js/reveal.js

   1 /*!
   2  * reveal.js
   3  * http://lab.hakim.se/reveal-js
   4  * MIT licensed
   5  *
   6  * Copyright (C) 2013 Hakim El Hattab, http://hakim.se
   7  */
   8 var Reveal = (function(){
   9
  10         'use strict';
  11
  12         var SLIDES_SELECTOR = '.reveal .slides section',
  13                 HORIZONTAL_SLIDES_SELECTOR = '.reveal .slides>section',
  14                 VERTICAL_SLIDES_SELECTOR = '.reveal .slides>section.present>section',
  15                 HOME_SLIDE_SELECTOR = '.reveal .slides>section:first-child',
  16
  17                 // Configurations defaults, can be overridden at initialization time
  18                 config = {
  19
  20                         // The "normal" size of the presentation, aspect ratio will be preserved
  21                         // when the presentation is scaled to fit different resolutions
  22                         width: 960,
  23                         height: 700,
  24
  25                         // Factor of the display size that should remain empty around the content
  26                         margin: 0.1,
  27
  28                         // Bounds for smallest/largest possible scale to apply to content
  29                         minScale: 0.2,
  30                         maxScale: 1.0,
  31
  32                         // Display controls in the bottom right corner
  33                         controls: true,
  34
  35                         // Display a presentation progress bar
  36                         progress: true,
  37
  38                         // Push each slide change to the browser history
  39                         history: false,
  40
  41                         // Enable keyboard shortcuts for navigation
  42                         keyboard: true,
  43
  44                         // Enable the slide overview mode
  45                         overview: true,
  46
  47                         // Vertical centering of slides
  48                         center: true,
  49
  50                         // Enables touch navigation on devices with touch input
  51                         touch: true,
  52
  53                         // Loop the presentation
  54                         loop: false,
  55
  56                         // Change the presentation direction to be RTL
  57                         rtl: false,
  58
  59                         // Number of milliseconds between automatically proceeding to the
  60                         // next slide, disabled when set to 0, this value can be overwritten
  61                         // by using a data-autoslide attribute on your slides
  62                         autoSlide: 0,
  63
  64                         // Enable slide navigation via mouse wheel
  65                         mouseWheel: false,
  66
  67                         // Apply a 3D roll to links on hover
  68                         rollingLinks: true,
  69
  70                         // Theme (see /css/theme)
  71                         theme: null,
  72
  73                         // Transition style
  74                         transition: 'default', // default/cube/page/concave/zoom/linear/fade/none
  75
  76                         // Script dependencies to load
  77                         dependencies: []
  78                 },
  79
  80                 // Stores if the next slide should be shown automatically
  81                 // after n milliseconds
  82                 autoSlide = config.autoSlide,
  83
  84                 // The horizontal and verical index of the currently active slide
  85                 indexh = 0,
  86                 indexv = 0,
  87
  88                 // The previous and current slide HTML elements
  89                 previousSlide,
  90                 currentSlide,
  91
  92                 // Slides may hold a data-state attribute which we pick up and apply
  93                 // as a class to the body. This list contains the combined state of
  94                 // all current slides.
  95                 state = [],
  96
  97                 // The current scale of the presentation (see width/height config)
  98                 scale = 1,
  99
 100                 // Cached references to DOM elements
 101                 dom = {},
 102
 103                 // Detect support for CSS 3D transforms
 104                 supports3DTransforms =  'WebkitPerspective' in document.body.style ||
 105                                                                 'MozPerspective' in document.body.style ||
 106                                                                 'msPerspective' in document.body.style ||
 107                                                                 'OPerspective' in document.body.style ||
 108                                                                 'perspective' in document.body.style,
 109
 110                 // Detect support for CSS 2D transforms
 111                 supports2DTransforms =  'WebkitTransform' in document.body.style ||
 112                                                                 'MozTransform' in document.body.style ||
 113                                                                 'msTransform' in document.body.style ||
 114                                                                 'OTransform' in document.body.style ||
 115                                                                 'transform' in document.body.style,
 116
 117                 // Throttles mouse wheel navigation
 118                 mouseWheelTimeout = 0,
 119
 120                 // An interval used to automatically move on to the next slide
 121                 autoSlideTimeout = 0,
 122
 123                 // Delays updates to the URL due to a Chrome thumbnailer bug
 124                 writeURLTimeout = 0,
 125
 126                 // A delay used to activate the overview mode
 127                 activateOverviewTimeout = 0,
 128
 129                 // A delay used to deactivate the overview mode
 130                 deactivateOverviewTimeout = 0,
 131
 132                 // Holds information about the currently ongoing touch input
 133                 touch = {
 134                         startX: 0,
 135                         startY: 0,
 136                         startSpan: 0,
 137                         startCount: 0,
 138                         handled: false,
 139                         threshold: 80
 140                 };
 141
 142         /**
 143          * Starts up the presentation if the client is capable.
 144          */
 145         function initialize( options ) {
 146
 147                 if( !supports2DTransforms && !supports3DTransforms ) {
 148                         document.body.setAttribute( 'class', 'no-transforms' );
 149
 150                         // If the browser doesn't support core features we won't be
 151                         // using JavaScript to control the presentation
 152                         return;
 153                 }
 154
 155                 // Force a layout when the whole page, incl fonts, has loaded
 156                 window.addEventListener( 'load', layout, false );
 157
 158                 // Copy options over to our config object
 159                 extend( config, options );
 160
 161                 // Hide the address bar in mobile browsers
 162                 hideAddressBar();
 163
 164                 // Loads the dependencies and continues to #start() once done
 165                 load();
 166
 167         }
 168
 169         /**
 170          * Finds and stores references to DOM elements which are
 171          * required by the presentation. If a required element is
 172          * not found, it is created.
 173          */
 174         function setupDOM() {
 175
 176                 // Cache references to key DOM elements
 177                 dom.theme = document.querySelector( '#theme' );
 178                 dom.wrapper = document.querySelector( '.reveal' );
 179                 dom.slides = document.querySelector( '.reveal .slides' );
 180
 181                 // Progress bar
 182                 if( !dom.wrapper.querySelector( '.progress' ) && config.progress ) {
 183                         var progressElement = document.createElement( 'div' );
 184                         progressElement.classList.add( 'progress' );
 185                         progressElement.innerHTML = '<span></span>';
 186                         dom.wrapper.appendChild( progressElement );
 187                 }
 188
 189                 // Arrow controls
 190                 if( !dom.wrapper.querySelector( '.controls' ) && config.controls ) {
 191                         var controlsElement = document.createElement( 'aside' );
 192                         controlsElement.classList.add( 'controls' );
 193                         controlsElement.innerHTML = '<div class="navigate-left"></div>' +
 194                                                                                 '<div class="navigate-right"></div>' +
 195                                                                                 '<div class="navigate-up"></div>' +
 196                                                                                 '<div class="navigate-down"></div>';
 197                         dom.wrapper.appendChild( controlsElement );
 198                 }
 199
 200                 // Presentation background element
 201                 if( !dom.wrapper.querySelector( '.state-background' ) ) {
 202                         var backgroundElement = document.createElement( 'div' );
 203                         backgroundElement.classList.add( 'state-background' );
 204                         dom.wrapper.appendChild( backgroundElement );
 205                 }
 206
 207                 // Overlay graphic which is displayed during the paused mode
 208                 if( !dom.wrapper.querySelector( '.pause-overlay' ) ) {
 209                         var pausedElement = document.createElement( 'div' );
 210                         pausedElement.classList.add( 'pause-overlay' );
 211                         dom.wrapper.appendChild( pausedElement );
 212                 }
 213
 214                 // Cache references to elements
 215                 dom.progress = document.querySelector( '.reveal .progress' );
 216                 dom.progressbar = document.querySelector( '.reveal .progress span' );
 217
 218                 if ( config.controls ) {
 219                         dom.controls = document.querySelector( '.reveal .controls' );
 220
 221                         // There can be multiple instances of controls throughout the page
 222                         dom.controlsLeft = toArray( document.querySelectorAll( '.navigate-left' ) );
 223                         dom.controlsRight = toArray( document.querySelectorAll( '.navigate-right' ) );
 224                         dom.controlsUp = toArray( document.querySelectorAll( '.navigate-up' ) );
 225                         dom.controlsDown = toArray( document.querySelectorAll( '.navigate-down' ) );
 226                         dom.controlsPrev = toArray( document.querySelectorAll( '.navigate-prev' ) );
 227                         dom.controlsNext = toArray( document.querySelectorAll( '.navigate-next' ) );
 228                 }
 229
 230         }
 231
 232         /**
 233          * Hides the address bar if we're on a mobile device.
