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Diffstat (limited to 'js/reveal.js')
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diff --git a/js/reveal.js b/js/reveal.js new file mode 100644 index 0000000..67ad0b8 --- /dev/null +++ b/js/reveal.js @@ -0,0 +1,2624 @@ +import SlideContent from './controllers/slidecontent.js' +import SlideNumber from './controllers/slidenumber.js' +import Backgrounds from './controllers/backgrounds.js' +import AutoAnimate from './controllers/autoanimate.js' +import Fragments from './controllers/fragments.js' +import Overview from './controllers/overview.js' +import Keyboard from './controllers/keyboard.js' +import Location from './controllers/location.js' +import Controls from './controllers/controls.js' +import Progress from './controllers/progress.js' +import Pointer from './controllers/pointer.js' +import Plugins from './controllers/plugins.js' +import Print from './controllers/print.js' +import Touch from './controllers/touch.js' +import Focus from './controllers/focus.js' +import Notes from './controllers/notes.js' +import Playback from './components/playback.js' +import defaultConfig from './config.js' +import * as Util from './utils/util.js' +import * as Device from './utils/device.js' +import { + SLIDES_SELECTOR, + HORIZONTAL_SLIDES_SELECTOR, + VERTICAL_SLIDES_SELECTOR, + POST_MESSAGE_METHOD_BLACKLIST +} from './utils/constants.js' + +// The reveal.js version +export const VERSION = '4.1.0'; + +/** + * reveal.js + * https://revealjs.com + * MIT licensed + * + * Copyright (C) 2020 Hakim El Hattab, https://hakim.se + */ +export default function( revealElement, options ) { + + // Support initialization with no args, one arg + // [options] or two args [revealElement, options] + if( arguments.length < 2 ) { + options = arguments[0]; + revealElement = document.querySelector( '.reveal' ); + } + + const Reveal = {}; + + // Configuration defaults, can be overridden at initialization time + let config = {}, + + // Flags if reveal.js is loaded (has dispatched the 'ready' event) + ready = false, + + // The horizontal and vertical index of the currently active slide + indexh, + indexv, + + // The previous and current slide HTML elements + previousSlide, + currentSlide, + + // Remember which directions that the user has navigated towards + navigationHistory = { + hasNavigatedHorizontally: false, + hasNavigatedVertically: false + }, + + // Slides may have 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 = {}, + + // Flags if the interaction event listeners are bound + eventsAreBound = false, + + // The current slide transition state; idle or running + transition = 'idle', + + // The current auto-slide duration + autoSlide = 0, + + // Auto slide properties + autoSlidePlayer, + autoSlideTimeout = 0, + autoSlideStartTime = -1, + autoSlidePaused = false, + + // Controllers for different aspects of our presentation. They're + // all given direct references to this Reveal instance since there + // may be multiple presentations running in parallel. + slideContent = new SlideContent( Reveal ), + slideNumber = new SlideNumber( Reveal ), + autoAnimate = new AutoAnimate( Reveal ), + backgrounds = new Backgrounds( Reveal ), + fragments = new Fragments( Reveal ), + overview = new Overview( Reveal ), + keyboard = new Keyboard( Reveal ), + location = new Location( Reveal ), + controls = new Controls( Reveal ), + progress = new Progress( Reveal ), + pointer = new Pointer( Reveal ), + plugins = new Plugins( Reveal ), + print = new Print( Reveal ), + focus = new Focus( Reveal ), + touch = new Touch( Reveal ), + notes = new Notes( Reveal ); + + /** + * Starts up the presentation. + */ + function initialize( initOptions ) { + + // Cache references to key DOM elements + dom.wrapper = revealElement; + dom.slides = revealElement.querySelector( '.slides' ); + + // Compose our config object in order of increasing precedence: + // 1. Default reveal.js options + // 2. Options provided via Reveal.configure() prior to + // initialization + // 3. Options passed to the Reveal constructor + // 4. Options passed to Reveal.initialize + // 5. Query params + config = { ...defaultConfig, ...config, ...options, ...initOptions, ...Util.getQueryHash() }; + + setViewport(); + + // Force a layout when the whole page, incl fonts, has loaded + window.addEventListener( 'load', layout, false ); + + // Register plugins and load dependencies, then move on to #start() + plugins.load( config.plugins, config.dependencies ).then( start ); + + return new Promise( resolve => Reveal.on( 'ready', resolve ) ); + + } + + /** + * Encase the presentation in a reveal.js viewport. The + * extent of the viewport differs based on configuration. + */ + function setViewport() { + + // Embedded decks use the reveal element as their viewport + if( config.embedded === true ) { + dom.viewport = Util.closest( revealElement, '.reveal-viewport' ) || revealElement; + } + // Full-page decks use the body as their viewport + else { + dom.viewport = document.body; + document.documentElement.classList.add( 'reveal-full-page' ); + } + + dom.viewport.classList.add( 'reveal-viewport' ); + + } + + /** + * Starts up reveal.js by binding input events and navigating + * to the current URL deeplink if there is one. + */ + function start() { + + ready = true; + + // Remove slides hidden with data-visibility + removeHiddenSlides(); + + // 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 + location.readURL(); + + // Create slide backgrounds + backgrounds.update( true ); + + // Notify listeners that the presentation is ready but use a 1ms + // timeout to ensure it's not fired synchronously after #initialize() + setTimeout( () => { + // Enable transitions now that we're loaded + dom.slides.classList.remove( 'no-transition' ); + + dom.wrapper.classList.add( 'ready' ); + + dispatchEvent({ + type: 'ready', + data: { + indexh, + indexv, + currentSlide + } + }); + }, 1 ); + + // Special setup and config is required when printing to PDF + if( print.isPrintingPDF() ) { + removeEventListeners(); + + // The document needs to have loaded for the PDF layout + // measurements to be accurate + if( document.readyState === 'complete' ) { + print.setupPDF(); + } + else { + window.addEventListener( 'load', () => { + print.setupPDF(); + } ); + } + } + + } + + /** + * Removes all slides with data-visibility="hidden". This + * is done right before the rest of the presentation is + * initialized. + * + * If you want to show all hidden slides, initialize + * reveal.js with showHiddenSlides set to true. + */ + function removeHiddenSlides() { + + if( !config.showHiddenSlides ) { + Util.queryAll( dom.wrapper, 'section[data-visibility="hidden"]' ).forEach( slide => { + slide.parentNode.removeChild( slide ); + } ); + } + + } + + /** + * 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( Device.isMobile ) { + dom.wrapper.classList.add( 'no-hover' ); + } + else { + dom.wrapper.classList.remove( 'no-hover' ); + } + + backgrounds.render(); + slideNumber.render(); + controls.render(); + progress.render(); + notes.render(); + + // Overlay graphic which is displayed during the paused mode + dom.pauseOverlay = Util.createSingletonNode( dom.wrapper, 'div', 'pause-overlay', config.controls ? '<button class="resume-button">Resume presentation</button>' : null ); + + dom.statusElement = createStatusElement(); + + dom.wrapper.setAttribute( 'role', 'application' ); + } + + /** + * 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 createStatusElement() { + + let statusElement = dom.wrapper.querySelector( '.aria-status' ); + if( !statusElement ) { + statusElement = document.createElement( 'div' ); + statusElement.style.position = 'absolute'; + statusElement.style.height = '1px'; + statusElement.style.width = '1px'; + statusElement.style.overflow = 'hidden'; + statusElement.style.clip = 'rect( 1px, 1px, 1px, 1px )'; + statusElement.classList.add( 'aria-status' ); + statusElement.setAttribute( 'aria-live', 'polite' ); + statusElement.setAttribute( 'aria-atomic','true' ); + dom.wrapper.appendChild( statusElement ); + } + return statusElement; + + } + + /** + * Announces the given text to screen readers. + */ + function announceStatus( value ) { + + dom.statusElement.textContent = value; + + } + + /** + * 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 ) { + + let text = ''; + + // Text node + if( node.nodeType === 3 ) { + text += node.textContent; + } + // Element node + else if( node.nodeType === 1 ) { + + let isAriaHidden = node.getAttribute( 'aria-hidden' ); + let isDisplayHidden = window.getComputedStyle( node )['display'] === 'none'; + if( isAriaHidden !== 'true' && !isDisplayHidden ) { + + Array.from( node.childNodes ).forEach( child => { + text += getStatusText( child ); + } ); + + } + + } + + text = text.trim(); + + return text === '' ? '' : text + ' '; + + } + + /** + * 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( () => { + if( dom.wrapper.scrollTop !== 0 || dom.wrapper.scrollLeft !== 0 ) { + dom.wrapper.scrollTop = 0; + dom.wrapper.scrollLeft = 0; + } + }, 1000 ); + + } + + /** + * 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', event => { + let 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' ) { + + if( POST_MESSAGE_METHOD_BLACKLIST.test( data.method ) === false ) { + + const result = Reveal[data.method].apply( Reveal, data.args ); + + // Dispatch a postMessage event with the returned value from + // our method invocation for getter functions + dispatchPostMessage( 'callback', { method: data.method, result: result } ); + + } + else { + console.warn( 'reveal.js: "'+ data.method +'" is is blacklisted from the postMessage API' ); + } + + } + } + }, false ); + } + + } + + /** + * Applies the configuration settings from the config + * object. May be called multiple times. + * + * @param {object} options + */ + function configure( options ) { + + const oldConfig = { ...config } + + // New config options may be passed when this method + // is invoked through the API after initialization + if( typeof options === 'object' ) Util.extend( config, options ); + + // Abort if reveal.js hasn't finished loading, config + // changes will be applied automatically once ready + if( Reveal.isReady() === false ) return; + + const numberOfSlides = dom.wrapper.querySelectorAll( SLIDES_SELECTOR ).length; + + // The transition is added as a class on the .reveal element + dom.wrapper.classList.remove( oldConfig.transition ); + dom.wrapper.classList.add( config.transition ); + + dom.wrapper.setAttribute( 'data-transition-speed', config.transitionSpeed ); + dom.wrapper.setAttribute( 'data-background-transition', config.backgroundTransition ); + + // Expose our configured slide dimensions as custom props + dom.viewport.style.setProperty( '--slide-width', config.width + 'px' ); + dom.viewport.style.setProperty( '--slide-height', config.height + 'px' ); + + if( config.shuffle ) { + shuffle(); + } + + Util.toggleClass( dom.wrapper, 'embedded', config.embedded ); + Util.toggleClass( dom.wrapper, 'rtl', config.rtl ); + Util.toggleClass( dom.wrapper, 'center', config.center ); + + // Exit the paused mode if it was configured off + if( config.pause === false ) { + resume(); + } + + // Iframe link previews + if( config.previewLinks ) { + enablePreviewLinks(); + disablePreviewLinks( '[data-preview-link=false]' ); + } + else { + disablePreviewLinks(); + enablePreviewLinks( '[data-preview-link]:not([data-preview-link=false])' ); + } + + // Reset all changes made by auto-animations + autoAnimate.reset(); + + // Remove existing auto-slide controls + if( autoSlidePlayer ) { + autoSlidePlayer.destroy(); + autoSlidePlayer = null; + } + + // Generate auto-slide controls if needed + if( numberOfSlides > 1 && config.autoSlide && config.autoSlideStoppable ) { + autoSlidePlayer = new Playback( dom.wrapper, () => { + return Math.min( Math.max( ( Date.now() - autoSlideStartTime ) / autoSlide, 0 ), 1 ); + } ); + + autoSlidePlayer.on( 'click', onAutoSlidePlayerClick ); + autoSlidePaused = false; + } + + // Add the navigation mode to the DOM so we can adjust styling + if( config.navigationMode !