this.el.find('.fc-time-grid');
                this.timeGrid.render();

                // the <hr> that sometimes displays under the time-grid
                this.bottomRuleEl = $('<hr class="' + this.widgetHeaderClass + '"/>')
                        .appendTo(this.timeGrid.el); // inject it into the time-grid

                if (this.dayGrid) {
                        this.dayGrid.el = this.el.find('.fc-day-grid');
                        this.dayGrid.render();

                        // have the day-grid extend it's coordinate area over the <hr> dividing the two grids
                        this.dayGrid.bottomCoordPadding = this.dayGrid.el.next('hr').outerHeight();
                }

                this.noScrollRowEls = this.el.find('.fc-row:not(.fc-scroller *)'); // fake rows not within the scroller
        },


        // Make subcomponents ready for cleanup
        destroy: function() {
                this.timeGrid.destroy();
                if (this.dayGrid) {
                        this.dayGrid.destroy();
                }
                View.prototype.destroy.call(this); // call the super-method
        },


        // Builds the HTML skeleton for the view.
        // The day-grid and time-grid components will render inside containers defined by this HTML.
        renderHtml: function() {
                return '' +
                        '<table>' +
                                '<thead>' +
                                        '<tr>' +
                                                '<td class="' + this.widgetHeaderClass + '">' +
                                                        this.timeGrid.headHtml() + // render the day-of-week headers
                                                '</td>' +
                                        '</tr>' +
                                '</thead>' +
                                '<tbody>' +
                                        '<tr>' +
                                                '<td class="' + this.widgetContentClass + '">' +
                                                        (this.dayGrid ?
                                                                '<div class="fc-day-grid"/>' +
                                                                '<hr class="' + this.widgetHeaderClass + '"/>' :
                                                                ''
                                                                ) +
                                                        '<div class="fc-time-grid-container">' +
                                                                '<div class="fc-time-grid"/>' +
                                                        '</div>' +
                                                '</td>' +
                                        '</tr>' +
                                '</tbody>' +
                        '</table>';
        },


        // Generates the HTML that will go before the day-of week header cells.
        // Queried by the TimeGrid subcomponent when generating rows. Ordering depends on isRTL.
        headIntroHtml: function() {
                var date;
                var weekNumber;
                var weekTitle;
                var weekText;

                if (this.opt('weekNumbers')) {
                        date = this.timeGrid.getCell(0).start;
                        weekNumber = this.calendar.calculateWeekNumber(date);
                        weekTitle = this.opt('weekNumberTitle');

                        if (this.opt('isRTL')) {
                                weekText = weekNumber + weekTitle;
                        }
                        else {
                                weekText = weekTitle + weekNumber;
                        }

                        return '' +
                                '<th class="fc-axis fc-week-number ' + this.widgetHeaderClass + '" ' + this.axisStyleAttr() + '>' +
                                        '<span>' + // needed for matchCellWidths
                                                htmlEscape(weekText) +
                                        '</span>' +
                                '</th>';
                }
                else {
                        return '<th class="fc-axis ' + this.widgetHeaderClass + '" ' + this.axisStyleAttr() + '></th>';
                }
        },


        // Generates the HTML that goes before the all-day cells.
        // Queried by the DayGrid subcomponent when generating rows. Ordering depends on isRTL.
        dayIntroHtml: function() {
                return '' +
                        '<td class="fc-axis ' + this.widgetContentClass + '" ' + this.axisStyleAttr() + '>' +
                                '<span>' + // needed for matchCellWidths
                                        (this.opt('allDayHtml') || htmlEscape(this.opt('allDayText'))) +
                                '</span>' +
                        '</td>';
        },


        // Generates the HTML that goes before the bg of the TimeGrid slot area. Long vertical column.
        slotBgIntroHtml: function() {
                return '<td class="fc-axis ' + this.widgetContentClass + '" ' + this.axisStyleAttr() + '></td>';
        },


        // Generates the HTML that goes before all other types of cells.
        // Affects content-skeleton, helper-skeleton, highlight-skeleton for both the time-grid and day-grid.
        // Queried by the TimeGrid and DayGrid subcomponents when generating rows. Ordering depends on isRTL.
        introHtml: function() {
                return '<td class="fc-axis" ' + this.axisStyleAttr() + '></td>';
        },


        // Generates an HTML attribute string for setting the width of the axis, if it is known
        axisStyleAttr: function() {
                if (this.axisWidth !== null) {
                         return 'style="width:' + this.axisWidth + 'px"';
                }
                return '';
        },


        /* Dimensions
        ------------------------------------------------------------------------------------------------------------------*/


        updateSize: function(isResize) {
                if (isResize) {
                        this.timeGrid.resize();
                }
                View.prototype.updateSize.call(this, isResize);
        },


        // Refreshes the horizontal dimensions of the view
        updateWidth: function() {
                // make all axis cells line up, and record the width so newly created axis cells will have it
                this.axisWidth = matchCellWidths(this.el.find('.fc-axis'));
        },


        // Adjusts the vertical dimensions of the view to the specified values
        setHeight: function(totalHeight, isAuto) {
                var eventLimit;
                var scrollerHeight;

                if (this.bottomRuleHeight === null) {
                        // calculate the height of the rule the very first time
                        this.bottomRuleHeight = this.bottomRuleEl.outerHeight();
                }
                this.bottomRuleEl.hide(); // .show() will be called later if this <hr> is necessary

                // reset all dimensions back to the original state
                this.scrollerEl.css('overflow', '');
                unsetScroller(this.scrollerEl);
                uncompensateScroll(this.noScrollRowEls);

                // limit number of events in the all-day area
                if (this.dayGrid) {
                        this.dayGrid.destroySegPopover(); // kill the "more" popover if displayed

                        eventLimit = this.opt('eventLimit');
                        if (eventLimit && typeof eventLimit !== 'number') {
                                eventLimit = AGENDA_ALL_DAY_EVENT_LIMIT; // make sure "auto" goes to a real number
                        }
                        if (eventLimit) {
                                this.dayGrid.limitRows(eventLimit);
                        }
                }

                if (!isAuto) { // should we force dimensions of the scroll container, or let the contents be natural height?