 234          */
 235         function hideAddressBar() {
 236
 237                 if( /iphone|ipod|android/gi.test( navigator.userAgent ) && !/crios/gi.test( navigator.userAgent ) ) {
 238                         // Events that should trigger the address bar to hide
 239                         window.addEventListener( 'load', removeAddressBar, false );
 240                         window.addEventListener( 'orientationchange', removeAddressBar, false );
 241                 }
 242
 243         }
 244
 245         /**
 246          * Loads the dependencies of reveal.js. Dependencies are
 247          * defined via the configuration option 'dependencies'
 248          * and will be loaded prior to starting/binding reveal.js.
 249          * Some dependencies may have an 'async' flag, if so they
 250          * will load after reveal.js has been started up.
 251          */
 252         function load() {
 253
 254                 var scripts = [],
 255                         scriptsAsync = [];
 256
 257                 for( var i = 0, len = config.dependencies.length; i < len; i++ ) {
 258                         var s = config.dependencies[i];
 259
 260                         // Load if there's no condition or the condition is truthy
 261                         if( !s.condition || s.condition() ) {
 262                                 if( s.async ) {
 263                                         scriptsAsync.push( s.src );
 264                                 }
 265                                 else {
 266                                         scripts.push( s.src );
 267                                 }
 268
 269                                 // Extension may contain callback functions
 270                                 if( typeof s.callback === 'function' ) {
 271                                         head.ready( s.src.match( /([\w\d_\-]*)\.?js$|[^\\\/]*$/i )[0], s.callback );
 272                                 }
 273                         }
 274                 }
 275
 276                 // Called once synchronous scritps finish loading
 277                 function proceed() {
 278                         if( scriptsAsync.length ) {
 279                                 // Load asynchronous scripts
 280                                 head.js.apply( null, scriptsAsync );
 281                         }
 282
 283                         start();
 284                 }
 285
 286                 if( scripts.length ) {
 287                         head.ready( proceed );
 288
 289                         // Load synchronous scripts
 290                         head.js.apply( null, scripts );
 291                 }
 292                 else {
 293                         proceed();
 294                 }
 295
 296         }
 297
 298         /**
 299          * Starts up reveal.js by binding input events and navigating
 300          * to the current URL deeplink if there is one.
 301          */
 302         function start() {
 303
 304                 // Make sure we've got all the DOM elements we need
 305                 setupDOM();
 306
 307                 // Subscribe to input
 308                 addEventListeners();
 309
 310                 // Updates the presentation to match the current configuration values
 311                 configure();
 312
 313                 // Force an initial layout, will thereafter be invoked as the window
 314                 // is resized
 315                 layout();
 316
 317                 // Read the initial hash
 318                 readURL();
 319
 320                 // Start auto-sliding if it's enabled
 321                 cueAutoSlide();
 322
 323                 // Notify listeners that the presentation is ready but use a 1ms
 324                 // timeout to ensure it's not fired synchronously after #initialize()
 325                 setTimeout( function() {
 326                         dispatchEvent( 'ready', {
 327                                 'indexh': indexh,
 328                                 'indexv': indexv,
 329                                 'currentSlide': currentSlide
 330                         } );
 331                 }, 1 );
 332
 333         }
 334
 335         /**
 336          * Applies the configuration settings from the config object.
 337          */
 338         function configure() {
 339
 340                 if( supports3DTransforms === false ) {
 341                         config.transition = 'linear';
 342                 }
 343
 344                 if( config.controls && dom.controls ) {
 345                         dom.controls.style.display = 'block';
 346                 }
 347
 348                 if( config.progress && dom.progress ) {
 349                         dom.progress.style.display = 'block';
 350                 }
 351
 352                 if( config.transition !== 'default' ) {
 353                         dom.wrapper.classList.add( config.transition );
 354                 }
 355
 356                 if( config.rtl ) {
 357                         dom.wrapper.classList.add( 'rtl' );
 358                 }
 359
 360                 if( config.center ) {
 361                         dom.wrapper.classList.add( 'center' );
 362                 }
 363
 364                 if( config.mouseWheel ) {
 365                         document.addEventListener( 'DOMMouseScroll', onDocumentMouseScroll, false ); // FF
 366                         document.addEventListener( 'mousewheel', onDocumentMouseScroll, false );
 367                 }
 368
 369                 // 3D links
 370                 if( config.rollingLinks ) {
 371                         linkify();
 372                 }
 373
 374                 // Load the theme in the config, if it's not already loaded
 375                 if( config.theme && dom.theme ) {
 376                         var themeURL = dom.theme.getAttribute( 'href' );
 377                         var themeFinder = /[^\/]*?(?=\.css)/;
 378                         var themeName = themeURL.match(themeFinder)[0];
 379
 380                         if(  config.theme !== themeName ) {
 381                                 themeURL = themeURL.replace(themeFinder, config.theme);
 382                                 dom.theme.setAttribute( 'href', themeURL );
 383                         }
 384                 }
 385
 386         }
 387
 388         /**
 389          * Binds all event listeners.
 390          */
 391         function addEventListeners() {
 392
 393                 window.addEventListener( 'hashchange', onWindowHashChange, false );
 394                 window.addEventListener( 'resize', onWindowResize, false );
 395
 396                 if( config.touch ) {
 397                         document.addEventListener( 'touchstart', onDocumentTouchStart, false );
 398                         document.addEventListener( 'touchmove', onDocumentTouchMove, false );
 399                         document.addEventListener( 'touchend', onDocumentTouchEnd, false );
 400                 }
 401
 402                 if( config.keyboard ) {
 403                         document.addEventListener( 'keydown', onDocumentKeyDown, false );
 404                 }
 405
 406                 if ( config.progress && dom.progress ) {
 407                         dom.progress.addEventListener( 'click', onProgressClicked, false );
 408                 }
 409
 410                 if ( config.controls && dom.controls ) {
 411                         var actionEvent = 'ontouchstart' in window ? 'touchstart' : 'click';
 412                         dom.controlsLeft.forEach( function( el ) { el.addEventListener( actionEvent, onNavigateLeftClicked, false ); } );
 413                         dom.controlsRight.forEach( function( el ) { el.addEventListener( actionEvent, onNavigateRightClicked, false ); } );
 414                         dom.controlsUp.forEach( function( el ) { el.addEventListener( actionEvent, onNavigateUpClicked, false ); } );
 415                         dom.controlsDown.forEach( function( el ) { el.addEventListener( actionEvent, onNavigateDownClicked, false ); } );
 416                         dom.controlsPrev.forEach( function( el ) { el.addEventListener( actionEvent, onNavigatePrevClicked, false ); } );
 417                         dom.controlsNext.forEach( function( el ) { el.addEventListener( actionEvent, onNavigateNextClicked, false ); } );
 418                 }
 419
 420         }
 421
 422         /**
 423          * Unbinds all event listeners.
 424          */
 425         function removeEventListeners() {
 426
 427                 document.removeEventListener( 'keydown', onDocumentKeyDown, false );
 428                 window.removeEventListener( 'hashchange', onWindowHashChange, false );
 429                 window.removeEventListener( 'resize', onWindowResize, false );
 430
 431                 if( config.touch ) {
 432                         document.removeEventListener( 'touchstart', onDocumentTouchStart, false );
 433                         document.removeEventListener( 'touchmove', onDocumentTouchMove, false );
 434                         document.removeEventListener( 'touchend', onDocumentTouchEnd, false );
 435                 }
 436
 437                 if ( config.progress && dom.progress ) {
 438                         dom.progress.removeEventListener( 'click', onProgressClicked, false );
 439                 }
 440
 441                 if ( config.controls && dom.controls ) {
 442                         var actionEvent = 'ontouchstart' in window && window.ontouchstart != null ? 'touchstart' : 'click';
 443                         dom.controlsLeft.forEach( function( el ) { el.removeEventListener( actionEvent, onNavigateLeftClicked, false ); } );
 444                         dom.controlsRight.forEach( function( el ) { el.removeEventListener( actionEvent, onNavigateRightClicked, false ); } );
 445                         dom.controlsUp.forEach( function( el ) { el.removeEventListener( actionEvent, onNavigateUpClicked, false ); } );
 446                         dom.controlsDown.forEach( function( el ) { el.removeEventListener( actionEvent, onNavigateDownClicked, false ); } );
 447                         dom.controlsPrev.forEach( function( el ) { el.removeEventListener( actionEvent, onNavigatePrevClicked, false ); } );
 448                         dom.controlsNext.forEach( function( el ) { el.removeEventListener( actionEvent, onNavigateNextClicked, false ); } );
 449                 }
 450
 451         }
 452
 453         /**
 454          * Extend object a with the properties of object b.