== 'default' ) { + dom.wrapper.setAttribute( 'data-navigation-mode', config.navigationMode ); + } + else { + dom.wrapper.removeAttribute( 'data-navigation-mode' ); + } + + notes.configure( config, oldConfig ); + focus.configure( config, oldConfig ); + pointer.configure( config, oldConfig ); + controls.configure( config, oldConfig ); + progress.configure( config, oldConfig ); + keyboard.configure( config, oldConfig ); + fragments.configure( config, oldConfig ); + slideNumber.configure( config, oldConfig ); + + sync(); + + } + + /** + * Binds all event listeners. + */ + function addEventListeners() { + + eventsAreBound = true; + + window.addEventListener( 'resize', onWindowResize, false ); + + if( config.touch ) touch.bind(); + if( config.keyboard ) keyboard.bind(); + if( config.progress ) progress.bind(); + if( config.respondToHashChanges ) location.bind(); + controls.bind(); + focus.bind(); + + dom.slides.addEventListener( 'transitionend', onTransitionEnd, false ); + dom.pauseOverlay.addEventListener( 'click', resume, false ); + + if( config.focusBodyOnPageVisibilityChange ) { + document.addEventListener( 'visibilitychange', onPageVisibilityChange, false ); + } + + } + + /** + * Unbinds all event listeners. + */ + function removeEventListeners() { + + eventsAreBound = false; + + touch.unbind(); + focus.unbind(); + keyboard.unbind(); + controls.unbind(); + progress.unbind(); + location.unbind(); + + window.removeEventListener( 'resize', onWindowResize, false ); + + dom.slides.removeEventListener( 'transitionend', onTransitionEnd, false ); + dom.pauseOverlay.removeEventListener( 'click', resume, false ); + + } + + /** + * Adds a listener to one of our custom reveal.js events, + * like slidechanged. + */ + function on( type, listener, useCapture ) { + + revealElement.addEventListener( type, listener, useCapture ); + + } + + /** + * Unsubscribes from a reveal.js event. + */ + function off( type, listener, useCapture ) { + + revealElement.removeEventListener( type, listener, useCapture ); + + } + + /** + * 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 ) { + Util.transformElement( dom.slides, slidesTransform.layout + ' ' + slidesTransform.overview ); + } + else { + Util.transformElement( dom.slides, slidesTransform.overview ); + } + + } + + /** + * Dispatches an event of the specified type from the + * reveal DOM element. + */ + function dispatchEvent({ target=dom.wrapper, type, data, bubbles=true }) { + + let event = document.createEvent( 'HTMLEvents', 1, 2 ); + event.initEvent( type, bubbles, true ); + Util.extend( event, data ); + target.dispatchEvent( event ); + + if( target === dom.wrapper ) { + // If we're in an iframe, post each reveal.js event to the + // parent window. Used by the notes plugin + dispatchPostMessage( type ); + } + + } + + /** + * Dispatched a postMessage of the given type from our window. + */ + function dispatchPostMessage( type, data ) { + + if( config.postMessageEvents && window.parent !== window.self ) { + let message = { + namespace: 'reveal', + eventName: type, + state: getState() + }; + + Util.extend( message, data ); + + window.parent.postMessage( JSON.stringify( message ), '*' ); + } + + } + + /** + * Bind preview frame links. + * + * @param {string} [selector=a] - selector for anchors + */ + function enablePreviewLinks( selector = 'a' ) { + + Array.from( dom.wrapper.querySelectorAll( selector ) ).forEach( element => { + if( /^(http|www)/gi.test( element.getAttribute( 'href' ) ) ) { + element.addEventListener( 'click', onPreviewLinkClicked, false ); + } + } ); + + } + + /** + * Unbind preview frame links. + */ + function disablePreviewLinks( selector = 'a' ) { + + Array.from( dom.wrapper.querySelectorAll( selector ) ).forEach( 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 = + `<header> + <a class="close" href="#"><span class="icon"></span></a> + <a class="external" href="${url}" target="_blank"><span class="icon"></span></a> + </header> + <div class="spinner"></div> + <div class="viewport"> + <iframe src="${url}"></iframe> + <small class="viewport-inner"> + <span class="x-frame-error">Unable to load iframe. This is likely due to the site's policy (x-frame-options).</span> + </small> + </div>`; + + dom.overlay.querySelector( 'iframe' ).addEventListener( 'load', event => { + dom.overlay.classList.add( 'loaded' ); + }, false ); + + dom.overlay.querySelector( '.close' ).addEventListener( 'click', event => { + closeOverlay(); + event.preventDefault(); + }, false ); + + dom.overlay.querySelector( '.external' ).addEventListener( 'click', event => { + closeOverlay(); + }, false ); + + } + + /** + * 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 ); + + let html = '<p class="title">Keyboard Shortcuts</p><br/>'; + + let shortcuts = keyboard.getShortcuts(), + bindings = keyboard.getBindings(); + + html += '<table><th>KEY</th><th>ACTION</th>'; + for( let key in shortcuts ) { + html += `<tr><td>${key}</td><td>${shortcuts[ key ]}</td></tr>`; + } + + // Add custom key bindings that have associated descriptions + for( let binding in bindings ) { + if( bindings[binding].key && bindings[binding].description ) { + html += `<tr><td>${bindings[binding].key}</td><td>${bindings[binding].description}</td></tr>`; + } + } + + html += '</table>'; + + dom.overlay.innerHTML = ` + <header> + <a class="close" href="#"><span class="icon"></span></a> + </header> + <div class="viewport"> + <div class="viewport-inner">${html}</div> + </div> + `; + + dom.overlay.querySelector( '.close' ).addEventListener( 'click', event => { + closeOverlay(); + event.preventDefault(); + }, false ); + + } + + } + + /** + * Closes any currently open overlay. + */ + function closeOverlay() { + + if( dom.overlay ) { + dom.overlay.parentNode.removeChild( dom.overlay ); + dom.overlay = null; + return true; + } + + return false; + + } + + /** + * Applies JavaScript-controlled layout rules to the + * presentation. + */ + function layout() { + + if( dom.wrapper && !print.isPrintingPDF() ) { + + if( !config.disableLayout ) { + + // On some mobile devices '100vh' is taller than the visible + // viewport which leads to part of the presentation being + // cut off. To work around this we define our own '--vh' custom + // property where 100x adds up to the correct height. + // + // https://css-tricks.com/the-trick-to-viewport-units-on-mobile/ + if( Device.isMobile && !config.embedded ) { + document.documentElement.style.setProperty( '--vh', ( window.innerHeight * 0.01 ) + 'px' ); + } + + const size = getComputedSlideSize(); + + const oldScale = scale; + + // 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 { + // Zoom Scaling + // Content remains crisp no matter how much we scale. Side + // effects are minor differences in text layout and iframe + // viewports changing size. A 200x200 iframe viewport in a + // 2x zoomed presentation ends up having a 400x400 viewport. + if( scale > 1 && Device.supportsZoom && window.devicePixelRatio < 2 ) { + dom.slides.style.zoom = scale; + dom.slides.style.left = ''; + dom.slides.style.top = ''; + dom.slides.style.bottom = ''; + dom.slides.style.right = ''; + transformSlides( { layout: '' } ); + } + // Transform Scaling + // Content layout remains the exact same when scaled up. + // Side effect is content becoming blurred, especially with + // high scale values on ldpi screens. + 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 + const slides = Array.from( dom.wrapper.querySelectorAll( SLIDES_SELECTOR ) ); + + for( let i = 0, len = slides.length; i < len; i++ ) { + const 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 = ''; + } + + } + + if( oldScale !== scale ) { + dispatchEvent({ + type: 'resize', + data: { + oldScale, + scale, + size + } + }); + } + } + + progress.update(); + backgrounds.updateParallax(); + + if( overview.isActive() ) { + overview.update(); + } + + } + + } + + /** + * 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 'r-stretch' class + Util.queryAll( dom.slides, 'section > .stretch, section > .r-stretch' ).forEach( element => { + + // Determine how much vertical space we can use + let remainingHeight = Util.getRemainingHeight( element, height ); + + // Consider the aspect ratio of media elements + if( /(img|video)/gi.test( element.nodeName ) ) { + const nw = element.naturalWidth || element.videoWidth, + nh = element.naturalHeight || element.videoHeight; + + const 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 ) { + + const 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 + const attributeName = stack.hasAttribute( 'data-start-indexv' ) ? 'data-start-indexv' : 'data-previous-indexv'; + + return parseInt( stack.getAttribute( attributeName ) || 0, 10 ); + } + + return 0; + + } + + /** + * 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 = currentSlide ) { + + return slide && slide.parentNode && !!slide.parentNode.nodeName.match( /section/i ); + + } + + /** + * Returns true if we're on the last slide in the current + * vertical stack. + */ + function isLastVerticalSlide() { + + if( currentSlide && isVerticalSlide( currentSlide ) ) { + // Does this slide have a next sibling? + if( currentSlide.nextElementSibling ) return false; + + return true; + } + + return false; + + } + + /** + * Returns true if we're currently on the first slide in + * the presentation. + */ + function isFirstSlide() { + + return indexh === 0 && indexv === 0; + + } + + /** + * Returns true if we're currently on the last slide in + * the presenation. If the last slide is a stack, we only + * consider this the last slide if it's at the end of the + * stack. + */ + function isLastSlide() { + + if( currentSlide ) { + // Does this slide have a next sibling? + if( currentSlide.nextElementSibling ) return false; + + // If it's vertical, does its parent have a next sibling? + if( isVerticalSlide( currentSlide ) && currentSlide.parentNode.nextElementSibling ) return false; + + return true; + } + + return false; + + } + + /** + * Enters the paused mode which fades everything on screen to + * black. + */ + function pause() { + + if( config.pause ) { + const wasPaused = dom.wrapper.classList.contains( 'paused' ); + + cancelAutoSlide(); + dom.wrapper.classList.add( 'paused' ); + + if( wasPaused === false ) { + dispatchEvent({ type: 'paused' }); + } + } + + } + + /** + * Exits from the paused mode. + */ + function resume() { + + const wasPaused = dom.wrapper.classList.contains( 'paused' ); + dom.wrapper.classList.remove( 'paused' ); + + cueAutoSlide(); + + if( wasPaused ) { + dispatchEvent({ type: '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 + const 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 && !overview.isActive() ) { + 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 + const stateBefore = state.concat(); + + // Reset the state array + state.length = 0; + + let 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 ); + + // Dispatch an event if the slide changed + let slideChanged = ( indexh !== indexhBefore || indexv !