From 9569679f3e5afa71b7973301801cc0864fc32ec2 Mon Sep 17 00:00:00 2001 From: Lars Wirzenius Date: Sun, 1 Jul 2018 15:20:46 +0300 Subject: Add: reveal.js --- js/reveal.js | 5239 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 5239 insertions(+) create mode 100644 js/reveal.js (limited to 'js') diff --git a/js/reveal.js b/js/reveal.js new file mode 100644 index 0000000..f125c55 --- /dev/null +++ b/js/reveal.js @@ -0,0 +1,5239 @@ +/*! + * reveal.js + * http://revealjs.com + * MIT licensed + * + * Copyright (C) 2017 Hakim El Hattab, http://hakim.se + */ +(function( root, factory ) { + if( typeof define === 'function' && define.amd ) { + // AMD. Register as an anonymous module. + define( function() { + root.Reveal = factory(); + return root.Reveal; + } ); + } else if( typeof exports === 'object' ) { + // Node. Does not work with strict CommonJS. + module.exports = factory(); + } else { + // Browser globals. + root.Reveal = factory(); + } +}( this, function() { + + 'use strict'; + + var Reveal; + + // The reveal.js version + var VERSION = '3.6.0'; + + var SLIDES_SELECTOR = '.slides section', + HORIZONTAL_SLIDES_SELECTOR = '.slides>section', + VERTICAL_SLIDES_SELECTOR = '.slides>section.present>section', + HOME_SLIDE_SELECTOR = '.slides>section:first-of-type', + UA = navigator.userAgent, + + // Configuration defaults, can be overridden at initialization time + config = { + + // The "normal" size of the presentation, aspect ratio will be preserved + // when the presentation is scaled to fit different resolutions + width: 960, + height: 700, + + // Factor of the display size that should remain empty around the content + margin: 0.04, + + // Bounds for smallest/largest possible scale to apply to content + minScale: 0.2, + maxScale: 2.0, + + // Display presentation control arrows + controls: true, + + // Help the user learn the controls by providing hints, for example by + // bouncing the down arrow when they first encounter a vertical slide + controlsTutorial: true, + + // Determines where controls appear, "edges" or "bottom-right" + controlsLayout: 'bottom-right', + + // Visibility rule for backwards navigation arrows; "faded", "hidden" + // or "visible" + controlsBackArrows: 'faded', + + // Display a presentation progress bar + progress: true, + + // Display the page number of the current slide + slideNumber: false, + + // Determine which displays to show the slide number on + showSlideNumber: 'all', + + // Push each slide change to the browser history + history: false, + + // Enable keyboard shortcuts for navigation + keyboard: true, + + // Optional function that blocks keyboard events when retuning false + keyboardCondition: null, + + // Enable the slide overview mode + overview: true, + + // Vertical centering of slides + center: true, + + // Enables touch navigation on devices with touch input + touch: true, + + // Loop the presentation + loop: false, + + // Change the presentation direction to be RTL + rtl: false, + + // Randomizes the order of slides each time the presentation loads + shuffle: false, + + // Turns fragments on and off globally + fragments: true, + + // Flags if the presentation is running in an embedded mode, + // i.e. contained within a limited portion of the screen + embedded: false, + + // Flags if we should show a help overlay when the question-mark + // key is pressed + help: true, + + // Flags if it should be possible to pause the presentation (blackout) + pause: true, + + // Flags if speaker notes should be visible to all viewers + showNotes: false, + + // Global override for autolaying embedded media (video/audio/iframe) + // - null: Media will only autoplay if data-autoplay is present + // - true: All media will autoplay, regardless of individual setting + // - false: No media will autoplay, regardless of individual setting + autoPlayMedia: null, + + // Controls automatic progression to the next slide + // - 0: Auto-sliding only happens if the data-autoslide HTML attribute + // is present on the current slide or fragment + // - 1+: All slides will progress automatically at the given interval + // - false: No auto-sliding, even if data-autoslide is present + autoSlide: 0, + + // Stop auto-sliding after user input + autoSlideStoppable: true, + + // Use this method for navigation when auto-sliding (defaults to navigateNext) + autoSlideMethod: null, + + // Enable slide navigation via mouse wheel + mouseWheel: false, + + // Apply a 3D roll to links on hover + rollingLinks: false, + + // Hides the address bar on mobile devices + hideAddressBar: true, + + // Opens links in an iframe preview overlay + previewLinks: false, + + // Exposes the reveal.js API through window.postMessage + postMessage: true, + + // Dispatches all reveal.js events to the parent window through postMessage + postMessageEvents: false, + + // Focuses body when page changes visibility to ensure keyboard shortcuts work + focusBodyOnPageVisibilityChange: true, + + // Transition style + transition: 'slide', // none/fade/slide/convex/concave/zoom + + // Transition speed + transitionSpeed: 'default', // default/fast/slow + + // Transition style for full page slide backgrounds + backgroundTransition: 'fade', // none/fade/slide/convex/concave/zoom + + // Parallax background image + parallaxBackgroundImage: '', // CSS syntax, e.g. "a.jpg" + + // Parallax background size + parallaxBackgroundSize: '', // CSS syntax, e.g. "3000px 2000px" + + // Amount of pixels to move the parallax background per slide step + parallaxBackgroundHorizontal: null, + parallaxBackgroundVertical: null, + + // The maximum number of pages a single slide can expand onto when printing + // to PDF, unlimited by default + pdfMaxPagesPerSlide: Number.POSITIVE_INFINITY, + + // Offset used to reduce the height of content within exported PDF pages. + // This exists to account for environment differences based on how you + // print to PDF. CLI printing options, like phantomjs and wkpdf, can end + // on precisely the total height of the document whereas in-browser + // printing has to end one pixel before. + pdfPageHeightOffset: -1, + + // Number of slides away from the current that are visible + viewDistance: 3, + + // The display mode that will be used to show slides + display: 'block', + + // Script dependencies to load + dependencies: [] + + }, + + // Flags if Reveal.initialize() has been called + initialized = false, + + // Flags if reveal.js is loaded (has dispatched the 'ready' event) + loaded = false, + + // Flags if the overview mode is currently active + overview = false, + + // Holds the dimensions of our overview slides, including margins + overviewSlideWidth = null, + overviewSlideHeight = null, + + // The horizontal and vertical index of the currently active slide + indexh, + indexv, + + // The previous and current slide HTML elements + previousSlide, + currentSlide, + + previousBackground, + + // Remember which directions that the user has navigated towards + hasNavigatedRight = false, + hasNavigatedDown = false, + + // Slides may hold a data-state attribute which we pick up and apply + // as a class to the body. This list contains the combined state of + // all current slides. + state = [], + + // The current scale of the presentation (see width/height config) + scale = 1, + + // CSS transform that is currently applied to the slides container, + // split into two groups + slidesTransform = { layout: '', overview: '' }, + + // Cached references to DOM elements + dom = {}, + + // Features supported by the browser, see #checkCapabilities() + features = {}, + + // Client is a mobile device, see #checkCapabilities() + isMobileDevice, + + // Client is a desktop Chrome, see #checkCapabilities() + isChrome, + + // Throttles mouse wheel navigation + lastMouseWheelStep = 0, + + // Delays updates to the URL due to a Chrome thumbnailer bug + writeURLTimeout = 0, + + // Flags if the interaction event listeners are bound + eventsAreBound = false, + + // The current auto-slide duration + autoSlide = 0, + + // Auto slide properties + autoSlidePlayer, + autoSlideTimeout = 0, + autoSlideStartTime = -1, + autoSlidePaused = false, + + // Holds information about the currently ongoing touch input + touch = { + startX: 0, + startY: 0, + startSpan: 0, + startCount: 0, + captured: false, + threshold: 40 + }, + + // Holds information about the keyboard shortcuts + keyboardShortcuts = { + 'N , SPACE': 'Next slide', + 'P': 'Previous slide', + '← , H': 'Navigate left', + '→ , L': 'Navigate right', + '↑ , K': 'Navigate up', + '↓ , J': 'Navigate down', + 'Home': 'First slide', + 'End': 'Last slide', + 'B , .': 'Pause', + 'F': 'Fullscreen', + 'ESC, O': 'Slide overview' + }; + + /** + * Starts up the presentation if the client is capable. + */ + function initialize( options ) { + + // Make sure we only initialize once + if( initialized === true ) return; + + initialized = true; + + checkCapabilities(); + + if( !features.transforms2d && !features.transforms3d ) { + document.body.setAttribute( 'class', 'no-transforms' ); + + // Since JS won't be running any further, we load all lazy + // loading elements upfront + var images = toArray( document.getElementsByTagName( 'img' ) ), + iframes = toArray( document.getElementsByTagName( 'iframe' ) ); + + var lazyLoadable = images.concat( iframes ); + + for( var i = 0, len = lazyLoadable.length; i < len; i++ ) { + var element = lazyLoadable[i]; + if( element.getAttribute( 'data-src' ) ) { + element.setAttribute( 'src', element.getAttribute( 'data-src' ) ); + element.removeAttribute( 'data-src' ); + } + } + + // If the browser doesn't support core features we won't be + // using JavaScript to control the presentation + return; + } + + // Cache references to key DOM elements + dom.wrapper = document.querySelector( '.reveal' ); + dom.slides = document.querySelector( '.reveal .slides' ); + + // Force a layout when the whole page, incl fonts, has loaded + window.addEventListener( 'load', layout, false ); + + var query = Reveal.getQueryHash(); + + // Do not accept new dependencies via query config to avoid + // the potential of malicious script injection + if( typeof query['dependencies'] !== 'undefined' ) delete query['dependencies']; + + // Copy options over to our config object + extend( config, options ); + extend( config, query ); + + // Hide the address bar in mobile browsers + hideAddressBar(); + + // Loads the dependencies and continues to #start() once done + load(); + + } + + /** + * Inspect the client to see what it's capable of, this + * should only happens once per runtime. + */ + function checkCapabilities() { + + isMobileDevice = /(iphone|ipod|ipad|android)/gi.test( UA ); + isChrome = /chrome/i.test( UA ) && !/edge/i.test( UA ); + + var testElement = document.createElement( 'div' ); + + features.transforms3d = 'WebkitPerspective' in testElement.style || + 'MozPerspective' in testElement.style || + 'msPerspective' in testElement.style || + 'OPerspective' in testElement.style || + 'perspective' in testElement.style; + + features.transforms2d = 'WebkitTransform' in testElement.style || + 'MozTransform' in testElement.style || + 'msTransform' in testElement.style || + 'OTransform' in testElement.style || + 'transform' in testElement.style; + + features.requestAnimationFrameMethod = window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame; + features.requestAnimationFrame = typeof features.requestAnimationFrameMethod === 'function'; + + features.canvas = !!document.createElement( 'canvas' ).getContext; + + // Transitions in the overview are disabled in desktop and + // Safari due to lag + features.overviewTransitions = !/Version\/[\d\.]+.*Safari/.test( UA ); + + // Flags if we should use zoom instead of transform to scale + // up slides. Zoom produces crisper results but has a lot of + // xbrowser quirks so we only use it in whitelsited browsers. + features.zoom = 'zoom' in testElement.style && !isMobileDevice && + ( isChrome || /Version\/[\d\.]+.