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                 // Flags if the interaction event listeners are bound
 133                 eventsAreBound = false,
 134
 135                 // Holds information about the currently ongoing touch input
 136                 touch = {
 137                         startX: 0,
 138                         startY: 0,
 139                         startSpan: 0,
 140                         startCount: 0,
 141                         handled: false,
 142                         threshold: 80
 143                 };
 144
 145         /**
 146          * Starts up the presentation if the client is capable.
 147          */
 148         function initialize( options ) {
 149
 150                 if( !supports2DTransforms && !supports3DTransforms ) {
 151                         document.body.setAttribute( 'class', 'no-transforms' );
 152
 153                         // If the browser doesn't support core features we won't be
 154                         // using JavaScript to control the presentation
 155                         return;
 156                 }
 157
 158                 // Force a layout when the whole page, incl fonts, has loaded
 159                 window.addEventListener( 'load', layout, false );
 160
 161                 // Copy options over to our config object
 162                 extend( config, options );
 163
 164                 // Hide the address bar in mobile browsers
 165                 hideAddressBar();
 166
 167                 // Loads the dependencies and continues to #start() once done
 168                 load();
 169
 170         }
 171
 172         /**
 173          * Finds and stores references to DOM elements which are
 174          * required by the presentation. If a required element is
 175          * not found, it is created.
 176          */
 177         function setupDOM() {
 178
 179                 // Cache references to key DOM elements
 180                 dom.theme = document.querySelector( '#theme' );
 181                 dom.wrapper = document.querySelector( '.reveal' );
 182                 dom.slides = document.querySelector( '.reveal .slides' );
 183
 184                 // Progress bar
 185                 if( !dom.wrapper.querySelector( '.progress' ) && config.progress ) {
 186                         var progressElement = document.createElement( 'div' );
 187                         progressElement.classList.add( 'progress' );
 188                         progressElement.innerHTML = '<span></span>';
 189                         dom.wrapper.appendChild( progressElement );
 190                 }
 191
 192                 // Arrow controls
 193                 if( !dom.wrapper.querySelector( '.controls' ) && config.controls ) {
 194                         var controlsElement = document.createElement( 'aside' );
 195                         controlsElement.classList.add( 'controls' );
 196                         controlsElement.innerHTML = '<div class="navigate-left"></div>' +
 197                                                                                 '<div class="navigate-right"></div>' +
 198                                                                                 '<div class="navigate-up"></div>' +
 199                                                                                 '<div class="navigate-down"></div>';
 200                         dom.wrapper.appendChild( controlsElement );
 201                 }
 202
 203                 // Presentation background element
 204                 if( !dom.wrapper.querySelector( '.state-background' ) ) {
 205                         var backgroundElement = document.createElement( 'div' );
 206                         backgroundElement.classList.add( 'state-background' );
 207                         dom.wrapper.appendChild( backgroundElement );
 208                 }
 209
 210                 // Overlay graphic which is displayed during the paused mode
 211                 if( !dom.wrapper.querySelector( '.pause-overlay' ) ) {
 212                         var pausedElement = document.createElement( 'div' );
 213                         pausedElement.classList.add( 'pause-overlay' );
 214                         dom.wrapper.appendChild( pausedElement );
 215                 }
 216
 217                 // Cache references to elements
 218                 dom.progress = document.querySelector( '.reveal .progress' );
 219                 dom.progressbar = document.querySelector( '.reveal .progress span' );
 220
 221                 if ( config.controls ) {
 222                         dom.controls = document.querySelector( '.reveal .controls' );
 223
 224                         // There can be multiple instances of controls throughout the page
 225                         dom.controlsLeft = toArray( document.querySelectorAll( '.navigate-left' ) );
 226                         dom.controlsRight = toArray( document.querySelectorAll( '.navigate-right' ) );
 227                         dom.controlsUp = toArray( document.querySelectorAll( '.navigate-up' ) );
 228                         dom.controlsDown = toArray( document.querySelectorAll( '.navigate-down' ) );
 229                         dom.controlsPrev = toArray( document.querySelectorAll( '.navigate-prev' ) );
 230                         dom.controlsNext = toArray( document.querySelectorAll( '.navigate-next' ) );
 231                 }
 232
 233         }
 234
 235         /**
 236          * Hides the address bar if we're on a mobile device.
 237          */
 238         function hideAddressBar() {
 239
 240                 if( /iphone|ipod|android/gi.test( navigator.userAgent ) && !/crios/gi.test( navigator.userAgent ) ) {
 241                         // Events that should trigger the address bar to hide
 242                         window.addEventListener( 'load', removeAddressBar, false );
 243                         window.addEventListener( 'orientationchange', removeAddressBar, false );
 244                 }
 245
 246         }
 247
 248         /**
 249          * Loads the dependencies of reveal.js. Dependencies are
 250          * defined via the configuration option 'dependencies'
 251          * and will be loaded prior to starting/binding reveal.js.
 252          * Some dependencies may have an 'async' flag, if so they
 253          * will load after reveal.js has been started up.
 254          */
 255         function load() {
 256
 257                 var scripts = [],
 258                         scriptsAsync = [];
 259
 260                 for( var i = 0, len = config.dependencies.length; i < len; i++ ) {
 261                         var s = config.dependencies[i];
 262
 263                         // Load if there's no condition or the condition is truthy
 264                         if( !s.condition || s.condition() ) {
 265                                 if( s.async ) {
 266                                         scriptsAsync.push( s.src );
 267                                 }
 268                                 else {
 269                                         scripts.push( s.src );
 270                                 }
 271
 272                                 // Extension may contain callback functions
 273                                 if( typeof s.callback === 'function' ) {
 274                                         head.ready( s.src.match( /([\w\d_\-]*)\.?js$|[^\\\/]*$/i )[0], s.callback );
 275                                 }
 276                         }
 277                 }
 278
 279                 // Called once synchronous scritps finish loading
 280                 function proceed() {
 281                         if( scriptsAsync.length ) {
 282                                 // Load asynchronous scripts
 283                                 head.js.apply( null, scriptsAsync );
 284                         }
 285
 286                         start();
 287                 }
 288
 289                 if( scripts.length ) {
 290                         head.ready( proceed );
 291
 292                         // Load synchronous scripts
 293                         head.js.apply( null, scripts );
 294                 }
 295                 else {
 296                         proceed();
 297                 }
 298
 299         }
 300
 301         /**
 302          * Starts up reveal.js by binding input events and navigating
 303          * to the current URL deeplink if there is one.
 304          */
 305         function start() {
 306
 307                 // Make sure we've got all the DOM elements we need
 308                 setupDOM();
 309
 310                 // Subscribe to input
 311                 addEventListeners();
 312
 313                 // Updates the presentation to match the current configuration values
 314                 configure();
 315
 316                 // Force an initial layout, will thereafter be invoked as the window
 317                 // is resized
 318                 layout();
 319
 320                 // Read the initial hash
 321                 readURL();
 322
 323                 // Start auto-sliding if it's enabled
 324                 cueAutoSlide();
 325
 326                 // Notify listeners that the presentation is ready but use a 1ms
 327                 // timeout to ensure it's not fired synchronously after #initialize()
 328                 setTimeout( function() {
 329                         dispatchEvent( 'ready', {
 330                                 'indexh': indexh,
 331                                 'indexv': indexv,
 332                                 'currentSlide': currentSlide
 333                         } );
 334                 }, 1 );
 335
 336         }
 337
 338         /**
 339          * Applies the configuration settings from the config object.
