Tom-Marble/deck.js/extensions/scale/deck.scale.js

   1 /*!
   2 Deck JS - deck.scale
   3 Copyright (c) 2011-2014 Caleb Troughton
   4 Dual licensed under the MIT license.
   5 https://github.com/imakewebthings/deck.js/blob/master/MIT-license.txt
   6 */
   7
   8 /*
   9 This module adds automatic scaling to the deck.  Slides are scaled down
  10 using CSS transforms to fit within the deck container. If the container is
  11 big enough to hold the slides without scaling, no scaling occurs. The user
  12 can disable and enable scaling with a keyboard shortcut.
  13
  14 Note: CSS transforms may make Flash videos render incorrectly.  Presenters
  15 that need to use video may want to disable scaling to play them.  HTML5 video
  16 works fine.
  17 */
  18 (function($, undefined) {
  19   var $document = $(document);
  20   var $window = $(window);
  21   var baseHeight, timer, rootSlides;
  22
  23   /*
  24   Internal function to do all the dirty work of scaling the slides.
  25   */
  26   var scaleDeck = function() {
  27     var options = $.deck('getOptions');
  28     var $container = $.deck('getContainer');
  29     var baseHeight = options.baseHeight;
  30
  31     if (!baseHeight) {
  32       baseHeight = $container.height();
  33     }
  34
  35     // Scale each slide down if necessary (but don't scale up)
  36     $.each(rootSlides, function(i, $slide) {
  37       var slideHeight = $slide.innerHeight();
  38       var $scaler = $slide.find('.' + options.classes.scaleSlideWrapper);
  39       var shouldScale = $container.hasClass(options.classes.scale);
  40       var scale = shouldScale ? baseHeight / slideHeight : 1;
  41
  42       if (scale === 1) {
  43         $scaler.css('transform', '');
  44       }
  45       else {
  46         $scaler.css('transform', 'scale(' + scale + ')');
  47         window.setTimeout(function() {
  48           $container.scrollTop(0)
  49         }, 1);
  50       }
  51     });
  52   };
  53
  54   var populateRootSlides = function() {
  55     var options = $.deck('getOptions');
  56     var slideTest = $.map([
  57       options.classes.before,
  58       options.classes.previous,
  59       options.classes.current,
  60       options.classes.next,
  61       options.classes.after
  62     ], function(el, i) {
  63       return '.' + el;
  64     }).join(', ');
  65
  66     rootSlides = [];
  67     $.each($.deck('getSlides'), function(i, $slide) {
  68       var $parentSlides = $slide.parentsUntil(
  69         options.selectors.container,
  70         slideTest
  71       );
  72       if (!$parentSlides.length) {
  73         rootSlides.push($slide);
  74       }
  75     });
  76   };
  77
  78   var wrapRootSlideContent = function() {
  79     var options = $.deck('getOptions');
  80     var wrap = '<div class="' + options.classes.scaleSlideWrapper + '"/>';
  81     $.each(rootSlides, function(i, $slide) {
  82       $slide.children().wrapAll(wrap);
  83     });
  84   };
  85
  86   var scaleOnResizeAndLoad = function() {
  87     var options = $.deck('getOptions');
  88
  89     $window.unbind('resize.deckscale');
  90     $window.bind('resize.deckscale', function() {
  91       window.clearTimeout(timer);
  92       timer = window.setTimeout(scaleDeck, options.scaleDebounce);
  93     });
  94     $.deck('enableScale');
  95     $window.unbind('load.deckscale');
  96     $window.bind('load.deckscale', scaleDeck);
  97   };
  98
  99   var bindKeyEvents = function() {
 100     var options = $.deck('getOptions');
 101     $document.unbind('keydown.deckscale');
 102     $document.bind('keydown.deckscale', function(event) {
 103       var isKey = event.which === options.keys.scale;
 104       isKey = isKey || $.inArray(event.which, options.keys.scale) > -1;
 105       if (isKey) {
 106         $.deck('toggleScale');
 107         event.preventDefault();
 108       }
 109     });
 110   };
 111
 112   /*
 113   Extends defaults/options.
 114
 115   options.classes.scale
 116     This class is added to the deck container when scaling is enabled.
 117     It is enabled by default when the module is included.
 118
 119   options.classes.scaleSlideWrapper
 120     Scaling is done using a wrapper around the contents of each slide. This
 121     class is applied to that wrapper.
 122
 123   options.keys.scale
 124     The numeric keycode used to toggle enabling and disabling scaling.
 125
 126   options.baseHeight
 127     When baseHeight is falsy, as it is by default, the deck is scaled in
 128     proportion to the height of the deck container. You may instead specify
 129     a height as a number of px, and slides will be scaled against this
 130     height regardless of the container size.
 131
 132   options.scaleDebounce
 133     Scaling on the browser resize event is debounced. This number is the
 134     threshold in milliseconds. You can learn more about debouncing here:
 135     http://unscriptable.com/index.php/2009/03/20/debouncing-javascript-methods/
 136
 137   */
 138   $.extend(true, $.deck.defaults, {
 139     classes: {
 140       scale: 'deck-scale',
 141       scaleSlideWrapper: 'deck-slide-scaler'
 142     },
 143
 144     keys: {
 145       scale: 83 // s
 146     },
 147
 148     baseHeight: null,
 149     scaleDebounce: 200
 150   });
 151
 152   /*
 153   jQuery.deck('disableScale')
 154
 155   Disables scaling and removes the scale class from the deck container.
 156   */
 157   $.deck('extend', 'disableScale', function() {
 158     $.deck('getContainer').removeClass($.deck('getOptions').classes.scale);
 159     scaleDeck();
 160   });
 161
 162   /*
 163   jQuery.deck('enableScale')
 164
 165   Enables scaling and adds the scale class to the deck container.
 166   */
 167   $.deck('extend', 'enableScale', function() {
 168     $.deck('getContainer').addClass($.deck('getOptions').classes.scale);
 169     scaleDeck();
 170   });
 171
 172   /*
 173   jQuery.deck('toggleScale')
 174
 175   Toggles between enabling and disabling scaling.
 176   */
 177   $.deck('extend', 'toggleScale', function() {
 178     var $container = $.deck('getContainer');
 179     var isScaled = $container.hasClass($.deck('getOptions').classes.scale);
 180     $.deck(isScaled? 'disableScale' : 'enableScale');
 181   });
 182
 183   $document.bind('deck.init', function() {
 184     populateRootSlides();
 185     wrapRootSlideContent();
 186     scaleOnResizeAndLoad();
 187     bindKeyEvents();
 188   });
 189 })(jQuery, 'deck', this);
 190