js/reveal.js

   1 /*!
   2  * reveal.js 2.1 r29
   3  * http://lab.hakim.se/reveal-js
   4  * MIT licensed
   5  *
   6  * Copyright (C) 2011-2012 Hakim El Hattab, http://hakim.se
   7  */
   8 var Reveal = (function(){
   9
  10         'use strict';
  11
  12         var HORIZONTAL_SLIDES_SELECTOR = '.reveal .slides>section',
  13                 VERTICAL_SLIDES_SELECTOR = '.reveal .slides>section.present>section',
  14
  15                 // Configurations defaults, can be overridden at initialization time
  16                 config = {
  17                         // Display controls in the bottom right corner
  18                         controls: true,
  19
  20                         // Display a presentation progress bar
  21                         progress: true,
  22
  23                         // Push each slide change to the browser history
  24                         history: false,
  25
  26                         // Enable keyboard shortcuts for navigation
  27                         keyboard: true,
  28
  29                         // Enable the slide overview mode
  30                         overview: true,
  31
  32                         // Loop the presentation
  33                         loop: false,
  34
  35                         // Number of milliseconds between automatically proceeding to the
  36                         // next slide, disabled when set to 0
  37                         autoSlide: 0,
  38
  39                         // Enable slide navigation via mouse wheel
  40                         mouseWheel: true,
  41
  42                         // Apply a 3D roll to links on hover
  43                         rollingLinks: true,
  44
  45                         // Transition style (see /css/theme)
  46                         theme: 'default',
  47
  48                         // Transition style
  49                         transition: 'default', // default/cube/page/concave/linear(2d),
  50
  51                         // Script dependencies to load
  52                         dependencies: []
  53                 },
  54
  55                 // The horizontal and verical index of the currently active slide
  56                 indexh = 0,
  57                 indexv = 0,
  58
  59                 // The previous and current slide HTML elements
  60                 previousSlide,
  61                 currentSlide,
  62
  63                 // Slides may hold a data-state attribute which we pick up and apply
  64                 // as a class to the body. This list contains the combined state of
  65                 // all current slides.
  66                 state = [],
  67
  68                 // Cached references to DOM elements
  69                 dom = {},
  70
  71                 // Detect support for CSS 3D transforms
  72                 supports3DTransforms =  'WebkitPerspective' in document.body.style ||
  73                                                                 'MozPerspective' in document.body.style ||
  74                                                                 'msPerspective' in document.body.style ||
  75                                                                 'OPerspective' in document.body.style ||
  76                                                                 'perspective' in document.body.style,
  77
  78                 supports2DTransforms =  'WebkitTransform' in document.body.style ||
  79                                                                 'MozTransform' in document.body.style ||
  80                                                                 'msTransform' in document.body.style ||
  81                                                                 'OTransform' in document.body.style ||
  82                                                                 'transform' in document.body.style,
  83
  84                 // Throttles mouse wheel navigation
  85                 mouseWheelTimeout = 0,
  86
  87                 // An interval used to automatically move on to the next slide
  88                 autoSlideTimeout = 0,
  89
  90                 // Delays updates to the URL due to a Chrome thumbnailer bug
  91                 writeURLTimeout = 0,
  92
  93                 // Holds information about the currently ongoing touch input
  94                 touch = {
  95                         startX: 0,
  96                         startY: 0,
  97                         startSpan: 0,
  98                         startCount: 0,
  99                         handled: false,
 100                         threshold: 40
 101                 };
 102
 103
 104         /**
 105          * Starts up the presentation if the client is capable.
 106          */
 107         function initialize( options ) {
 108                 if( ( !supports2DTransforms && !supports3DTransforms ) ) {
 109                         document.body.setAttribute( 'class', 'no-transforms' );
 110
 111                         // If the browser doesn't support core features we won't be
 112                         // using JavaScript to control the presentation
 113                         return;
 114                 }
 115
 116                 // Copy options over to our config object
 117                 extend( config, options );
 118
 119                 // Make sure we've got all the DOM elements we need
 120                 setupDOM();
 121
 122                 // Hide the address bar in mobile browsers
 123                 hideAddressBar();
 124
 125                 // Loads the dependencies and continues to #start() once done
 126                 load();
 127
 128         }
 129
 130         /**
 131          * Finds and stores references to DOM elements which are
 132          * required by the presentation. If a required element is
 133          * not found, it is created.
 134          */
 135         function setupDOM() {
 136                 // Cache references to key DOM elements
 137                 dom.theme = document.querySelector( '#theme' );
 138                 dom.wrapper = document.querySelector( '.reveal' );
 139
 140                 // Progress bar
 141                 if( !dom.wrapper.querySelector( '.progress' ) && config.progress ) {
 142                         var progressElement = document.createElement( 'div' );
 143                         progressElement.classList.add( 'progress' );
 144                         progressElement.innerHTML = '<span></span>';
 145                         dom.wrapper.appendChild( progressElement );
 146                 }
 147
 148                 // Arrow controls
 149                 if( !dom.wrapper.querySelector( '.controls' ) && config.controls ) {
 150                         var controlsElement = document.createElement( 'aside' );
 151                         controlsElement.classList.add( 'controls' );
 152                         controlsElement.innerHTML = '<a class="left" href="#">&#x25C4;</a>' +
 153                                                                                 '<a class="right" href="#">&#x25BA;</a>' +
 154                                                                                 '<a class="up" href="#">&#x25B2;</a>' +
 155                                                                                 '<a class="down" href="#">&#x25BC;</a>';
 156                         dom.wrapper.appendChild( controlsElement );
 157                 }
 158
 159                 // Presentation background element
 160                 if( !dom.wrapper.querySelector( '.state-background' ) ) {
 161                         var backgroundElement = document.createElement( 'div' );
 162                         backgroundElement.classList.add( 'state-background' );
 163                         dom.wrapper.appendChild( backgroundElement );
 164                 }
 165
 166                 // Overlay graphic which is displayed during the paused mode
 167                 if( !dom.wrapper.querySelector( '.pause-overlay' ) ) {
 168                         var pausedElement = document.createElement( 'div' );
 169                         pausedElement.classList.add( 'pause-overlay' );
 170                         dom.wrapper.appendChild( pausedElement );
 171                 }
 172
 173                 // Cache references to elements
 174                 dom.progress = document.querySelector( '.reveal .progress' );
 175                 dom.progressbar = document.querySelector( '.reveal .progress span' );
 176
 177                 if ( config.controls ) {
 178                         dom.controls = document.querySelector( '.reveal .controls' );
 179                         dom.controlsLeft = document.querySelector( '.reveal .controls .left' );
 180                         dom.controlsRight = document.querySelector( '.reveal .controls .right' );
 181                         dom.controlsUp = document.querySelector( '.reveal .controls .up' );
 182                         dom.controlsDown = document.querySelector( '.reveal .controls .down' );
 183                 }
 184         }
 185
 186         /**
 187          * Hides the address bar if we're on a mobile device.