 455          * If there's a conflict, object b takes precedence.
 456          */
 457         function extend( a, b ) {
 458
 459                 for( var i in b ) {
 460                         a[ i ] = b[ i ];
 461                 }
 462
 463         }
 464
 465         /**
 466          * Converts the target object to an array.
 467          */
 468         function toArray( o ) {
 469
 470                 return Array.prototype.slice.call( o );
 471
 472         }
 473
 474         /**
 475          * Measures the distance in pixels between point a
 476          * and point b.
 477          *
 478          * @param {Object} a point with x/y properties
 479          * @param {Object} b point with x/y properties
 480          */
 481         function distanceBetween( a, b ) {
 482
 483                 var dx = a.x - b.x,
 484                         dy = a.y - b.y;
 485
 486                 return Math.sqrt( dx*dx + dy*dy );
 487
 488         }
 489
 490         /**
 491          * Causes the address bar to hide on mobile devices,
 492          * more vertical space ftw.
 493          */
 494         function removeAddressBar() {
 495
 496                 if( window.orientation === 0 ) {
 497                         document.documentElement.style.overflow = 'scroll';
 498                         document.body.style.height = '120%';
 499                 }
 500                 else {
 501                         document.documentElement.style.overflow = '';
 502                         document.body.style.height = '100%';
 503                 }
 504
 505                 setTimeout( function() {
 506                         window.scrollTo( 0, 1 );
 507                 }, 10 );
 508
 509         }
 510
 511         /**
 512          * Dispatches an event of the specified type from the
 513          * reveal DOM element.
 514          */
 515         function dispatchEvent( type, properties ) {
 516
 517                 var event = document.createEvent( "HTMLEvents", 1, 2 );
 518                 event.initEvent( type, true, true );
 519                 extend( event, properties );
 520                 dom.wrapper.dispatchEvent( event );
 521
 522         }
 523
 524         /**
 525          * Wrap all links in 3D goodness.
 526          */
 527         function linkify() {
 528
 529                 if( supports3DTransforms && !( 'msPerspective' in document.body.style ) ) {
 530                         var nodes = document.querySelectorAll( SLIDES_SELECTOR + ' a:not(.image)' );
 531
 532                         for( var i = 0, len = nodes.length; i < len; i++ ) {
 533                                 var node = nodes[i];
 534
 535                                 if( node.textContent && !node.querySelector( '*' ) && ( !node.className || !node.classList.contains( node, 'roll' ) ) ) {
 536                                         var span = document.createElement('span');
 537                                         span.setAttribute('data-title', node.text);
 538                                         span.innerHTML = node.innerHTML;
 539
 540                                         node.classList.add( 'roll' );
 541                                         node.innerHTML = '';
 542                                         node.appendChild(span);
 543                                 }
 544                         }
 545                 }
 546
 547         }
 548
 549         /**
 550          * Applies JavaScript-controlled layout rules to the
 551          * presentation.
 552          */
 553         function layout() {
 554
 555                 if( dom.wrapper ) {
 556
 557                         // Available space to scale within
 558                         var availableWidth = dom.wrapper.offsetWidth,
 559                                 availableHeight = dom.wrapper.offsetHeight;
 560
 561                         // Reduce availabe space by margin
 562                         availableWidth -= ( availableHeight * config.margin );
 563                         availableHeight -= ( availableHeight * config.margin );
 564
 565                         // Dimensions of the content
 566                         var slideWidth = config.width,
 567                                 slideHeight = config.height;
 568
 569                         // Slide width may be a percentage of available width
 570                         if( typeof slideWidth === 'string' && /%$/.test( slideWidth ) ) {
 571                                 slideWidth = parseInt( slideWidth, 10 ) / 100 * availableWidth;
 572                         }
 573
 574                         // Slide height may be a percentage of available height
 575                         if( typeof slideHeight === 'string' && /%$/.test( slideHeight ) ) {
 576                                 slideHeight = parseInt( slideHeight, 10 ) / 100 * availableHeight;
 577                         }
 578
 579                         dom.slides.style.width = slideWidth + 'px';
 580                         dom.slides.style.height = slideHeight + 'px';
 581
 582                         // Determine scale of content to fit within available space
 583                         scale = Math.min( availableWidth / slideWidth, availableHeight / slideHeight );
 584
 585                         // Respect max/min scale settings
 586                         scale = Math.max( scale, config.minScale );
 587                         scale = Math.min( scale, config.maxScale );
 588
 589                         // Prefer applying scale via zoom since Chrome blurs scaled content
 590                         // with nested transforms
 591                         if( typeof dom.slides.style.zoom !== 'undefined' && !navigator.userAgent.match( /(iphone|ipod|ipad|android)/gi ) ) {
 592                                 dom.slides.style.zoom = scale;
 593                         }
 594                         // Apply scale transform as a fallback
 595                         else {
 596                                 var transform = 'translate(-50%, -50%) scale('+ scale +') translate(50%, 50%)';
 597
 598                                 dom.slides.style.WebkitTransform = transform;
 599                                 dom.slides.style.MozTransform = transform;
 600                                 dom.slides.style.msTransform = transform;
 601                                 dom.slides.style.OTransform = transform;
 602                                 dom.slides.style.transform = transform;
 603                         }
 604
 605                         if( config.center ) {
 606
 607                                 // Select all slides, vertical and horizontal
 608                                 var slides = toArray( document.querySelectorAll( SLIDES_SELECTOR ) );
 609
 610                                 // Determine the minimum top offset for slides
 611                                 var minTop = -slideHeight / 2;
 612
 613                                 for( var i = 0, len = slides.length; i < len; i++ ) {
 614                                         var slide = slides[ i ];
 615
 616                                         // Don't bother updating invisible slides
 617                                         if( slide.style.display === 'none' ) {
 618                                                 continue;
 619                                         }
 620
 621                                         // Vertical stacks are not centered since their section
 622                                         // children will be
 623                                         if( slide.classList.contains( 'stack' ) ) {
 624                                                 slide.style.top = 0;
 625                                         }
 626                                         else {
 627                                                 slide.style.top = Math.max( - ( slide.offsetHeight / 2 ) - 20, minTop ) + 'px';
 628                                         }
 629                                 }
 630
 631                         }
 632
 633                 }
 634
 635         }
 636
 637         /**
 638          * Stores the vertical index of a stack so that the same
 639          * vertical slide can be selected when navigating to and
 640          * from the stack.
 641          *
 642          * @param {HTMLElement} stack The vertical stack element
 643          * @param {int} v Index to memorize
 644          */
 645         function setPreviousVerticalIndex( stack, v ) {
 646
 647                 if( stack ) {
 648                         stack.setAttribute( 'data-previous-indexv', v || 0 );
 649                 }
 650
 651         }
 652
 653         /**
 654          * Retrieves the vertical index which was stored using
 655          * #setPreviousVerticalIndex() or 0 if no previous index
 656          * exists.
 657          *
 658          * @param {HTMLElement} stack The vertical stack element
 659          */
 660         function getPreviousVerticalIndex( stack ) {
 661
 662                 if( stack && stack.classList.contains( 'stack' ) ) {
 663                         return parseInt( stack.getAttribute( 'data-previous-indexv' ) || 0, 10 );
 664                 }
 665
 666                 return 0;
 667
 668         }
 669
 670         /**
 671          * Displays the overview of slides (quick nav) by
 672          * scaling down and arranging all slide elements.
 673          *
 674          * Experimental feature, might be dropped if perf
 675          * can't be improved.