 340          */
 341         function configure( options ) {
 342
 343                 dom.wrapper.classList.remove( config.transition );
 344
 345                 // New config options may be passed when this method
 346                 // is invoked through the API after initialization
 347                 if( typeof options === 'object' ) extend( config, options );
 348
 349                 // Force linear transition based on browser capabilities
 350                 if( supports3DTransforms === false ) config.transition = 'linear';
 351
 352                 dom.wrapper.classList.add( config.transition );
 353
 354                 dom.controls.style.display = ( config.controls && dom.controls ) ? 'block' : 'none';
 355                 dom.progress.style.display = ( config.progress && dom.progress ) ? 'block' : 'none';
 356
 357                 dom.wrapper.classList.toggle( 'rtl', config.rtl );
 358                 dom.wrapper.classList.toggle( 'center', config.center );
 359
 360                 if( config.mouseWheel ) {
 361                         document.addEventListener( 'DOMMouseScroll', onDocumentMouseScroll, false ); // FF
 362                         document.addEventListener( 'mousewheel', onDocumentMouseScroll, false );
 363                 }
 364                 else {
 365                         document.removeEventListener( 'DOMMouseScroll', onDocumentMouseScroll, false ); // FF
 366                         document.removeEventListener( 'mousewheel', onDocumentMouseScroll, false );
 367                 }
 368
 369                 // 3D links
 370                 if( config.rollingLinks ) {
 371                         enable3DLinks();
 372                 }
 373                 else {
 374                         disable3DLinks();
 375                 }
 376
 377                 // Load the theme in the config, if it's not already loaded
 378                 if( config.theme && dom.theme ) {
 379                         var themeURL = dom.theme.getAttribute( 'href' );
 380                         var themeFinder = /[^\/]*?(?=\.css)/;
 381                         var themeName = themeURL.match(themeFinder)[0];
 382
 383                         if(  config.theme !== themeName ) {
 384                                 themeURL = themeURL.replace(themeFinder, config.theme);
 385                                 dom.theme.setAttribute( 'href', themeURL );
 386                         }
 387                 }
 388
 389         }
 390
 391         /**
 392          * Binds all event listeners.
 393          */
 394         function addEventListeners() {
 395
 396                 eventsAreBound = true;
 397
 398                 window.addEventListener( 'hashchange', onWindowHashChange, false );
 399                 window.addEventListener( 'resize', onWindowResize, false );
 400
 401                 if( config.touch ) {
 402                         document.addEventListener( 'touchstart', onDocumentTouchStart, false );
 403                         document.addEventListener( 'touchmove', onDocumentTouchMove, false );
 404                         document.addEventListener( 'touchend', onDocumentTouchEnd, false );
 405                 }
 406
 407                 if( config.keyboard ) {
 408                         document.addEventListener( 'keydown', onDocumentKeyDown, false );
 409                 }
 410
 411                 if ( config.progress && dom.progress ) {
 412                         dom.progress.addEventListener( 'click', onProgressClicked, false );
 413                 }
 414
 415                 if ( config.controls && dom.controls ) {
 416                         var actionEvent = 'ontouchstart' in window && window.ontouchstart != null ? 'touchstart' : 'click';
 417                         dom.controlsLeft.forEach( function( el ) { el.addEventListener( actionEvent, onNavigateLeftClicked, false ); } );
 418                         dom.controlsRight.forEach( function( el ) { el.addEventListener( actionEvent, onNavigateRightClicked, false ); } );
 419                         dom.controlsUp.forEach( function( el ) { el.addEventListener( actionEvent, onNavigateUpClicked, false ); } );
 420                         dom.controlsDown.forEach( function( el ) { el.addEventListener( actionEvent, onNavigateDownClicked, false ); } );
 421                         dom.controlsPrev.forEach( function( el ) { el.addEventListener( actionEvent, onNavigatePrevClicked, false ); } );
 422                         dom.controlsNext.forEach( function( el ) { el.addEventListener( actionEvent, onNavigateNextClicked, false ); } );
 423                 }
 424
 425         }
 426
 427         /**
 428          * Unbinds all event listeners.
 429          */
 430         function removeEventListeners() {
 431
 432                 eventsAreBound = false;
 433
 434                 document.removeEventListener( 'keydown', onDocumentKeyDown, false );
 435                 window.removeEventListener( 'hashchange', onWindowHashChange, false );
 436                 window.removeEventListener( 'resize', onWindowResize, false );
 437
 438                 if( config.touch ) {
 439                         document.removeEventListener( 'touchstart', onDocumentTouchStart, false );
 440                         document.removeEventListener( 'touchmove', onDocumentTouchMove, false );
 441                         document.removeEventListener( 'touchend', onDocumentTouchEnd, false );
 442                 }
 443
 444                 if ( config.progress && dom.progress ) {
 445                         dom.progress.removeEventListener( 'click', onProgressClicked, false );
 446                 }
 447
 448                 if ( config.controls && dom.controls ) {
 449                         var actionEvent = 'ontouchstart' in window && window.ontouchstart != null ? 'touchstart' : 'click';
 450                         dom.controlsLeft.forEach( function( el ) { el.removeEventListener( actionEvent, onNavigateLeftClicked, false ); } );
 451                         dom.controlsRight.forEach( function( el ) { el.removeEventListener( actionEvent, onNavigateRightClicked, false ); } );
 452                         dom.controlsUp.forEach( function( el ) { el.removeEventListener( actionEvent, onNavigateUpClicked, false ); } );
 453                         dom.controlsDown.forEach( function( el ) { el.removeEventListener( actionEvent, onNavigateDownClicked, false ); } );
 454                         dom.controlsPrev.forEach( function( el ) { el.removeEventListener( actionEvent, onNavigatePrevClicked, false ); } );
 455                         dom.controlsNext.forEach( function( el ) { el.removeEventListener( actionEvent, onNavigateNextClicked, false ); } );
 456                 }
 457
 458         }
 459
 460         /**
 461          * Extend object a with the properties of object b.
 462          * If there's a conflict, object b takes precedence.
 463          */
 464         function extend( a, b ) {
 465
 466                 for( var i in b ) {
 467                         a[ i ] = b[ i ];
 468                 }
 469
 470         }
 471
 472         /**
 473          * Converts the target object to an array.
 474          */
 475         function toArray( o ) {
 476
 477                 return Array.prototype.slice.call( o );
 478
 479         }
 480
 481         /**
 482          * Measures the distance in pixels between point a
 483          * and point b.
 484          *
 485          * @param {Object} a point with x/y properties
 486          * @param {Object} b point with x/y properties
 487          */
 488         function distanceBetween( a, b ) {
 489
 490                 var dx = a.x - b.x,
 491                         dy = a.y - b.y;
 492
 493                 return Math.sqrt( dx*dx + dy*dy );
 494
 495         }
 496
 497         /**
 498          * Causes the address bar to hide on mobile devices,
 499          * more vertical space ftw.
 500          */
 501         function removeAddressBar() {
 502
 503                 if( window.orientation === 0 ) {
 504                         document.documentElement.style.overflow = 'scroll';
 505                         document.body.style.height = '120%';
 506                 }
 507                 else {
 508                         document.documentElement.style.overflow = '';
 509                         document.body.style.height = '100%';
 510                 }
 511
 512                 setTimeout( function() {
 513                         window.scrollTo( 0, 1 );
 514                 }, 10 );
 515
 516         }
 517
 518         /**
 519          * Dispatches an event of the specified type from the
 520          * reveal DOM element.
 521          */
 522         function dispatchEvent( type, properties ) {
 523
 524                 var event = document.createEvent( "HTMLEvents", 1, 2 );
 525                 event.initEvent( type, true, true );
 526                 extend( event, properties );
 527                 dom.wrapper.dispatchEvent( event );
 528
 529         }
 530
 531         /**
 532          * Wrap all links in 3D goodness.
 533          */
 534         function enable3DLinks() {
 535
 536                 if( supports3DTransforms && !( 'msPerspective' in document.body.style ) ) {
 537                         var anchors = document.querySelectorAll( SLIDES_SELECTOR + ' a:not(.image)' );
 538
 539                         for( var i = 0, len = anchors.length; i < len; i++ ) {
 540                                 var anchor = anchors[i];
 541
 542                                 if( anchor.textContent && !anchor.querySelector( '*' ) && ( !anchor.className || !anchor.classList.contains( anchor, 'roll' ) ) ) {
 543                                         var span = document.createElement('span');
 544                                         span.setAttribute('data-title', anchor.text);
 545                                         span.innerHTML = anchor.innerHTML;
 546
 547                                         anchor.classList.add( 'roll' );
 548                                         anchor.innerHTML = '';
 549                                         anchor.appendChild(span);
 550                                 }
 551                         }
 552                 }
 553
 554         }
 555
 556         /**
 557          * Unwrap all 3D links.