 188          */
 189         function hideAddressBar() {
 190                 if( navigator.userAgent.match( /(iphone|ipod|android)/i ) ) {
 191                         // Give the page some scrollable overflow
 192                         document.documentElement.style.overflow = 'scroll';
 193                         document.body.style.height = '120%';
 194
 195                         // Events that should trigger the address bar to hide
 196                         window.addEventListener( 'load', removeAddressBar, false );
 197                         window.addEventListener( 'orientationchange', removeAddressBar, false );
 198                 }
 199         }
 200
 201         /**
 202          * Loads the dependencies of reveal.js. Dependencies are
 203          * defined via the configuration option 'dependencies'
 204          * and will be loaded prior to starting/binding reveal.js.
 205          * Some dependencies may have an 'async' flag, if so they
 206          * will load after reveal.js has been started up.
 207          */
 208         function load() {
 209                 var scripts = [],
 210                         scriptsAsync = [];
 211
 212                 for( var i = 0, len = config.dependencies.length; i < len; i++ ) {
 213                         var s = config.dependencies[i];
 214
 215                         // Load if there's no condition or the condition is truthy
 216                         if( !s.condition || s.condition() ) {
 217                                 if( s.async ) {
 218                                         scriptsAsync.push( s.src );
 219                                 }
 220                                 else {
 221                                         scripts.push( s.src );
 222                                 }
 223
 224                                 // Extension may contain callback functions
 225                                 if( typeof s.callback === 'function' ) {
 226                                         head.ready( s.src.match( /([\w\d_\-]*)\.?[^\\\/]*$/i )[0], s.callback );
 227                                 }
 228                         }
 229                 }
 230
 231                 // Called once synchronous scritps finish loading
 232                 function proceed() {
 233                         // Load asynchronous scripts
 234                         head.js.apply( null, scriptsAsync );
 235
 236                         start();
 237                 }
 238
 239                 if( scripts.length ) {
 240                         head.ready( proceed );
 241
 242                         // Load synchronous scripts
 243                         head.js.apply( null, scripts );
 244                 }
 245                 else {
 246                         proceed();
 247                 }
 248         }
 249
 250         /**
 251          * Starts up reveal.js by binding input events and navigating
 252          * to the current URL deeplink if there is one.
 253          */
 254         function start() {
 255                 // Subscribe to input
 256                 addEventListeners();
 257
 258                 // Updates the presentation to match the current configuration values
 259                 configure();
 260
 261                 // Read the initial hash
 262                 readURL();
 263
 264                 // Start auto-sliding if it's enabled
 265                 cueAutoSlide();
 266         }
 267
 268         /**
 269          * Applies the configuration settings from the config object.
 270          */
 271         function configure() {
 272                 if( supports3DTransforms === false ) {
 273                         config.transition = 'linear';
 274                 }
 275
 276                 if( config.controls && dom.controls ) {
 277                         dom.controls.style.display = 'block';
 278                 }
 279
 280                 if( config.progress && dom.progress ) {
 281                         dom.progress.style.display = 'block';
 282                 }
 283
 284                 // Load the theme in the config, if it's not already loaded
 285                 if( config.theme && dom.theme ) {
 286                         var themeURL = dom.theme.getAttribute( 'href' );
 287                         var themeFinder = /[^\/]*?(?=\.css)/;
 288                         var themeName = themeURL.match(themeFinder)[0];
 289
 290                         if(  config.theme !== themeName ) {
 291                                 themeURL = themeURL.replace(themeFinder, config.theme);
 292                                 dom.theme.setAttribute( 'href', themeURL );
 293                         }
 294                 }
 295
 296                 if( config.transition !== 'default' ) {
 297                         dom.wrapper.classList.add( config.transition );
 298                 }
 299
 300                 if( config.mouseWheel ) {
 301                         document.addEventListener( 'DOMMouseScroll', onDocumentMouseScroll, false ); // FF
 302                         document.addEventListener( 'mousewheel', onDocumentMouseScroll, false );
 303                 }
 304
 305                 if( config.rollingLinks ) {
 306                         // Add some 3D magic to our anchors
 307                         linkify();
 308                 }
 309         }
 310
 311         function addEventListeners() {
 312                 document.addEventListener( 'touchstart', onDocumentTouchStart, false );
 313                 document.addEventListener( 'touchmove', onDocumentTouchMove, false );
 314                 document.addEventListener( 'touchend', onDocumentTouchEnd, false );
 315                 window.addEventListener( 'hashchange', onWindowHashChange, false );
 316
 317                 if( config.keyboard ) {
 318                         document.addEventListener( 'keydown', onDocumentKeyDown, false );
 319                 }
 320
 321                 if ( config.controls && dom.controls ) {
 322                         dom.controlsLeft.addEventListener( 'click', preventAndForward( navigateLeft ), false );
 323                         dom.controlsRight.addEventListener( 'click', preventAndForward( navigateRight ), false );
 324                         dom.controlsUp.addEventListener( 'click', preventAndForward( navigateUp ), false );
 325                         dom.controlsDown.addEventListener( 'click', preventAndForward( navigateDown ), false );
 326                 }
 327         }
 328
 329         function removeEventListeners() {
 330                 document.removeEventListener( 'keydown', onDocumentKeyDown, false );
 331                 document.removeEventListener( 'touchstart', onDocumentTouchStart, false );
 332                 document.removeEventListener( 'touchmove', onDocumentTouchMove, false );
 333                 document.removeEventListener( 'touchend', onDocumentTouchEnd, false );
 334                 window.removeEventListener( 'hashchange', onWindowHashChange, false );
 335
 336                 if ( config.controls && dom.controls ) {
 337                         dom.controlsLeft.removeEventListener( 'click', preventAndForward( navigateLeft ), false );
 338                         dom.controlsRight.removeEventListener( 'click', preventAndForward( navigateRight ), false );
 339                         dom.controlsUp.removeEventListener( 'click', preventAndForward( navigateUp ), false );
 340                         dom.controlsDown.removeEventListener( 'click', preventAndForward( navigateDown ), false );
 341                 }
 342         }
 343
 344         /**
 345          * Extend object a with the properties of object b.