 676          */
 677         function activateOverview() {
 678
 679                 // Only proceed if enabled in config
 680                 if( config.overview ) {
 681
 682                         // Don't auto-slide while in overview mode
 683                         cancelAutoSlide();
 684
 685                         var wasActive = dom.wrapper.classList.contains( 'overview' );
 686
 687                         dom.wrapper.classList.add( 'overview' );
 688                         dom.wrapper.classList.remove( 'exit-overview' );
 689
 690                         clearTimeout( activateOverviewTimeout );
 691                         clearTimeout( deactivateOverviewTimeout );
 692
 693                         // Not the pretties solution, but need to let the overview
 694                         // class apply first so that slides are measured accurately
 695                         // before we can position them
 696                         activateOverviewTimeout = setTimeout( function(){
 697
 698                                 var horizontalSlides = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR );
 699
 700                                 for( var i = 0, len1 = horizontalSlides.length; i < len1; i++ ) {
 701                                         var hslide = horizontalSlides[i],
 702                                                 htransform = 'translateZ(-2500px) translate(' + ( ( i - indexh ) * 105 ) + '%, 0%)';
 703
 704                                         hslide.setAttribute( 'data-index-h', i );
 705                                         hslide.style.display = 'block';
 706                                         hslide.style.WebkitTransform = htransform;
 707                                         hslide.style.MozTransform = htransform;
 708                                         hslide.style.msTransform = htransform;
 709                                         hslide.style.OTransform = htransform;
 710                                         hslide.style.transform = htransform;
 711
 712                                         if( hslide.classList.contains( 'stack' ) ) {
 713
 714                                                 var verticalSlides = hslide.querySelectorAll( 'section' );
 715
 716                                                 for( var j = 0, len2 = verticalSlides.length; j < len2; j++ ) {
 717                                                         var verticalIndex = i === indexh ? indexv : getPreviousVerticalIndex( hslide );
 718
 719                                                         var vslide = verticalSlides[j],
 720                                                                 vtransform = 'translate(0%, ' + ( ( j - verticalIndex ) * 105 ) + '%)';
 721
 722                                                         vslide.setAttribute( 'data-index-h', i );
 723                                                         vslide.setAttribute( 'data-index-v', j );
 724                                                         vslide.style.display = 'block';
 725                                                         vslide.style.WebkitTransform = vtransform;
 726                                                         vslide.style.MozTransform = vtransform;
 727                                                         vslide.style.msTransform = vtransform;
 728                                                         vslide.style.OTransform = vtransform;
 729                                                         vslide.style.transform = vtransform;
 730
 731                                                         // Navigate to this slide on click
 732                                                         vslide.addEventListener( 'click', onOverviewSlideClicked, true );
 733                                                 }
 734
 735                                         }
 736                                         else {
 737
 738                                                 // Navigate to this slide on click
 739                                                 hslide.addEventListener( 'click', onOverviewSlideClicked, true );
 740
 741                                         }
 742                                 }
 743
 744                                 layout();
 745
 746                                 if( !wasActive ) {
 747                                         // Notify observers of the overview showing
 748                                         dispatchEvent( 'overviewshown', {
 749                                                 'indexh': indexh,
 750                                                 'indexv': indexv,
 751                                                 'currentSlide': currentSlide
 752                                         } );
 753                                 }
 754
 755                         }, 10 );
 756
 757                 }
 758
 759         }
 760
 761         /**
 762          * Exits the slide overview and enters the currently
 763          * active slide.
 764          */
 765         function deactivateOverview() {
 766
 767                 // Only proceed if enabled in config
 768                 if( config.overview ) {
 769
 770                         clearTimeout( activateOverviewTimeout );
 771                         clearTimeout( deactivateOverviewTimeout );
 772
 773                         dom.wrapper.classList.remove( 'overview' );
 774
 775                         // Temporarily add a class so that transitions can do different things
 776                         // depending on whether they are exiting/entering overview, or just
 777                         // moving from slide to slide
 778                         dom.wrapper.classList.add( 'exit-overview' );
 779
 780                         deactivateOverviewTimeout = setTimeout( function () {
 781                                 dom.wrapper.classList.remove( 'exit-overview' );
 782                         }, 10);
 783
 784                         // Select all slides
 785                         var slides = toArray( document.querySelectorAll( SLIDES_SELECTOR ) );
 786
 787                         for( var i = 0, len = slides.length; i < len; i++ ) {
 788                                 var element = slides[i];
 789
 790                                 element.style.display = '';
 791
 792                                 // Resets all transforms to use the external styles
 793                                 element.style.WebkitTransform = '';
 794                                 element.style.MozTransform = '';
 795                                 element.style.msTransform = '';
 796                                 element.style.OTransform = '';
 797                                 element.style.transform = '';
 798
 799                                 element.removeEventListener( 'click', onOverviewSlideClicked, true );
 800                         }
 801
 802                         slide( indexh, indexv );
 803
 804                         cueAutoSlide();
 805
 806                         // Notify observers of the overview hiding
 807                         dispatchEvent( 'overviewhidden', {
 808                                 'indexh': indexh,
 809                                 'indexv': indexv,
 810                                 'currentSlide': currentSlide
 811                         } );
 812
 813                 }
 814         }
 815
 816         /**
 817          * Toggles the slide overview mode on and off.
 818          *
 819          * @param {Boolean} override Optional flag which overrides the
 820          * toggle logic and forcibly sets the desired state. True means
 821          * overview is open, false means it's closed.
 822          */
 823         function toggleOverview( override ) {
 824
 825                 if( typeof override === 'boolean' ) {
 826                         override ? activateOverview() : deactivateOverview();
 827                 }
 828                 else {
 829                         isOverview() ? deactivateOverview() : activateOverview();
 830                 }
 831
 832         }
 833
 834         /**
 835          * Checks if the overview is currently active.
 836          *
 837          * @return {Boolean} true if the overview is active,
 838          * false otherwise
 839          */
 840         function isOverview() {
 841
 842                 return dom.wrapper.classList.contains( 'overview' );
 843
 844         }
 845
 846         /**
 847          * Handling the fullscreen functionality via the fullscreen API
 848          *
 849          * @see http://fullscreen.spec.whatwg.org/
 850          * @see https://developer.mozilla.org/en-US/docs/DOM/Using_fullscreen_mode
 851          */
 852         function enterFullscreen() {
 853
 854                 var element = document.body;
 855
 856                 // Check which implementation is available
 857                 var requestMethod = element.requestFullScreen ||
 858                                                         element.webkitRequestFullScreen ||
 859                                                         element.mozRequestFullScreen ||
 860                                                         element.msRequestFullScreen;
 861
 862                 if( requestMethod ) {
 863                         requestMethod.apply( element );
 864                 }
 865
 866         }
 867
 868         /**
 869          * Enters the paused mode which fades everything on screen to
 870          * black.
 871          */
 872         function pause() {
 873
 874                 cancelAutoSlide();
 875                 dom.wrapper.classList.add( 'paused' );
 876
 877         }
 878
 879         /**
 880          * Exits from the paused mode.
 881          */
 882         function resume() {
 883
 884                 cueAutoSlide();
 885                 dom.wrapper.classList.remove( 'paused' );
 886
 887         }
 888
 889         /**
 890          * Toggles the paused mode on and off.
 891          */
 892         function togglePause() {
 893
 894                 if( isPaused() ) {
 895                         resume();
 896                 }
 897                 else {
 898                         pause();
 899                 }
 900
 901         }
 902
 903         /**
 904          * Checks if we are currently in the paused mode.
 905          */
 906         function isPaused() {
 907
 908                 return dom.wrapper.classList.contains( 'paused' );
 909
 910         }
 911
 912         /**
 913          * Steps from the current point in the presentation to the
 914          * slide which matches the specified horizontal and vertical
 915          * indices.
