docs/com/plugin/zoom-js/zoom.js

   1 // Custom reveal.js integration
   2 (function(){
   3         var isEnabled = true;
   4
   5         document.querySelector( '.reveal .slides' ).addEventListener( 'mousedown', function( event ) {
   6                 var modifier = ( Reveal.getConfig().zoomKey ? Reveal.getConfig().zoomKey : 'alt' ) + 'Key';
   7
   8                 var zoomPadding = 20;
   9                 var revealScale = Reveal.getScale();
  10
  11                 if( event[ modifier ] && isEnabled ) {
  12                         event.preventDefault();
  13
  14                         var bounds = event.target.getBoundingClientRect();
  15
  16                         zoom.to({
  17                                 x: ( bounds.left * revealScale ) - zoomPadding,
  18                                 y: ( bounds.top * revealScale ) - zoomPadding,
  19                                 width: ( bounds.width * revealScale ) + ( zoomPadding * 2 ),
  20                                 height: ( bounds.height * revealScale ) + ( zoomPadding * 2 ),
  21                                 pan: false
  22                         });
  23                 }
  24         } );
  25
  26         Reveal.addEventListener( 'overviewshown', function() { isEnabled = false; } );
  27         Reveal.addEventListener( 'overviewhidden', function() { isEnabled = true; } );
  28 })();
  29
  30 /*!
  31  * zoom.js 0.3 (modified for use with reveal.js)
  32  * http://lab.hakim.se/zoom-js
  33  * MIT licensed
  34  *
  35  * Copyright (C) 2011-2014 Hakim El Hattab, http://hakim.se
  36  */
  37 var zoom = (function(){
  38
  39         // The current zoom level (scale)
  40         var level = 1;
  41
  42         // The current mouse position, used for panning
  43         var mouseX = 0,
  44                 mouseY = 0;
  45
  46         // Timeout before pan is activated
  47         var panEngageTimeout = -1,
  48                 panUpdateInterval = -1;
  49
  50         // Check for transform support so that we can fallback otherwise
  51         var supportsTransforms =        'WebkitTransform' in document.body.style ||
  52                                                                 'MozTransform' in document.body.style ||
  53                                                                 'msTransform' in document.body.style ||
  54                                                                 'OTransform' in document.body.style ||
  55                                                                 'transform' in document.body.style;
  56
  57         if( supportsTransforms ) {
  58                 // The easing that will be applied when we zoom in/out
  59                 document.body.style.transition = 'transform 0.8s ease';
  60                 document.body.style.OTransition = '-o-transform 0.8s ease';
  61                 document.body.style.msTransition = '-ms-transform 0.8s ease';
  62                 document.body.style.MozTransition = '-moz-transform 0.8s ease';
  63                 document.body.style.WebkitTransition = '-webkit-transform 0.8s ease';
  64         }
  65
  66         // Zoom out if the user hits escape
  67         document.addEventListener( 'keyup', function( event ) {
  68                 if( level !== 1 && event.keyCode === 27 ) {
  69                         zoom.out();
  70                 }
  71         } );
  72
  73         // Monitor mouse movement for panning
  74         document.addEventListener( 'mousemove', function( event ) {
  75                 if( level !== 1 ) {
  76                         mouseX = event.clientX;
  77                         mouseY = event.clientY;
  78                 }
  79         } );
  80
  81         /**
  82          * Applies the CSS required to zoom in, prefers the use of CSS3
  83          * transforms but falls back on zoom for IE.
  84          *
  85          * @param {Object} rect
  86          * @param {Number} scale
  87          */
  88         function magnify( rect, scale ) {
  89
  90                 var scrollOffset = getScrollOffset();
  91
  92                 // Ensure a width/height is set
  93                 rect.width = rect.width || 1;
  94                 rect.height = rect.height || 1;
  95
  96                 // Center the rect within the zoomed viewport
  97                 rect.x -= ( window.innerWidth - ( rect.width * scale ) ) / 2;
  98                 rect.y -= ( window.innerHeight - ( rect.height * scale ) ) / 2;
  99
 100                 if( supportsTransforms ) {
 101                         // Reset
 102                         if( scale === 1 ) {
 103                                 document.body.style.transform = '';
 104                                 document.body.style.OTransform = '';
 105                                 document.body.style.msTransform = '';
 106                                 document.body.style.MozTransform = '';
 107                                 document.body.style.WebkitTransform = '';
 108                         }
 109                         // Scale
 110                         else {
 111                                 var origin = scrollOffset.x +'px '+ scrollOffset.y +'px',
 112                                         transform = 'translate('+ -rect.x +'px,'+ -rect.y +'px) scale('+ scale +')';
 113
 114                                 document.body.style.transformOrigin = origin;
 115                                 document.body.style.OTransformOrigin = origin;
 116                                 document.body.style.msTransformOrigin = origin;
 117                                 document.body.style.MozTransformOrigin = origin;
 118                                 document.body.style.WebkitTransformOrigin = origin;
 119
 120                                 document.body.style.transform = transform;
 121                                 document.body.style.OTransform = transform;
 122                                 document.body.style.msTransform = transform;
 123                                 document.body.style.MozTransform = transform;
 124                                 document.body.style.WebkitTransform = transform;
 125                         }
 126                 }
 127                 else {
 128                         // Reset
 129                         if( scale === 1 ) {
 130                                 document.body.style.position = '';
 131                                 document.body.style.left = '';
 132                                 document.body.style.top = '';
 133                                 document.body.style.width = '';
 134                                 document.body.style.height = '';
 135                                 document.body.style.zoom = '';
 136                         }
 137                         // Scale
 138                         else {
 139                                 document.body.style.position = 'relative';
 140                                 document.body.style.left = ( - ( scrollOffset.x + rect.x ) / scale ) + 'px';
 141                                 document.body.style.top = ( - ( scrollOffset.y + rect.y ) / scale ) + 'px';
 142                                 document.body.style.width = ( scale * 100 ) + '%';
 143                                 document.body.style.height = ( scale * 100 ) + '%';
 144                                 document.body.style.zoom = scale;
 145                         }
 146                 }
 147
 148                 level = scale;
 149
 150                 if( document.documentElement.classList ) {
 151                         if( level !== 1 ) {
 152                                 document.documentElement.classList.add( 'zoomed' );
 153                         }
 154                         else {
 155                                 document.documentElement.classList.remove( 'zoomed' );
 156                         }
 157                 }
 158         }
 159
 160         /**
 161          * Pan the document when the mosue cursor approaches the edges
 162          * of the window.