 558          */
 559         function disable3DLinks() {
 560
 561                 var anchors = document.querySelectorAll( SLIDES_SELECTOR + ' a.roll' );
 562
 563                 for( var i = 0, len = anchors.length; i < len; i++ ) {
 564                         var anchor = anchors[i];
 565                         var span = anchor.querySelector( 'span' );
 566
 567                         if( span ) {
 568                                 anchor.classList.remove( 'roll' );
 569                                 anchor.innerHTML = span.innerHTML;
 570                         }
 571                 }
 572
 573         }
 574
 575         /**
 576          * Return a sorted fragments list, ordered by an increasing
 577          * "data-fragment-index" attribute.
 578          *
 579          * Fragments will be revealed in the order that they are returned by
 580          * this function, so you can use the index attributes to control the
 581          * order of fragment appearance.
 582          *
 583          * To maintain a sensible default fragment order, fragments are presumed
 584          * to be passed in document order. This function adds a "fragment-index"
 585          * attribute to each node if such an attribute is not already present,
 586          * and sets that attribute to an integer value which is the position of
 587          * the fragment within the fragments list.
 588          */
 589         function sortFragments( fragments ) {
 590
 591                 var a = toArray( fragments );
 592
 593                 a.forEach( function( el, idx ) {
 594                         if( !el.hasAttribute( 'data-fragment-index' ) ) {
 595                                 el.setAttribute( 'data-fragment-index', idx );
 596                         }
 597                 } );
 598
 599                 a.sort( function( l, r ) {
 600                         return l.getAttribute( 'data-fragment-index' ) - r.getAttribute( 'data-fragment-index');
 601                 } );
 602
 603                 return a
 604
 605         }
 606
 607         /**
 608          * Applies JavaScript-controlled layout rules to the
 609          * presentation.
 610          */
 611         function layout() {
 612
 613                 if( dom.wrapper ) {
 614
 615                         // Available space to scale within
 616                         var availableWidth = dom.wrapper.offsetWidth,
 617                                 availableHeight = dom.wrapper.offsetHeight;
 618
 619                         // Reduce availabe space by margin
 620                         availableWidth -= ( availableHeight * config.margin );
 621                         availableHeight -= ( availableHeight * config.margin );
 622
 623                         // Dimensions of the content
 624                         var slideWidth = config.width,
 625                                 slideHeight = config.height;
 626
 627                         // Slide width may be a percentage of available width
 628                         if( typeof slideWidth === 'string' && /%$/.test( slideWidth ) ) {
 629                                 slideWidth = parseInt( slideWidth, 10 ) / 100 * availableWidth;
 630                         }
 631
 632                         // Slide height may be a percentage of available height
 633                         if( typeof slideHeight === 'string' && /%$/.test( slideHeight ) ) {
 634                                 slideHeight = parseInt( slideHeight, 10 ) / 100 * availableHeight;
 635                         }
 636
 637                         dom.slides.style.width = slideWidth + 'px';
 638                         dom.slides.style.height = slideHeight + 'px';
 639
 640                         // Determine scale of content to fit within available space
 641                         scale = Math.min( availableWidth / slideWidth, availableHeight / slideHeight );
 642
 643                         // Respect max/min scale settings
 644                         scale = Math.max( scale, config.minScale );
 645                         scale = Math.min( scale, config.maxScale );
 646
 647                         // Prefer applying scale via zoom since Chrome blurs scaled content
 648                         // with nested transforms
 649                         if( typeof dom.slides.style.zoom !== 'undefined' && !navigator.userAgent.match( /(iphone|ipod|ipad|android)/gi ) ) {
 650                                 dom.slides.style.zoom = scale;
 651                         }
 652                         // Apply scale transform as a fallback
 653                         else {
 654                                 var transform = 'translate(-50%, -50%) scale('+ scale +') translate(50%, 50%)';
 655
 656                                 dom.slides.style.WebkitTransform = transform;
 657                                 dom.slides.style.MozTransform = transform;
 658                                 dom.slides.style.msTransform = transform;
 659                                 dom.slides.style.OTransform = transform;
 660                                 dom.slides.style.transform = transform;
 661                         }
 662
 663                         // Select all slides, vertical and horizontal
 664                         var slides = toArray( document.querySelectorAll( SLIDES_SELECTOR ) );
 665
 666                         for( var i = 0, len = slides.length; i < len; i++ ) {
 667                                 var slide = slides[ i ];
 668
 669                                 // Don't bother updating invisible slides
 670                                 if( slide.style.display === 'none' ) {
 671                                         continue;
 672                                 }
 673
 674                                 if( config.center ) {
 675                                         // Vertical stacks are not centered since their section
 676                                         // children will be
 677                                         if( slide.classList.contains( 'stack' ) ) {
 678                                                 slide.style.top = 0;
 679                                         }
 680                                         else {
 681                                                 slide.style.top = Math.max( - ( slide.offsetHeight / 2 ) - 20, -slideHeight / 2 ) + 'px';
 682                                         }
 683                                 }
 684                                 else {
 685                                         slide.style.top = '';
 686                                 }
 687
 688                         }
 689
 690                 }
 691
 692         }
 693
 694         /**
 695          * Stores the vertical index of a stack so that the same
 696          * vertical slide can be selected when navigating to and
 697          * from the stack.
 698          *
 699          * @param {HTMLElement} stack The vertical stack element
 700          * @param {int} v Index to memorize
 701          */
 702         function setPreviousVerticalIndex( stack, v ) {
 703
 704                 if( stack ) {
 705                         stack.setAttribute( 'data-previous-indexv', v || 0 );
 706                 }
 707
 708         }
 709
 710         /**
 711          * Retrieves the vertical index which was stored using
 712          * #setPreviousVerticalIndex() or 0 if no previous index
 713          * exists.
 714          *
 715          * @param {HTMLElement} stack The vertical stack element
 716          */
 717         function getPreviousVerticalIndex( stack ) {
 718
 719                 if( stack && stack.classList.contains( 'stack' ) ) {
 720                         return parseInt( stack.getAttribute( 'data-previous-indexv' ) || 0, 10 );
 721                 }
 722
 723                 return 0;
 724
 725         }
 726
 727         /**
 728          * Displays the overview of slides (quick nav) by
 729          * scaling down and arranging all slide elements.
 730          *
 731          * Experimental feature, might be dropped if perf
 732          * can't be improved.
 733          */
 734         function activateOverview() {
 735
 736                 // Only proceed if enabled in config
 737                 if( config.overview ) {
 738
 739                         // Don't auto-slide while in overview mode
 740                         cancelAutoSlide();
 741
 742                         var wasActive = dom.wrapper.classList.contains( 'overview' );
 743
 744                         dom.wrapper.classList.add( 'overview' );
 745                         dom.wrapper.classList.remove( 'exit-overview' );
 746
 747                         clearTimeout( activateOverviewTimeout );
 748                         clearTimeout( deactivateOverviewTimeout );
 749
 750                         // Not the pretties solution, but need to let the overview
 751                         // class apply first so that slides are measured accurately
 752                         // before we can position them
 753                         activateOverviewTimeout = setTimeout( function(){
 754
 755                                 var horizontalSlides = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR );
 756
 757                                 for( var i = 0, len1 = horizontalSlides.length; i < len1; i++ ) {
 758                                         var hslide = horizontalSlides[i],
 759                                                 htransform = 'translateZ(-2500px) translate(' + ( ( i - indexh ) * 105 ) + '%, 0%)';
 760
 761                                         hslide.setAttribute( 'data-index-h', i );
 762                                         hslide.style.display = 'block';
 763                                         hslide.style.WebkitTransform = htransform;
 764                                         hslide.style.MozTransform = htransform;
 765                                         hslide.style.msTransform = htransform;
 766                                         hslide.style.OTransform = htransform;
 767                                         hslide.style.transform = htransform;
 768
 769                                         if( hslide.classList.contains( 'stack' ) ) {
 770
 771                                                 var verticalSlides = hslide.querySelectorAll( 'section' );
 772
 773                                                 for( var j = 0, len2 = verticalSlides.length; j < len2; j++ ) {
 774                                                         var verticalIndex = i === indexh ? indexv : getPreviousVerticalIndex( hslide );
 775
 776                                                         var vslide = verticalSlides[j],
 777                                                                 vtransform = 'translate(0%, ' + ( ( j - verticalIndex ) * 105 ) + '%)';
 778
 779                                                         vslide.setAttribute( 'data-index-h', i );
 780                                                         vslide.setAttribute( 'data-index-v', j );
 781                                                         vslide.style.display = 'block';
 782                                                         vslide.style.WebkitTransform = vtransform;
 783                                                         vslide.style.MozTransform = vtransform;
 784                                                         vslide.style.msTransform = vtransform;
 785                                                         vslide.style.OTransform = vtransform;
 786                                                         vslide.style.transform = vtransform;
 787
 788                                                         // Navigate to this slide on click
 789                                                         vslide.addEventListener( 'click', onOverviewSlideClicked, true );
 790                                                 }
 791
 792                                         }
 793                                         else {
 794
 795                                                 // Navigate to this slide on click
 796                                                 hslide.addEventListener( 'click', onOverviewSlideClicked, true );
 797
 798                                         }
 799                                 }
 800
 801                                 layout();
 802
 803                                 if( !wasActive ) {
 804                                         // Notify observers of the overview showing
 805                                         dispatchEvent( 'overviewshown', {
 806                                                 'indexh': indexh,
 807                                                 'indexv': indexv,
 808                                                 'currentSlide': currentSlide
 809                                         } );
 810                                 }
 811
 812                         }, 10 );
 813
 814                 }
 815
 816         }
 817
 818         /**
 819          * Exits the slide overview and enters the currently
 820          * active slide.