 916          *
 917          * @param {int} h Horizontal index of the target slide
 918          * @param {int} v Vertical index of the target slide
 919          * @param {int} f Optional index of a fragment within the
 920          * target slide to activate
 921          */
 922         function slide( h, v, f ) {
 923
 924                 // Remember where we were at before
 925                 previousSlide = currentSlide;
 926
 927                 // Query all horizontal slides in the deck
 928                 var horizontalSlides = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR );
 929
 930                 // If no vertical index is specified and the upcoming slide is a
 931                 // stack, resume at its previous vertical index
 932                 if( v === undefined ) {
 933                         v = getPreviousVerticalIndex( horizontalSlides[ h ] );
 934                 }
 935
 936                 // If we were on a vertical stack, remember what vertical index
 937                 // it was on so we can resume at the same position when returning
 938                 if( previousSlide && previousSlide.parentNode && previousSlide.parentNode.classList.contains( 'stack' ) ) {
 939                         setPreviousVerticalIndex( previousSlide.parentNode, indexv );
 940                 }
 941
 942                 // Remember the state before this slide
 943                 var stateBefore = state.concat();
 944
 945                 // Reset the state array
 946                 state.length = 0;
 947
 948                 var indexhBefore = indexh,
 949                         indexvBefore = indexv;
 950
 951                 // Activate and transition to the new slide
 952                 indexh = updateSlides( HORIZONTAL_SLIDES_SELECTOR, h === undefined ? indexh : h );
 953                 indexv = updateSlides( VERTICAL_SLIDES_SELECTOR, v === undefined ? indexv : v );
 954
 955                 layout();
 956
 957                 // Apply the new state
 958                 stateLoop: for( var i = 0, len = state.length; i < len; i++ ) {
 959                         // Check if this state existed on the previous slide. If it
 960                         // did, we will avoid adding it repeatedly
 961                         for( var j = 0; j < stateBefore.length; j++ ) {
 962                                 if( stateBefore[j] === state[i] ) {
 963                                         stateBefore.splice( j, 1 );
 964                                         continue stateLoop;
 965                                 }
 966                         }
 967
 968                         document.documentElement.classList.add( state[i] );
 969
 970                         // Dispatch custom event matching the state's name
 971                         dispatchEvent( state[i] );
 972                 }
 973
 974                 // Clean up the remains of the previous state
 975                 while( stateBefore.length ) {
 976                         document.documentElement.classList.remove( stateBefore.pop() );
 977                 }
 978
 979                 // If the overview is active, re-activate it to update positions
 980                 if( isOverview() ) {
 981                         activateOverview();
 982                 }
 983
 984                 // Update the URL hash after a delay since updating it mid-transition
 985                 // is likely to cause visual lag
 986                 writeURL( 1500 );
 987
 988                 // Find the current horizontal slide and any possible vertical slides
 989                 // within it
 990                 var currentHorizontalSlide = horizontalSlides[ indexh ],
 991                         currentVerticalSlides = currentHorizontalSlide.querySelectorAll( 'section' );
 992
 993                 // Store references to the previous and current slides
 994                 currentSlide = currentVerticalSlides[ indexv ] || currentHorizontalSlide;
 995
 996
 997                 // Show fragment, if specified
 998                 if( typeof f !== 'undefined' ) {
 999                         var fragments = currentSlide.querySelectorAll( '.fragment' );
1000
1001                         toArray( fragments ).forEach( function( fragment, indexf ) {
1002                                 if( indexf < f ) {
1003                                         fragment.classList.add( 'visible' );
1004                                 }
1005                                 else {
1006                                         fragment.classList.remove( 'visible' );
1007                                 }
1008                         } );
1009                 }
1010
1011                 // Dispatch an event if the slide changed
1012                 if( indexh !== indexhBefore || indexv !== indexvBefore ) {
1013                         dispatchEvent( 'slidechanged', {
1014                                 'indexh': indexh,
1015                                 'indexv': indexv,
1016                                 'previousSlide': previousSlide,
1017                                 'currentSlide': currentSlide
1018                         } );
1019                 }
1020                 else {
1021                         // Ensure that the previous slide is never the same as the current
1022                         previousSlide = null;
1023                 }
1024
1025                 // Solves an edge case where the previous slide maintains the
1026                 // 'present' class when navigating between adjacent vertical
1027                 // stacks
1028                 if( previousSlide ) {
1029                         previousSlide.classList.remove( 'present' );
1030
1031                         // Reset all slides upon navigate to home
1032                         // Issue: #285
1033                         if ( document.querySelector( HOME_SLIDE_SELECTOR ).classList.contains( 'present' ) ) {
1034                                 // Launch async task
1035                                 setTimeout( function () {
1036                                         var slides = toArray( document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR + '.stack') ), i;
1037                                         for( i in slides ) {
1038                                                 if( slides[i] ) {
1039                                                         // Reset stack
1040                                                         setPreviousVerticalIndex( slides[i], 0 );
1041                                                 }
1042                                         }
1043                                 }, 0 );
1044                         }
1045                 }
1046
1047                 updateControls();
1048                 updateProgress();
1049
1050         }
1051
1052         /**
1053          * Updates one dimension of slides by showing the slide
1054          * with the specified index.
1055          *
1056          * @param {String} selector A CSS selector that will fetch
1057          * the group of slides we are working with
1058          * @param {Number} index The index of the slide that should be
1059          * shown
1060          *
1061          * @return {Number} The index of the slide that is now shown,
1062          * might differ from the passed in index if it was out of
1063          * bounds.
1064          */
1065         function updateSlides( selector, index ) {
1066
1067                 // Select all slides and convert the NodeList result to
1068                 // an array
1069                 var slides = toArray( document.querySelectorAll( selector ) ),
1070                         slidesLength = slides.length;
1071
1072                 if( slidesLength ) {
1073
1074                         // Should the index loop?
1075                         if( config.loop ) {
1076                                 index %= slidesLength;
1077
1078                                 if( index < 0 ) {
1079                                         index = slidesLength + index;
1080                                 }
1081                         }
1082
1083                         // Enforce max and minimum index bounds
1084                         index = Math.max( Math.min( index, slidesLength - 1 ), 0 );
1085
1086                         for( var i = 0; i < slidesLength; i++ ) {
1087                                 var element = slides[i];
1088
1089                                 // Optimization; hide all slides that are three or more steps
1090                                 // away from the present slide
1091                                 if( isOverview() === false ) {
1092                                         // The distance loops so that it measures 1 between the first
1093                                         // and last slides
1094                                         var distance = Math.abs( ( index - i ) % ( slidesLength - 3 ) ) || 0;
1095
1096                                         element.style.display = distance > 3 ? 'none' : 'block';
1097                                 }
1098
1099                                 slides[i].classList.remove( 'past' );
1100                                 slides[i].classList.remove( 'present' );
1101                                 slides[i].classList.remove( 'future' );
1102
1103                                 if( i < index ) {
1104                                         // Any element previous to index is given the 'past' class
1105                                         slides[i].classList.add( 'past' );
1106                                 }
1107                                 else if( i > index ) {
1108                                         // Any element subsequent to index is given the 'future' class
1109                                         slides[i].classList.add( 'future' );
1110                                 }
1111
1112                                 // If this element contains vertical slides
1113                                 if( element.querySelector( 'section' ) ) {
1114                                         slides[i].classList.add( 'stack' );
1115                                 }
1116                         }
1117
1118                         // Mark the current slide as present
1119                         slides[index].classList.add( 'present' );
1120
1121                         // If this slide has a state associated with it, add it
1122                         // onto the current state of the deck
1123                         var slideState = slides[index].getAttribute( 'data-state' );
1124                         if( slideState ) {
1125                                 state = state.concat( slideState.split( ' ' ) );
1126                         }
1127
1128                         // If this slide has a data-autoslide attribtue associated use this as
1129                         // autoSlide value otherwise use the global configured time
1130                         var slideAutoSlide = slides[index].getAttribute( 'data-autoslide' );
1131                         if( slideAutoSlide ) {
1132                                 autoSlide = parseInt( slideAutoSlide, 10 );
1133                         }
1134                         else {
1135                                 autoSlide = config.autoSlide;
1136                         }
1137
1138                 }
1139                 else {
1140                         // Since there are no slides we can't be anywhere beyond the
1141                         // zeroth index
1142                         index = 0;
1143                 }
1144
1145                 return index;
1146
1147         }
1148
1149         /**
1150          * Updates the progress bar to reflect the current slide.