 346          * If there's a conflict, object b takes precedence.
 347          */
 348         function extend( a, b ) {
 349                 for( var i in b ) {
 350                         a[ i ] = b[ i ];
 351                 }
 352         }
 353
 354         /**
 355          * Measures the distance in pixels between point a
 356          * and point b.
 357          *
 358          * @param {Object} a point with x/y properties
 359          * @param {Object} b point with x/y properties
 360          */
 361         function distanceBetween( a, b ) {
 362                 var dx = a.x - b.x,
 363                         dy = a.y - b.y;
 364
 365                 return Math.sqrt( dx*dx + dy*dy );
 366         }
 367
 368         /**
 369          * Prevents an events defaults behavior calls the
 370          * specified delegate.
 371          *
 372          * @param {Function} delegate The method to call
 373          * after the wrapper has been executed
 374          */
 375         function preventAndForward( delegate ) {
 376                 return function( event ) {
 377                         event.preventDefault();
 378                         delegate.call();
 379                 };
 380         }
 381
 382         /**
 383          * Causes the address bar to hide on mobile devices,
 384          * more vertical space ftw.
 385          */
 386         function removeAddressBar() {
 387                 setTimeout( function() {
 388                         window.scrollTo( 0, 1 );
 389                 }, 0 );
 390         }
 391
 392         /**
 393          * Dispatches an event of the specified type from the
 394          * reveal DOM element.
 395          */
 396         function dispatchEvent( type, properties ) {
 397                 var event = document.createEvent( "HTMLEvents", 1, 2 );
 398                 event.initEvent( type, true, true );
 399                 extend( event, properties );
 400                 dom.wrapper.dispatchEvent( event );
 401         }
 402
 403         /**
 404          * Handler for the document level 'keydown' event.
 405          *
 406          * @param {Object} event
 407          */
 408         function onDocumentKeyDown( event ) {
 409                 // Disregard the event if the target is editable or a
 410                 // modifier is present
 411                 if ( document.querySelector( ':focus' ) !== null || event.shiftKey || event.altKey || event.ctrlKey || event.metaKey ) return;
 412
 413                 var triggered = true;
 414
 415                 switch( event.keyCode ) {
 416                         // p, page up
 417                         case 80: case 33: navigatePrev(); break;
 418                         // n, page down
 419                         case 78: case 34: navigateNext(); break;
 420                         // h, left
 421                         case 72: case 37: navigateLeft(); break;
 422                         // l, right
 423                         case 76: case 39: navigateRight(); break;
 424                         // k, up
 425                         case 75: case 38: navigateUp(); break;
 426                         // j, down
 427                         case 74: case 40: navigateDown(); break;
 428                         // home
 429                         case 36: navigateTo( 0 ); break;
 430                         // end
 431                         case 35: navigateTo( Number.MAX_VALUE ); break;
 432                         // space
 433                         case 32: isOverviewActive() ? deactivateOverview() : navigateNext(); break;
 434                         // return
 435                         case 13: isOverviewActive() ? deactivateOverview() : triggered = false; break;
 436                         // b, period
 437                         case 66: case 190: togglePause(); break;
 438                         default:
 439                                 triggered = false;
 440                 }
 441
 442                 // If the input resulted in a triggered action we should prevent
 443                 // the browsers default behavior
 444                 if( triggered ) {
 445                         event.preventDefault();
 446                 }
 447                 else if ( event.keyCode === 27 && supports3DTransforms ) {
 448                         toggleOverview();
 449
 450                         event.preventDefault();
 451                 }
 452
 453                 // If auto-sliding is enabled we need to cue up
 454                 // another timeout
 455                 cueAutoSlide();
 456
 457         }
 458
 459         /**
 460          * Handler for the document level 'touchstart' event,
 461          * enables support for swipe and pinch gestures.