 821          */
 822         function deactivateOverview() {
 823
 824                 // Only proceed if enabled in config
 825                 if( config.overview ) {
 826
 827                         clearTimeout( activateOverviewTimeout );
 828                         clearTimeout( deactivateOverviewTimeout );
 829
 830                         dom.wrapper.classList.remove( 'overview' );
 831
 832                         // Temporarily add a class so that transitions can do different things
 833                         // depending on whether they are exiting/entering overview, or just
 834                         // moving from slide to slide
 835                         dom.wrapper.classList.add( 'exit-overview' );
 836
 837                         deactivateOverviewTimeout = setTimeout( function () {
 838                                 dom.wrapper.classList.remove( 'exit-overview' );
 839                         }, 10);
 840
 841                         // Select all slides
 842                         var slides = toArray( document.querySelectorAll( SLIDES_SELECTOR ) );
 843
 844                         for( var i = 0, len = slides.length; i < len; i++ ) {
 845                                 var element = slides[i];
 846
 847                                 element.style.display = '';
 848
 849                                 // Resets all transforms to use the external styles
 850                                 element.style.WebkitTransform = '';
 851                                 element.style.MozTransform = '';
 852                                 element.style.msTransform = '';
 853                                 element.style.OTransform = '';
 854                                 element.style.transform = '';
 855
 856                                 element.removeEventListener( 'click', onOverviewSlideClicked, true );
 857                         }
 858
 859                         slide( indexh, indexv );
 860
 861                         cueAutoSlide();
 862
 863                         // Notify observers of the overview hiding
 864                         dispatchEvent( 'overviewhidden', {
 865                                 'indexh': indexh,
 866                                 'indexv': indexv,
 867                                 'currentSlide': currentSlide
 868                         } );
 869
 870                 }
 871         }
 872
 873         /**
 874          * Toggles the slide overview mode on and off.
 875          *
 876          * @param {Boolean} override Optional flag which overrides the
 877          * toggle logic and forcibly sets the desired state. True means
 878          * overview is open, false means it's closed.
 879          */
 880         function toggleOverview( override ) {
 881
 882                 if( typeof override === 'boolean' ) {
 883                         override ? activateOverview() : deactivateOverview();
 884                 }
 885                 else {
 886                         isOverview() ? deactivateOverview() : activateOverview();
 887                 }
 888
 889         }
 890
 891         /**
 892          * Checks if the overview is currently active.
 893          *
 894          * @return {Boolean} true if the overview is active,
 895          * false otherwise
 896          */
 897         function isOverview() {
 898
 899                 return dom.wrapper.classList.contains( 'overview' );
 900
 901         }
 902
 903         /**
 904          * Handling the fullscreen functionality via the fullscreen API
 905          *
 906          * @see http://fullscreen.spec.whatwg.org/
 907          * @see https://developer.mozilla.org/en-US/docs/DOM/Using_fullscreen_mode
 908          */
 909         function enterFullscreen() {
 910
 911                 var element = document.body;
 912
 913                 // Check which implementation is available
 914                 var requestMethod = element.requestFullScreen ||
 915                                                         element.webkitRequestFullScreen ||
 916                                                         element.mozRequestFullScreen ||
 917                                                         element.msRequestFullScreen;
 918
 919                 if( requestMethod ) {
 920                         requestMethod.apply( element );
 921                 }
 922
 923         }
 924
 925         /**
 926          * Enters the paused mode which fades everything on screen to
 927          * black.
 928          */
 929         function pause() {
 930
 931                 cancelAutoSlide();
 932                 dom.wrapper.classList.add( 'paused' );
 933
 934         }
 935
 936         /**
 937          * Exits from the paused mode.
 938          */
 939         function resume() {
 940
 941                 cueAutoSlide();
 942                 dom.wrapper.classList.remove( 'paused' );
 943
 944         }
 945
 946         /**
 947          * Toggles the paused mode on and off.
 948          */
 949         function togglePause() {
 950
 951                 if( isPaused() ) {
 952                         resume();
 953                 }
 954                 else {
 955                         pause();
 956                 }
 957
 958         }
 959
 960         /**
 961          * Checks if we are currently in the paused mode.
 962          */
 963         function isPaused() {
 964
 965                 return dom.wrapper.classList.contains( 'paused' );
 966
 967         }
 968
 969         /**
 970          * Steps from the current point in the presentation to the
 971          * slide which matches the specified horizontal and vertical
 972          * indices.