== indexvBefore ); + + // Ensure that the previous slide is never the same as the current + if( !slideChanged ) previousSlide = null; + + // Find the current horizontal slide and any possible vertical slides + // within it + let currentHorizontalSlide = horizontalSlides[ indexh ], + currentVerticalSlides = currentHorizontalSlide.querySelectorAll( 'section' ); + + // Store references to the previous and current slides + currentSlide = currentVerticalSlides[ indexv ] || currentHorizontalSlide; + + let autoAnimateTransition = false; + + // Detect if we're moving between two auto-animated slides + if( slideChanged && previousSlide && currentSlide && !overview.isActive() ) { + + // If this is an auto-animated transition, we disable the + // regular slide transition + // + // Note 20-03-2020: + // This needs to happen before we update slide visibility, + // otherwise transitions will still run in Safari. + if( previousSlide.hasAttribute( 'data-auto-animate' ) && currentSlide.hasAttribute( 'data-auto-animate' ) ) { + autoAnimateTransition = true; + dom.slides.classList.add( 'disable-slide-transitions' ); + } + + transition = 'running'; + + } + + // Update the visibility of slides now that the indices have changed + updateSlidesVisibility(); + + layout(); + + // Update the overview if it's currently active + if( overview.isActive() ) { + overview.update(); + } + + // Show fragment, if specified + if( typeof f !== 'undefined' ) { + fragments.goto( f ); + } + + // Solves an edge case where the previous slide maintains the + // 'present' class when navigating between adjacent vertical + // stacks + if( previousSlide && previousSlide !== currentSlide ) { + previousSlide.classList.remove( 'present' ); + previousSlide.setAttribute( 'aria-hidden', 'true' ); + + // Reset all slides upon navigate to home + if( isFirstSlide() ) { + // Launch async task + setTimeout( () => { + getVerticalStacks().forEach( slide => { + setPreviousVerticalIndex( slide, 0 ); + } ); + }, 0 ); + } + } + + // Apply the new state + stateLoop: for( let 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( let j = 0; j < stateBefore.length; j++ ) { + if( stateBefore[j] === state[i] ) { + stateBefore.splice( j, 1 ); + continue stateLoop; + } + } + + dom.viewport.classList.add( state[i] ); + + // Dispatch custom event matching the state's name + dispatchEvent({ type: state[i] }); + } + + // Clean up the remains of the previous state + while( stateBefore.length ) { + dom.viewport.classList.remove( stateBefore.pop() ); + } + + if( slideChanged ) { + dispatchEvent({ + type: 'slidechanged', + data: { + indexh, + indexv, + previousSlide, + currentSlide, + origin: o + } + }); + } + + // Handle embedded content + if( slideChanged || !previousSlide ) { + slideContent.stopEmbeddedContent( previousSlide ); + slideContent.startEmbeddedContent( currentSlide ); + } + + // Announce the current slide contents to screen readers + announceStatus( getStatusText( currentSlide ) ); + + progress.update(); + controls.update(); + notes.update(); + backgrounds.update(); + backgrounds.updateParallax(); + slideNumber.update(); + fragments.update(); + + // Update the URL hash + location.writeURL(); + + cueAutoSlide(); + + // Auto-animation + if( autoAnimateTransition ) { + + setTimeout( () => { + dom.slides.classList.remove( 'disable-slide-transitions' ); + }, 0 ); + + if( config.autoAnimate ) { + // Run the auto-animation between our slides + autoAnimate.run( previousSlide, currentSlide ); + } + + } + + } + + /** + * 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 all slide backgrounds + backgrounds.create(); + + // Write the current hash to the URL + location.writeURL(); + + fragments.sortAll(); + + controls.update(); + progress.update(); + + updateSlidesVisibility(); + + notes.update(); + notes.updateVisibility(); + backgrounds.update( true ); + slideNumber.update(); + slideContent.formatEmbeddedContent(); + + // Start or stop embedded content depending on global config + if( config.autoPlayMedia === false ) { + slideContent.stopEmbeddedContent( currentSlide, { unloadIframes: false } ); + } + else { + slideContent.startEmbeddedContent( currentSlide ); + } + + if( overview.isActive() ) { + overview.layout(); + } + + } + + /** + * Updates reveal.js to keep in sync with new slide attributes. For + * example, if you add a new `data-background-image` you can call + * this to have reveal.js render the new background image. + * + * Similar to #sync() but more efficient when you only need to + * refresh a specific slide. + * + * @param {HTMLElement} slide + */ + function syncSlide( slide = currentSlide ) { + + backgrounds.sync( slide ); + fragments.sync( slide ); + + slideContent.load( slide ); + + backgrounds.update(); + notes.update(); + + } + + /** + * Resets all vertical slides so that only the first + * is visible. + */ + function resetVerticalSlides() { + + getHorizontalSlides().forEach( horizontalSlide => { + + Util.queryAll( horizontalSlide, 'section' ).forEach( ( verticalSlide, y ) => { + + if( y > 0 ) { + verticalSlide.classList.remove( 'present' ); + verticalSlide.classList.remove( 'past' ); + verticalSlide.classList.add( 'future' ); + verticalSlide.setAttribute( 'aria-hidden', 'true' ); + } + + } ); + + } ); + + } + + /** + * Randomly shuffles all slides in the deck. + */ + function shuffle( slides = getHorizontalSlides() ) { + + slides.forEach( ( slide, i ) => { + + // Insert the slide next to a randomly picked sibling slide + // slide. This may cause the slide to insert before itself, + // but that's not an issue. + let beforeSlide = slides[ Math.floor( Math.random() * slides.length ) ]; + if( beforeSlide.parentNode === slide.parentNode ) { + slide.parentNode.insertBefore( slide, beforeSlide ); + } + + // Randomize the order of vertical slides (if there are any) + let verticalSlides = slide.querySelectorAll( 'section' ); + if( verticalSlides.length ) { + shuffle( verticalSlides ); + } + + } ); + + } + + /** + * 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 + let slides = Util.queryAll( dom.wrapper, selector ), + slidesLength = slides.length; + + let printMode = print.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( let i = 0; i < slidesLength; i++ ) { + let element = slides[i]; + + let reverse = config.rtl && !isVerticalSlide( element ); + + // Avoid .remove() with multiple args for IE11 support + 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 ) { + // Show all fragments in prior slides + Util.queryAll( element, '.fragment' ).forEach( fragment => { + fragment.classList.add( 'visible' ); + fragment.