*Safari/.test( UA ) ); + + } + + /** + * Loads the dependencies of reveal.js. Dependencies are + * defined via the configuration option 'dependencies' + * and will be loaded prior to starting/binding reveal.js. + * Some dependencies may have an 'async' flag, if so they + * will load after reveal.js has been started up. + */ + function load() { + + var scripts = [], + scriptsAsync = [], + scriptsToPreload = 0; + + // Called once synchronous scripts finish loading + function proceed() { + if( scriptsAsync.length ) { + // Load asynchronous scripts + head.js.apply( null, scriptsAsync ); + } + + start(); + } + + function loadScript( s ) { + head.ready( s.src.match( /([\w\d_\-]*)\.?js$|[^\\\/]*$/i )[0], function() { + // Extension may contain callback functions + if( typeof s.callback === 'function' ) { + s.callback.apply( this ); + } + + if( --scriptsToPreload === 0 ) { + proceed(); + } + }); + } + + for( var i = 0, len = config.dependencies.length; i < len; i++ ) { + var s = config.dependencies[i]; + + // Load if there's no condition or the condition is truthy + if( !s.condition || s.condition() ) { + if( s.async ) { + scriptsAsync.push( s.src ); + } + else { + scripts.push( s.src ); + } + + loadScript( s ); + } + } + + if( scripts.length ) { + scriptsToPreload = scripts.length; + + // Load synchronous scripts + head.js.apply( null, scripts ); + } + else { + proceed(); + } + + } + + /** + * Starts up reveal.js by binding input events and navigating + * to the current URL deeplink if there is one. + */ + function start() { + + loaded = true; + + // Make sure we've got all the DOM elements we need + setupDOM(); + + // Listen to messages posted to this window + setupPostMessage(); + + // Prevent the slides from being scrolled out of view + setupScrollPrevention(); + + // Resets all vertical slides so that only the first is visible + resetVerticalSlides(); + + // Updates the presentation to match the current configuration values + configure(); + + // Read the initial hash + readURL(); + + // Update all backgrounds + updateBackground( true ); + + // Notify listeners that the presentation is ready but use a 1ms + // timeout to ensure it's not fired synchronously after #initialize() + setTimeout( function() { + // Enable transitions now that we're loaded + dom.slides.classList.remove( 'no-transition' ); + + dom.wrapper.classList.add( 'ready' ); + + dispatchEvent( 'ready', { + 'indexh': indexh, + 'indexv': indexv, + 'currentSlide': currentSlide + } ); + }, 1 ); + + // Special setup and config is required when printing to PDF + if( isPrintingPDF() ) { + removeEventListeners(); + + // The document needs to have loaded for the PDF layout + // measurements to be accurate + if( document.readyState === 'complete' ) { + setupPDF(); + } + else { + window.addEventListener( 'load', setupPDF ); + } + } + + } + + /** + * Finds and stores references to DOM elements which are + * required by the presentation. If a required element is + * not found, it is created. + */ + function setupDOM() { + + // Prevent transitions while we're loading + dom.slides.classList.add( 'no-transition' ); + + if( isMobileDevice ) { + dom.wrapper.classList.add( 'no-hover' ); + } + else { + dom.wrapper.classList.remove( 'no-hover' ); + } + + if( /iphone/gi.test( UA ) ) { + dom.wrapper.classList.add( 'ua-iphone' ); + } + else { + dom.wrapper.classList.remove( 'ua-iphone' ); + } + + // Background element + dom.background = createSingletonNode( dom.wrapper, 'div', 'backgrounds', null ); + + // Progress bar + dom.progress = createSingletonNode( dom.wrapper, 'div', 'progress', '' ); + dom.progressbar = dom.progress.querySelector( 'span' ); + + // Arrow controls + dom.controls = createSingletonNode( dom.wrapper, 'aside', 'controls', + '' + + '' + + '' + + '' ); + + // Slide number + dom.slideNumber = createSingletonNode( dom.wrapper, 'div', 'slide-number', '' ); + + // Element containing notes that are visible to the audience + dom.speakerNotes = createSingletonNode( dom.wrapper, 'div', 'speaker-notes', null ); + dom.speakerNotes.setAttribute( 'data-prevent-swipe', '' ); + dom.speakerNotes.setAttribute( 'tabindex', '0' ); + + // Overlay graphic which is displayed during the paused mode + createSingletonNode( dom.wrapper, 'div', 'pause-overlay', null ); + + dom.wrapper.setAttribute( 'role', 'application' ); + + // There can be multiple instances of controls throughout the page + dom.controlsLeft = toArray( document.querySelectorAll( '.navigate-left' ) ); + dom.controlsRight = toArray( document.querySelectorAll( '.navigate-right' ) ); + dom.controlsUp = toArray( document.querySelectorAll( '.navigate-up' ) ); + dom.controlsDown = toArray( document.querySelectorAll( '.navigate-down' ) ); + dom.controlsPrev = toArray( document.querySelectorAll( '.navigate-prev' ) ); + dom.controlsNext = toArray( document.querySelectorAll( '.navigate-next' ) ); + + // The right and down arrows in the standard reveal.js controls + dom.controlsRightArrow = dom.controls.querySelector( '.navigate-right' ); + dom.controlsDownArrow = dom.controls.querySelector( '.navigate-down' ); + + dom.statusDiv = createStatusDiv(); + } + + /** + * Creates a hidden div with role aria-live to announce the + * current slide content. Hide the div off-screen to make it + * available only to Assistive Technologies. + * + * @return {HTMLElement} + */ + function createStatusDiv() { + + var statusDiv = document.getElementById( 'aria-status-div' ); + if( !statusDiv ) { + statusDiv = document.createElement( 'div' ); + statusDiv.style.position = 'absolute'; + statusDiv.style.height = '1px'; + statusDiv.style.width = '1px'; + statusDiv.style.overflow = 'hidden'; + statusDiv.style.clip = 'rect( 1px, 1px, 1px, 1px )'; + statusDiv.setAttribute( 'id', 'aria-status-div' ); + statusDiv.setAttribute( 'aria-live', 'polite' ); + statusDiv.setAttribute( 'aria-atomic','true' ); + dom.wrapper.appendChild( statusDiv ); + } + return statusDiv; + + } + + /** + * Converts the given HTML element into a string of text + * that can be announced to a screen reader. Hidden + * elements are excluded. + */ + function getStatusText( node ) { + + var text = ''; + + // Text node + if( node.nodeType === 3 ) { + text += node.textContent; + } + // Element node + else if( node.nodeType === 1 ) { + + var isAriaHidden = node.getAttribute( 'aria-hidden' ); + var isDisplayHidden = window.getComputedStyle( node )['display'] === 'none'; + if( isAriaHidden !== 'true' && !isDisplayHidden ) { + + toArray( node.childNodes ).forEach( function( child ) { + text += getStatusText( child ); + } ); + + } + + } + + return text; + + } + + /** + * Configures the presentation for printing to a static + * PDF. + */ + function setupPDF() { + + var slideSize = getComputedSlideSize( window.innerWidth, window.innerHeight ); + + // Dimensions of the PDF pages + var pageWidth = Math.floor( slideSize.width * ( 1 + config.margin ) ), + pageHeight = Math.floor( slideSize.height * ( 1 + config.margin ) ); + + // Dimensions of slides within the pages + var slideWidth = slideSize.width, + slideHeight = slideSize.height; + + // Let the browser know what page size we want to print + injectStyleSheet( '@page{size:'+ pageWidth +'px '+ pageHeight +'px; margin: 0px;}' ); + + // Limit the size of certain elements to the dimensions of the slide + injectStyleSheet( '.reveal section>img, .reveal section>video, .reveal section>iframe{max-width: '+ slideWidth +'px; max-height:'+ slideHeight +'px}' ); + + document.body.classList.add( 'print-pdf' ); + document.body.style.width = pageWidth + 'px'; + document.body.style.height = pageHeight + 'px'; + + // Make sure stretch elements fit on slide + layoutSlideContents( slideWidth, slideHeight ); + + // Add each slide's index as attributes on itself, we need these + // indices to generate slide numbers below + toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) ).forEach( function( hslide, h ) { + hslide.setAttribute( 'data-index-h', h ); + + if( hslide.classList.contains( 'stack' ) ) { + toArray( hslide.querySelectorAll( 'section' ) ).forEach( function( vslide, v ) { + vslide.setAttribute( 'data-index-h', h ); + vslide.setAttribute( 'data-index-v', v ); + } ); + } + } ); + + // Slide and slide background layout + toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR ) ).forEach( function( slide ) { + + // Vertical stacks are not centred since their section + // children will be + if( slide.classList.contains( 'stack' ) === false ) { + // Center the slide inside of the page, giving the slide some margin + var left = ( pageWidth - slideWidth ) / 2, + top = ( pageHeight - slideHeight ) / 2; + + var contentHeight = slide.scrollHeight; + var numberOfPages = Math.max( Math.ceil( contentHeight / pageHeight ), 1 ); + + // Adhere to configured pages per slide limit + numberOfPages = Math.min( numberOfPages, config.pdfMaxPagesPerSlide ); + + // Center slides vertically + if( numberOfPages === 1 && config.center || slide.classList.contains( 'center' ) ) { + top = Math.max( ( pageHeight - contentHeight ) / 2, 0 ); + } + + // Wrap the slide in a page element and hide its overflow + // so that no page ever flows onto another + var page = document.createElement( 'div' ); + page.className = 'pdf-page'; + page.style.height = ( ( pageHeight + config.pdfPageHeightOffset ) * numberOfPages ) + 'px'; + slide.parentNode.insertBefore( page, slide ); + page.appendChild( slide ); + + // Position the slide inside of the page + slide.style.left = left + 'px'; + slide.style.top = top + 'px'; + slide.style.width = slideWidth + 'px'; + + if( slide.slideBackgroundElement ) { + page.insertBefore( slide.slideBackgroundElement, slide ); + } + + // Inject notes if `showNotes` is enabled + if( config.showNotes ) { + + // Are there notes for this slide? + var notes = getSlideNotes( slide ); + if( notes ) { + + var notesSpacing = 8; + var notesLayout = typeof config.showNotes === 'string' ? config.showNotes : 'inline'; + var notesElement = document.createElement( 'div' ); + notesElement.classList.add( 'speaker-notes' ); + notesElement.classList.add( 'speaker-notes-pdf' ); + notesElement.setAttribute( 'data-layout', notesLayout ); + notesElement.innerHTML = notes; + + if( notesLayout === 'separate-page' ) { + page.parentNode.insertBefore( notesElement, page.nextSibling ); + } + else { + notesElement.style.left = notesSpacing + 'px'; + notesElement.style.bottom = notesSpacing + 'px'; + notesElement.style.width = ( pageWidth - notesSpacing*2 ) + 'px'; + page.appendChild( notesElement ); + } + + } + + } + + // Inject slide numbers if `slideNumbers` are enabled + if( config.slideNumber && /all|print/i.test( config.showSlideNumber ) ) { + var slideNumberH = parseInt( slide.getAttribute( 'data-index-h' ), 10 ) + 1, + slideNumberV = parseInt( slide.getAttribute( 'data-index-v' ), 10 ) + 1; + + var numberElement = document.createElement( 'div' ); + numberElement.classList.add( 'slide-number' ); + numberElement.classList.add( 'slide-number-pdf' ); + numberElement.innerHTML = formatSlideNumber( slideNumberH, '.', slideNumberV ); + page.appendChild( numberElement ); + } + } + + } ); + + // Show all fragments + toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR + ' .fragment' ) ).forEach( function( fragment ) { + fragment.classList.add( 'visible' ); + } ); + + // Notify subscribers that the PDF layout is good to go + dispatchEvent( 'pdf-ready' ); + + } + + /** + * This is an unfortunate necessity. Some actions – such as + * an input field being focused in an iframe or using the + * keyboard to expand text selection beyond the bounds of + * a slide – can trigger our content to be pushed out of view. + * This scrolling can not be prevented by hiding overflow in + * CSS (we already do) so we have to resort to repeatedly + * checking if the slides have been offset :( + */ + function setupScrollPrevention() { + + setInterval( function() { + if( dom.wrapper.scrollTop !== 0 || dom.wrapper.scrollLeft !== 0 ) { + dom.wrapper.scrollTop = 0; + dom.wrapper.scrollLeft = 0; + } + }, 1000 ); + + } + + /** + * Creates an HTML element and returns a reference to it. + * If the element already exists the existing instance will + * be returned. + * + * @param {HTMLElement} container + * @param {string} tagname + * @param {string} classname + * @param {string} innerHTML + * + * @return {HTMLElement} + */ + function createSingletonNode( container, tagname, classname, innerHTML ) { + + // Find all nodes matching the description + var nodes = container.querySelectorAll( '.' + classname ); + + // Check all matches to find one which is a direct child of + // the specified container + for( var i = 0; i < nodes.length; i++ ) { + var testNode = nodes[i]; + if( testNode.parentNode === container ) { + return testNode; + } + } + + // If no node was found, create it now + var node = document.createElement( tagname ); + node.className = classname; + if( typeof innerHTML === 'string' ) { + node.innerHTML = innerHTML; + } + container.appendChild( node ); + + return node; + + } + + /** + * Creates the slide background elements and appends them + * to the background container. One element is created per + * slide no matter if the given slide has visible background. + */ + function createBackgrounds() { + + var printMode = isPrintingPDF(); + + // Clear prior backgrounds + dom.background.innerHTML = ''; + dom.background.classList.add( 'no-transition' ); + + // Iterate over all horizontal slides + toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) ).forEach( function( slideh ) { + + var backgroundStack = createBackground( slideh, dom.background ); + + // Iterate over all vertical slides + toArray( slideh.querySelectorAll( 'section' ) ).forEach( function( slidev ) { + + createBackground( slidev, backgroundStack ); + + backgroundStack.classList.add( 'stack' ); + + } ); + + } ); + + // Add parallax background if specified + if( config.parallaxBackgroundImage ) { + + dom.background.style.backgroundImage = 'url("' + config.parallaxBackgroundImage + '")'; + dom.background.style.backgroundSize = config.parallaxBackgroundSize; + + // Make sure the below properties are set on the element - these properties are + // needed for proper transitions to be set on the element via CSS. To remove + // annoying background slide-in effect when the presentation starts, apply + // these properties after short time delay + setTimeout( function() { + dom.wrapper.classList.add( 'has-parallax-background' ); + }, 1 ); + + } + else { + + dom.background.style.backgroundImage = ''; + dom.wrapper.classList.remove( 'has-parallax-background' ); + + } + + } + + /** + * Creates a background for the given slide. + * + * @param {HTMLElement} slide + * @param {HTMLElement} container The element that the background + * should be appended to + * @return {HTMLElement} New background div + */ + function createBackground( slide, container ) { + + var data = { + background: slide.getAttribute( 'data-background' ), + backgroundSize: slide.getAttribute( 'data-background-size' ), + backgroundImage: slide.getAttribute( 'data-background-image' ), + backgroundVideo: slide.getAttribute( 'data-background-video' ), + backgroundIframe: slide.getAttribute( 'data-background-iframe' ), + backgroundColor: slide.getAttribute( 'data-background-color' ), + backgroundRepeat: slide.getAttribute( 'data-background-repeat' ), + backgroundPosition: slide.getAttribute( 'data-background-position' ), + backgroundTransition: slide.getAttribute( 'data-background-transition' ) + }; + + var element = document.createElement( 'div' ); + + // Carry over custom classes from the slide to the background + element.className = 'slide-background ' + slide.className.replace( /present|past|future/, '' ); + + if( data.background ) { + // Auto-wrap image urls in url(...) + if( /^(http|file|\/\/)/gi.test( data.background ) || /\.