1151          */
1152         function updateProgress() {
1153
1154                 // Update progress if enabled
1155                 if( config.progress && dom.progress ) {
1156
1157                         var horizontalSlides = toArray( document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) );
1158
1159                         // The number of past and total slides
1160                         var totalCount = document.querySelectorAll( SLIDES_SELECTOR + ':not(.stack)' ).length;
1161                         var pastCount = 0;
1162
1163                         // Step through all slides and count the past ones
1164                         mainLoop: for( var i = 0; i < horizontalSlides.length; i++ ) {
1165
1166                                 var horizontalSlide = horizontalSlides[i];
1167                                 var verticalSlides = toArray( horizontalSlide.querySelectorAll( 'section' ) );
1168
1169                                 for( var j = 0; j < verticalSlides.length; j++ ) {
1170
1171                                         // Stop as soon as we arrive at the present
1172                                         if( verticalSlides[j].classList.contains( 'present' ) ) {
1173                                                 break mainLoop;
1174                                         }
1175
1176                                         pastCount++;
1177
1178                                 }
1179
1180                                 // Stop as soon as we arrive at the present
1181                                 if( horizontalSlide.classList.contains( 'present' ) ) {
1182                                         break;
1183                                 }
1184
1185                                 // Don't count the wrapping section for vertical slides
1186                                 if( horizontalSlide.classList.contains( 'stack' ) === false ) {
1187                                         pastCount++;
1188                                 }
1189
1190                         }
1191
1192                         dom.progressbar.style.width = ( pastCount / ( totalCount - 1 ) ) * window.innerWidth + 'px';
1193
1194                 }
1195
1196         }
1197
1198         /**
1199          * Updates the state of all control/navigation arrows.
1200          */
1201         function updateControls() {
1202
1203                 if ( config.controls && dom.controls ) {
1204
1205                         var routes = availableRoutes();
1206
1207                         // Remove the 'enabled' class from all directions
1208                         dom.controlsLeft.concat( dom.controlsRight )
1209                                                         .concat( dom.controlsUp )
1210                                                         .concat( dom.controlsDown )
1211                                                         .concat( dom.controlsPrev )
1212                                                         .concat( dom.controlsNext ).forEach( function( node ) {
1213                                 node.classList.remove( 'enabled' );
1214                         } );
1215
1216                         // Add the 'enabled' class to the available routes
1217                         if( routes.left ) dom.controlsLeft.forEach( function( el ) { el.classList.add( 'enabled' );     } );
1218                         if( routes.right ) dom.controlsRight.forEach( function( el ) { el.classList.add( 'enabled' ); } );
1219                         if( routes.up ) dom.controlsUp.forEach( function( el ) { el.classList.add( 'enabled' ); } );
1220                         if( routes.down ) dom.controlsDown.forEach( function( el ) { el.classList.add( 'enabled' ); } );
1221
1222                         // Prev/next buttons
1223                         if( routes.left || routes.up ) dom.controlsPrev.forEach( function( el ) { el.classList.add( 'enabled' ); } );
1224                         if( routes.right || routes.down ) dom.controlsNext.forEach( function( el ) { el.classList.add( 'enabled' ); } );
1225
1226                 }
1227
1228         }
1229
1230         /**
1231          * Determine what available routes there are for navigation.
1232          *
1233          * @return {Object} containing four booleans: left/right/up/down
1234          */
1235         function availableRoutes() {
1236
1237                 var horizontalSlides = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ),
1238                         verticalSlides = document.querySelectorAll( VERTICAL_SLIDES_SELECTOR );
1239
1240                 return {
1241                         left: indexh > 0,
1242                         right: indexh < horizontalSlides.length - 1,
1243                         up: indexv > 0,
1244                         down: indexv < verticalSlides.length - 1
1245                 };
1246
1247         }
1248
1249         /**
1250          * Reads the current URL (hash) and navigates accordingly.
1251          */
1252         function readURL() {
1253
1254                 var hash = window.location.hash;
1255
1256                 // Attempt to parse the hash as either an index or name
1257                 var bits = hash.slice( 2 ).split( '/' ),
1258                         name = hash.replace( /#|\//gi, '' );
1259
1260                 // If the first bit is invalid and there is a name we can
1261                 // assume that this is a named link
1262                 if( isNaN( parseInt( bits[0], 10 ) ) && name.length ) {
1263                         // Find the slide with the specified name
1264                         var element = document.querySelector( '#' + name );
1265
1266                         if( element ) {
1267                                 // Find the position of the named slide and navigate to it
1268                                 var indices = Reveal.getIndices( element );
1269                                 slide( indices.h, indices.v );
1270                         }
1271                         // If the slide doesn't exist, navigate to the current slide
1272                         else {
1273                                 slide( indexh, indexv );
1274                         }
1275                 }
1276                 else {
1277                         // Read the index components of the hash
1278                         var h = parseInt( bits[0], 10 ) || 0,
1279                                 v = parseInt( bits[1], 10 ) || 0;
1280
1281                         slide( h, v );
1282                 }
1283
1284         }
1285
1286         /**
1287          * Updates the page URL (hash) to reflect the current
1288          * state.
1289          *
1290          * @param {Number} delay The time in ms to wait before
1291          * writing the hash
1292          */
1293         function writeURL( delay ) {
1294
1295                 if( config.history ) {
1296
1297                         // Make sure there's never more than one timeout running
1298                         clearTimeout( writeURLTimeout );
1299
1300                         // If a delay is specified, timeout this call
1301                         if( typeof delay === 'number' ) {
1302                                 writeURLTimeout = setTimeout( writeURL, delay );
1303                         }
1304                         else {
1305                                 var url = '/';
1306
1307                                 // If the current slide has an ID, use that as a named link
1308                                 if( currentSlide && typeof currentSlide.getAttribute( 'id' ) === 'string' ) {
1309                                         url = '/' + currentSlide.getAttribute( 'id' );
1310                                 }
1311                                 // Otherwise use the /h/v index
1312                                 else {
1313                                         if( indexh > 0 || indexv > 0 ) url += indexh;
1314                                         if( indexv > 0 ) url += '/' + indexv;
1315                                 }
1316
1317                                 window.location.hash = url;
1318                         }
1319                 }
1320
1321         }
1322
1323         /**
1324          * Retrieves the h/v location of the current, or specified,
1325          * slide.
1326          *
1327          * @param {HTMLElement} slide If specified, the returned
1328          * index will be for this slide rather than the currently
1329          * active one
1330          *
1331          * @return {Object} { h: <int>, v: <int> }
1332          */
1333         function getIndices( slide ) {
1334
1335                 // By default, return the current indices
1336                 var h = indexh,
1337                         v = indexv;
1338
1339                 // If a slide is specified, return the indices of that slide
1340                 if( slide ) {
1341                         var isVertical = !!slide.parentNode.nodeName.match( /section/gi );
1342                         var slideh = isVertical ? slide.parentNode : slide;
1343
1344                         // Select all horizontal slides
1345                         var horizontalSlides = toArray( document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) );
1346
1347                         // Now that we know which the horizontal slide is, get its index
1348                         h = Math.max( horizontalSlides.indexOf( slideh ), 0 );
1349
1350                         // If this is a vertical slide, grab the vertical index
1351                         if( isVertical ) {
1352                                 v = Math.max( toArray( slide.parentNode.querySelectorAll( 'section' ) ).indexOf( slide ), 0 );
1353                         }
1354                 }
1355
1356                 return { h: h, v: v };
1357
1358         }
1359
1360         /**
1361          * Navigate to the next slide fragment.
1362          *
1363          * @return {Boolean} true if there was a next fragment,
1364          * false otherwise
1365          */
1366         function nextFragment() {
1367
1368                 // Vertical slides:
1369                 if( document.querySelector( VERTICAL_SLIDES_SELECTOR + '.present' ) ) {
1370                         var verticalFragments = document.querySelectorAll( VERTICAL_SLIDES_SELECTOR + '.present .fragment:not(.visible)' );
1371                         if( verticalFragments.length ) {
1372                                 verticalFragments[0].classList.add( 'visible' );
1373
1374                                 // Notify subscribers of the change
1375                                 dispatchEvent( 'fragmentshown', { fragment: verticalFragments[0] } );
1376                                 return true;
1377                         }
1378                 }
1379                 // Horizontal slides:
1380                 else {
1381                         var horizontalFragments = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR + '.present .fragment:not(.visible)' );
1382                         if( horizontalFragments.length ) {
1383                                 horizontalFragments[0].classList.add( 'visible' );
1384
1385                                 // Notify subscribers of the change
1386                                 dispatchEvent( 'fragmentshown', { fragment: horizontalFragments[0] } );
1387                                 return true;
1388                         }
1389                 }
1390
1391                 return false;
1392
1393         }
1394
1395         /**
1396          * Navigate to the previous slide fragment.