 973          *
 974          * @param {int} h Horizontal index of the target slide
 975          * @param {int} v Vertical index of the target slide
 976          * @param {int} f Optional index of a fragment within the
 977          * target slide to activate
 978          */
 979         function slide( h, v, f ) {
 980
 981                 // Remember where we were at before
 982                 previousSlide = currentSlide;
 983
 984                 // Query all horizontal slides in the deck
 985                 var horizontalSlides = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR );
 986
 987                 // If no vertical index is specified and the upcoming slide is a
 988                 // stack, resume at its previous vertical index
 989                 if( v === undefined ) {
 990                         v = getPreviousVerticalIndex( horizontalSlides[ h ] );
 991                 }
 992
 993                 // If we were on a vertical stack, remember what vertical index
 994                 // it was on so we can resume at the same position when returning
 995                 if( previousSlide && previousSlide.parentNode && previousSlide.parentNode.classList.contains( 'stack' ) ) {
 996                         setPreviousVerticalIndex( previousSlide.parentNode, indexv );
 997                 }
 998
 999                 // Remember the state before this slide
1000                 var stateBefore = state.concat();
1001
1002                 // Reset the state array
1003                 state.length = 0;
1004
1005                 var indexhBefore = indexh,
1006                         indexvBefore = indexv;
1007
1008                 // Activate and transition to the new slide
1009                 indexh = updateSlides( HORIZONTAL_SLIDES_SELECTOR, h === undefined ? indexh : h );
1010                 indexv = updateSlides( VERTICAL_SLIDES_SELECTOR, v === undefined ? indexv : v );
1011
1012                 layout();
1013
1014                 // Apply the new state
1015                 stateLoop: for( var i = 0, len = state.length; i < len; i++ ) {
1016                         // Check if this state existed on the previous slide. If it
1017                         // did, we will avoid adding it repeatedly
1018                         for( var j = 0; j < stateBefore.length; j++ ) {
1019                                 if( stateBefore[j] === state[i] ) {
1020                                         stateBefore.splice( j, 1 );
1021                                         continue stateLoop;
1022                                 }
1023                         }
1024
1025                         document.documentElement.classList.add( state[i] );
1026
1027                         // Dispatch custom event matching the state's name
1028                         dispatchEvent( state[i] );
1029                 }
1030
1031                 // Clean up the remains of the previous state
1032                 while( stateBefore.length ) {
1033                         document.documentElement.classList.remove( stateBefore.pop() );
1034                 }
1035
1036                 // If the overview is active, re-activate it to update positions
1037                 if( isOverview() ) {
1038                         activateOverview();
1039                 }
1040
1041                 // Update the URL hash after a delay since updating it mid-transition
1042                 // is likely to cause visual lag
1043                 writeURL( 1500 );
1044
1045                 // Find the current horizontal slide and any possible vertical slides
1046                 // within it
1047                 var currentHorizontalSlide = horizontalSlides[ indexh ],
1048                         currentVerticalSlides = currentHorizontalSlide.querySelectorAll( 'section' );
1049
1050                 // Store references to the previous and current slides
1051                 currentSlide = currentVerticalSlides[ indexv ] || currentHorizontalSlide;
1052
1053
1054                 // Show fragment, if specified
1055                 if( typeof f !== 'undefined' ) {
1056                         var fragments = sortFragments( currentSlide.querySelectorAll( '.fragment' ) );
1057
1058                         toArray( fragments ).forEach( function( fragment, indexf ) {
1059                                 if( indexf < f ) {
1060                                         fragment.classList.add( 'visible' );
1061                                 }
1062                                 else {
1063                                         fragment.classList.remove( 'visible' );
1064                                 }
1065                         } );
1066                 }
1067
1068                 // Dispatch an event if the slide changed
1069                 if( indexh !== indexhBefore || indexv !== indexvBefore ) {
1070                         dispatchEvent( 'slidechanged', {
1071                                 'indexh': indexh,
1072                                 'indexv': indexv,
1073                                 'previousSlide': previousSlide,
1074                                 'currentSlide': currentSlide
1075                         } );
1076                 }
1077                 else {
1078                         // Ensure that the previous slide is never the same as the current
1079                         previousSlide = null;
1080                 }
1081
1082                 // Solves an edge case where the previous slide maintains the
1083                 // 'present' class when navigating between adjacent vertical
1084                 // stacks
1085                 if( previousSlide ) {
1086                         previousSlide.classList.remove( 'present' );
1087
1088                         // Reset all slides upon navigate to home
1089                         // Issue: #285
1090                         if ( document.querySelector( HOME_SLIDE_SELECTOR ).classList.contains( 'present' ) ) {
1091                                 // Launch async task
1092                                 setTimeout( function () {
1093                                         var slides = toArray( document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR + '.stack') ), i;
1094                                         for( i in slides ) {
1095                                                 if( slides[i] ) {
1096                                                         // Reset stack
1097                                                         setPreviousVerticalIndex( slides[i], 0 );
1098                                                 }
1099                                         }
1100                                 }, 0 );
1101                         }
1102                 }
1103
1104                 updateControls();
1105                 updateProgress();
1106
1107         }
1108
1109         /**
1110          * Updates one dimension of slides by showing the slide
1111          * with the specified index.
1112          *
1113          * @param {String} selector A CSS selector that will fetch
1114          * the group of slides we are working with
1115          * @param {Number} index The index of the slide that should be
1116          * shown
1117          *
1118          * @return {Number} The index of the slide that is now shown,
1119          * might differ from the passed in index if it was out of
1120          * bounds.
1121          */
1122         function updateSlides( selector, index ) {
1123
1124                 // Select all slides and convert the NodeList result to
1125                 // an array
1126                 var slides = toArray( document.querySelectorAll( selector ) ),
1127                         slidesLength = slides.length;
1128
1129                 if( slidesLength ) {
1130
1131                         // Should the index loop?
1132                         if( config.loop ) {
1133                                 index %= slidesLength;
1134
1135                                 if( index < 0 ) {
1136                                         index = slidesLength + index;
1137                                 }
1138                         }
1139
1140                         // Enforce max and minimum index bounds
1141                         index = Math.max( Math.min( index, slidesLength - 1 ), 0 );
1142
1143                         for( var i = 0; i < slidesLength; i++ ) {
1144                                 var element = slides[i];
1145
1146                                 // Optimization; hide all slides that are three or more steps
1147                                 // away from the present slide
1148                                 if( isOverview() === false ) {
1149                                         // The distance loops so that it measures 1 between the first
1150                                         // and last slides
1151                                         var distance = Math.abs( ( index - i ) % ( slidesLength - 3 ) ) || 0;
1152
1153                                         element.style.display = distance > 3 ? 'none' : 'block';
1154                                 }
1155
1156                                 slides[i].classList.remove( 'past' );
1157                                 slides[i].classList.remove( 'present' );
1158                                 slides[i].classList.remove( 'future' );
1159
1160                                 if( i < index ) {
1161                                         // Any element previous to index is given the 'past' class
1162                                         slides[i].classList.add( 'past' );
1163                                 }
1164                                 else if( i > index ) {
1165                                         // Any element subsequent to index is given the 'future' class
1166                                         slides[i].classList.add( 'future' );
1167                                 }
1168
1169                                 // If this element contains vertical slides
1170                                 if( element.querySelector( 'section' ) ) {
1171                                         slides[i].classList.add( 'stack' );
1172                                 }
1173                         }
1174
1175                         // Mark the current slide as present
1176                         slides[index].classList.add( 'present' );
1177
1178                         // If this slide has a state associated with it, add it
1179                         // onto the current state of the deck
1180                         var slideState = slides[index].getAttribute( 'data-state' );
1181                         if( slideState ) {
1182                                 state = state.concat( slideState.split( ' ' ) );
1183                         }
1184
1185                         // If this slide has a data-autoslide attribtue associated use this as
1186                         // autoSlide value otherwise use the global configured time
1187                         var slideAutoSlide = slides[index].getAttribute( 'data-autoslide' );
1188                         if( slideAutoSlide ) {
1189                                 autoSlide = parseInt( slideAutoSlide, 10 );
1190                         }
1191                         else {
1192                                 autoSlide = config.autoSlide;
1193                         }
1194
1195                 }
1196                 else {
1197                         // Since there are no slides we can't be anywhere beyond the
1198                         // zeroth index
1199                         index = 0;
1200                 }
1201
1202                 return index;
1203
1204         }
1205
1206         /**
1207          * Updates the progress bar to reflect the current slide.
1208          */
1209         function updateProgress() {
1210
1211                 // Update progress if enabled
1212                 if( config.progress && dom.progress ) {
1213
1214                         var horizontalSlides = toArray( document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) );
1215
1216                         // The number of past and total slides
1217                         var totalCount = document.querySelectorAll( SLIDES_SELECTOR + ':not(.stack)' ).length;
1218                         var pastCount = 0;
1219
1220                         // Step through all slides and count the past ones
1221                         mainLoop: for( var i = 0; i < horizontalSlides.length; i++ ) {
1222
1223                                 var horizontalSlide = horizontalSlides[i];
1224                                 var verticalSlides = toArray( horizontalSlide.querySelectorAll( 'section' ) );
1225
1226                                 for( var j = 0; j < verticalSlides.length; j++ ) {
1227
1228                                         // Stop as soon as we arrive at the present
1229                                         if( verticalSlides[j].classList.contains( 'present' ) ) {
1230                                                 break mainLoop;
1231                                         }
1232
1233                                         pastCount++;
1234
1235                                 }
1236
1237                                 // Stop as soon as we arrive at the present
1238                                 if( horizontalSlide.classList.contains( 'present' ) ) {
1239                                         break;
1240                                 }
1241
1242                                 // Don't count the wrapping section for vertical slides
1243                                 if( horizontalSlide.classList.contains( 'stack' ) === false ) {
1244                                         pastCount++;
1245                                 }
1246
1247                         }
1248
1249                         dom.progressbar.style.width = ( pastCount / ( totalCount - 1 ) ) * window.innerWidth + 'px';
1250
1251                 }
1252
1253         }
1254
1255         /**
1256          * Updates the state of all control/navigation arrows.