 462          */
 463         function onDocumentTouchStart( event ) {
 464                 touch.startX = event.touches[0].clientX;
 465                 touch.startY = event.touches[0].clientY;
 466                 touch.startCount = event.touches.length;
 467
 468                 // If there's two touches we need to memorize the distance
 469                 // between those two points to detect pinching
 470                 if( event.touches.length === 2 ) {
 471                         touch.startSpan = distanceBetween( {
 472                                 x: event.touches[1].clientX,
 473                                 y: event.touches[1].clientY
 474                         }, {
 475                                 x: touch.startX,
 476                                 y: touch.startY
 477                         } );
 478                 }
 479         }
 480
 481         /**
 482          * Handler for the document level 'touchmove' event.
 483          */
 484         function onDocumentTouchMove( event ) {
 485                 // Each touch should only trigger one action
 486                 if( !touch.handled ) {
 487                         var currentX = event.touches[0].clientX;
 488                         var currentY = event.touches[0].clientY;
 489
 490                         // If the touch started off with two points and still has
 491                         // two active touches; test for the pinch gesture
 492                         if( event.touches.length === 2 && touch.startCount === 2 ) {
 493
 494                                 // The current distance in pixels between the two touch points
 495                                 var currentSpan = distanceBetween( {
 496                                         x: event.touches[1].clientX,
 497                                         y: event.touches[1].clientY
 498                                 }, {
 499                                         x: touch.startX,
 500                                         y: touch.startY
 501                                 } );
 502
 503                                 // If the span is larger than the desire amount we've got
 504                                 // ourselves a pinch
 505                                 if( Math.abs( touch.startSpan - currentSpan ) > touch.threshold ) {
 506                                         touch.handled = true;
 507
 508                                         if( currentSpan < touch.startSpan ) {
 509                                                 activateOverview();
 510                                         }
 511                                         else {
 512                                                 deactivateOverview();
 513                                         }
 514                                 }
 515
 516                         }
 517                         // There was only one touch point, look for a swipe
 518                         else if( event.touches.length === 1 ) {
 519                                 var deltaX = currentX - touch.startX,
 520                                         deltaY = currentY - touch.startY;
 521
 522                                 if( deltaX > touch.threshold && Math.abs( deltaX ) > Math.abs( deltaY ) ) {
 523                                         touch.handled = true;
 524                                         navigateLeft();
 525                                 }
 526                                 else if( deltaX < -touch.threshold && Math.abs( deltaX ) > Math.abs( deltaY ) ) {
 527                                         touch.handled = true;
 528                                         navigateRight();
 529                                 }
 530                                 else if( deltaY > touch.threshold ) {
 531                                         touch.handled = true;
 532                                         navigateUp();
 533                                 }
 534                                 else if( deltaY < -touch.threshold ) {
 535                                         touch.handled = true;
 536                                         navigateDown();
 537                                 }
 538                         }
 539
 540                         event.preventDefault();
 541                 }
 542                 // There's a bug with swiping on some Android devices unless
 543                 // the default action is always prevented
 544                 else if( navigator.userAgent.match( /android/gi ) ) {
 545                         event.preventDefault();
 546                 }
 547         }
 548
 549         /**
 550          * Handler for the document level 'touchend' event.
 551          */
 552         function onDocumentTouchEnd( event ) {
 553                 touch.handled = false;
 554         }
 555
 556         /**
 557          * Handles mouse wheel scrolling, throttled to avoid
 558          * skipping multiple slides.
 559          */
 560         function onDocumentMouseScroll( event ){
 561                 clearTimeout( mouseWheelTimeout );
 562
 563                 mouseWheelTimeout = setTimeout( function() {
 564                         var delta = event.detail || -event.wheelDelta;
 565                         if( delta > 0 ) {
 566                                 navigateNext();
 567                         }
 568                         else {
 569                                 navigatePrev();
 570                         }
 571                 }, 100 );
 572         }
 573
 574         /**
 575          * Handler for the window level 'hashchange' event.
 576          *
 577          * @param {Object} event
 578          */
 579         function onWindowHashChange( event ) {
 580                 readURL();
 581         }
 582
 583         /**
 584          * Invoked when a slide is and we're in the overview.
 585          */
 586         function onOverviewSlideClicked( event ) {
 587                 // TODO There's a bug here where the event listeners are not
 588                 // removed after deactivating the overview.
 589                 if( isOverviewActive() ) {
 590                         event.preventDefault();
 591
 592                         deactivateOverview();
 593
 594                         indexh = this.getAttribute( 'data-index-h' );
 595                         indexv = this.getAttribute( 'data-index-v' );
 596
 597                         slide();
 598                 }
 599         }
 600
 601         /**
 602          * Wrap all links in 3D goodness.
 603          */
 604         function linkify() {
 605                 if( supports3DTransforms && !( 'msPerspective' in document.body.style ) ) {
 606                         var nodes = document.querySelectorAll( '.reveal .slides section a:not(.image)' );
 607
 608                         for( var i = 0, len = nodes.length; i < len; i++ ) {
 609                                 var node = nodes[i];
 610
 611                                 if( node.textContent && !node.querySelector( 'img' ) && ( !node.className || !node.classList.contains( node, 'roll' ) ) ) {
 612                                         node.classList.add( 'roll' );
 613                                         node.innerHTML = '<span data-title="'+ node.text +'">' + node.innerHTML + '</span>';
 614                                 }
 615                         }
 616                 }
 617         }
 618
 619         /**
 620          * Displays the overview of slides (quick nav) by
 621          * scaling down and arranging all slide elements.
 622          *
 623          * Experimental feature, might be dropped if perf
 624          * can't be improved.