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 ) { + // Hide all fragments in future slides + Util.queryAll( element, '.fragment.visible' ).forEach( fragment => { + fragment.classList.remove( 'visible', 'current-fragment' ); + } ); + } + } + } + + let slide = slides[index]; + let wasPresent = slide.classList.contains( 'present' ); + + // Mark the current slide as present + slide.classList.add( 'present' ); + slide.removeAttribute( 'hidden' ); + slide.removeAttribute( 'aria-hidden' ); + + if( !wasPresent ) { + // Dispatch an event indicating the slide is now visible + dispatchEvent({ + target: slide, + type: 'visible', + bubbles: false + }); + } + + // If this slide has a state associated with it, add it + // onto the current state of the deck + let slideState = slide.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 + let horizontalSlides = getHorizontalSlides(), + horizontalSlidesLength = horizontalSlides.length, + distanceX, + distanceY; + + if( horizontalSlidesLength && typeof indexh !== 'undefined' ) { + + // The number of steps away from the present slide that will + // be visible + let viewDistance = overview.isActive() ? 10 : config.viewDistance; + + // Shorten the view distance on devices that typically have + // less resources + if( Device.isMobile ) { + viewDistance = overview.isActive() ? 6 : config.mobileViewDistance; + } + + // All slides need to be visible when exporting to PDF + if( print.isPrintingPDF() ) { + viewDistance = Number.MAX_VALUE; + } + + for( let x = 0; x < horizontalSlidesLength; x++ ) { + let horizontalSlide = horizontalSlides[x]; + + let verticalSlides = Util.queryAll( horizontalSlide, '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 ) { + slideContent.load( horizontalSlide ); + } + else { + slideContent.unload( horizontalSlide ); + } + + if( verticalSlidesLength ) { + + let oy = getPreviousVerticalIndex( horizontalSlide ); + + for( let y = 0; y < verticalSlidesLength; y++ ) { + let verticalSlide = verticalSlides[y]; + + distanceY = x === ( indexh || 0 ) ? Math.abs( ( indexv || 0 ) - y ) : Math.abs( y - oy ); + + if( distanceX + distanceY < viewDistance ) { + slideContent.load( verticalSlide ); + } + else { + slideContent.unload( verticalSlide ); + } + } + + } + } + + // Flag if there are ANY vertical slides, anywhere in the deck + if( hasVerticalSlides() ) { + 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( hasHorizontalSlides() ) { + dom.wrapper.classList.add( 'has-horizontal-slides' ); + } + else { + dom.wrapper.classList.remove( 'has-horizontal-slides' ); + } + + } + + } + + /** + * Determine what available routes there are for navigation. + * + * @return {{left: boolean, right: boolean, up: boolean, down: boolean}} + */ + function availableRoutes({ includeFragments = false } = {}) { + + let horizontalSlides = dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ), + verticalSlides = dom.wrapper.querySelectorAll( VERTICAL_SLIDES_SELECTOR ); + + let routes = { + left: indexh > 0, + right: indexh < horizontalSlides.length - 1, + up: indexv > 0, + down: indexv < verticalSlides.length - 1 + }; + + // Looped presentations can always be navigated as long as + // there are slides available + if( config.loop ) { + if( horizontalSlides.length > 1 ) { + routes.left = true; + routes.right = true; + } + + if( verticalSlides.length > 1 ) { + routes.up = true; + routes.down = true; + } + } + + if ( horizontalSlides.length > 1 && config.navigationMode === 'linear' ) { + routes.right = routes.right || routes.down; + routes.left = routes.left || routes.up; + } + + // If includeFragments is set, a route will be considered + // availalbe if either a slid OR fragment is available in + // the given direction + if( includeFragments === true ) { + let fragmentRoutes = fragments.availableRoutes(); + routes.left = routes.left || fragmentRoutes.prev; + routes.up = routes.up || fragmentRoutes.prev; + routes.down = routes.down || fragmentRoutes.next; + routes.right = routes.right || fragmentRoutes.next; + } + + // Reverse horizontal controls for rtl + if( config.rtl ) { + let left = routes.left; + routes.left = routes.right; + routes.right = left; + } + + return routes; + + } + + /** + * Returns the number of past slides. This can be used as a global + * flattened index for slides. + * + * @param {HTMLElement} [slide=currentSlide] The slide we're counting before + * + * @return {number} Past slide count + */ + function getSlidePastCount( slide = currentSlide ) { + + let horizontalSlides = getHorizontalSlides(); + + // The number of past slides + let pastCount = 0; + + // Step through all slides and count the past ones + mainLoop: for( let i = 0; i < horizontalSlides.length; i++ ) { + + let horizontalSlide = horizontalSlides[i]; + let verticalSlides = horizontalSlide.querySelectorAll( 'section' ); + + for( let j = 0; j < verticalSlides.length; j++ ) { + + // Stop as soon as we arrive at the present + if( verticalSlides[j] === slide ) { + break mainLoop; + } + + // Don't count slides with the "uncounted" class + if( verticalSlides[j].dataset.visibility !== 'uncounted' ) { + pastCount++; + } + + } + + // Stop as soon as we arrive at the present + if( horizontalSlide === slide ) { + break; + } + + // Don't count the wrapping section for vertical slides and + // slides marked as uncounted + if( horizontalSlide.classList.contains( 'stack' ) === false && horizontalSlide.dataset.visibility !