1257          */
1258         function updateControls() {
1259
1260                 if ( config.controls && dom.controls ) {
1261
1262                         var routes = availableRoutes();
1263
1264                         // Remove the 'enabled' class from all directions
1265                         dom.controlsLeft.concat( dom.controlsRight )
1266                                                         .concat( dom.controlsUp )
1267                                                         .concat( dom.controlsDown )
1268                                                         .concat( dom.controlsPrev )
1269                                                         .concat( dom.controlsNext ).forEach( function( node ) {
1270                                 node.classList.remove( 'enabled' );
1271                         } );
1272
1273                         // Add the 'enabled' class to the available routes
1274                         if( routes.left ) dom.controlsLeft.forEach( function( el ) { el.classList.add( 'enabled' );     } );
1275                         if( routes.right ) dom.controlsRight.forEach( function( el ) { el.classList.add( 'enabled' ); } );
1276                         if( routes.up ) dom.controlsUp.forEach( function( el ) { el.classList.add( 'enabled' ); } );
1277                         if( routes.down ) dom.controlsDown.forEach( function( el ) { el.classList.add( 'enabled' ); } );
1278
1279                         // Prev/next buttons
1280                         if( routes.left || routes.up ) dom.controlsPrev.forEach( function( el ) { el.classList.add( 'enabled' ); } );
1281                         if( routes.right || routes.down ) dom.controlsNext.forEach( function( el ) { el.classList.add( 'enabled' ); } );
1282
1283                 }
1284
1285         }
1286
1287         /**
1288          * Determine what available routes there are for navigation.
1289          *
1290          * @return {Object} containing four booleans: left/right/up/down
1291          */
1292         function availableRoutes() {
1293
1294                 var horizontalSlides = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ),
1295                         verticalSlides = document.querySelectorAll( VERTICAL_SLIDES_SELECTOR );
1296
1297                 return {
1298                         left: indexh > 0,
1299                         right: indexh < horizontalSlides.length - 1,
1300                         up: indexv > 0,
1301                         down: indexv < verticalSlides.length - 1
1302                 };
1303
1304         }
1305
1306         /**
1307          * Reads the current URL (hash) and navigates accordingly.
1308          */
1309         function readURL() {
1310
1311                 var hash = window.location.hash;
1312
1313                 // Attempt to parse the hash as either an index or name
1314                 var bits = hash.slice( 2 ).split( '/' ),
1315                         name = hash.replace( /#|\//gi, '' );
1316
1317                 // If the first bit is invalid and there is a name we can
1318                 // assume that this is a named link
1319                 if( isNaN( parseInt( bits[0], 10 ) ) && name.length ) {
1320                         // Find the slide with the specified name
1321                         var element = document.querySelector( '#' + name );
1322
1323                         if( element ) {
1324                                 // Find the position of the named slide and navigate to it
1325                                 var indices = Reveal.getIndices( element );
1326                                 slide( indices.h, indices.v );
1327                         }
1328                         // If the slide doesn't exist, navigate to the current slide
1329                         else {
1330                                 slide( indexh, indexv );
1331                         }
1332                 }
1333                 else {
1334                         // Read the index components of the hash
1335                         var h = parseInt( bits[0], 10 ) || 0,
1336                                 v = parseInt( bits[1], 10 ) || 0;
1337
1338                         slide( h, v );
1339                 }
1340
1341         }
1342
1343         /**
1344          * Updates the page URL (hash) to reflect the current
1345          * state.
1346          *
1347          * @param {Number} delay The time in ms to wait before
1348          * writing the hash
1349          */
1350         function writeURL( delay ) {
1351
1352                 if( config.history ) {
1353
1354                         // Make sure there's never more than one timeout running
1355                         clearTimeout( writeURLTimeout );
1356
1357                         // If a delay is specified, timeout this call
1358                         if( typeof delay === 'number' ) {
1359                                 writeURLTimeout = setTimeout( writeURL, delay );
1360                         }
1361                         else {
1362                                 var url = '/';
1363
1364                                 // If the current slide has an ID, use that as a named link
1365                                 if( currentSlide && typeof currentSlide.getAttribute( 'id' ) === 'string' ) {
1366                                         url = '/' + currentSlide.getAttribute( 'id' );
1367                                 }
1368                                 // Otherwise use the /h/v index
1369                                 else {
1370                                         if( indexh > 0 || indexv > 0 ) url += indexh;
1371                                         if( indexv > 0 ) url += '/' + indexv;
1372                                 }
1373
1374                                 window.location.hash = url;
1375                         }
1376                 }
1377
1378         }
1379
1380         /**
1381          * Retrieves the h/v location of the current, or specified,
1382          * slide.
1383          *
1384          * @param {HTMLElement} slide If specified, the returned
1385          * index will be for this slide rather than the currently
1386          * active one
1387          *
1388          * @return {Object} { h: <int>, v: <int> }
1389          */
1390         function getIndices( slide ) {
1391
1392                 // By default, return the current indices
1393                 var h = indexh,
1394                         v = indexv;
1395
1396                 // If a slide is specified, return the indices of that slide
1397                 if( slide ) {
1398                         var isVertical = !!slide.parentNode.nodeName.match( /section/gi );
1399                         var slideh = isVertical ? slide.parentNode : slide;
1400
1401                         // Select all horizontal slides
1402                         var horizontalSlides = toArray( document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) );
1403
1404                         // Now that we know which the horizontal slide is, get its index
1405                         h = Math.max( horizontalSlides.indexOf( slideh ), 0 );
1406
1407                         // If this is a vertical slide, grab the vertical index
1408                         if( isVertical ) {
1409                                 v = Math.max( toArray( slide.parentNode.querySelectorAll( 'section' ) ).indexOf( slide ), 0 );
1410                         }
1411                 }
1412
1413                 return { h: h, v: v };
1414
1415         }
1416
1417         /**
1418          * Navigate to the next slide fragment.
1419          *
1420          * @return {Boolean} true if there was a next fragment,
1421          * false otherwise
1422          */
1423         function nextFragment() {
1424
1425                 // Vertical slides:
1426                 if( document.querySelector( VERTICAL_SLIDES_SELECTOR + '.present' ) ) {
1427                         var verticalFragments = sortFragments( document.querySelectorAll( VERTICAL_SLIDES_SELECTOR + '.present .fragment:not(.visible)' ) );
1428
1429                         if( verticalFragments.length ) {
1430                                 verticalFragments[0].classList.add( 'visible' );
1431
1432                                 // Notify subscribers of the change
1433                                 dispatchEvent( 'fragmentshown', { fragment: verticalFragments[0] } );
1434                                 return true;
1435                         }
1436                 }
1437                 // Horizontal slides:
1438                 else {
1439                         var horizontalFragments = sortFragments( document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR + '.present .fragment:not(.visible)' ) );
1440
1441                         if( horizontalFragments.length ) {
1442                                 horizontalFragments[0].classList.add( 'visible' );
1443
1444                                 // Notify subscribers of the change
1445                                 dispatchEvent( 'fragmentshown', { fragment: horizontalFragments[0] } );
1446                                 return true;
1447                         }
1448                 }
1449
1450                 return false;
1451
1452         }
1453
1454         /**
1455          * Navigate to the previous slide fragment.
1456          *
1457          * @return {Boolean} true if there was a previous fragment,
1458          * false otherwise
1459          */
1460         function previousFragment() {
1461
1462                 // Vertical slides:
1463                 if( document.querySelector( VERTICAL_SLIDES_SELECTOR + '.present' ) ) {
1464                         var verticalFragments = sortFragments( document.querySelectorAll( VERTICAL_SLIDES_SELECTOR + '.present .fragment.visible' ) );
1465
1466                         if( verticalFragments.length ) {
1467                                 verticalFragments[ verticalFragments.length - 1 ].classList.remove( 'visible' );
1468
1469                                 // Notify subscribers of the change
1470                                 dispatchEvent( 'fragmenthidden', { fragment: verticalFragments[ verticalFragments.length - 1 ] } );
1471                                 return true;
1472                         }
1473                 }
1474                 // Horizontal slides:
1475                 else {
1476                         var horizontalFragments = sortFragments( document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR + '.present .fragment.visible' ) );
1477
1478                         if( horizontalFragments.length ) {
1479                                 horizontalFragments[ horizontalFragments.length - 1 ].classList.remove( 'visible' );
1480
1481                                 // Notify subscribers of the change
1482                                 dispatchEvent( 'fragmenthidden', { fragment: horizontalFragments[ horizontalFragments.length - 1 ] } );
1483                                 return true;
1484                         }
1485                 }
1486
1487                 return false;
1488
1489         }
1490
1491         /**
1492          * Cues a new automated slide if enabled in the config.