 625          */
 626         function activateOverview() {
 627
 628                 // Only proceed if enabled in config
 629                 if( config.overview ) {
 630
 631                         dom.wrapper.classList.add( 'overview' );
 632
 633                         var horizontalSlides = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR );
 634
 635                         for( var i = 0, len1 = horizontalSlides.length; i < len1; i++ ) {
 636                                 var hslide = horizontalSlides[i],
 637                                         htransform = 'translateZ(-2500px) translate(' + ( ( i - indexh ) * 105 ) + '%, 0%)';
 638
 639                                 hslide.setAttribute( 'data-index-h', i );
 640                                 hslide.style.display = 'block';
 641                                 hslide.style.WebkitTransform = htransform;
 642                                 hslide.style.MozTransform = htransform;
 643                                 hslide.style.msTransform = htransform;
 644                                 hslide.style.OTransform = htransform;
 645                                 hslide.style.transform = htransform;
 646
 647                                 if( !hslide.classList.contains( 'stack' ) ) {
 648                                         // Navigate to this slide on click
 649                                         hslide.addEventListener( 'click', onOverviewSlideClicked, true );
 650                                 }
 651
 652                                 var verticalSlides = hslide.querySelectorAll( 'section' );
 653
 654                                 for( var j = 0, len2 = verticalSlides.length; j < len2; j++ ) {
 655                                         var vslide = verticalSlides[j],
 656                                                 vtransform = 'translate(0%, ' + ( ( j - ( i === indexh ? indexv : 0 ) ) * 105 ) + '%)';
 657
 658                                         vslide.setAttribute( 'data-index-h', i );
 659                                         vslide.setAttribute( 'data-index-v', j );
 660                                         vslide.style.display = 'block';
 661                                         vslide.style.WebkitTransform = vtransform;
 662                                         vslide.style.MozTransform = vtransform;
 663                                         vslide.style.msTransform = vtransform;
 664                                         vslide.style.OTransform = vtransform;
 665                                         vslide.style.transform = vtransform;
 666
 667                                         // Navigate to this slide on click
 668                                         vslide.addEventListener( 'click', onOverviewSlideClicked, true );
 669                                 }
 670
 671                         }
 672
 673                 }
 674
 675         }
 676
 677         /**
 678          * Exits the slide overview and enters the currently
 679          * active slide.
 680          */
 681         function deactivateOverview() {
 682
 683                 // Only proceed if enabled in config
 684                 if( config.overview ) {
 685
 686                         dom.wrapper.classList.remove( 'overview' );
 687
 688                         // Select all slides
 689                         var slides = Array.prototype.slice.call( document.querySelectorAll( '.reveal .slides section' ) );
 690
 691                         for( var i = 0, len = slides.length; i < len; i++ ) {
 692                                 var element = slides[i];
 693
 694                                 // Resets all transforms to use the external styles
 695                                 element.style.WebkitTransform = '';
 696                                 element.style.MozTransform = '';
 697                                 element.style.msTransform = '';
 698                                 element.style.OTransform = '';
 699                                 element.style.transform = '';
 700
 701                                 element.removeEventListener( 'click', onOverviewSlideClicked );
 702                         }
 703
 704                         slide();
 705
 706                 }
 707         }
 708
 709         /**
 710          * Toggles the slide overview mode on and off.
 711          *
 712          * @param {Boolean} override Optional flag which overrides the
 713          * toggle logic and forcibly sets the desired state. True means
 714          * overview is open, false means it's closed.
 715          */
 716         function toggleOverview( override ) {
 717                 if( typeof override === 'boolean' ) {
 718                         override ? activateOverview() : deactivateOverview();
 719                 }
 720                 else {
 721                         isOverviewActive() ? deactivateOverview() : activateOverview();
 722                 }
 723         }
 724
 725         /**
 726          * Checks if the overview is currently active.
 727          *
 728          * @return {Boolean} true if the overview is active,
 729          * false otherwise
 730          */
 731         function isOverviewActive() {
 732                 return dom.wrapper.classList.contains( 'overview' );
 733         }
 734
 735         /**
 736          * Enters the paused mode which fades everything on screen to
 737          * black.
 738          */
 739         function pause() {
 740                 dom.wrapper.classList.add( 'paused' );
 741         }
 742
 743         /**
 744          * Exits from the paused mode.
 745          */
 746         function resume() {
 747                 dom.wrapper.classList.remove( 'paused' );
 748         }
 749
 750         /**
 751          * Toggles the paused mode on and off.
 752          */
 753         function togglePause() {
 754                 if( isPaused() ) {
 755                         resume();
 756                 }
 757                 else {
 758                         pause();
 759                 }
 760         }
 761
 762         /**
 763          * Checks if we are currently in the paused mode.
 764          */
 765         function isPaused() {
 766                 return dom.wrapper.classList.contains( 'paused' );
 767         }
 768
 769         /**
 770          * Updates one dimension of slides by showing the slide
 771          * with the specified index.
 772          *
 773          * @param {String} selector A CSS selector that will fetch
 774          * the group of slides we are working with
 775          * @param {Number} index The index of the slide that should be
 776          * shown
 777          *
 778          * @return {Number} The index of the slide that is now shown,
 779          * might differ from the passed in index if it was out of
 780          * bounds.
 781          */
 782         function updateSlides( selector, index ) {
 783
 784                 // Select all slides and convert the NodeList result to
 785                 // an array
 786                 var slides = Array.prototype.slice.call( document.querySelectorAll( selector ) ),
 787                         slidesLength = slides.length;
 788
 789                 if( slidesLength ) {
 790
 791                         // Should the index loop?