== 'uncounted' ) { + 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 + let totalCount = getTotalSlides(); + let pastCount = getSlidePastCount(); + + if( currentSlide ) { + + let allFragments = currentSlide.querySelectorAll( '.fragment' ); + + // If there are fragments in the current slide those should be + // accounted for in the progress. + if( allFragments.length > 0 ) { + let 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) + let fragmentWeight = 0.9; + + // Add fragment progress to the past slide count + pastCount += ( visibleFragments.length / allFragments.length ) * fragmentWeight; + } + + } + + return Math.min( pastCount / ( totalCount - 1 ), 1 ); + + } + + /** + * 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 + let h = indexh, + v = indexv, + f; + + // If a slide is specified, return the indices of that slide + if( slide ) { + let isVertical = isVerticalSlide( slide ); + let slideh = isVertical ? slide.parentNode : slide; + + // Select all horizontal slides + let horizontalSlides = getHorizontalSlides(); + + // 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( Util.queryAll( slide.parentNode, 'section' ).indexOf( slide ), 0 ); + } + } + + if( !slide && currentSlide ) { + let hasFragments = currentSlide.querySelectorAll( '.fragment' ).length > 0; + if( hasFragments ) { + let 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, v, f }; + + } + + /** + * Retrieves all slides in this presentation. + */ + function getSlides() { + + return Util.queryAll( dom.wrapper, SLIDES_SELECTOR + ':not(.stack):not([data-visibility="uncounted"])' ); + + } + + /** + * Returns a list of all horizontal slides in the deck. Each + * vertical stack is included as one horizontal slide in the + * resulting array. + */ + function getHorizontalSlides() { + + return Util.queryAll( dom.wrapper, HORIZONTAL_SLIDES_SELECTOR ); + + } + + /** + * Returns all vertical slides that exist within this deck. + */ + function getVerticalSlides() { + + return Util.queryAll( dom.wrapper, '.slides>section>section' ); + + } + + /** + * Returns all vertical stacks (each stack can contain multiple slides). + */ + function getVerticalStacks() { + + return Util.queryAll( dom.wrapper, HORIZONTAL_SLIDES_SELECTOR + '.stack'); + + } + + /** + * Returns true if there are at least two horizontal slides. + */ + function hasHorizontalSlides() { + + return getHorizontalSlides().length > 1; + } + + /** + * Returns true if there are at least two vertical slides. + */ + function hasVerticalSlides() { + + return getVerticalSlides().length > 1; + + } + + /** + * Returns an array of objects where each object represents the + * attributes on its respective slide. + */ + function getSlidesAttributes() { + + return getSlides().map( slide => { + + let attributes = {}; + for( let i = 0; i < slide.attributes.length; i++ ) { + let attribute = slide.attributes[ i ]; + attributes[ attribute.name ] = attribute.value; + } + return attributes; + + } ); + + } + + /** + * 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 ) { + + let horizontalSlide = getHorizontalSlides()[ x ]; + let 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 {mixed} x Horizontal background index OR a slide + * HTML element + * @param {number} y Vertical background index + * @return {(HTMLElement[]|*)} + */ + function getSlideBackground( x, y ) { + + let slide = typeof x === 'number' ? getSlide( x, y ) : x; + if( slide ) { + return slide.slideBackgroundElement; + } + + return undefined; + + } + + /** + * Retrieves the current state of the presentation as + * an object. This state can then be restored at any + * time. + * + * @return {{indexh: number, indexv: number, indexf: number, paused: boolean, overview: boolean}} + */ + function getState() { + + let indices = getIndices(); + + return { + indexh: indices.h, + indexv: indices.v, + indexf: indices.f, + paused: isPaused(), + overview: overview.isActive() + }; + + } + + /** + * Restores the presentation to the given state. + * + * @param {object} state As generated by getState() + * @see {@link getState} generates the parameter `state` + */ + function setState( state ) { + + if( typeof state === 'object' ) { + slide( Util.deserialize( state.indexh ), Util.deserialize( state.indexv ), Util.deserialize( state.indexf ) ); + + let pausedFlag = Util.deserialize( state.paused ), + overviewFlag = Util.deserialize( state.overview ); + + if( typeof pausedFlag === 'boolean' && pausedFlag !== isPaused() ) { + togglePause( pausedFlag ); + } + + if( typeof overviewFlag === 'boolean' && overviewFlag !== overview.isActive() ) { + overview.toggle( overviewFlag ); + } + } + + } + + /** + * Cues a new automated slide if enabled in the config. + */ + function cueAutoSlide() { + + cancelAutoSlide(); + + if( currentSlide && config.autoSlide !== false ) { + + let fragment = currentSlide.querySelector( '.current-fragment' ); + + // When the slide first appears there is no "current" fragment so + // we look for a data-autoslide timing on the first fragment + if( !fragment ) fragment = currentSlide.querySelector( '.fragment' ); + + let fragmentAutoSlide = fragment ? fragment.getAttribute( 'data-autoslide' ) : null; + let parentAutoSlide = currentSlide.parentNode ? currentSlide.parentNode.getAttribute( 'data-autoslide' ) : null; + let slideAutoSlide = currentSlide.getAttribute( 'data-autoslide' ); + + // Pick value in the following priority order: + // 1. Current fragment's data-autoslide + // 2. Current slide's data-autoslide + // 3. Parent slide's data-autoslide + // 4. Global autoSlide setting + if( fragmentAutoSlide ) { + autoSlide = parseInt( fragmentAutoSlide, 10 ); + } + else if( slideAutoSlide ) { + autoSlide = parseInt( slideAutoSlide, 10 ); + } + else if( parentAutoSlide ) { + autoSlide = parseInt( parentAutoSlide, 10 ); + } + else { + autoSlide = config.autoSlide; + + // If there are media elements with data-autoplay, + // automatically set the autoSlide duration to the + // length of that media. Not applicable if the slide + // is divided up into fragments. + // playbackRate is accounted for in the duration. + if( currentSlide.querySelectorAll( '.fragment' ).length === 0 ) { + Util.queryAll( currentSlide, 'video, audio' ).forEach( el => { + if( el.hasAttribute( 'data-autoplay' ) ) { + if( autoSlide && (el.duration * 1000 / el.playbackRate ) > autoSlide ) { + autoSlide = ( el.duration * 1000 / el.playbackRate ) + 1000; + } + } + } ); + } + } + + // Cue the next auto-slide if: + // - There is an autoSlide value + // - Auto-sliding isn't paused by the user + // - The presentation isn't paused + // - The overview isn't active + // - The presentation isn't over + if( autoSlide && !autoSlidePaused && !isPaused() && !overview.isActive() && ( !isLastSlide() || fragments.availableRoutes().next || config.loop === true ) ) { + autoSlideTimeout = setTimeout( () => { + if( typeof config.autoSlideMethod === 'function' ) { + config.autoSlideMethod() + } + else { + navigateNext(); + } + cueAutoSlide(); + }, autoSlide ); + autoSlideStartTime = Date.now(); + } + + if( autoSlidePlayer ) { + autoSlidePlayer.setPlaying( autoSlideTimeout !