1397          *
1398          * @return {Boolean} true if there was a previous fragment,
1399          * false otherwise
1400          */
1401         function previousFragment() {
1402
1403                 // Vertical slides:
1404                 if( document.querySelector( VERTICAL_SLIDES_SELECTOR + '.present' ) ) {
1405                         var verticalFragments = document.querySelectorAll( VERTICAL_SLIDES_SELECTOR + '.present .fragment.visible' );
1406                         if( verticalFragments.length ) {
1407                                 verticalFragments[ verticalFragments.length - 1 ].classList.remove( 'visible' );
1408
1409                                 // Notify subscribers of the change
1410                                 dispatchEvent( 'fragmenthidden', { fragment: verticalFragments[ verticalFragments.length - 1 ] } );
1411                                 return true;
1412                         }
1413                 }
1414                 // Horizontal slides:
1415                 else {
1416                         var horizontalFragments = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR + '.present .fragment.visible' );
1417                         if( horizontalFragments.length ) {
1418                                 horizontalFragments[ horizontalFragments.length - 1 ].classList.remove( 'visible' );
1419
1420                                 // Notify subscribers of the change
1421                                 dispatchEvent( 'fragmenthidden', { fragment: horizontalFragments[ horizontalFragments.length - 1 ] } );
1422                                 return true;
1423                         }
1424                 }
1425
1426                 return false;
1427
1428         }
1429
1430         /**
1431          * Cues a new automated slide if enabled in the config.
1432          */
1433         function cueAutoSlide() {
1434
1435                 clearTimeout( autoSlideTimeout );
1436
1437                 // Cue the next auto-slide if enabled
1438                 if( autoSlide && !isPaused() && !isOverview() ) {
1439                         autoSlideTimeout = setTimeout( navigateNext, autoSlide );
1440                 }
1441
1442         }
1443
1444         /**
1445          * Cancels any ongoing request to auto-slide.
1446          */
1447         function cancelAutoSlide() {
1448
1449                 clearTimeout( autoSlideTimeout );
1450
1451         }
1452
1453         function navigateLeft() {
1454
1455                 // Prioritize hiding fragments
1456                 if( availableRoutes().left && isOverview() || previousFragment() === false ) {
1457                         slide( indexh - 1 );
1458                 }
1459
1460         }
1461
1462         function navigateRight() {
1463
1464                 // Prioritize revealing fragments
1465                 if( availableRoutes().right && isOverview() || nextFragment() === false ) {
1466                         slide( indexh + 1 );
1467                 }
1468
1469         }
1470
1471         function navigateUp() {
1472
1473                 // Prioritize hiding fragments
1474                 if( availableRoutes().up && isOverview() || previousFragment() === false ) {
1475                         slide( indexh, indexv - 1 );
1476                 }
1477
1478         }
1479
1480         function navigateDown() {
1481
1482                 // Prioritize revealing fragments
1483                 if( availableRoutes().down && isOverview() || nextFragment() === false ) {
1484                         slide( indexh, indexv + 1 );
1485                 }
1486
1487         }
1488
1489         /**
1490          * Navigates backwards, prioritized in the following order:
1491          * 1) Previous fragment
1492          * 2) Previous vertical slide
1493          * 3) Previous horizontal slide
1494          */
1495         function navigatePrev() {
1496
1497                 // Prioritize revealing fragments
1498                 if( previousFragment() === false ) {
1499                         if( availableRoutes().up ) {
1500                                 navigateUp();
1501                         }
1502                         else {
1503                                 // Fetch the previous horizontal slide, if there is one
1504                                 var previousSlide = document.querySelector( HORIZONTAL_SLIDES_SELECTOR + '.past:nth-child(' + indexh + ')' );
1505
1506                                 if( previousSlide ) {
1507                                         indexv = ( previousSlide.querySelectorAll( 'section' ).length + 1 ) || undefined;
1508                                         indexh --;
1509                                         slide();
1510                                 }
1511                         }
1512                 }
1513
1514         }
1515
1516         /**
1517          * Same as #navigatePrev() but navigates forwards.
1518          */
1519         function navigateNext() {
1520
1521                 // Prioritize revealing fragments
1522                 if( nextFragment() === false ) {
1523                         availableRoutes().down ? navigateDown() : navigateRight();
1524                 }
1525
1526                 // If auto-sliding is enabled we need to cue up
1527                 // another timeout
1528                 cueAutoSlide();
1529
1530         }
1531
1532
1533         // --------------------------------------------------------------------//
1534         // ----------------------------- EVENTS -------------------------------//
1535         // --------------------------------------------------------------------//
1536
1537
1538         /**
1539          * Handler for the document level 'keydown' event.
1540          *
1541          * @param {Object} event
1542          */
1543         function onDocumentKeyDown( event ) {
1544
1545                 // Check if there's a focused element that could be using
1546                 // the keyboard
1547                 var activeElement = document.activeElement;
1548                 var hasFocus = !!( document.activeElement && ( document.activeElement.type || document.activeElement.href || document.activeElement.contentEditable !== 'inherit' ) );
1549
1550                 // Disregard the event if there's a focused element or a
1551                 // keyboard modifier key is present
1552                 if( hasFocus || event.shiftKey || event.altKey || event.ctrlKey || event.metaKey ) return;
1553
1554                 var triggered = true;
1555
1556                 // while paused only allow "unpausing" keyboard events (b and .)
1557                 if( isPaused() && [66,190,191].indexOf( event.keyCode ) === -1 ) {
1558                         return false;
1559                 }
1560
1561                 switch( event.keyCode ) {
1562                         // p, page up
1563                         case 80: case 33: navigatePrev(); break;
1564                         // n, page down
1565                         case 78: case 34: navigateNext(); break;
1566                         // h, left
1567                         case 72: case 37: navigateLeft(); break;
1568                         // l, right
1569                         case 76: case 39: navigateRight(); break;
1570                         // k, up
1571                         case 75: case 38: navigateUp(); break;
1572                         // j, down
1573                         case 74: case 40: navigateDown(); break;
1574                         // home
1575                         case 36: slide( 0 ); break;
1576                         // end
1577                         case 35: slide( Number.MAX_VALUE ); break;
1578                         // space
1579                         case 32: isOverview() ? deactivateOverview() : navigateNext(); break;
1580                         // return
1581                         case 13: isOverview() ? deactivateOverview() : triggered = false; break;
1582                         // b, period, Logitech presenter tools "black screen" button
1583                         case 66: case 190: case 191: togglePause(); break;
1584                         // f
1585                         case 70: enterFullscreen(); break;
1586                         default:
1587                                 triggered = false;
1588                 }
1589
1590                 // If the input resulted in a triggered action we should prevent
1591                 // the browsers default behavior
1592                 if( triggered ) {
1593                         event.preventDefault();
1594                 }
1595                 else if ( event.keyCode === 27 && supports3DTransforms ) {
1596                         toggleOverview();
1597
1598                         event.preventDefault();
1599                 }
1600
1601                 // If auto-sliding is enabled we need to cue up
1602                 // another timeout
1603                 cueAutoSlide();
1604
1605         }
1606
1607         /**
1608          * Handler for the document level 'touchstart' event,
1609          * enables support for swipe and pinch gestures.
1610          */
1611         function onDocumentTouchStart( event ) {
1612
1613                 touch.startX = event.touches[0].clientX;
1614                 touch.startY = event.touches[0].clientY;
1615                 touch.startCount = event.touches.length;
1616
1617                 // If there's two touches we need to memorize the distance
1618                 // between those two points to detect pinching
1619                 if( event.touches.length === 2 && config.overview ) {
1620                         touch.startSpan = distanceBetween( {
1621                                 x: event.touches[1].clientX,
1622                                 y: event.touches[1].clientY
1623                         }, {
1624                                 x: touch.startX,
1625                                 y: touch.startY
1626                         } );
1627                 }
1628
1629         }
1630
1631         /**
1632          * Handler for the document level 'touchmove' event.