 792                         if( config.loop ) {
 793                                 index %= slidesLength;
 794
 795                                 if( index < 0 ) {
 796                                         index = slidesLength + index;
 797                                 }
 798                         }
 799
 800                         // Enforce max and minimum index bounds
 801                         index = Math.max( Math.min( index, slidesLength - 1 ), 0 );
 802
 803                         for( var i = 0; i < slidesLength; i++ ) {
 804                                 var slide = slides[i];
 805
 806                                 // Optimization; hide all slides that are three or more steps
 807                                 // away from the present slide
 808                                 if( isOverviewActive() === false ) {
 809                                         // The distance loops so that it measures 1 between the first
 810                                         // and last slides
 811                                         var distance = Math.abs( ( index - i ) % ( slidesLength - 3 ) ) || 0;
 812
 813                                         slide.style.display = distance > 3 ? 'none' : 'block';
 814                                 }
 815
 816                                 slides[i].classList.remove( 'past' );
 817                                 slides[i].classList.remove( 'present' );
 818                                 slides[i].classList.remove( 'future' );
 819
 820                                 if( i < index ) {
 821                                         // Any element previous to index is given the 'past' class
 822                                         slides[i].classList.add( 'past' );
 823                                 }
 824                                 else if( i > index ) {
 825                                         // Any element subsequent to index is given the 'future' class
 826                                         slides[i].classList.add( 'future' );
 827                                 }
 828
 829                                 // If this element contains vertical slides
 830                                 if( slide.querySelector( 'section' ) ) {
 831                                         slides[i].classList.add( 'stack' );
 832                                 }
 833                         }
 834
 835                         // Mark the current slide as present
 836                         slides[index].classList.add( 'present' );
 837
 838                         // If this slide has a state associated with it, add it
 839                         // onto the current state of the deck
 840                         var slideState = slides[index].getAttribute( 'data-state' );
 841                         if( slideState ) {
 842                                 state = state.concat( slideState.split( ' ' ) );
 843                         }
 844                 }
 845                 else {
 846                         // Since there are no slides we can't be anywhere beyond the
 847                         // zeroth index
 848                         index = 0;
 849                 }
 850
 851                 return index;
 852
 853         }
 854
 855         /**
 856          * Steps from the current point in the presentation to the
 857          * slide which matches the specified horizontal and vertical
 858          * indices.
 859          *
 860          * @param {int} h Horizontal index of the target slide
 861          * @param {int} v Vertical index of the target slide
 862          */
 863         function slide( h, v ) {
 864                 // Remember where we were at before
 865                 previousSlide = currentSlide;
 866
 867                 // Remember the state before this slide
 868                 var stateBefore = state.concat();
 869
 870                 // Reset the state array
 871                 state.length = 0;
 872
 873                 var indexhBefore = indexh,
 874                         indexvBefore = indexv;
 875
 876                 // Activate and transition to the new slide
 877                 indexh = updateSlides( HORIZONTAL_SLIDES_SELECTOR, h === undefined ? indexh : h );
 878                 indexv = updateSlides( VERTICAL_SLIDES_SELECTOR, v === undefined ? indexv : v );
 879
 880                 // Apply the new state
 881                 stateLoop: for( var i = 0, len = state.length; i < len; i++ ) {
 882                         // Check if this state existed on the previous slide. If it
 883                         // did, we will avoid adding it repeatedly.
 884                         for( var j = 0; j < stateBefore.length; j++ ) {
 885                                 if( stateBefore[j] === state[i] ) {
 886                                         stateBefore.splice( j, 1 );
 887                                         continue stateLoop;
 888                                 }
 889                         }
 890
 891                         document.documentElement.classList.add( state[i] );
 892
 893                         // Dispatch custom event matching the state's name
 894                         dispatchEvent( state[i] );
 895                 }
 896
 897                 // Clean up the remaints of the previous state
 898                 while( stateBefore.length ) {
 899                         document.documentElement.classList.remove( stateBefore.pop() );
 900                 }
 901
 902                 // Update progress if enabled
 903                 if( config.progress && dom.progress ) {
 904                         dom.progressbar.style.width = ( indexh / ( document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ).length - 1 ) ) * window.innerWidth + 'px';
 905                 }
 906
 907                 // If the overview is active, re-activate it to update positions
 908                 if( isOverviewActive() ) {
 909                         activateOverview();
 910                 }
 911
 912                 updateControls();
 913
 914                 clearTimeout( writeURLTimeout );
 915                 writeURLTimeout = setTimeout( writeURL, 1500 );
 916
 917                 // Query all horizontal slides in the deck
 918                 var horizontalSlides = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR );
 919
 920                 // Find the current horizontal slide and any possible vertical slides
 921                 // within it
 922                 var currentHorizontalSlide = horizontalSlides[ indexh ],
 923                         currentVerticalSlides = currentHorizontalSlide.querySelectorAll( 'section' );
 924
 925                 // Store references to the previous and current slides
 926                 currentSlide = currentVerticalSlides[ indexv ] || currentHorizontalSlide;
 927
 928                 // Dispatch an event if the slide changed
 929                 if( indexh !== indexhBefore || indexv !== indexvBefore ) {
 930                         dispatchEvent( 'slidechanged', {
 931                                 'indexh': indexh,
 932                                 'indexv': indexv,
 933                                 'previousSlide': previousSlide,
 934                                 'currentSlide': currentSlide
 935                         } );
 936                 }
 937                 else {
 938                         // Ensure that the previous slide is never the same as the current
 939                         previousSlide = null;
 940                 }
 941
 942                 // Solves an edge case where the previous slide maintains the
 943                 // 'present' class when navigating between adjacent vertical
 944                 // stacks
 945                 if( previousSlide ) {
 946                         previousSlide.classList.remove( 'present' );
 947                 }
 948         }
 949
 950         /**
 951          * Updates the state and link pointers of the controls.