 163          */
 164         function pan() {
 165                 var range = 0.12,
 166                         rangeX = window.innerWidth * range,
 167                         rangeY = window.innerHeight * range,
 168                         scrollOffset = getScrollOffset();
 169
 170                 // Up
 171                 if( mouseY < rangeY ) {
 172                         window.scroll( scrollOffset.x, scrollOffset.y - ( 1 - ( mouseY / rangeY ) ) * ( 14 / level ) );
 173                 }
 174                 // Down
 175                 else if( mouseY > window.innerHeight - rangeY ) {
 176                         window.scroll( scrollOffset.x, scrollOffset.y + ( 1 - ( window.innerHeight - mouseY ) / rangeY ) * ( 14 / level ) );
 177                 }
 178
 179                 // Left
 180                 if( mouseX < rangeX ) {
 181                         window.scroll( scrollOffset.x - ( 1 - ( mouseX / rangeX ) ) * ( 14 / level ), scrollOffset.y );
 182                 }
 183                 // Right
 184                 else if( mouseX > window.innerWidth - rangeX ) {
 185                         window.scroll( scrollOffset.x + ( 1 - ( window.innerWidth - mouseX ) / rangeX ) * ( 14 / level ), scrollOffset.y );
 186                 }
 187         }
 188
 189         function getScrollOffset() {
 190                 return {
 191                         x: window.scrollX !== undefined ? window.scrollX : window.pageXOffset,
 192                         y: window.scrollY !== undefined ? window.scrollY : window.pageYOffset
 193                 }
 194         }
 195
 196         return {
 197                 /**
 198                  * Zooms in on either a rectangle or HTML element.
 199                  *
 200                  * @param {Object} options
 201                  *   - element: HTML element to zoom in on
 202                  *   OR
 203                  *   - x/y: coordinates in non-transformed space to zoom in on
 204                  *   - width/height: the portion of the screen to zoom in on
 205                  *   - scale: can be used instead of width/height to explicitly set scale
 206                  */
 207                 to: function( options ) {
 208
 209                         // Due to an implementation limitation we can't zoom in
 210                         // to another element without zooming out first
 211                         if( level !== 1 ) {
 212                                 zoom.out();
 213                         }
 214                         else {
 215                                 options.x = options.x || 0;
 216                                 options.y = options.y || 0;
 217
 218                                 // If an element is set, that takes precedence
 219                                 if( !!options.element ) {
 220                                         // Space around the zoomed in element to leave on screen
 221                                         var padding = 20;
 222                                         var bounds = options.element.getBoundingClientRect();
 223
 224                                         options.x = bounds.left - padding;
 225                                         options.y = bounds.top - padding;
 226                                         options.width = bounds.width + ( padding * 2 );
 227                                         options.height = bounds.height + ( padding * 2 );
 228                                 }
 229
 230                                 // If width/height values are set, calculate scale from those values
 231                                 if( options.width !== undefined && options.height !== undefined ) {
 232                                         options.scale = Math.max( Math.min( window.innerWidth / options.width, window.innerHeight / options.height ), 1 );
 233                                 }
 234
 235                                 if( options.scale > 1 ) {
 236                                         options.x *= options.scale;
 237                                         options.y *= options.scale;
 238
 239                                         magnify( options, options.scale );
 240
 241                                         if( options.pan !== false ) {
 242
 243                                                 // Wait with engaging panning as it may conflict with the
 244                                                 // zoom transition
 245                                                 panEngageTimeout = setTimeout( function() {
 246                                                         panUpdateInterval = setInterval( pan, 1000 / 60 );
 247                                                 }, 800 );
 248
 249                                         }
 250                                 }
 251                         }
 252                 },
 253
 254                 /**
 255                  * Resets the document zoom state to its default.
 256                  */
 257                 out: function() {
 258                         clearTimeout( panEngageTimeout );
 259                         clearInterval( panUpdateInterval );
 260
 261                         magnify( { x: 0, y: 0 }, 1 );
 262
 263                         level = 1;
 264                 },
 265
 266                 // Alias
 267                 magnify: function( options ) { this.to( options ) },
 268                 reset: function() { this.out() },
 269
 270                 zoomLevel: function() {
 271                         return level;
 272                 }
 273         }
 274
 275 })();
 276
 277
 278