1493          */
1494         function cueAutoSlide() {
1495
1496                 clearTimeout( autoSlideTimeout );
1497
1498                 // Cue the next auto-slide if enabled
1499                 if( autoSlide && !isPaused() && !isOverview() ) {
1500                         autoSlideTimeout = setTimeout( navigateNext, autoSlide );
1501                 }
1502
1503         }
1504
1505         /**
1506          * Cancels any ongoing request to auto-slide.
1507          */
1508         function cancelAutoSlide() {
1509
1510                 clearTimeout( autoSlideTimeout );
1511
1512         }
1513
1514         function navigateLeft() {
1515
1516                 // Prioritize hiding fragments
1517                 if( availableRoutes().left && isOverview() || previousFragment() === false ) {
1518                         slide( indexh - 1 );
1519                 }
1520
1521         }
1522
1523         function navigateRight() {
1524
1525                 // Prioritize revealing fragments
1526                 if( availableRoutes().right && isOverview() || nextFragment() === false ) {
1527                         slide( indexh + 1 );
1528                 }
1529
1530         }
1531
1532         function navigateUp() {
1533
1534                 // Prioritize hiding fragments
1535                 if( availableRoutes().up && isOverview() || previousFragment() === false ) {
1536                         slide( indexh, indexv - 1 );
1537                 }
1538
1539         }
1540
1541         function navigateDown() {
1542
1543                 // Prioritize revealing fragments
1544                 if( availableRoutes().down && isOverview() || nextFragment() === false ) {
1545                         slide( indexh, indexv + 1 );
1546                 }
1547
1548         }
1549
1550         /**
1551          * Navigates backwards, prioritized in the following order:
1552          * 1) Previous fragment
1553          * 2) Previous vertical slide
1554          * 3) Previous horizontal slide
1555          */
1556         function navigatePrev() {
1557
1558                 // Prioritize revealing fragments
1559                 if( previousFragment() === false ) {
1560                         if( availableRoutes().up ) {
1561                                 navigateUp();
1562                         }
1563                         else {
1564                                 // Fetch the previous horizontal slide, if there is one
1565                                 var previousSlide = document.querySelector( HORIZONTAL_SLIDES_SELECTOR + '.past:nth-child(' + indexh + ')' );
1566
1567                                 if( previousSlide ) {
1568                                         indexv = ( previousSlide.querySelectorAll( 'section' ).length + 1 ) || undefined;
1569                                         indexh --;
1570                                         slide();
1571                                 }
1572                         }
1573                 }
1574
1575         }
1576
1577         /**
1578          * Same as #navigatePrev() but navigates forwards.
1579          */
1580         function navigateNext() {
1581
1582                 // Prioritize revealing fragments
1583                 if( nextFragment() === false ) {
1584                         availableRoutes().down ? navigateDown() : navigateRight();
1585                 }
1586
1587                 // If auto-sliding is enabled we need to cue up
1588                 // another timeout
1589                 cueAutoSlide();
1590
1591         }
1592
1593
1594         // --------------------------------------------------------------------//
1595         // ----------------------------- EVENTS -------------------------------//
1596         // --------------------------------------------------------------------//
1597
1598
1599         /**
1600          * Handler for the document level 'keydown' event.
1601          *
1602          * @param {Object} event
1603          */
1604         function onDocumentKeyDown( event ) {
1605
1606                 // Check if there's a focused element that could be using
1607                 // the keyboard
1608                 var activeElement = document.activeElement;
1609                 var hasFocus = !!( document.activeElement && ( document.activeElement.type || document.activeElement.href || document.activeElement.contentEditable !== 'inherit' ) );
1610
1611                 // Disregard the event if there's a focused element or a
1612                 // keyboard modifier key is present
1613                 if( hasFocus || event.shiftKey || event.altKey || event.ctrlKey || event.metaKey ) return;
1614
1615                 var triggered = true;
1616
1617                 // while paused only allow "unpausing" keyboard events (b and .)
1618                 if( isPaused() && [66,190,191].indexOf( event.keyCode ) === -1 ) {
1619                         return false;
1620                 }
1621
1622                 switch( event.keyCode ) {
1623                         // p, page up
1624                         case 80: case 33: navigatePrev(); break;
1625                         // n, page down
1626                         case 78: case 34: navigateNext(); break;
1627                         // h, left
1628                         case 72: case 37: navigateLeft(); break;
1629                         // l, right
1630                         case 76: case 39: navigateRight(); break;
1631                         // k, up
1632                         case 75: case 38: navigateUp(); break;
1633                         // j, down
1634                         case 74: case 40: navigateDown(); break;
1635                         // home
1636                         case 36: slide( 0 ); break;
1637                         // end
1638                         case 35: slide( Number.MAX_VALUE ); break;
1639                         // space
1640                         case 32: isOverview() ? deactivateOverview() : navigateNext(); break;
1641                         // return
1642                         case 13: isOverview() ? deactivateOverview() : triggered = false; break;
1643                         // b, period, Logitech presenter tools "black screen" button
1644                         case 66: case 190: case 191: togglePause(); break;
1645                         // f
1646                         case 70: enterFullscreen(); break;
1647                         default:
1648                                 triggered = false;
1649                 }
1650
1651                 // If the input resulted in a triggered action we should prevent
1652                 // the browsers default behavior
1653                 if( triggered ) {
1654                         event.preventDefault();
1655                 }
1656                 else if ( event.keyCode === 27 && supports3DTransforms ) {
1657                         toggleOverview();
1658
1659                         event.preventDefault();
1660                 }
1661
1662                 // If auto-sliding is enabled we need to cue up
1663                 // another timeout
1664                 cueAutoSlide();
1665
1666         }
1667
1668         /**
1669          * Handler for the document level 'touchstart' event,
1670          * enables support for swipe and pinch gestures.
1671          */
1672         function onDocumentTouchStart( event ) {
1673
1674                 touch.startX = event.touches[0].clientX;
1675                 touch.startY = event.touches[0].clientY;
1676                 touch.startCount = event.touches.length;
1677
1678                 // If there's two touches we need to memorize the distance
1679                 // between those two points to detect pinching
1680                 if( event.touches.length === 2 && config.overview ) {
1681                         touch.startSpan = distanceBetween( {
1682                                 x: event.touches[1].clientX,
1683                                 y: event.touches[1].clientY
1684                         }, {
1685                                 x: touch.startX,
1686                                 y: touch.startY
1687                         } );
1688                 }
1689
1690         }
1691
1692         /**
1693          * Handler for the document level 'touchmove' event.
1694          */
1695         function onDocumentTouchMove( event ) {
1696
1697                 // Each touch should only trigger one action
1698                 if( !touch.handled ) {
1699                         var currentX = event.touches[0].clientX;
1700                         var currentY = event.touches[0].clientY;
1701
1702                         // If the touch started off with two points and still has
1703                         // two active touches; test for the pinch gesture
1704                         if( event.touches.length === 2 && touch.startCount === 2 && config.overview ) {
1705
1706                                 // The current distance in pixels between the two touch points
1707                                 var currentSpan = distanceBetween( {
1708                                         x: event.touches[1].clientX,
1709                                         y: event.touches[1].clientY
1710                                 }, {
1711                                         x: touch.startX,
1712                                         y: touch.startY
1713                                 } );
1714
1715                                 // If the span is larger than the desire amount we've got
1716                                 // ourselves a pinch
1717                                 if( Math.abs( touch.startSpan - currentSpan ) > touch.threshold ) {
1718                                         touch.handled = true;
1719
1720                                         if( currentSpan < touch.startSpan ) {
1721                                                 activateOverview();
1722                                         }
1723                                         else {
1724                                                 deactivateOverview();
1725                                         }
1726                                 }
1727
1728                                 event.preventDefault();
1729
1730                         }
1731                         // There was only one touch point, look for a swipe
1732                         else if( event.touches.length === 1 && touch.startCount !== 2 ) {
1733
1734                                 var deltaX = currentX - touch.startX,
1735                                         deltaY = currentY - touch.startY;
1736
1737                                 if( deltaX > touch.threshold && Math.abs( deltaX ) > Math.abs( deltaY ) ) {
1738                                         touch.handled = true;
1739                                         navigateLeft();
1740                                 }
1741                                 else if( deltaX < -touch.threshold && Math.abs( deltaX ) > Math.abs( deltaY ) ) {
1742                                         touch.handled = true;
1743                                         navigateRight();
1744                                 }
1745                                 else if( deltaY > touch.threshold ) {
1746                                         touch.handled = true;
1747                                         navigateUp();
1748                                 }
1749                                 else if( deltaY < -touch.threshold ) {
1750                                         touch.handled = true;
1751                                         navigateDown();
1752                                 }
1753
1754                                 event.preventDefault();
1755
1756                         }
1757                 }
1758                 // There's a bug with swiping on some Android devices unless
1759                 // the default action is always prevented
1760                 else if( navigator.userAgent.match( /android/gi ) ) {
1761                         event.preventDefault();
1762                 }
1763
1764         }
1765
1766         /**
1767          * Handler for the document level 'touchend' event.