(svg|png|jpg|jpeg|gif|bmp)([?#]|$)/gi.test( data.background ) ) { + slide.setAttribute( 'data-background-image', data.background ); + } + else { + element.style.background = data.background; + } + } + + // Create a hash for this combination of background settings. + // This is used to determine when two slide backgrounds are + // the same. + if( data.background || data.backgroundColor || data.backgroundImage || data.backgroundVideo || data.backgroundIframe ) { + element.setAttribute( 'data-background-hash', data.background + + data.backgroundSize + + data.backgroundImage + + data.backgroundVideo + + data.backgroundIframe + + data.backgroundColor + + data.backgroundRepeat + + data.backgroundPosition + + data.backgroundTransition ); + } + + // Additional and optional background properties + if( data.backgroundSize ) element.style.backgroundSize = data.backgroundSize; + if( data.backgroundSize ) element.setAttribute( 'data-background-size', data.backgroundSize ); + if( data.backgroundColor ) element.style.backgroundColor = data.backgroundColor; + if( data.backgroundRepeat ) element.style.backgroundRepeat = data.backgroundRepeat; + if( data.backgroundPosition ) element.style.backgroundPosition = data.backgroundPosition; + if( data.backgroundTransition ) element.setAttribute( 'data-background-transition', data.backgroundTransition ); + + container.appendChild( element ); + + // If backgrounds are being recreated, clear old classes + slide.classList.remove( 'has-dark-background' ); + slide.classList.remove( 'has-light-background' ); + + slide.slideBackgroundElement = element; + + // If this slide has a background color, add a class that + // signals if it is light or dark. If the slide has no background + // color, no class will be set + var computedBackgroundStyle = window.getComputedStyle( element ); + if( computedBackgroundStyle && computedBackgroundStyle.backgroundColor ) { + var rgb = colorToRgb( computedBackgroundStyle.backgroundColor ); + + // Ignore fully transparent backgrounds. Some browsers return + // rgba(0,0,0,0) when reading the computed background color of + // an element with no background + if( rgb && rgb.a !== 0 ) { + if( colorBrightness( computedBackgroundStyle.backgroundColor ) < 128 ) { + slide.classList.add( 'has-dark-background' ); + } + else { + slide.classList.add( 'has-light-background' ); + } + } + } + + return element; + + } + + /** + * Registers a listener to postMessage events, this makes it + * possible to call all reveal.js API methods from another + * window. For example: + * + * revealWindow.postMessage( JSON.stringify({ + * method: 'slide', + * args: [ 2 ] + * }), '*' ); + */ + function setupPostMessage() { + + if( config.postMessage ) { + window.addEventListener( 'message', function ( event ) { + var data = event.data; + + // Make sure we're dealing with JSON + if( typeof data === 'string' && data.charAt( 0 ) === '{' && data.charAt( data.length - 1 ) === '}' ) { + data = JSON.parse( data ); + + // Check if the requested method can be found + if( data.method && typeof Reveal[data.method] === 'function' ) { + Reveal[data.method].apply( Reveal, data.args ); + } + } + }, false ); + } + + } + + /** + * Applies the configuration settings from the config + * object. May be called multiple times. + * + * @param {object} options + */ + function configure( options ) { + + var oldTransition = config.transition; + + // New config options may be passed when this method + // is invoked through the API after initialization + if( typeof options === 'object' ) extend( config, options ); + + // Abort if reveal.js hasn't finished loading, config + // changes will be applied automatically once loading + // finishes + if( loaded === false ) return; + + var numberOfSlides = dom.wrapper.querySelectorAll( SLIDES_SELECTOR ).length; + + // Remove the previously configured transition class + dom.wrapper.classList.remove( oldTransition ); + + // Force linear transition based on browser capabilities + if( features.transforms3d === false ) config.transition = 'linear'; + + dom.wrapper.classList.add( config.transition ); + + dom.wrapper.setAttribute( 'data-transition-speed', config.transitionSpeed ); + dom.wrapper.setAttribute( 'data-background-transition', config.backgroundTransition ); + + dom.controls.style.display = config.controls ? 'block' : 'none'; + dom.progress.style.display = config.progress ? 'block' : 'none'; + + dom.controls.setAttribute( 'data-controls-layout', config.controlsLayout ); + dom.controls.setAttribute( 'data-controls-back-arrows', config.controlsBackArrows ); + + if( config.shuffle ) { + shuffle(); + } + + if( config.rtl ) { + dom.wrapper.classList.add( 'rtl' ); + } + else { + dom.wrapper.classList.remove( 'rtl' ); + } + + if( config.center ) { + dom.wrapper.classList.add( 'center' ); + } + else { + dom.wrapper.classList.remove( 'center' ); + } + + // Exit the paused mode if it was configured off + if( config.pause === false ) { + resume(); + } + + if( config.showNotes ) { + dom.speakerNotes.setAttribute( 'data-layout', typeof config.showNotes === 'string' ? config.showNotes : 'inline' ); + } + + if( config.mouseWheel ) { + document.addEventListener( 'DOMMouseScroll', onDocumentMouseScroll, false ); // FF + document.addEventListener( 'mousewheel', onDocumentMouseScroll, false ); + } + else { + document.removeEventListener( 'DOMMouseScroll', onDocumentMouseScroll, false ); // FF + document.removeEventListener( 'mousewheel', onDocumentMouseScroll, false ); + } + + // Rolling 3D links + if( config.rollingLinks ) { + enableRollingLinks(); + } + else { + disableRollingLinks(); + } + + // Iframe link previews + if( config.previewLinks ) { + enablePreviewLinks(); + disablePreviewLinks( '[data-preview-link=false]' ); + } + else { + disablePreviewLinks(); + enablePreviewLinks( '[data-preview-link]:not([data-preview-link=false])' ); + } + + // Remove existing auto-slide controls + if( autoSlidePlayer ) { + autoSlidePlayer.destroy(); + autoSlidePlayer = null; + } + + // Generate auto-slide controls if needed + if( numberOfSlides > 1 && config.autoSlide && config.autoSlideStoppable && features.canvas && features.requestAnimationFrame ) { + autoSlidePlayer = new Playback( dom.wrapper, function() { + return Math.min( Math.max( ( Date.now() - autoSlideStartTime ) / autoSlide, 0 ), 1 ); + } ); + + autoSlidePlayer.on( 'click', onAutoSlidePlayerClick ); + autoSlidePaused = false; + } + + // When fragments are turned off they should be visible + if( config.fragments === false ) { + toArray( dom.slides.querySelectorAll( '.fragment' ) ).forEach( function( element ) { + element.classList.add( 'visible' ); + element.classList.remove( 'current-fragment' ); + } ); + } + + // Slide numbers + var slideNumberDisplay = 'none'; + if( config.slideNumber && !isPrintingPDF() ) { + if( config.showSlideNumber === 'all' ) { + slideNumberDisplay = 'block'; + } + else if( config.showSlideNumber === 'speaker' && isSpeakerNotes() ) { + slideNumberDisplay = 'block'; + } + } + + dom.slideNumber.style.display = slideNumberDisplay; + + sync(); + + } + + /** + * Binds all event listeners. + */ + function addEventListeners() { + + eventsAreBound = true; + + window.addEventListener( 'hashchange', onWindowHashChange, false ); + window.addEventListener( 'resize', onWindowResize, false ); + + if( config.touch ) { + dom.wrapper.addEventListener( 'touchstart', onTouchStart, false ); + dom.wrapper.addEventListener( 'touchmove', onTouchMove, false ); + dom.wrapper.addEventListener( 'touchend', onTouchEnd, false ); + + // Support pointer-style touch interaction as well + if( window.navigator.pointerEnabled ) { + // IE 11 uses un-prefixed version of pointer events + dom.wrapper.addEventListener( 'pointerdown', onPointerDown, false ); + dom.wrapper.addEventListener( 'pointermove', onPointerMove, false ); + dom.wrapper.addEventListener( 'pointerup', onPointerUp, false ); + } + else if( window.navigator.msPointerEnabled ) { + // IE 10 uses prefixed version of pointer events + dom.wrapper.addEventListener( 'MSPointerDown', onPointerDown, false ); + dom.wrapper.addEventListener( 'MSPointerMove', onPointerMove, false ); + dom.wrapper.addEventListener( 'MSPointerUp', onPointerUp, false ); + } + } + + if( config.keyboard ) { + document.addEventListener( 'keydown', onDocumentKeyDown, false ); + document.addEventListener( 'keypress', onDocumentKeyPress, false ); + } + + if( config.progress && dom.progress ) { + dom.progress.addEventListener( 'click', onProgressClicked, false ); + } + + if( config.focusBodyOnPageVisibilityChange ) { + var visibilityChange; + + if( 'hidden' in document ) { + visibilityChange = 'visibilitychange'; + } + else if( 'msHidden' in document ) { + visibilityChange = 'msvisibilitychange'; + } + else if( 'webkitHidden' in document ) { + visibilityChange = 'webkitvisibilitychange'; + } + + if( visibilityChange ) { + document.addEventListener( visibilityChange, onPageVisibilityChange, false ); + } + } + + // Listen to both touch and click events, in case the device + // supports both + var pointerEvents = [ 'touchstart', 'click' ]; + + // Only support touch for Android, fixes double navigations in + // stock browser + if( UA.match( /android/gi ) ) { + pointerEvents = [ 'touchstart' ]; + } + + pointerEvents.forEach( function( eventName ) { + dom.controlsLeft.forEach( function( el ) { el.addEventListener( eventName, onNavigateLeftClicked, false ); } ); + dom.controlsRight.forEach( function( el ) { el.addEventListener( eventName, onNavigateRightClicked, false ); } ); + dom.controlsUp.forEach( function( el ) { el.addEventListener( eventName, onNavigateUpClicked, false ); } ); + dom.controlsDown.forEach( function( el ) { el.addEventListener( eventName, onNavigateDownClicked, false ); } ); + dom.controlsPrev.forEach( function( el ) { el.addEventListener( eventName, onNavigatePrevClicked, false ); } ); + dom.controlsNext.forEach( function( el ) { el.addEventListener( eventName, onNavigateNextClicked, false ); } ); + } ); + + } + + /** + * Unbinds all event listeners. + */ + function removeEventListeners() { + + eventsAreBound = false; + + document.removeEventListener( 'keydown', onDocumentKeyDown, false ); + document.removeEventListener( 'keypress', onDocumentKeyPress, false ); + window.removeEventListener( 'hashchange', onWindowHashChange, false ); + window.removeEventListener( 'resize', onWindowResize, false ); + + dom.wrapper.removeEventListener( 'touchstart', onTouchStart, false ); + dom.wrapper.removeEventListener( 'touchmove', onTouchMove, false ); + dom.wrapper.removeEventListener( 'touchend', onTouchEnd, false ); + + // IE11 + if( window.navigator.pointerEnabled ) { + dom.wrapper.removeEventListener( 'pointerdown', onPointerDown, false ); + dom.wrapper.removeEventListener( 'pointermove', onPointerMove, false ); + dom.wrapper.removeEventListener( 'pointerup', onPointerUp, false ); + } + // IE10 + else if( window.navigator.msPointerEnabled ) { + dom.wrapper.removeEventListener( 'MSPointerDown', onPointerDown, false ); + dom.wrapper.removeEventListener( 'MSPointerMove', onPointerMove, false ); + dom.wrapper.removeEventListener( 'MSPointerUp', onPointerUp, false ); + } + + if ( config.progress && dom.progress ) { + dom.progress.removeEventListener( 'click', onProgressClicked, false ); + } + + [ 'touchstart', 'click' ].forEach( function( eventName ) { + dom.controlsLeft.forEach( function( el ) { el.removeEventListener( eventName, onNavigateLeftClicked, false ); } ); + dom.controlsRight.forEach( function( el ) { el.removeEventListener( eventName, onNavigateRightClicked, false ); } ); + dom.controlsUp.forEach( function( el ) { el.removeEventListener( eventName, onNavigateUpClicked, false ); } ); + dom.controlsDown.forEach( function( el ) { el.removeEventListener( eventName, onNavigateDownClicked, false ); } ); + dom.controlsPrev.forEach( function( el ) { el.removeEventListener( eventName, onNavigatePrevClicked, false ); } ); + dom.controlsNext.forEach( function( el ) { el.removeEventListener( eventName, onNavigateNextClicked, false ); } ); + } ); + + } + + /** + * Extend object a with the properties of object b. + * If there's a conflict, object b takes precedence. + * + * @param {object} a + * @param {object} b + */ + function extend( a, b ) { + + for( var i in b ) { + a[ i ] = b[ i ]; + } + + return a; + + } + + /** + * Converts the target object to an array. + * + * @param {object} o + * @return {object[]} + */ + function toArray( o ) { + + return Array.prototype.slice.call( o ); + + } + + /** + * Utility for deserializing a value. + * + * @param {*} value + * @return {*} + */ + function deserialize( value ) { + + if( typeof value === 'string' ) { + if( value === 'null' ) return null; + else if( value === 'true' ) return true; + else if( value === 'false' ) return false; + else if( value.match( /^-?[\d\.]