 952          */
 953         function updateControls() {
 954                 if ( !config.controls || !dom.controls ) {
 955                         return;
 956                 }
 957
 958                 var routes = availableRoutes();
 959
 960                 // Remove the 'enabled' class from all directions
 961                 [ dom.controlsLeft, dom.controlsRight, dom.controlsUp, dom.controlsDown ].forEach( function( node ) {
 962                         node.classList.remove( 'enabled' );
 963                 } );
 964
 965                 // Add the 'enabled' class to the available routes
 966                 if( routes.left ) dom.controlsLeft.classList.add( 'enabled' );
 967                 if( routes.right ) dom.controlsRight.classList.add( 'enabled' );
 968                 if( routes.up ) dom.controlsUp.classList.add( 'enabled' );
 969                 if( routes.down ) dom.controlsDown.classList.add( 'enabled' );
 970         }
 971
 972         /**
 973          * Determine what available routes there are for navigation.
 974          *
 975          * @return {Object} containing four booleans: left/right/up/down
 976          */
 977         function availableRoutes() {
 978                 var horizontalSlides = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ),
 979                         verticalSlides = document.querySelectorAll( VERTICAL_SLIDES_SELECTOR );
 980
 981                 return {
 982                         left: indexh > 0,
 983                         right: indexh < horizontalSlides.length - 1,
 984                         up: indexv > 0,
 985                         down: indexv < verticalSlides.length - 1
 986                 };
 987         }
 988
 989         /**
 990          * Reads the current URL (hash) and navigates accordingly.
 991          */
 992         function readURL() {
 993                 var hash = window.location.hash;
 994
 995                 // Attempt to parse the hash as either an index or name
 996                 var bits = hash.slice( 2 ).split( '/' ),
 997                         name = hash.replace( /#|\//gi, '' );
 998
 999                 // If the first bit is invalid and there is a name we can
1000                 // assume that this is a named link
1001                 if( isNaN( parseInt( bits[0], 10 ) ) && name.length ) {
1002                         // Find the slide with the specified name
1003                         var slide = document.querySelector( '#' + name );
1004
1005                         if( slide ) {
1006                                 // Find the position of the named slide and navigate to it
1007                                 var indices = Reveal.getIndices( slide );
1008                                 navigateTo( indices.h, indices.v );
1009                         }
1010                         // If the slide doesn't exist, navigate to the current slide
1011                         else {
1012                                 navigateTo( indexh, indexv );
1013                         }
1014                 }
1015                 else {
1016                         // Read the index components of the hash
1017                         var h = parseInt( bits[0], 10 ) || 0,
1018                                 v = parseInt( bits[1], 10 ) || 0;
1019
1020                         navigateTo( h, v );
1021                 }
1022         }
1023
1024         /**
1025          * Updates the page URL (hash) to reflect the current
1026          * state.
1027          */
1028         function writeURL() {
1029                 if( config.history ) {
1030                         var url = '/';
1031
1032                         // Only include the minimum possible number of components in
1033                         // the URL
1034                         if( indexh > 0 || indexv > 0 ) url += indexh;
1035                         if( indexv > 0 ) url += '/' + indexv;
1036
1037                         window.location.hash = url;
1038                 }
1039         }
1040
1041         /**
1042          * Navigate to the next slide fragment.
1043          *
1044          * @return {Boolean} true if there was a next fragment,
1045          * false otherwise
1046          */
1047         function nextFragment() {
1048                 // Vertical slides:
1049                 if( document.querySelector( VERTICAL_SLIDES_SELECTOR + '.present' ) ) {
1050                         var verticalFragments = document.querySelectorAll( VERTICAL_SLIDES_SELECTOR + '.present .fragment:not(.visible)' );
1051                         if( verticalFragments.length ) {
1052                                 verticalFragments[0].classList.add( 'visible' );
1053
1054                                 // Notify subscribers of the change
1055                                 dispatchEvent( 'fragmentshown', { fragment: verticalFragments[0] } );
1056                                 return true;
1057                         }
1058                 }
1059                 // Horizontal slides:
1060                 else {
1061                         var horizontalFragments = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR + '.present .fragment:not(.visible)' );
1062                         if( horizontalFragments.length ) {
1063                                 horizontalFragments[0].classList.add( 'visible' );
1064
1065                                 // Notify subscribers of the change
1066                                 dispatchEvent( 'fragmentshown', { fragment: horizontalFragments[0] } );
1067                                 return true;
1068                         }
1069                 }
1070
1071                 return false;
1072         }
1073
1074         /**
1075          * Navigate to the previous slide fragment.
1076          *
1077          * @return {Boolean} true if there was a previous fragment,
1078          * false otherwise
1079          */
1080         function previousFragment() {
1081                 // Vertical slides:
1082                 if( document.querySelector( VERTICAL_SLIDES_SELECTOR + '.present' ) ) {
1083                         var verticalFragments = document.querySelectorAll( VERTICAL_SLIDES_SELECTOR + '.present .fragment.visible' );
1084                         if( verticalFragments.length ) {
1085                                 verticalFragments[ verticalFragments.length - 1 ].classList.remove( 'visible' );
1086
1087                                 // Notify subscribers of the change
1088                                 dispatchEvent( 'fragmenthidden', { fragment: verticalFragments[ verticalFragments.length - 1 ] } );
1089                                 return true;
1090                         }
1091                 }
1092                 // Horizontal slides:
1093                 else {
1094                         var horizontalFragments = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR + '.present .fragment.visible' );
1095                         if( horizontalFragments.length ) {
1096                                 horizontalFragments[ horizontalFragments.length - 1 ].classList.remove( 'visible' );
1097
1098                                 // Notify subscribers of the change
1099                                 dispatchEvent( 'fragmenthidden', { fragment: horizontalFragments[ horizontalFragments.length - 1 ] } );
1100                                 return true;
1101                         }
1102                 }
1103
1104                 return false;
1105         }
1106
1107         /**
1108          * Cues a new automated slide if enabled in the config.