1633          */
1634         function onDocumentTouchMove( event ) {
1635
1636                 // Each touch should only trigger one action
1637                 if( !touch.handled ) {
1638                         var currentX = event.touches[0].clientX;
1639                         var currentY = event.touches[0].clientY;
1640
1641                         // If the touch started off with two points and still has
1642                         // two active touches; test for the pinch gesture
1643                         if( event.touches.length === 2 && touch.startCount === 2 && config.overview ) {
1644
1645                                 // The current distance in pixels between the two touch points
1646                                 var currentSpan = distanceBetween( {
1647                                         x: event.touches[1].clientX,
1648                                         y: event.touches[1].clientY
1649                                 }, {
1650                                         x: touch.startX,
1651                                         y: touch.startY
1652                                 } );
1653
1654                                 // If the span is larger than the desire amount we've got
1655                                 // ourselves a pinch
1656                                 if( Math.abs( touch.startSpan - currentSpan ) > touch.threshold ) {
1657                                         touch.handled = true;
1658
1659                                         if( currentSpan < touch.startSpan ) {
1660                                                 activateOverview();
1661                                         }
1662                                         else {
1663                                                 deactivateOverview();
1664                                         }
1665                                 }
1666
1667                                 event.preventDefault();
1668
1669                         }
1670                         // There was only one touch point, look for a swipe
1671                         else if( event.touches.length === 1 && touch.startCount !== 2 ) {
1672
1673                                 var deltaX = currentX - touch.startX,
1674                                         deltaY = currentY - touch.startY;
1675
1676                                 if( deltaX > touch.threshold && Math.abs( deltaX ) > Math.abs( deltaY ) ) {
1677                                         touch.handled = true;
1678                                         navigateLeft();
1679                                 }
1680                                 else if( deltaX < -touch.threshold && Math.abs( deltaX ) > Math.abs( deltaY ) ) {
1681                                         touch.handled = true;
1682                                         navigateRight();
1683                                 }
1684                                 else if( deltaY > touch.threshold ) {
1685                                         touch.handled = true;
1686                                         navigateUp();
1687                                 }
1688                                 else if( deltaY < -touch.threshold ) {
1689                                         touch.handled = true;
1690                                         navigateDown();
1691                                 }
1692
1693                                 event.preventDefault();
1694
1695                         }
1696                 }
1697                 // There's a bug with swiping on some Android devices unless
1698                 // the default action is always prevented
1699                 else if( navigator.userAgent.match( /android/gi ) ) {
1700                         event.preventDefault();
1701                 }
1702
1703         }
1704
1705         /**
1706          * Handler for the document level 'touchend' event.
1707          */
1708         function onDocumentTouchEnd( event ) {
1709
1710                 touch.handled = false;
1711
1712         }
1713
1714         /**
1715          * Handles mouse wheel scrolling, throttled to avoid skipping
1716          * multiple slides.
1717          */
1718         function onDocumentMouseScroll( event ) {
1719
1720                 clearTimeout( mouseWheelTimeout );
1721
1722                 mouseWheelTimeout = setTimeout( function() {
1723                         var delta = event.detail || -event.wheelDelta;
1724                         if( delta > 0 ) {
1725                                 navigateNext();
1726                         }
1727                         else {
1728                                 navigatePrev();
1729                         }
1730                 }, 100 );
1731
1732         }
1733
1734         /**
1735          * Clicking on the progress bar results in a navigation to the
1736          * closest approximate horizontal slide using this equation:
1737          *
1738          * ( clickX / presentationWidth ) * numberOfSlides
1739          */
1740         function onProgressClicked( event ) {
1741
1742                 event.preventDefault();
1743
1744                 var slidesTotal = toArray( document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) ).length;
1745                 var slideIndex = Math.floor( ( event.clientX / dom.wrapper.offsetWidth ) * slidesTotal );
1746
1747                 slide( slideIndex );
1748
1749         }
1750
1751         /**
1752          * Event handler for navigation control buttons.
1753          */
1754         function onNavigateLeftClicked( event ) { event.preventDefault(); navigateLeft(); }
1755         function onNavigateRightClicked( event ) { event.preventDefault(); navigateRight(); }
1756         function onNavigateUpClicked( event ) { event.preventDefault(); navigateUp(); }
1757         function onNavigateDownClicked( event ) { event.preventDefault(); navigateDown(); }
1758         function onNavigatePrevClicked( event ) { event.preventDefault(); navigatePrev(); }
1759         function onNavigateNextClicked( event ) { event.preventDefault(); navigateNext(); }
1760
1761         /**
1762          * Handler for the window level 'hashchange' event.
1763          */
1764         function onWindowHashChange( event ) {
1765
1766                 readURL();
1767
1768         }
1769
1770         /**
1771          * Handler for the window level 'resize' event.
1772          */
1773         function onWindowResize( event ) {
1774
1775                 layout();
1776
1777         }
1778
1779         /**
1780          * Invoked when a slide is and we're in the overview.
1781          */
1782         function onOverviewSlideClicked( event ) {
1783
1784                 // TODO There's a bug here where the event listeners are not
1785                 // removed after deactivating the overview.
1786                 if( isOverview() ) {
1787                         event.preventDefault();
1788
1789                         deactivateOverview();
1790
1791                         var element = event.target;
1792
1793                         while( element && !element.nodeName.match( /section/gi ) ) {
1794                                 element = element.parentNode;
1795                         }
1796
1797                         if( element.nodeName.match( /section/gi ) ) {
1798                                 var h = parseInt( element.getAttribute( 'data-index-h' ), 10 ),
1799                                         v = parseInt( element.getAttribute( 'data-index-v' ), 10 );
1800
1801                                 slide( h, v );
1802                         }
1803                 }
1804
1805         }
1806
1807
1808         // --------------------------------------------------------------------//
1809         // ------------------------------- API --------------------------------//
1810         // --------------------------------------------------------------------//
1811
1812
1813         return {
1814                 initialize: initialize,
1815
1816                 // Navigation methods
1817                 slide: slide,
1818                 left: navigateLeft,
1819                 right: navigateRight,
1820                 up: navigateUp,
1821                 down: navigateDown,
1822                 prev: navigatePrev,
1823                 next: navigateNext,
1824                 prevFragment: previousFragment,
1825                 nextFragment: nextFragment,
1826
1827                 // Deprecated aliases
1828                 navigateTo: slide,
1829                 navigateLeft: navigateLeft,
1830                 navigateRight: navigateRight,
1831                 navigateUp: navigateUp,
1832                 navigateDown: navigateDown,
1833                 navigatePrev: navigatePrev,
1834                 navigateNext: navigateNext,
1835
1836                 // Forces an update in slide layout
1837                 layout: layout,
1838
1839                 // Toggles the overview mode on/off
1840                 toggleOverview: toggleOverview,
1841
1842                 // Toggles the "black screen" mode on/off
1843                 togglePause: togglePause,
1844
1845                 // State checks
1846                 isOverview: isOverview,
1847                 isPaused: isPaused,
1848
1849                 // Adds or removes all internal event listeners (such as keyboard)
1850                 addEventListeners: addEventListeners,
1851                 removeEventListeners: removeEventListeners,
1852
1853                 // Returns the indices of the current, or specified, slide
1854                 getIndices: getIndices,
1855
1856                 // Returns the slide at the specified index, y is optional
1857                 getSlide: function( x, y ) {
1858                         var horizontalSlide = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR )[ x ];
1859                         var verticalSlides = horizontalSlide && horizontalSlide.querySelectorAll( 'section' );
1860
1861                         if( typeof y !== 'undefined' ) {
1862                                 return verticalSlides ? verticalSlides[ y ] : undefined;
1863                         }
1864
1865                         return horizontalSlide;
1866                 },
1867
1868                 // Returns the previous slide element, may be null
1869                 getPreviousSlide: function() {
1870                         return previousSlide;
1871                 },
1872
1873                 // Returns the current slide element
1874                 getCurrentSlide: function() {
1875                         return currentSlide;
1876                 },
1877
1878                 // Returns the current scale of the presentation content
1879                 getScale: function() {
1880                         return scale;
1881                 },
1882
1883                 // Helper method, retrieves query string as a key/value hash
1884                 getQueryHash: function() {
1885                         var query = {};
1886
1887                         location.search.replace( /[A-Z0-9]+?=(\w*)/gi, function(a) {
1888                                 query[ a.split( '=' ).shift() ] = a.split( '=' ).pop();
1889                         } );
1890
1891                         return query;
1892                 },
1893
1894                 // Forward event binding to the reveal DOM element
1895                 addEventListener: function( type, listener, useCapture ) {
1896                         if( 'addEventListener' in window ) {
1897                                 ( dom.wrapper || document.querySelector( '.reveal' ) ).addEventListener( type, listener, useCapture );
1898                         }
1899                 },
1900                 removeEventListener: function( type, listener, useCapture ) {
1901                         if( 'addEventListener' in window ) {
1902                                 ( dom.wrapper || document.querySelector( '.reveal' ) ).removeEventListener( type, listener, useCapture );
1903                         }
1904                 }
1905         };
1906
1907 })();