+$/ ) ) return parseFloat( value ); + } + + return value; + + } + + /** + * Measures the distance in pixels between point a + * and point b. + * + * @param {object} a point with x/y properties + * @param {object} b point with x/y properties + * + * @return {number} + */ + function distanceBetween( a, b ) { + + var dx = a.x - b.x, + dy = a.y - b.y; + + return Math.sqrt( dx*dx + dy*dy ); + + } + + /** + * Applies a CSS transform to the target element. + * + * @param {HTMLElement} element + * @param {string} transform + */ + function transformElement( element, transform ) { + + element.style.WebkitTransform = transform; + element.style.MozTransform = transform; + element.style.msTransform = transform; + element.style.transform = transform; + + } + + /** + * Applies CSS transforms to the slides container. The container + * is transformed from two separate sources: layout and the overview + * mode. + * + * @param {object} transforms + */ + function transformSlides( transforms ) { + + // Pick up new transforms from arguments + if( typeof transforms.layout === 'string' ) slidesTransform.layout = transforms.layout; + if( typeof transforms.overview === 'string' ) slidesTransform.overview = transforms.overview; + + // Apply the transforms to the slides container + if( slidesTransform.layout ) { + transformElement( dom.slides, slidesTransform.layout + ' ' + slidesTransform.overview ); + } + else { + transformElement( dom.slides, slidesTransform.overview ); + } + + } + + /** + * Injects the given CSS styles into the DOM. + * + * @param {string} value + */ + function injectStyleSheet( value ) { + + var tag = document.createElement( 'style' ); + tag.type = 'text/css'; + if( tag.styleSheet ) { + tag.styleSheet.cssText = value; + } + else { + tag.appendChild( document.createTextNode( value ) ); + } + document.getElementsByTagName( 'head' )[0].appendChild( tag ); + + } + + /** + * Find the closest parent that matches the given + * selector. + * + * @param {HTMLElement} target The child element + * @param {String} selector The CSS selector to match + * the parents against + * + * @return {HTMLElement} The matched parent or null + * if no matching parent was found + */ + function closestParent( target, selector ) { + + var parent = target.parentNode; + + while( parent ) { + + // There's some overhead doing this each time, we don't + // want to rewrite the element prototype but should still + // be enough to feature detect once at startup... + var matchesMethod = parent.matches || parent.matchesSelector || parent.msMatchesSelector; + + // If we find a match, we're all set + if( matchesMethod && matchesMethod.call( parent, selector ) ) { + return parent; + } + + // Keep searching + parent = parent.parentNode; + + } + + return null; + + } + + /** + * Converts various color input formats to an {r:0,g:0,b:0} object. + * + * @param {string} color The string representation of a color + * @example + * colorToRgb('#000'); + * @example + * colorToRgb('#000000'); + * @example + * colorToRgb('rgb(0,0,0)'); + * @example + * colorToRgb('rgba(0,0,0)'); + * + * @return {{r: number, g: number, b: number, [a]: number}|null} + */ + function colorToRgb( color ) { + + var hex3 = color.match( /^#([0-9a-f]{3})$/i ); + if( hex3 && hex3[1] ) { + hex3 = hex3[1]; + return { + r: parseInt( hex3.charAt( 0 ), 16 ) * 0x11, + g: parseInt( hex3.charAt( 1 ), 16 ) * 0x11, + b: parseInt( hex3.charAt( 2 ), 16 ) * 0x11 + }; + } + + var hex6 = color.match( /^#([0-9a-f]{6})$/i ); + if( hex6 && hex6[1] ) { + hex6 = hex6[1]; + return { + r: parseInt( hex6.substr( 0, 2 ), 16 ), + g: parseInt( hex6.substr( 2, 2 ), 16 ), + b: parseInt( hex6.substr( 4, 2 ), 16 ) + }; + } + + var rgb = color.match( /^rgb\s*\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*\)$/i ); + if( rgb ) { + return { + r: parseInt( rgb[1], 10 ), + g: parseInt( rgb[2], 10 ), + b: parseInt( rgb[3], 10 ) + }; + } + + var rgba = color.match( /^rgba\s*\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*\,\s*([\d]+|[\d]*.[\d]+)\s*\)$/i ); + if( rgba ) { + return { + r: parseInt( rgba[1], 10 ), + g: parseInt( rgba[2], 10 ), + b: parseInt( rgba[3], 10 ), + a: parseFloat( rgba[4] ) + }; + } + + return null; + + } + + /** + * Calculates brightness on a scale of 0-255. + * + * @param {string} color See colorToRgb for supported formats. + * @see {@link colorToRgb} + */ + function colorBrightness( color ) { + + if( typeof color === 'string' ) color = colorToRgb( color ); + + if( color ) { + return ( color.r * 299 + color.g * 587 + color.b * 114 ) / 1000; + } + + return null; + + } + + /** + * Returns the remaining height within the parent of the + * target element. + * + * remaining height = [ configured parent height ] - [ current parent height ] + * + * @param {HTMLElement} element + * @param {number} [height] + */ + function getRemainingHeight( element, height ) { + + height = height || 0; + + if( element ) { + var newHeight, oldHeight = element.style.height; + + // Change the .stretch element height to 0 in order find the height of all + // the other elements + element.style.height = '0px'; + newHeight = height - element.parentNode.offsetHeight; + + // Restore the old height, just in case + element.style.height = oldHeight + 'px'; + + return newHeight; + } + + return height; + + } + + /** + * Checks if this instance is being used to print a PDF. + */ + function isPrintingPDF() { + + return ( /print-pdf/gi ).test( window.location.search ); + + } + + /** + * Hides the address bar if we're on a mobile device. + */ + function hideAddressBar() { + + if( config.hideAddressBar && isMobileDevice ) { + // Events that should trigger the address bar to hide + window.addEventListener( 'load', removeAddressBar, false ); + window.addEventListener( 'orientationchange', removeAddressBar, false ); + } + + } + + /** + * Causes the address bar to hide on mobile devices, + * more vertical space ftw. + */ + function removeAddressBar() { + + setTimeout( function() { + window.scrollTo( 0, 1 ); + }, 10 ); + + } + + /** + * Dispatches an event of the specified type from the + * reveal DOM element. + */ + function dispatchEvent( type, args ) { + + var event = document.createEvent( 'HTMLEvents', 1, 2 ); + event.initEvent( type, true, true ); + extend( event, args ); + dom.wrapper.dispatchEvent( event ); + + // If we're in an iframe, post each reveal.js event to the + // parent window. Used by the notes plugin + if( config.postMessageEvents && window.parent !== window.self ) { + window.parent.postMessage( JSON.stringify({ namespace: 'reveal', eventName: type, state: getState() }), '*' ); + } + + } + + /** + * Wrap all links in 3D goodness. + */ + function enableRollingLinks() { + + if( features.transforms3d && !( 'msPerspective' in document.body.style ) ) { + var anchors = dom.wrapper.querySelectorAll( SLIDES_SELECTOR + ' a' ); + + for( var i = 0, len = anchors.length; i < len; i++ ) { + var anchor = anchors[i]; + + if( anchor.textContent && !anchor.querySelector( '*' ) && ( !anchor.className || !anchor.classList.contains( anchor, 'roll' ) ) ) { + var span = document.createElement('span'); + span.setAttribute('data-title', anchor.text); + span.innerHTML = anchor.innerHTML; + + anchor.classList.add( 'roll' ); + anchor.innerHTML = ''; + anchor.appendChild(span); + } + } + } + + } + + /** + * Unwrap all 3D links. + */ + function disableRollingLinks() { + + var anchors = dom.wrapper.querySelectorAll( SLIDES_SELECTOR + ' a.roll' ); + + for( var i = 0, len = anchors.length; i < len; i++ ) { + var anchor = anchors[i]; + var span = anchor.querySelector( 'span' ); + + if( span ) { + anchor.classList.remove( 'roll' ); + anchor.innerHTML = span.innerHTML; + } + } + + } + + /** + * Bind preview frame links. + * + * @param {string} [selector=a] - selector for anchors + */ + function enablePreviewLinks( selector ) { + + var anchors = toArray( document.querySelectorAll( selector ? selector : 'a' ) ); + + anchors.forEach( function( element ) { + if( /^(http|www)/gi.test( element.getAttribute( 'href' ) ) ) { + element.addEventListener( 'click', onPreviewLinkClicked, false ); + } + } ); + + } + + /** + * Unbind preview frame links. + */ + function disablePreviewLinks( selector ) { + + var anchors = toArray( document.querySelectorAll( selector ? selector : 'a' ) ); + + anchors.forEach( function( element ) { + if( /^(http|www)/gi.test( element.getAttribute( 'href' ) ) ) { + element.removeEventListener( 'click', onPreviewLinkClicked, false ); + } + } ); + + } + + /** + * Opens a preview window for the target URL. + * + * @param {string} url - url for preview iframe src + */ + function showPreview( url ) { + + closeOverlay(); + + dom.overlay = document.createElement( 'div' ); + dom.overlay.classList.add( 'overlay' ); + dom.overlay.classList.add( 'overlay-preview' ); + dom.wrapper.appendChild( dom.overlay ); + + dom.overlay.innerHTML = [ + '
', + '', + '', + '
', + '', + '
', + '', + '', + 'Unable to load iframe. This is likely due to the site\'s policy (x-frame-options).', + '', + '
' + ].join(''); + + dom.overlay.querySelector( 'iframe' ).addEventListener( 'load', function( event ) { + dom.overlay.classList.add( 'loaded' ); + }, false ); + + dom.overlay.querySelector( '.close' ).addEventListener( 'click', function( event ) { + closeOverlay(); + event.preventDefault(); + }, false ); + + dom.overlay.querySelector( '.external' ).addEventListener( 'click', function( event ) { + closeOverlay(); + }, false ); + + setTimeout( function() { + dom.overlay.classList.add( 'visible' ); + }, 1 ); + + } + + /** + * Open or close help overlay window. + * + * @param {Boolean} [override] Flag which overrides the + * toggle logic and forcibly sets the desired state. True means + * help is open, false means it's closed. + */ + function toggleHelp( override ){ + + if( typeof override === 'boolean' ) { + override ? showHelp() : closeOverlay(); + } + else { + if( dom.overlay ) { + closeOverlay(); + } + else { + showHelp(); + } + } + } + + /** + * Opens an overlay window with help material. + */ + function showHelp() { + + if( config.help ) { + + closeOverlay(); + + dom.overlay = document.createElement( 'div' ); + dom.overlay.classList.add( 'overlay' ); + dom.overlay.classList.add( 'overlay-help' ); + dom.wrapper.appendChild( dom.overlay ); + + var html = '

Keyboard Shortcuts


'; + + html += ''; + for( var key in keyboardShortcuts ) { + html += ''; + } + + html += '
KEYACTION
' + key + '' + keyboardShortcuts[ key ] + '
'; + + dom.overlay.innerHTML = [ + '
', + '', + '
', + '
', + '
'+ html +'
', + '
' + ].join(''); + + dom.overlay.querySelector( '.close' ).addEventListener( 'click', function( event ) { + closeOverlay(); + event.preventDefault(); + }, false ); + + setTimeout( function() { + dom.overlay.classList.add( 'visible' ); + }, 1 ); + + } + + } + + /** + * Closes any currently open overlay. + */ + function closeOverlay() { + + if( dom.overlay ) { + dom.overlay.parentNode.removeChild( dom.overlay ); + dom.overlay = null; + } + + } + + /** + * Applies JavaScript-controlled layout rules to the + * presentation. + */ + function layout() { + + if( dom.wrapper && !isPrintingPDF() ) { + + var size = getComputedSlideSize(); + + // Layout the contents of the slides + layoutSlideContents( config.width, config.height ); + + dom.slides.style.width = size.width + 'px'; + dom.slides.style.height = size.height + 'px'; + + // Determine scale of content to fit within available space + scale = Math.min( size.presentationWidth / size.width, size.presentationHeight / size.height ); + + // Respect max/min scale settings + scale = Math.max( scale, config.minScale ); + scale = Math.min( scale, config.maxScale ); + + // Don't apply any scaling styles if scale is 1 + if( scale === 1 ) { + dom.slides.style.zoom = ''; + dom.slides.style.left = ''; + dom.slides.style.top = ''; + dom.slides.style.bottom = ''; + dom.slides.style.right = ''; + transformSlides( { layout: '' } ); + } + else { + // Prefer zoom for scaling up so that content remains crisp. + // Don't use zoom to scale down since that can lead to shifts + // in text layout/line breaks. + if( scale > 1 && features.zoom ) { + dom.slides.style.zoom = scale; + dom.slides.style.left = ''; + dom.slides.style.top = ''; + dom.slides.style.bottom = ''; + dom.slides.style.right = ''; + transformSlides( { layout: '' } ); + } + // Apply scale transform as a fallback + else { + dom.slides.style.zoom = ''; + dom.slides.style.left = '50%'; + dom.slides.style.top = '50%'; + dom.slides.style.bottom = 'auto'; + dom.slides.style.right = 'auto'; + transformSlides( { layout: 'translate(-50%, -50%) scale('+ scale +')' } ); + } + } + + // Select all slides, vertical and horizontal + var slides = toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR ) ); + + for( var i = 0, len = slides.length; i < len; i++ ) { + var slide = slides[ i ]; + + // Don't bother updating invisible slides + if( slide.style.display === 'none' ) { + continue; + } + + if( config.center || slide.classList.contains( 'center' ) ) { + // Vertical stacks are not centred since their section + // children will be + if( slide.classList.contains( 'stack' ) ) { + slide.style.top = 0; + } + else { + slide.style.top = Math.max( ( size.height - slide.scrollHeight ) / 2, 0 ) + 'px'; + } + } + else { + slide.style.top = ''; + } + + } + + updateProgress(); + updateParallax(); + + if( isOverview() ) { + updateOverview(); + } + + } + + } + + /** + * Applies layout logic to the contents of all slides in + * the presentation. + * + * @param {string|number} width + * @param {string|number} height + */ + function layoutSlideContents( width, height ) { + + // Handle sizing of elements with the 'stretch' class + toArray( dom.slides.querySelectorAll( 'section > .stretch' ) ).forEach( function( element ) { + + // Determine how much vertical space we can use + var remainingHeight = getRemainingHeight( element, height ); + + // Consider the aspect ratio of media elements + if( /(img|video)/gi.test( element.nodeName ) ) { + var nw = element.naturalWidth || element.videoWidth, + nh = element.naturalHeight || element.videoHeight; + + var es = Math.min( width / nw, remainingHeight / nh ); + + element.style.width = ( nw * es ) + 'px'; + element.style.height = ( nh * es ) + 'px'; + + } + else { + element.style.width = width + 'px'; + element.style.height = remainingHeight + 'px'; + } + + } ); + + } + + /** + * Calculates the computed pixel size of our slides. These + * values are based on the width and height configuration + * options. + * + * @param {number} [presentationWidth=dom.wrapper.offsetWidth] + * @param {number} [presentationHeight=dom.wrapper.offsetHeight] + */ + function getComputedSlideSize( presentationWidth, presentationHeight ) { + + var size = { + // Slide size + width: config.width, + height: config.height, + + // Presentation size + presentationWidth: presentationWidth || dom.wrapper.offsetWidth, + presentationHeight: presentationHeight || dom.wrapper.offsetHeight + }; + + // Reduce available space by margin + size.presentationWidth -= ( size.presentationWidth * config.margin ); + size.presentationHeight -= ( size.presentationHeight * config.margin ); + + // Slide width may be a percentage of available width + if( typeof size.width === 'string' && /%$/.test( size.width ) ) { + size.width = parseInt( size.width, 10 ) / 100 * size.presentationWidth; + } + + // Slide height may be a percentage of available height + if( typeof size.height === 'string' && /%$/.test( size.height ) ) { + size.height = parseInt( size.height, 10 ) / 100 * size.presentationHeight; + } + + return size; + + } + + /** + * Stores the vertical index of a stack so that the same + * vertical slide can be selected when navigating to and + * from the stack. + * + * @param {HTMLElement} stack The vertical stack element + * @param {string|number} [v=0] Index to memorize + */ + function setPreviousVerticalIndex( stack, v ) { + + if( typeof stack === 'object' && typeof stack.setAttribute === 'function' ) { + stack.setAttribute( 'data-previous-indexv', v || 0 ); + } + + } + + /** + * Retrieves the vertical index which was stored using + * #setPreviousVerticalIndex() or 0 if no previous index + * exists. + * + * @param {HTMLElement} stack The vertical stack element + */ + function getPreviousVerticalIndex( stack ) { + + if( typeof stack === 'object' && typeof stack.setAttribute === 'function' && stack.classList.contains( 'stack' ) ) { + // Prefer manually defined start-indexv + var attributeName = stack.hasAttribute( 'data-start-indexv' ) ? 'data-start-indexv' : 'data-previous-indexv'; + + return parseInt( stack.getAttribute( attributeName ) || 0, 10 ); + } + + return 0; + + } + + /** + * Displays the overview of slides (quick nav) by scaling + * down and arranging all slide elements. + */ + function activateOverview() { + + // Only proceed if enabled in config + if( config.overview && !isOverview() ) { + + overview = true; + + dom.wrapper.classList.add( 'overview' ); + dom.wrapper.classList.remove( 'overview-deactivating' ); + + if( features.overviewTransitions ) { + setTimeout( function() { + dom.wrapper.classList.add( 'overview-animated' ); + }, 1 ); + } + + // Don't auto-slide while in overview mode + cancelAutoSlide(); + + // Move the backgrounds element into the slide container to + // that the same scaling is applied + dom.slides.appendChild( dom.background ); + + // Clicking on an overview slide navigates to it + toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR ) ).forEach( function( slide ) { + if( !slide.classList.contains( 'stack' ) ) { + slide.addEventListener( 'click', onOverviewSlideClicked, true ); + } + } ); + + // Calculate slide sizes + var margin = 70; + var slideSize = getComputedSlideSize(); + overviewSlideWidth = slideSize.width + margin; + overviewSlideHeight = slideSize.height + margin; + + // Reverse in RTL mode + if( config.rtl ) { + overviewSlideWidth = -overviewSlideWidth; + } + + updateSlidesVisibility(); + layoutOverview(); + updateOverview(); + + layout(); + + // Notify observers of the overview showing + dispatchEvent( 'overviewshown', { + 'indexh': indexh, + 'indexv': indexv, + 'currentSlide': currentSlide + } ); + + } + + } + + /** + * Uses CSS transforms to position all slides in a grid for + * display inside of the overview mode. + */ + function layoutOverview() { + + // Layout slides + toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) ).forEach( function( hslide, h ) { + hslide.setAttribute( 'data-index-h', h ); + transformElement( hslide, 'translate3d(' + ( h * overviewSlideWidth ) + 'px, 0, 0)' ); + + if( hslide.classList.contains( 'stack' ) ) { + + toArray( hslide.querySelectorAll( 'section' ) ).forEach( function( vslide, v ) { + vslide.setAttribute( 'data-index-h', h ); + vslide.setAttribute( 'data-index-v', v ); + + transformElement( vslide, 'translate3d(0, ' + ( v * overviewSlideHeight ) + 'px, 0)' ); + } ); + + } + } ); + + // Layout slide backgrounds + toArray( dom.background.childNodes ).forEach( function( hbackground, h ) { + transformElement( hbackground, 'translate3d(' + ( h * overviewSlideWidth ) + 'px, 0, 0)' ); + + toArray( hbackground.querySelectorAll( '.slide-background' ) ).forEach( function( vbackground, v ) { + transformElement( vbackground, 'translate3d(0, ' + ( v * overviewSlideHeight ) + 'px, 0)' ); + } ); + } ); + + } + + /** + * Moves the overview viewport to the current slides. + * Called each time the current slide changes. + */ + function updateOverview() { + + var vmin = Math.min( window.innerWidth, window.innerHeight ); + var scale = Math.max( vmin / 5, 150 ) / vmin; + + transformSlides( { + overview: [ + 'scale('+ scale +')', + 'translateX('+ ( -indexh * overviewSlideWidth ) +'px)', + 'translateY('+ ( -indexv * overviewSlideHeight ) +'px)' + ].join( ' ' ) + } ); + + } + + /** + * Exits the slide overview and enters the currently + * active slide. + */ + function deactivateOverview() { + + // Only proceed if enabled in config + if( config.overview ) { + + overview = false; + + dom.wrapper.classList.remove( 'overview' ); + dom.wrapper.classList.remove( 'overview-animated' ); + + // Temporarily add a class so that transitions can do different things + // depending on whether they are exiting/entering overview, or just + // moving from slide to slide + dom.wrapper.classList.add( 'overview-deactivating' ); + + setTimeout( function () { + dom.wrapper.classList.remove( 'overview-deactivating' ); + }, 1 ); + + // Move the background element back out + dom.wrapper.appendChild( dom.background ); + + // Clean up changes made to slides + toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR ) ).forEach( function( slide ) { + transformElement( slide, '' ); + + slide.removeEventListener( 'click', onOverviewSlideClicked, true ); + } ); + + // Clean up changes made to backgrounds + toArray( dom.background.querySelectorAll( '.slide-background' ) ).forEach( function( background ) { + transformElement( background, '' ); + } ); + + transformSlides( { overview: '' } ); + + slide( indexh, indexv ); + + layout(); + + cueAutoSlide(); + + // Notify observers of the overview hiding + dispatchEvent( 'overviewhidden', { + 'indexh': indexh, + 'indexv': indexv, + 'currentSlide': currentSlide + } ); + + } + } + + /** + * Toggles the slide overview mode on and off. + * + * @param {Boolean} [override] Flag which overrides the + * toggle logic and forcibly sets the desired state. True means + * overview is open, false means it's closed. + */ + function toggleOverview( override ) { + + if( typeof override === 'boolean' ) { + override ? activateOverview() : deactivateOverview(); + } + else { + isOverview() ? deactivateOverview() : activateOverview(); + } + + } + + /** + * Checks if the overview is currently active. + * + * @return {Boolean} true if the overview is active, + * false otherwise + */ + function isOverview() { + + return overview; + + } + + /** + * Checks if the current or specified slide is vertical + * (nested within another slide). + * + * @param {HTMLElement} [slide=currentSlide] The slide to check + * orientation of + * @return {Boolean} + */ + function isVerticalSlide( slide ) { + + // Prefer slide argument, otherwise use current slide + slide = slide ? slide : currentSlide; + + return slide && slide.parentNode && !!slide.parentNode.nodeName.match( /section/i ); + + } + + /** + * Handling the fullscreen functionality via the fullscreen API + * + * @see http://fullscreen.spec.whatwg.org/ + * @see https://developer.mozilla.org/en-US/docs/DOM/Using_fullscreen_mode + */ + function enterFullscreen() { + + var element = document.documentElement; + + // Check which implementation is available + var requestMethod = element.requestFullscreen || + element.webkitRequestFullscreen || + element.webkitRequestFullScreen || + element.mozRequestFullScreen || + element.msRequestFullscreen; + + if( requestMethod ) { + requestMethod.apply( element ); + } + + } + + /** + * Enters the paused mode which fades everything on screen to + * black. + */ + function pause() { + + if( config.pause ) { + var wasPaused = dom.wrapper.classList.contains( 'paused' ); + + cancelAutoSlide(); + dom.wrapper.classList.add( 'paused' ); + + if( wasPaused === false ) { + dispatchEvent( 'paused' ); + } + } + + } + + /** + * Exits from the paused mode. + */ + function resume() { + + var wasPaused = dom.wrapper.classList.contains( 'paused' ); + dom.wrapper.classList.remove( 'paused' ); + + cueAutoSlide(); + + if( wasPaused ) { + dispatchEvent( 'resumed' ); + } + + } + + /** + * Toggles the paused mode on and off. + */ + function togglePause( override ) { + + if( typeof override === 'boolean' ) { + override ? pause() : resume(); + } + else { + isPaused() ? resume() : pause(); + } + + } + + /** + * Checks if we are currently in the paused mode. + * + * @return {Boolean} + */ + function isPaused() { + + return dom.wrapper.classList.contains( 'paused' ); + + } + + /** + * Toggles the auto slide mode on and off. + * + * @param {Boolean} [override] Flag which sets the desired state. + * True means autoplay starts, false means it stops. + */ + + function toggleAutoSlide( override ) { + + if( typeof override === 'boolean' ) { + override ? resumeAutoSlide() : pauseAutoSlide(); + } + + else { + autoSlidePaused ? resumeAutoSlide() : pauseAutoSlide(); + } + + } + + /** + * Checks if the auto slide mode is currently on. + * + * @return {Boolean} + */ + function isAutoSliding() { + + return !!( autoSlide && !autoSlidePaused ); + + } + + /** + * Steps from the current point in the presentation to the + * slide which matches the specified horizontal and vertical + * indices. + * + * @param {number} [h=indexh] Horizontal index of the target slide + * @param {number} [v=indexv] Vertical index of the target slide + * @param {number} [f] Index of a fragment within the + * target slide to activate + * @param {number} [o] Origin for use in multimaster environments + */ + function slide( h, v, f, o ) { + + // Remember where we were at before + previousSlide = currentSlide; + + // Query all horizontal slides in the deck + var horizontalSlides = dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ); + + // Abort if there are no slides + if( horizontalSlides.length === 0 ) return; + + // If no vertical index is specified and the upcoming slide is a + // stack, resume at its previous vertical index + if( v === undefined && !isOverview() ) { + v = getPreviousVerticalIndex( horizontalSlides[ h ] ); + } + + // If we were on a vertical stack, remember what vertical index + // it was on so we can resume at the same position when returning + if( previousSlide && previousSlide.parentNode && previousSlide.parentNode.classList.contains( 'stack' ) ) { + setPreviousVerticalIndex( previousSlide.parentNode, indexv ); + } + + // Remember the state before this slide + var stateBefore = state.concat(); + + // Reset the state array + state.length = 0; + + var indexhBefore = indexh || 0, + indexvBefore = indexv || 0; + + // Activate and transition to the new slide + indexh = updateSlides( HORIZONTAL_SLIDES_SELECTOR, h === undefined ? indexh : h ); + indexv = updateSlides( VERTICAL_SLIDES_SELECTOR, v === undefined ? indexv : v ); + + // Update the visibility of slides now that the indices have changed + updateSlidesVisibility(); + + layout(); + + // Apply the new state + stateLoop: for( var i = 0, len = state.length; i < len; i++ ) { + // Check if this state existed on the previous slide. If it + // did, we will avoid adding it repeatedly + for( var j = 0; j < stateBefore.length; j++ ) { + if( stateBefore[j] === state[i] ) { + stateBefore.splice( j, 1 ); + continue stateLoop; + } + } + + document.documentElement.classList.add( state[i] ); + + // Dispatch custom event matching the state's name + dispatchEvent( state[i] ); + } + + // Clean up the remains of the previous state + while( stateBefore.length ) { + document.documentElement.classList.remove( stateBefore.pop() ); + } + + // Update the overview if it's currently active + if( isOverview() ) { + updateOverview(); + } + + // Find the current horizontal slide and any possible vertical slides + // within it + var currentHorizontalSlide = horizontalSlides[ indexh ], + currentVerticalSlides = currentHorizontalSlide.querySelectorAll( 'section' ); + + // Store references to the previous and current slides + currentSlide = currentVerticalSlides[ indexv ] || currentHorizontalSlide; + + // Show fragment, if specified + if( typeof f !== 'undefined' ) { + navigateFragment( f ); + } + + // Dispatch an event if the slide changed + var slideChanged = ( indexh !== indexhBefore || indexv !