1768          */
1769         function onDocumentTouchEnd( event ) {
1770
1771                 touch.handled = false;
1772
1773         }
1774
1775         /**
1776          * Handles mouse wheel scrolling, throttled to avoid skipping
1777          * multiple slides.
1778          */
1779         function onDocumentMouseScroll( event ) {
1780
1781                 clearTimeout( mouseWheelTimeout );
1782
1783                 mouseWheelTimeout = setTimeout( function() {
1784                         var delta = event.detail || -event.wheelDelta;
1785                         if( delta > 0 ) {
1786                                 navigateNext();
1787                         }
1788                         else {
1789                                 navigatePrev();
1790                         }
1791                 }, 100 );
1792
1793         }
1794
1795         /**
1796          * Clicking on the progress bar results in a navigation to the
1797          * closest approximate horizontal slide using this equation:
1798          *
1799          * ( clickX / presentationWidth ) * numberOfSlides
1800          */
1801         function onProgressClicked( event ) {
1802
1803                 event.preventDefault();
1804
1805                 var slidesTotal = toArray( document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) ).length;
1806                 var slideIndex = Math.floor( ( event.clientX / dom.wrapper.offsetWidth ) * slidesTotal );
1807
1808                 slide( slideIndex );
1809
1810         }
1811
1812         /**
1813          * Event handler for navigation control buttons.
1814          */
1815         function onNavigateLeftClicked( event ) { event.preventDefault(); navigateLeft(); }
1816         function onNavigateRightClicked( event ) { event.preventDefault(); navigateRight(); }
1817         function onNavigateUpClicked( event ) { event.preventDefault(); navigateUp(); }
1818         function onNavigateDownClicked( event ) { event.preventDefault(); navigateDown(); }
1819         function onNavigatePrevClicked( event ) { event.preventDefault(); navigatePrev(); }
1820         function onNavigateNextClicked( event ) { event.preventDefault(); navigateNext(); }
1821
1822         /**
1823          * Handler for the window level 'hashchange' event.
1824          */
1825         function onWindowHashChange( event ) {
1826
1827                 readURL();
1828
1829         }
1830
1831         /**
1832          * Handler for the window level 'resize' event.
1833          */
1834         function onWindowResize( event ) {
1835
1836                 layout();
1837
1838         }
1839
1840         /**
1841          * Invoked when a slide is and we're in the overview.
1842          */
1843         function onOverviewSlideClicked( event ) {
1844
1845                 // TODO There's a bug here where the event listeners are not
1846                 // removed after deactivating the overview.
1847                 if( eventsAreBound && isOverview() ) {
1848                         event.preventDefault();
1849
1850                         var element = event.target;
1851
1852                         while( element && !element.nodeName.match( /section/gi ) ) {
1853                                 element = element.parentNode;
1854                         }
1855
1856                         if( element && !element.classList.contains( 'disabled' ) ) {
1857
1858                                 deactivateOverview();
1859
1860                                 if( element.nodeName.match( /section/gi ) ) {
1861                                         var h = parseInt( element.getAttribute( 'data-index-h' ), 10 ),
1862                                                 v = parseInt( element.getAttribute( 'data-index-v' ), 10 );
1863
1864                                         slide( h, v );
1865                                 }
1866
1867                         }
1868                 }
1869
1870         }
1871
1872
1873         // --------------------------------------------------------------------//
1874         // ------------------------------- API --------------------------------//
1875         // --------------------------------------------------------------------//
1876
1877
1878         return {
1879                 initialize: initialize,
1880                 configure: configure,
1881
1882                 // Navigation methods
1883                 slide: slide,
1884                 left: navigateLeft,
1885                 right: navigateRight,
1886                 up: navigateUp,
1887                 down: navigateDown,
1888                 prev: navigatePrev,
1889                 next: navigateNext,
1890                 prevFragment: previousFragment,
1891                 nextFragment: nextFragment,
1892
1893                 // Deprecated aliases
1894                 navigateTo: slide,
1895                 navigateLeft: navigateLeft,
1896                 navigateRight: navigateRight,
1897                 navigateUp: navigateUp,
1898                 navigateDown: navigateDown,
1899                 navigatePrev: navigatePrev,
1900                 navigateNext: navigateNext,
1901
1902                 // Forces an update in slide layout
1903                 layout: layout,
1904
1905                 // Toggles the overview mode on/off
1906                 toggleOverview: toggleOverview,
1907
1908                 // Toggles the "black screen" mode on/off
1909                 togglePause: togglePause,
1910
1911                 // State checks
1912                 isOverview: isOverview,
1913                 isPaused: isPaused,
1914
1915                 // Adds or removes all internal event listeners (such as keyboard)
1916                 addEventListeners: addEventListeners,
1917                 removeEventListeners: removeEventListeners,
1918
1919                 // Returns the indices of the current, or specified, slide
1920                 getIndices: getIndices,
1921
1922                 // Returns the slide at the specified index, y is optional
1923                 getSlide: function( x, y ) {
1924                         var horizontalSlide = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR )[ x ];
1925                         var verticalSlides = horizontalSlide && horizontalSlide.querySelectorAll( 'section' );
1926
1927                         if( typeof y !== 'undefined' ) {
1928                                 return verticalSlides ? verticalSlides[ y ] : undefined;
1929                         }
1930
1931                         return horizontalSlide;
1932                 },
1933
1934                 // Returns the previous slide element, may be null
1935                 getPreviousSlide: function() {
1936                         return previousSlide;
1937                 },
1938
1939                 // Returns the current slide element
1940                 getCurrentSlide: function() {
1941                         return currentSlide;
1942                 },
1943
1944                 // Returns the current scale of the presentation content
1945                 getScale: function() {
1946                         return scale;
1947                 },
1948
1949                 // Helper method, retrieves query string as a key/value hash
1950                 getQueryHash: function() {
1951                         var query = {};
1952
1953                         location.search.replace( /[A-Z0-9]+?=(\w*)/gi, function(a) {
1954                                 query[ a.split( '=' ).shift() ] = a.split( '=' ).pop();
1955                         } );
1956
1957                         return query;
1958                 },
1959
1960                 // Returns true if we're currently on the first slide
1961                 isFirstSlide: function() {
1962                         return document.querySelector( SLIDES_SELECTOR + '.past' ) == null ? true : false;
1963                 },
1964
1965                 // Returns true if we're currently on the last slide
1966                 isLastSlide: function() {
1967                         if( currentSlide && currentSlide.classList.contains( '.stack' ) ) {
1968                                 return currentSlide.querySelector( SLIDES_SELECTOR + '.future' ) == null ? true : false;
1969                         }
1970                         else {
1971                                 return document.querySelector( SLIDES_SELECTOR + '.future' ) == null ? true : false;
1972                         }
1973                 },
1974
1975                 // Forward event binding to the reveal DOM element
1976                 addEventListener: function( type, listener, useCapture ) {
1977                         if( 'addEventListener' in window ) {
1978                                 ( dom.wrapper || document.querySelector( '.reveal' ) ).addEventListener( type, listener, useCapture );
1979                         }
1980                 },
1981                 removeEventListener: function( type, listener, useCapture ) {
1982                         if( 'addEventListener' in window ) {
1983                                 ( dom.wrapper || document.querySelector( '.reveal' ) ).removeEventListener( type, listener, useCapture );
1984                         }
1985                 }
1986         };
1987
1988 })();