                        scrollerHeight = this.computeScrollerHeight(totalHeight);
                        if (setPotentialScroller(this.scrollerEl, scrollerHeight)) { // using scrollbars?

                                // make the all-day and header rows lines up
                                compensateScroll(this.noScrollRowEls, getScrollbarWidths(this.scrollerEl));

                                // the scrollbar compensation might have changed text flow, which might affect height, so recalculate
                                // and reapply the desired height to the scroller.
                                scrollerHeight = this.computeScrollerHeight(totalHeight);
                                this.scrollerEl.height(scrollerHeight);

                                this.restoreScroll();
                        }
                        else { // no scrollbars
                                // still, force a height and display the bottom rule (marks the end of day)
                                this.scrollerEl.height(scrollerHeight).css('overflow', 'hidden'); // in case <hr> goes outside
                                this.bottomRuleEl.show();
                        }
                }
        },


        // Sets the scroll value of the scroller to the initial pre-configured state prior to allowing the user to change it
        initializeScroll: function() {
                var _this = this;
                var scrollTime = moment.duration(this.opt('scrollTime'));
                var top = this.timeGrid.computeTimeTop(scrollTime);

                // zoom can give weird floating-point values. rather scroll a little bit further
                top = Math.ceil(top);

                if (top) {
                        top++; // to overcome top border that slots beyond the first have. looks better
                }

                function scroll() {
                        _this.scrollerEl.scrollTop(top);
                }

                scroll();
                setTimeout(scroll, 0); // overrides any previous scroll state made by the browser
        },


        /* Events
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders events onto the view and populates the View's segment array
        renderEvents: function(events) {
                var dayEvents = [];
                var timedEvents = [];
                var daySegs = [];
                var timedSegs;
                var i;

                // separate the events into all-day and timed
                for (i = 0; i < events.length; i++) {
                        if (events[i].allDay) {
                                dayEvents.push(events[i]);
                        }
                        else {
                                timedEvents.push(events[i]);
                        }
                }

                // render the events in the subcomponents
                timedSegs = this.timeGrid.renderEvents(timedEvents);
                if (this.dayGrid) {
                        daySegs = this.dayGrid.renderEvents(dayEvents);
                }

                // the all-day area is flexible and might have a lot of events, so shift the height
                this.updateHeight();
        },


        // Retrieves all segment objects that are rendered in the view
        getEventSegs: function() {
                return this.timeGrid.getEventSegs().concat(
                        this.dayGrid ? this.dayGrid.getEventSegs() : []
                );
        },


        // Unrenders all event elements and clears internal segment data
        destroyEvents: function() {

                // if destroyEvents is being called as part of an event rerender, renderEvents will be called shortly
                // after, so remember what the scroll value was so we can restore it.
                this.recordScroll();

                // destroy the events in the subcomponents
                this.timeGrid.destroyEvents();
                if (this.dayGrid) {
                        this.dayGrid.destroyEvents();
                }

                // we DON'T need to call updateHeight() because:
                // A) a renderEvents() call always happens after this, which will eventually call updateHeight()
                // B) in IE8, this causes a flash whenever events are rerendered
        },


        /* Dragging (for events and external elements)
        ------------------------------------------------------------------------------------------------------------------*/


        // A returned value of `true` signals that a mock "helper" event has been rendered.
        renderDrag: function(dropLocation, seg) {
                if (dropLocation.start.hasTime()) {
                        return this.timeGrid.renderDrag(dropLocation, seg);
                }
                else if (this.dayGrid) {
                        return this.dayGrid.renderDrag(dropLocation, seg);
                }
        },


        destroyDrag: function() {
                this.timeGrid.destroyDrag();
                if (this.dayGrid) {
                        this.dayGrid.destroyDrag();
                }
        },


        /* Selection
        ------------------------------------------------------------------------------------------------------------------*/


        // Renders a visual indication of a selection
        renderSelection: function(range) {
                if (range.start.hasTime() || range.end.hasTime()) {
                        this.timeGrid.renderSelection(range);
                }
                else if (this.dayGrid) {
                        this.dayGrid.renderSelection(range);
                }
        },


        // Unrenders a visual indications of a selection
        destroySelection: function() {
                this.timeGrid.destroySelection();
                if (this.dayGrid) {
                        this.dayGrid.destroySelection();
                }
        }

});

    /* A week view with an all-day cell area at the top, and a time grid below
----------------------------------------------------------------------------------------------------------------------*/

fcViews.agendaWeek = {
        type: 'agenda',
        duration: { weeks: 1 }
};
    /* A day view with an all-day cell area at the top, and a time grid below
----------------------------------------------------------------------------------------------------------------------*/

fcViews.agendaDay = {
        type: 'agenda',
        duration: { days: 1 }
};
});