== indexvBefore ); + if( slideChanged ) { + dispatchEvent( 'slidechanged', { + 'indexh': indexh, + 'indexv': indexv, + 'previousSlide': previousSlide, + 'currentSlide': currentSlide, + 'origin': o + } ); + } + else { + // Ensure that the previous slide is never the same as the current + previousSlide = null; + } + + // Solves an edge case where the previous slide maintains the + // 'present' class when navigating between adjacent vertical + // stacks + if( previousSlide ) { + previousSlide.classList.remove( 'present' ); + previousSlide.setAttribute( 'aria-hidden', 'true' ); + + // Reset all slides upon navigate to home + // Issue: #285 + if ( dom.wrapper.querySelector( HOME_SLIDE_SELECTOR ).classList.contains( 'present' ) ) { + // Launch async task + setTimeout( function () { + var slides = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR + '.stack') ), i; + for( i in slides ) { + if( slides[i] ) { + // Reset stack + setPreviousVerticalIndex( slides[i], 0 ); + } + } + }, 0 ); + } + } + + // Handle embedded content + if( slideChanged || !previousSlide ) { + stopEmbeddedContent( previousSlide ); + startEmbeddedContent( currentSlide ); + } + + // Announce the current slide contents, for screen readers + dom.statusDiv.textContent = getStatusText( currentSlide ); + + updateControls(); + updateProgress(); + updateBackground(); + updateParallax(); + updateSlideNumber(); + updateNotes(); + + // Update the URL hash + writeURL(); + + cueAutoSlide(); + + } + + /** + * Syncs the presentation with the current DOM. Useful + * when new slides or control elements are added or when + * the configuration has changed. + */ + function sync() { + + // Subscribe to input + removeEventListeners(); + addEventListeners(); + + // Force a layout to make sure the current config is accounted for + layout(); + + // Reflect the current autoSlide value + autoSlide = config.autoSlide; + + // Start auto-sliding if it's enabled + cueAutoSlide(); + + // Re-create the slide backgrounds + createBackgrounds(); + + // Write the current hash to the URL + writeURL(); + + sortAllFragments(); + + updateControls(); + updateProgress(); + updateSlideNumber(); + updateSlidesVisibility(); + updateBackground( true ); + updateNotesVisibility(); + updateNotes(); + + formatEmbeddedContent(); + + // Start or stop embedded content depending on global config + if( config.autoPlayMedia === false ) { + stopEmbeddedContent( currentSlide, { unloadIframes: false } ); + } + else { + startEmbeddedContent( currentSlide ); + } + + if( isOverview() ) { + layoutOverview(); + } + + } + + /** + * Resets all vertical slides so that only the first + * is visible. + */ + function resetVerticalSlides() { + + var horizontalSlides = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) ); + horizontalSlides.forEach( function( horizontalSlide ) { + + var verticalSlides = toArray( horizontalSlide.querySelectorAll( 'section' ) ); + verticalSlides.forEach( function( verticalSlide, y ) { + + if( y > 0 ) { + verticalSlide.classList.remove( 'present' ); + verticalSlide.classList.remove( 'past' ); + verticalSlide.classList.add( 'future' ); + verticalSlide.setAttribute( 'aria-hidden', 'true' ); + } + + } ); + + } ); + + } + + /** + * Sorts and formats all of fragments in the + * presentation. + */ + function sortAllFragments() { + + var horizontalSlides = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) ); + horizontalSlides.forEach( function( horizontalSlide ) { + + var verticalSlides = toArray( horizontalSlide.querySelectorAll( 'section' ) ); + verticalSlides.forEach( function( verticalSlide, y ) { + + sortFragments( verticalSlide.querySelectorAll( '.fragment' ) ); + + } ); + + if( verticalSlides.length === 0 ) sortFragments( horizontalSlide.querySelectorAll( '.fragment' ) ); + + } ); + + } + + /** + * Randomly shuffles all slides in the deck. + */ + function shuffle() { + + var slides = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) ); + + slides.forEach( function( slide ) { + + // Insert this slide next to another random slide. This may + // cause the slide to insert before itself but that's fine. + dom.slides.insertBefore( slide, slides[ Math.floor( Math.random() * slides.length ) ] ); + + } ); + + } + + /** + * Updates one dimension of slides by showing the slide + * with the specified index. + * + * @param {string} selector A CSS selector that will fetch + * the group of slides we are working with + * @param {number} index The index of the slide that should be + * shown + * + * @return {number} The index of the slide that is now shown, + * might differ from the passed in index if it was out of + * bounds. + */ + function updateSlides( selector, index ) { + + // Select all slides and convert the NodeList result to + // an array + var slides = toArray( dom.wrapper.querySelectorAll( selector ) ), + slidesLength = slides.length; + + var printMode = isPrintingPDF(); + + if( slidesLength ) { + + // Should the index loop? + if( config.loop ) { + index %= slidesLength; + + if( index < 0 ) { + index = slidesLength + index; + } + } + + // Enforce max and minimum index bounds + index = Math.max( Math.min( index, slidesLength - 1 ), 0 ); + + for( var i = 0; i < slidesLength; i++ ) { + var element = slides[i]; + + var reverse = config.rtl && !isVerticalSlide( element ); + + element.classList.remove( 'past' ); + element.classList.remove( 'present' ); + element.classList.remove( 'future' ); + + // http://www.w3.org/html/wg/drafts/html/master/editing.html#the-hidden-attribute + element.setAttribute( 'hidden', '' ); + element.setAttribute( 'aria-hidden', 'true' ); + + // If this element contains vertical slides + if( element.querySelector( 'section' ) ) { + element.classList.add( 'stack' ); + } + + // If we're printing static slides, all slides are "present" + if( printMode ) { + element.classList.add( 'present' ); + continue; + } + + if( i < index ) { + // Any element previous to index is given the 'past' class + element.classList.add( reverse ? 'future' : 'past' ); + + if( config.fragments ) { + var pastFragments = toArray( element.querySelectorAll( '.fragment' ) ); + + // Show all fragments on prior slides + while( pastFragments.length ) { + var pastFragment = pastFragments.pop(); + pastFragment.classList.add( 'visible' ); + pastFragment.classList.remove( 'current-fragment' ); + } + } + } + else if( i > index ) { + // Any element subsequent to index is given the 'future' class + element.classList.add( reverse ? 'past' : 'future' ); + + if( config.fragments ) { + var futureFragments = toArray( element.querySelectorAll( '.fragment.visible' ) ); + + // No fragments in future slides should be visible ahead of time + while( futureFragments.length ) { + var futureFragment = futureFragments.pop(); + futureFragment.classList.remove( 'visible' ); + futureFragment.classList.remove( 'current-fragment' ); + } + } + } + } + + // Mark the current slide as present + slides[index].classList.add( 'present' ); + slides[index].removeAttribute( 'hidden' ); + slides[index].removeAttribute( 'aria-hidden' ); + + // If this slide has a state associated with it, add it + // onto the current state of the deck + var slideState = slides[index].getAttribute( 'data-state' ); + if( slideState ) { + state = state.concat( slideState.split( ' ' ) ); + } + + } + else { + // Since there are no slides we can't be anywhere beyond the + // zeroth index + index = 0; + } + + return index; + + } + + /** + * Optimization method; hide all slides that are far away + * from the present slide. + */ + function updateSlidesVisibility() { + + // Select all slides and convert the NodeList result to + // an array + var horizontalSlides = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) ), + horizontalSlidesLength = horizontalSlides.length, + distanceX, + distanceY; + + if( horizontalSlidesLength && typeof indexh !== 'undefined' ) { + + // The number of steps away from the present slide that will + // be visible + var viewDistance = isOverview() ? 10 : config.viewDistance; + + // Limit view distance on weaker devices + if( isMobileDevice ) { + viewDistance = isOverview() ? 6 : 2; + } + + // All slides need to be visible when exporting to PDF + if( isPrintingPDF() ) { + viewDistance = Number.MAX_VALUE; + } + + for( var x = 0; x < horizontalSlidesLength; x++ ) { + var horizontalSlide = horizontalSlides[x]; + + var verticalSlides = toArray( horizontalSlide.querySelectorAll( 'section' ) ), + verticalSlidesLength = verticalSlides.length; + + // Determine how far away this slide is from the present + distanceX = Math.abs( ( indexh || 0 ) - x ) || 0; + + // If the presentation is looped, distance should measure + // 1 between the first and last slides + if( config.loop ) { + distanceX = Math.abs( ( ( indexh || 0 ) - x ) % ( horizontalSlidesLength - viewDistance ) ) || 0; + } + + // Show the horizontal slide if it's within the view distance + if( distanceX < viewDistance ) { + loadSlide( horizontalSlide ); + } + else { + unloadSlide( horizontalSlide ); + } + + if( verticalSlidesLength ) { + + var oy = getPreviousVerticalIndex( horizontalSlide ); + + for( var y = 0; y < verticalSlidesLength; y++ ) { + var verticalSlide = verticalSlides[y]; + + distanceY = x === ( indexh || 0 ) ? Math.abs( ( indexv || 0 ) - y ) : Math.abs( y - oy ); + + if( distanceX + distanceY < viewDistance ) { + loadSlide( verticalSlide ); + } + else { + unloadSlide( verticalSlide ); + } + } + + } + } + + // Flag if there are ANY vertical slides, anywhere in the deck + if( dom.wrapper.querySelectorAll( '.slides>section>section' ).length ) { + dom.wrapper.classList.add( 'has-vertical-slides' ); + } + else { + dom.wrapper.classList.remove( 'has-vertical-slides' ); + } + + // Flag if there are ANY horizontal slides, anywhere in the deck + if( dom.wrapper.querySelectorAll( '.slides>section' ).length > 1 ) { + dom.wrapper.classList.add( 'has-horizontal-slides' ); + } + else { + dom.wrapper.classList.remove( 'has-horizontal-slides' ); + } + + } + + } + + /** + * Pick up notes from the current slide and display them + * to the viewer. + * + * @see {@link config.showNotes} + */ + function updateNotes() { + + if( config.showNotes && dom.speakerNotes && currentSlide && !isPrintingPDF() ) { + + dom.speakerNotes.innerHTML = getSlideNotes() || 'No notes on this slide.'; + + } + + } + + /** + * Updates the visibility of the speaker notes sidebar that + * is used to share annotated slides. The notes sidebar is + * only visible if showNotes is true and there are notes on + * one or more slides in the deck. + */ + function updateNotesVisibility() { + + if( config.showNotes && hasNotes() ) { + dom.wrapper.classList.add( 'show-notes' ); + } + else { + dom.wrapper.classList.remove( 'show-notes' ); + } + + } + + /** + * Checks if there are speaker notes for ANY slide in the + * presentation. + */ + function hasNotes() { + + return dom.slides.querySelectorAll( '[data-notes], aside.notes' ).length > 0; + + } + + /** + * Updates the progress bar to reflect the current slide. + */ + function updateProgress() { + + // Update progress if enabled + if( config.progress && dom.progressbar ) { + + dom.progressbar.style.width = getProgress() * dom.wrapper.offsetWidth + 'px'; + + } + + } + + /** + * Updates the slide number div to reflect the current slide. + * + * The following slide number formats are available: + * "h.v": horizontal . vertical slide number (default) + * "h/v": horizontal / vertical slide number + * "c": flattened slide number + * "c/t": flattened slide number / total slides + */ + function updateSlideNumber() { + + // Update slide number if enabled + if( config.slideNumber && dom.slideNumber ) { + + var value = []; + var format = 'h.v'; + + // Check if a custom number format is available + if( typeof config.slideNumber === 'string' ) { + format = config.slideNumber; + } + + switch( format ) { + case 'c': + value.push( getSlidePastCount() + 1 ); + break; + case 'c/t': + value.push( getSlidePastCount() + 1, '/', getTotalSlides() ); + break; + case 'h/v': + value.push( indexh + 1 ); + if( isVerticalSlide() ) value.push( '/', indexv + 1 ); + break; + default: + value.push( indexh + 1 ); + if( isVerticalSlide() ) value.push( '.', indexv + 1 ); + } + + dom.slideNumber.innerHTML = formatSlideNumber( value[0], value[1], value[2] ); + } + + } + + /** + * Applies HTML formatting to a slide number before it's + * written to the DOM. + * + * @param {number} a Current slide + * @param {string} delimiter Character to separate slide numbers + * @param {(number|*)} b Total slides + * @return {string} HTML string fragment + */ + function formatSlideNumber( a, delimiter, b ) { + + if( typeof b === 'number' && !isNaN( b ) ) { + return ''+ a +'' + + ''+ delimiter +'' + + ''+ b +''; + } + else { + return ''+ a +''; + } + + } + + /** + * Updates the state of all control/navigation arrows. + */ + function updateControls() { + + var routes = availableRoutes(); + var fragments = availableFragments(); + + // Remove the 'enabled' class from all directions + dom.controlsLeft.concat( dom.controlsRight ) + .concat( dom.controlsUp ) + .concat( dom.controlsDown ) + .concat( dom.controlsPrev ) + .concat( dom.controlsNext ).forEach( function( node ) { + node.classList.remove( 'enabled' ); + node.classList.remove( 'fragmented' ); + + // Set 'disabled' attribute on all directions + node.setAttribute( 'disabled', 'disabled' ); + } ); + + // Add the 'enabled' class to the available routes; remove 'disabled' attribute to enable buttons + if( routes.left ) dom.controlsLeft.forEach( function( el ) { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } ); + if( routes.right ) dom.controlsRight.forEach( function( el ) { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } ); + if( routes.up ) dom.controlsUp.forEach( function( el ) { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } ); + if( routes.down ) dom.controlsDown.forEach( function( el ) { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } ); + + // Prev/next buttons + if( routes.left || routes.up ) dom.controlsPrev.forEach( function( el ) { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } ); + if( routes.right || routes.down ) dom.controlsNext.forEach( function( el ) { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } ); + + // Highlight fragment directions + if( currentSlide ) { + + // Always apply fragment decorator to prev/next buttons + if( fragments.prev ) dom.controlsPrev.forEach( function( el ) { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } ); + if( fragments.next ) dom.controlsNext.forEach( function( el ) { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } ); + + // Apply fragment decorators to directional buttons based on + // what slide axis they are in + if( isVerticalSlide( currentSlide ) ) { + if( fragments.prev ) dom.controlsUp.forEach( function( el ) { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } ); + if( fragments.next ) dom.controlsDown.forEach( function( el ) { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } ); + } + else { + if( fragments.prev ) dom.controlsLeft.forEach( function( el ) { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } ); + if( fragments.next ) dom.controlsRight.forEach( function( el ) { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } ); + } + + } + + if( config.controlsTutorial ) { + + // Highlight control arrows with an animation to ensure + // that the viewer knows how to navigate + if( !hasNavigatedDown && routes.down ) { + dom.controlsDownArrow.classList.add( 'highlight' ); + } + else { + dom.controlsDownArrow.classList.remove( 'highlight' ); + + if( !hasNavigatedRight && routes.right && indexv === 0 ) { + dom.controlsRightArrow.classList.add( 'highlight' ); + } + else { + dom.controlsRightArrow.classList.remove( 'highlight' ); + } + } + + } + + } + + /** + * Updates the background elements to reflect the current + * slide. + * + * @param {boolean} includeAll If true, the backgrounds of + * all vertical slides (not just the present) will be updated. + */ + function updateBackground( includeAll ) { + + var currentBackground = null; + + // Reverse past/future classes when in RTL mode + var horizontalPast = config.rtl ? 'future' : 'past', + horizontalFuture = config.rtl ? 'past' : 'future'; + + // Update the classes of all backgrounds to match the + // states of their slides (past/present/future) + toArray( dom.background.childNodes ).forEach( function( backgroundh, h ) { + + backgroundh.classList.remove( 'past' ); + backgroundh.classList.remove( 'present' ); + backgroundh.classList.remove( 'future' ); + + if( h < indexh ) { + backgroundh.classList.add( horizontalPast ); + } + else if ( h > indexh ) { + backgroundh.classList.add( horizontalFuture ); + } + else { + backgroundh.classList.add( 'present' ); + + // Store a reference to the current background element + currentBackground = backgroundh; + } + + if( includeAll || h === indexh ) { + toArray( backgroundh.querySelectorAll( '.slide-background' ) ).forEach( function( backgroundv, v ) { + + backgroundv.classList.remove( 'past' ); + backgroundv.classList.remove( 'present' ); + backgroundv.classList.remove( 'future' ); + + if( v < indexv ) { + backgroundv.classList.add( 'past' ); + } + else if ( v > indexv ) { + backgroundv.classList.add( 'future' ); + } + else { + backgroundv.classList.add( 'present' ); + + // Only if this is the present horizontal and vertical slide + if( h === indexh ) currentBackground = backgroundv; + } + + } ); + } + + } ); + + // Stop content inside of previous backgrounds + if( previousBackground ) { + + stopEmbeddedContent( previousBackground ); + + } + + // Start content in the current background + if( currentBackground ) { + + startEmbeddedContent( currentBackground ); + + var backgroundImageURL = currentBackground.style.backgroundImage || ''; + + // Restart GIFs (doesn't work in Firefox) + if( /\.gif/i.test( backgroundImageURL ) ) { + currentBackground.style.backgroundImage = ''; + window.getComputedStyle( currentBackground ).opacity; + currentBackground.style.backgroundImage = backgroundImageURL; + } + + // Don't transition between identical backgrounds. This + // prevents unwanted flicker. + var previousBackgroundHash = previousBackground ? previousBackground.getAttribute( 'data-background-hash' ) : null; + var currentBackgroundHash = currentBackground.getAttribute( 'data-background-hash' ); + if( currentBackgroundHash && currentBackgroundHash === previousBackgroundHash && currentBackground !== previousBackground ) { + dom.background.classList.add( 'no-transition' ); + } + + previousBackground = currentBackground; + + } + + // If there's a background brightness flag for this slide, + // bubble it to the .reveal container + if( currentSlide ) { + [ 'has-light-background', 'has-dark-background' ].forEach( function( classToBubble ) { + if( currentSlide.classList.contains( classToBubble ) ) { + dom.wrapper.classList.add( classToBubble ); + } + else { + dom.wrapper.classList.remove( classToBubble ); + } + } ); + } + + // Allow the first background to apply without transition + setTimeout( function() { + dom.background.classList.remove( 'no-transition' ); + }, 1 ); + + } + + /** + * Updates the position of the parallax background based + * on the current slide index. + */ + function updateParallax() { + + if( config.parallaxBackgroundImage ) { + + var horizontalSlides = dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ), + verticalSlides = dom.wrapper.querySelectorAll( VERTICAL_SLIDES_SELECTOR ); + + var backgroundSize = dom.background.style.backgroundSize.split( ' ' ), + backgroundWidth, backgroundHeight; + + if( backgroundSize.length === 1 ) { + backgroundWidth = backgroundHeight = parseInt( backgroundSize[0], 10 ); + } + else { + backgroundWidth = parseInt( backgroundSize[0], 10 ); + backgroundHeight = parseInt( backgroundSize[1], 10 ); + } + + var slideWidth = dom.background.offsetWidth, + horizontalSlideCount = horizontalSlides.length, + horizontalOffsetMultiplier, + horizontalOffset; + + if( typeof config.parallaxBackgroundHorizontal === 'number' ) { + horizontalOffsetMultiplier = config.parallaxBackgroundHorizontal; + } + else { + horizontalOffsetMultiplier = horizontalSlideCount > 1 ? ( backgroundWidth - slideWidth ) / ( horizontalSlideCount-1 ) : 0; + } + + horizontalOffset = horizontalOffsetMultiplier * indexh * -1; + + var slideHeight = dom.background.offsetHeight, + verticalSlideCount = verticalSlides.length, + verticalOffsetMultiplier, + verticalOffset; + + if( typeof config.parallaxBackgroundVertical === 'number' ) { + verticalOffsetMultiplier = config.parallaxBackgroundVertical; + } + else { + verticalOffsetMultiplier = ( backgroundHeight - slideHeight ) / ( verticalSlideCount-1 ); + } + + verticalOffset = verticalSlideCount > 0 ? verticalOffsetMultiplier * indexv : 0; + + dom.background.style.backgroundPosition = horizontalOffset + 'px ' + -verticalOffset + 'px'; + + } + + } + + /** + * Called when the given slide is within the configured view + * distance. Shows the slide element and loads any content + * that is set to load lazily (data-src). + * + * @param {HTMLElement} slide Slide to show + */ + function loadSlide( slide, options ) { + + options = options || {}; + + // Show the slide element + slide.style.display = config.display; + + // Media elements with data-src attributes + toArray( slide.querySelectorAll( 'img[data-src], video[data-src], audio[data-src]' ) ).forEach( function( element ) { + element.setAttribute( 'src', element.getAttribute( 'data-src' ) ); + element.setAttribute( 'data-lazy-loaded', '' ); + element.removeAttribute( 'data-src' ); + } ); + + // Media elements with children + toArray( slide.querySelectorAll( 'video, audio' ) ).forEach( function( media ) { + var sources = 0; + + toArray( media.querySelectorAll( 'source[data-src]' ) ).forEach( function( source ) { + source.setAttribute( 'src', source.getAttribute( 'data-src' ) ); + source.removeAttribute( 'data-src' ); + source.setAttribute( 'data-lazy-loaded', '' ); + sources += 1; + } ); + + // If we rewrote sources for this video/audio element, we need + // to manually tell it to load from its new origin + if( sources > 0 ) { + media.load(); + } + } ); + + + // Show the corresponding background element + var indices = getIndices( slide ); + var background = getSlideBackground( indices.h, indices.v ); + if( background ) { + background.style.display = 'block'; + + // If the background contains media, load it + if( background.hasAttribute( 'data-loaded' ) === false ) { + background.setAttribute( 'data-loaded', 'true' ); + + var backgroundImage = slide.getAttribute( 'data-background-image' ), + backgroundVideo = slide.getAttribute( 'data-background-video' ), + backgroundVideoLoop = slide.hasAttribute( 'data-background-video-loop' ), + backgroundVideoMuted = slide.hasAttribute( 'data-background-video-muted' ), + backgroundIframe = slide.getAttribute( 'data-background-iframe' ); + + // Images + if( backgroundImage ) { + background.style.backgroundImage = 'url('+ backgroundImage +')'; + } + // Videos + else if ( backgroundVideo && !isSpeakerNotes() ) { + var video = document.createElement( 'video' ); + + if( backgroundVideoLoop ) { + video.setAttribute( 'loop', '' ); + } + + if( backgroundVideoMuted ) { + video.muted = true; + } + + // Inline video playback works (at least in Mobile Safari) as + // long as the video is muted and the `playsinline` attribute is + // present + if( isMobileDevice ) { + video.muted = true; + video.autoplay = true; + video.setAttribute( 'playsinline', '' ); + } + + // Support comma separated lists of video sources + backgroundVideo.split( ',' ).forEach( function( source ) { + video.innerHTML += ''; + } ); + + background.appendChild( video ); + } + // Iframes + else if( backgroundIframe && options.excludeIframes !== true ) { + var iframe = document.createElement( 'iframe' ); + iframe.setAttribute( 'allowfullscreen', '' ); + iframe.setAttribute( 'mozallowfullscreen', '' ); + iframe.setAttribute( 'webkitallowfullscreen', '' ); + + // Only load autoplaying content when the slide is shown to + // avoid having it play in the background + if( /autoplay=(1|true|yes)/gi.test( backgroundIframe ) ) { + iframe.setAttribute( 'data-src', backgroundIframe ); + } + else { + iframe.setAttribute( 'src', backgroundIframe ); + } + + iframe.style.width = '100%'; + iframe.style.height = '100%'; + iframe.style.maxHeight = '100%'; + iframe.style.maxWidth = '100%'; + + background.appendChild( iframe ); + } + } + + } + + } + + /** + * Unloads and hides the given slide. This is called when the + * slide is moved outside of the configured view distance. + * + * @param {HTMLElement} slide + */ + function unloadSlide( slide ) { + + // Hide the slide element + slide.style.display = 'none'; + + // Hide the corresponding background element + var indices = getIndices( slide ); + var background = getSlideBackground( indices.h, indices.v ); + if( background ) { + background.style.display = 'none'; + } + + // Reset lazy-loaded media elements with src attributes + toArray( slide.querySelectorAll( 'video[data-lazy-loaded][src], audio[data-lazy-loaded][src]' ) ).forEach( function( element ) { + element.setAttribute( 'data-src', element.getAttribute( 'src' ) ); + element.removeAttribute( 'src' ); + } ); + + // Reset lazy-loaded media elements with children + toArray( slide.querySelectorAll( 'video[data-lazy-loaded] source[src], audio source[src]' ) ).forEach( function( source ) { + source.setAttribute( 'data-src', source.getAttribute( 'src' ) ); + source.removeAttribute( 'src' ); + } ); + + } + + /** + * Determine what available routes there are for navigation. + * + * @return {{left: boolean, right: boolean, up: boolean, down: boolean}} + */ + function availableRoutes() { + + var horizontalSlides = dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ), + verticalSlides = dom.wrapper.querySelectorAll( VERTICAL_SLIDES_SELECTOR ); + + var routes = { + left: indexh > 0 || config.loop, + right: indexh < horizontalSlides.length - 1 || config.loop, + up: indexv > 0, + down: indexv < verticalSlides.length - 1 + }; + + // reverse horizontal controls for rtl + if( config.rtl ) { + var left = routes.left; + routes.left = routes.right; + routes.right = left; + } + + return routes; + + } + + /** + * Returns an object describing the available fragment + * directions. + * + * @return {{prev: boolean, next: boolean}} + */ + function availableFragments() { + + if( currentSlide && config.fragments ) { + var fragments = currentSlide.querySelectorAll( '.fragment' ); + var hiddenFragments = currentSlide.querySelectorAll( '.fragment:not(.visible)' ); + + return { + prev: fragments.length - hiddenFragments.length > 0, + next: !!hiddenFragments.length + }; + } + else { + return { prev: false, next: false }; + } + + } + + /** + * Enforces origin-specific format rules for embedded media. + */ + function formatEmbeddedContent() { + + var _appendParamToIframeSource = function( sourceAttribute, sourceURL, param ) { + toArray( dom.slides.querySelectorAll( 'iframe['+ sourceAttribute +'*="'+ sourceURL +'"]' ) ).forEach( function( el ) { + var src = el.getAttribute( sourceAttribute ); + if( src && src.indexOf( param ) === -1 ) { + el.setAttribute( sourceAttribute, src + ( !/\?