1109          */
1110         function cueAutoSlide() {
1111                 clearTimeout( autoSlideTimeout );
1112
1113                 // Cue the next auto-slide if enabled
1114                 if( config.autoSlide ) {
1115                         autoSlideTimeout = setTimeout( navigateNext, config.autoSlide );
1116                 }
1117         }
1118
1119         /**
1120          * Triggers a navigation to the specified indices.
1121          *
1122          * @param {Number} h The horizontal index of the slide to show
1123          * @param {Number} v The vertical index of the slide to show
1124          */
1125         function navigateTo( h, v ) {
1126                 slide( h, v );
1127         }
1128
1129         function navigateLeft() {
1130                 // Prioritize hiding fragments
1131                 if( isOverviewActive() || previousFragment() === false ) {
1132                         slide( indexh - 1, 0 );
1133                 }
1134         }
1135
1136         function navigateRight() {
1137                 // Prioritize revealing fragments
1138                 if( isOverviewActive() || nextFragment() === false ) {
1139                         slide( indexh + 1, 0 );
1140                 }
1141         }
1142
1143         function navigateUp() {
1144                 // Prioritize hiding fragments
1145                 if( isOverviewActive() || previousFragment() === false ) {
1146                         slide( indexh, indexv - 1 );
1147                 }
1148         }
1149
1150         function navigateDown() {
1151                 // Prioritize revealing fragments
1152                 if( isOverviewActive() || nextFragment() === false ) {
1153                         slide( indexh, indexv + 1 );
1154                 }
1155         }
1156
1157         /**
1158          * Navigates backwards, prioritized in the following order:
1159          * 1) Previous fragment
1160          * 2) Previous vertical slide
1161          * 3) Previous horizontal slide
1162          */
1163         function navigatePrev() {
1164                 // Prioritize revealing fragments
1165                 if( previousFragment() === false ) {
1166                         if( availableRoutes().up ) {
1167                                 navigateUp();
1168                         }
1169                         else {
1170                                 // Fetch the previous horizontal slide, if there is one
1171                                 var previousSlide = document.querySelector( '.reveal .slides>section.past:nth-child(' + indexh + ')' );
1172
1173                                 if( previousSlide ) {
1174                                         indexv = ( previousSlide.querySelectorAll('section').length + 1 ) || 0;
1175                                         indexh --;
1176                                         slide();
1177                                 }
1178                         }
1179                 }
1180         }
1181
1182         /**
1183          * Same as #navigatePrev() but navigates forwards.
1184          */
1185         function navigateNext() {
1186                 // Prioritize revealing fragments
1187                 if( nextFragment() === false ) {
1188                         availableRoutes().down ? navigateDown() : navigateRight();
1189                 }
1190
1191                 // If auto-sliding is enabled we need to cue up
1192                 // another timeout
1193                 cueAutoSlide();
1194         }
1195
1196         // Expose some methods publicly
1197         return {
1198                 initialize: initialize,
1199                 navigateTo: navigateTo,
1200                 navigateLeft: navigateLeft,
1201                 navigateRight: navigateRight,
1202                 navigateUp: navigateUp,
1203                 navigateDown: navigateDown,
1204                 navigatePrev: navigatePrev,
1205                 navigateNext: navigateNext,
1206                 toggleOverview: toggleOverview,
1207
1208                 // Adds or removes all internal event listeners (such as keyboard)
1209                 addEventListeners: addEventListeners,
1210                 removeEventListeners: removeEventListeners,
1211
1212                 // Returns the indices of the current, or specified, slide
1213                 getIndices: function( slide ) {
1214                         // By default, return the current indices
1215                         var h = indexh,
1216                                 v = indexv;
1217
1218                         // If a slide is specified, return the indices of that slide
1219                         if( slide ) {
1220                                 var isVertical = !!slide.parentNode.nodeName.match( /section/gi );
1221                                 var slideh = isVertical ? slide.parentNode : slide;
1222
1223                                 // Select all horizontal slides
1224                                 var horizontalSlides = Array.prototype.slice.call( document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) );
1225
1226                                 // Now that we know which the horizontal slide is, get its index
1227                                 h = Math.max( horizontalSlides.indexOf( slideh ), 0 );
1228
1229                                 // If this is a vertical slide, grab the vertical index
1230                                 if( isVertical ) {
1231                                         v = Math.max( Array.prototype.slice.call( slide.parentNode.children ).indexOf( slide ), 0 );
1232                                 }
1233                         }
1234
1235                         return { h: h, v: v };
1236                 },
1237
1238                 // Returns the previous slide element, may be null
1239                 getPreviousSlide: function() {
1240                         return previousSlide;
1241                 },
1242
1243                 // Returns the current slide element
1244                 getCurrentSlide: function() {
1245                         return currentSlide;
1246                 },
1247
1248                 // Helper method, retrieves query string as a key/value hash
1249                 getQueryHash: function() {
1250                         var query = {};
1251
1252                         location.search.replace( /[A-Z0-9]+?=(\w*)/gi, function(a) {
1253                                 query[ a.split( '=' ).shift() ] = a.split( '=' ).pop();
1254                         } );
1255
1256                         return query;
1257                 },
1258
1259                 // Forward event binding to the reveal DOM element
1260                 addEventListener: function( type, listener, useCapture ) {
1261                         if( 'addEventListener' in window ) {
1262                                 ( dom.wrapper || document.querySelector( '.reveal' ) ).addEventListener( type, listener, useCapture );
1263                         }
1264                 },
1265                 removeEventListener: function( type, listener, useCapture ) {
1266                         if( 'addEventListener' in window ) {
1267                                 ( dom.wrapper || document.querySelector( '.reveal' ) ).removeEventListener( type, listener, useCapture );
1268                         }
1269                 }
1270         };
1271
1272 })();