/*! * reveal.js * http://lab.hakim.se/reveal-js * 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