/.test( src ) ? '?' : '&' ) + param ); + } + }); + }; + + // YouTube frames must include "?enablejsapi=1" + _appendParamToIframeSource( 'src', 'youtube.com/embed/', 'enablejsapi=1' ); + _appendParamToIframeSource( 'data-src', 'youtube.com/embed/', 'enablejsapi=1' ); + + // Vimeo frames must include "?api=1" + _appendParamToIframeSource( 'src', 'player.vimeo.com/', 'api=1' ); + _appendParamToIframeSource( 'data-src', 'player.vimeo.com/', 'api=1' ); + + // Always show media controls on mobile devices + if( isMobileDevice ) { + toArray( dom.slides.querySelectorAll( 'video, audio' ) ).forEach( function( el ) { + el.controls = true; + } ); + } + + } + + /** + * Start playback of any embedded content inside of + * the given element. + * + * @param {HTMLElement} element + */ + function startEmbeddedContent( element ) { + + if( element && !isSpeakerNotes() ) { + + // Restart GIFs + toArray( element.querySelectorAll( 'img[src$=".gif"]' ) ).forEach( function( el ) { + // Setting the same unchanged source like this was confirmed + // to work in Chrome, FF & Safari + el.setAttribute( 'src', el.getAttribute( 'src' ) ); + } ); + + // HTML5 media elements + toArray( element.querySelectorAll( 'video, audio' ) ).forEach( function( el ) { + if( closestParent( el, '.fragment' ) && !closestParent( el, '.fragment.visible' ) ) { + return; + } + + // Prefer an explicit global autoplay setting + var autoplay = config.autoPlayMedia; + + // If no global setting is available, fall back on the element's + // own autoplay setting + if( typeof autoplay !== 'boolean' ) { + autoplay = el.hasAttribute( 'data-autoplay' ) || !!closestParent( el, '.slide-background' ); + } + + if( autoplay && typeof el.play === 'function' ) { + + if( el.readyState > 1 ) { + startEmbeddedMedia( { target: el } ); + } + else { + el.removeEventListener( 'loadeddata', startEmbeddedMedia ); // remove first to avoid dupes + el.addEventListener( 'loadeddata', startEmbeddedMedia ); + } + + } + } ); + + // Normal iframes + toArray( element.querySelectorAll( 'iframe[src]' ) ).forEach( function( el ) { + if( closestParent( el, '.fragment' ) && !closestParent( el, '.fragment.visible' ) ) { + return; + } + + startEmbeddedIframe( { target: el } ); + } ); + + // Lazy loading iframes + toArray( element.querySelectorAll( 'iframe[data-src]' ) ).forEach( function( el ) { + if( closestParent( el, '.fragment' ) && !closestParent( el, '.fragment.visible' ) ) { + return; + } + + if( el.getAttribute( 'src' ) !== el.getAttribute( 'data-src' ) ) { + el.removeEventListener( 'load', startEmbeddedIframe ); // remove first to avoid dupes + el.addEventListener( 'load', startEmbeddedIframe ); + el.setAttribute( 'src', el.getAttribute( 'data-src' ) ); + } + } ); + + } + + } + + /** + * Starts playing an embedded video/audio element after + * it has finished loading. + * + * @param {object} event + */ + function startEmbeddedMedia( event ) { + + var isAttachedToDOM = !!closestParent( event.target, 'html' ), + isVisible = !!closestParent( event.target, '.present' ); + + if( isAttachedToDOM && isVisible ) { + event.target.currentTime = 0; + event.target.play(); + } + + event.target.removeEventListener( 'loadeddata', startEmbeddedMedia ); + + } + + /** + * "Starts" the content of an embedded iframe using the + * postMessage API. + * + * @param {object} event + */ + function startEmbeddedIframe( event ) { + + var iframe = event.target; + + if( iframe && iframe.contentWindow ) { + + var isAttachedToDOM = !!closestParent( event.target, 'html' ), + isVisible = !!closestParent( event.target, '.present' ); + + if( isAttachedToDOM && isVisible ) { + + // Prefer an explicit global autoplay setting + var autoplay = config.autoPlayMedia; + + // If no global setting is available, fall back on the element's + // own autoplay setting + if( typeof autoplay !== 'boolean' ) { + autoplay = iframe.hasAttribute( 'data-autoplay' ) || !!closestParent( iframe, '.slide-background' ); + } + + // YouTube postMessage API + if( /youtube\.com\/embed\//.test( iframe.getAttribute( 'src' ) ) && autoplay ) { + iframe.contentWindow.postMessage( '{"event":"command","func":"playVideo","args":""}', '*' ); + } + // Vimeo postMessage API + else if( /player\.vimeo\.com\//.test( iframe.getAttribute( 'src' ) ) && autoplay ) { + iframe.contentWindow.postMessage( '{"method":"play"}', '*' ); + } + // Generic postMessage API + else { + iframe.contentWindow.postMessage( 'slide:start', '*' ); + } + + } + + } + + } + + /** + * Stop playback of any embedded content inside of + * the targeted slide. + * + * @param {HTMLElement} element + */ + function stopEmbeddedContent( element, options ) { + + options = extend( { + // Defaults + unloadIframes: true + }, options || {} ); + + if( element && element.parentNode ) { + // HTML5 media elements + toArray( element.querySelectorAll( 'video, audio' ) ).forEach( function( el ) { + if( !el.hasAttribute( 'data-ignore' ) && typeof el.pause === 'function' ) { + el.setAttribute('data-paused-by-reveal', ''); + el.pause(); + } + } ); + + // Generic postMessage API for non-lazy loaded iframes + toArray( element.querySelectorAll( 'iframe' ) ).forEach( function( el ) { + if( el.contentWindow ) el.contentWindow.postMessage( 'slide:stop', '*' ); + el.removeEventListener( 'load', startEmbeddedIframe ); + }); + + // YouTube postMessage API + toArray( element.querySelectorAll( 'iframe[src*="youtube.com/embed/"]' ) ).forEach( function( el ) { + if( !el.hasAttribute( 'data-ignore' ) && el.contentWindow && typeof el.contentWindow.postMessage === 'function' ) { + el.contentWindow.postMessage( '{"event":"command","func":"pauseVideo","args":""}', '*' ); + } + }); + + // Vimeo postMessage API + toArray( element.querySelectorAll( 'iframe[src*="player.vimeo.com/"]' ) ).forEach( function( el ) { + if( !el.hasAttribute( 'data-ignore' ) && el.contentWindow && typeof el.contentWindow.postMessage === 'function' ) { + el.contentWindow.postMessage( '{"method":"pause"}', '*' ); + } + }); + + if( options.unloadIframes === true ) { + // Unload lazy-loaded iframes + toArray( element.querySelectorAll( 'iframe[data-src]' ) ).forEach( function( el ) { + // Only removing the src doesn't actually unload the frame + // in all browsers (Firefox) so we set it to blank first + el.setAttribute( 'src', 'about:blank' ); + el.removeAttribute( 'src' ); + } ); + } + } + + } + + /** + * Returns the number of past slides. This can be used as a global + * flattened index for slides. + * + * @return {number} Past slide count + */ + function getSlidePastCount() { + + var horizontalSlides = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) ); + + // The number of past slides + var pastCount = 0; + + // Step through all slides and count the past ones + mainLoop: for( var i = 0; i < horizontalSlides.length; i++ ) { + + var horizontalSlide = horizontalSlides[i]; + var verticalSlides = toArray( horizontalSlide.querySelectorAll( 'section' ) ); + + for( var j = 0; j < verticalSlides.length; j++ ) { + + // Stop as soon as we arrive at the present + if( verticalSlides[j].classList.contains( 'present' ) ) { + break mainLoop; + } + + pastCount++; + + } + + // Stop as soon as we arrive at the present + if( horizontalSlide.classList.contains( 'present' ) ) { + break; + } + + // Don't count the wrapping section for vertical slides + if( horizontalSlide.classList.contains( 'stack' ) === false ) { + pastCount++; + } + + } + + return pastCount; + + } + + /** + * Returns a value ranging from 0-1 that represents + * how far into the presentation we have navigated. + * + * @return {number} + */ + function getProgress() { + + // The number of past and total slides + var totalCount = getTotalSlides(); + var pastCount = getSlidePastCount(); + + if( currentSlide ) { + + var allFragments = currentSlide.querySelectorAll( '.fragment' ); + + // If there are fragments in the current slide those should be + // accounted for in the progress. + if( allFragments.length > 0 ) { + var visibleFragments = currentSlide.querySelectorAll( '.fragment.visible' ); + + // This value represents how big a portion of the slide progress + // that is made up by its fragments (0-1) + var fragmentWeight = 0.9; + + // Add fragment progress to the past slide count + pastCount += ( visibleFragments.length / allFragments.length ) * fragmentWeight; + } + + } + + return pastCount / ( totalCount - 1 ); + + } + + /** + * Checks if this presentation is running inside of the + * speaker notes window. + * + * @return {boolean} + */ + function isSpeakerNotes() { + + return !!window.location.search.match( /receiver/gi ); + + } + + /** + * Reads the current URL (hash) and navigates accordingly. + */ + function readURL() { + + var hash = window.location.hash; + + // Attempt to parse the hash as either an index or name + var bits = hash.slice( 2 ).split( '/' ), + name = hash.replace( /#|\//gi, '' ); + + // If the first bit is invalid and there is a name we can + // assume that this is a named link + if( isNaN( parseInt( bits[0], 10 ) ) && name.length ) { + var element; + + // Ensure the named link is a valid HTML ID attribute + if( /^[a-zA-Z][\w:.-]*$/.test( name ) ) { + // Find the slide with the specified ID + element = document.getElementById( name ); + } + + if( element ) { + // Find the position of the named slide and navigate to it + var indices = Reveal.getIndices( element ); + slide( indices.h, indices.v ); + } + // If the slide doesn't exist, navigate to the current slide + else { + slide( indexh || 0, indexv || 0 ); + } + } + else { + // Read the index components of the hash + var h = parseInt( bits[0], 10 ) || 0, + v = parseInt( bits[1], 10 ) || 0; + + if( h !== indexh || v !== indexv ) { + slide( h, v ); + } + } + + } + + /** + * Updates the page URL (hash) to reflect the current + * state. + * + * @param {number} delay The time in ms to wait before + * writing the hash + */ + function writeURL( delay ) { + + if( config.history ) { + + // Make sure there's never more than one timeout running + clearTimeout( writeURLTimeout ); + + // If a delay is specified, timeout this call + if( typeof delay === 'number' ) { + writeURLTimeout = setTimeout( writeURL, delay ); + } + else if( currentSlide ) { + var url = '/'; + + // Attempt to create a named link based on the slide's ID + var id = currentSlide.getAttribute( 'id' ); + if( id ) { + id = id.replace( /[^a-zA-Z0-9\-\_\:\.]/g, '' ); + } + + // If the current slide has an ID, use that as a named link + if( typeof id === 'string' && id.length ) { + url = '/' + id; + } + // Otherwise use the /h/v index + else { + if( indexh > 0 || indexv > 0 ) url += indexh; + if( indexv > 0 ) url += '/' + indexv; + } + + window.location.hash = url; + } + } + + } + /** + * Retrieves the h/v location and fragment of the current, + * or specified, slide. + * + * @param {HTMLElement} [slide] If specified, the returned + * index will be for this slide rather than the currently + * active one + * + * @return {{h: number, v: number, f: number}} + */ + function getIndices( slide ) { + + // By default, return the current indices + var h = indexh, + v = indexv, + f; + + // If a slide is specified, return the indices of that slide + if( slide ) { + var isVertical = isVerticalSlide( slide ); + var slideh = isVertical ? slide.parentNode : slide; + + // Select all horizontal slides + var horizontalSlides = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) ); + + // Now that we know which the horizontal slide is, get its index + h = Math.max( horizontalSlides.indexOf( slideh ), 0 ); + + // Assume we're not vertical + v = undefined; + + // If this is a vertical slide, grab the vertical index + if( isVertical ) { + v = Math.max( toArray( slide.parentNode.querySelectorAll( 'section' ) ).indexOf( slide ), 0 ); + } + } + + if( !slide && currentSlide ) { + var hasFragments = currentSlide.querySelectorAll( '.fragment' ).length > 0; + if( hasFragments ) { + var currentFragment = currentSlide.querySelector( '.current-fragment' ); + if( currentFragment && currentFragment.hasAttribute( 'data-fragment-index' ) ) { + f = parseInt( currentFragment.getAttribute( 'data-fragment-index' ), 10 ); + } + else { + f = currentSlide.querySelectorAll( '.fragment.visible' ).length - 1; + } + } + } + + return { h: h, v: v, f: f }; + + } + + /** + * Retrieves all slides in this presentation. + */ + function getSlides() { + + return toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR + ':not(.stack)' )); + + } + + /** + * Retrieves the total number of slides in this presentation. + * + * @return {number} + */ + function getTotalSlides() { + + return getSlides().length; + + } + + /** + * Returns the slide element matching the specified index. + * + * @return {HTMLElement} + */ + function getSlide( x, y ) { + + var horizontalSlide = dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR )[ x ]; + var verticalSlides = horizontalSlide && horizontalSlide.querySelectorAll( 'section' ); + + if( verticalSlides && verticalSlides.length && typeof y === 'number' ) { + return verticalSlides ? verticalSlides[ y ] : undefined; + } + + return horizontalSlide; + + } + + /** + * Returns the background element for the given slide. + * All slides, even the ones with no background properties + * defined, have a background element so as long as the + * index is valid an element will be returned. + * + * @param {number} x Horizontal background index + * @param {number} y Vertical background index + * @return {(HTMLElement[]|*)} + */ + function getSlideBackground( x, y ) { + + var slide = getSlide( x, y ); + if( slide ) { + return slide.slideBackgroundElement; + } + + return undefined; + + } + + /** + * Retrieves the speaker notes from a slide. Notes can be + * defined in two ways: + * 1. As a data-notes attribute on the slide
+ * 2. As an