== -1 ); + } + + } + + } + + /** + * Cancels any ongoing request to auto-slide. + */ + function cancelAutoSlide() { + + clearTimeout( autoSlideTimeout ); + autoSlideTimeout = -1; + + } + + function pauseAutoSlide() { + + if( autoSlide && !autoSlidePaused ) { + autoSlidePaused = true; + dispatchEvent({ type: 'autoslidepaused' }); + clearTimeout( autoSlideTimeout ); + + if( autoSlidePlayer ) { + autoSlidePlayer.setPlaying( false ); + } + } + + } + + function resumeAutoSlide() { + + if( autoSlide && autoSlidePaused ) { + autoSlidePaused = false; + dispatchEvent({ type: 'autoslideresumed' }); + cueAutoSlide(); + } + + } + + function navigateLeft() { + + navigationHistory.hasNavigatedHorizontally = true; + + // Reverse for RTL + if( config.rtl ) { + if( ( overview.isActive() || fragments.next() === false ) && availableRoutes().left ) { + slide( indexh + 1, config.navigationMode === 'grid' ? indexv : undefined ); + } + } + // Normal navigation + else if( ( overview.isActive() || fragments.prev() === false ) && availableRoutes().left ) { + slide( indexh - 1, config.navigationMode === 'grid' ? indexv : undefined ); + } + + } + + function navigateRight() { + + navigationHistory.hasNavigatedHorizontally = true; + + // Reverse for RTL + if( config.rtl ) { + if( ( overview.isActive() || fragments.prev() === false ) && availableRoutes().right ) { + slide( indexh - 1, config.navigationMode === 'grid' ? indexv : undefined ); + } + } + // Normal navigation + else if( ( overview.isActive() || fragments.next() === false ) && availableRoutes().right ) { + slide( indexh + 1, config.navigationMode === 'grid' ? indexv : undefined ); + } + + } + + function navigateUp() { + + // Prioritize hiding fragments + if( ( overview.isActive() || fragments.prev() === false ) && availableRoutes().up ) { + slide( indexh, indexv - 1 ); + } + + } + + function navigateDown() { + + navigationHistory.hasNavigatedVertically = true; + + // Prioritize revealing fragments + if( ( overview.isActive() || fragments.next() === false ) && availableRoutes().down ) { + slide( indexh, indexv + 1 ); + } + + } + + /** + * Navigates backwards, prioritized in the following order: + * 1) Previous fragment + * 2) Previous vertical slide + * 3) Previous horizontal slide + */ + function navigatePrev() { + + // Prioritize revealing fragments + if( fragments.prev() === false ) { + if( availableRoutes().up ) { + navigateUp(); + } + else { + // Fetch the previous horizontal slide, if there is one + let previousSlide; + + if( config.rtl ) { + previousSlide = Util.queryAll( dom.wrapper, HORIZONTAL_SLIDES_SELECTOR + '.future' ).pop(); + } + else { + previousSlide = Util.queryAll( dom.wrapper, HORIZONTAL_SLIDES_SELECTOR + '.past' ).pop(); + } + + if( previousSlide ) { + let v = ( previousSlide.querySelectorAll( 'section' ).length - 1 ) || undefined; + let h = indexh - 1; + slide( h, v ); + } + } + } + + } + + /** + * The reverse of #navigatePrev(). + */ + function navigateNext() { + + navigationHistory.hasNavigatedHorizontally = true; + navigationHistory.hasNavigatedVertically = true; + + // Prioritize revealing fragments + if( fragments.next() === false ) { + + let routes = availableRoutes(); + + // When looping is enabled `routes.down` is always available + // so we need a separate check for when we've reached the + // end of a stack and should move horizontally + if( routes.down && routes.right && config.loop && isLastVerticalSlide( currentSlide ) ) { + routes.down = false; + } + + if( routes.down ) { + navigateDown(); + } + else if( config.rtl ) { + navigateLeft(); + } + else { + navigateRight(); + } + } + + } + + + // --------------------------------------------------------------------// + // ----------------------------- EVENTS -------------------------------// + // --------------------------------------------------------------------// + + /** + * Called by all event handlers that are based on user + * input. + * + * @param {object} [event] + */ + function onUserInput( event ) { + + if( config.autoSlideStoppable ) { + pauseAutoSlide(); + } + + } + + /** + * Event listener for transition end on the current slide. + * + * @param {object} [event] + */ + function onTransitionEnd( event ) { + + if( transition === 'running' && /section/gi.test( event.target.nodeName ) ) { + transition = 'idle'; + dispatchEvent({ + type: 'slidetransitionend', + data: { indexh, indexv, previousSlide, currentSlide } + }); + } + + } + + /** + * Handler for the window level 'resize' event. + * + * @param {object} [event] + */ + function onWindowResize( event ) { + + layout(); + + } + + /** + * Handle for the window level 'visibilitychange' event. + * + * @param {object} [event] + */ + function onPageVisibilityChange( event ) { + + // If, after clicking a link or similar and we're coming back, + // focus the document.body to ensure we can use keyboard shortcuts + if( document.hidden === false && document.activeElement !== document.body ) { + // Not all elements support .blur() - SVGs among them. + if( typeof document.activeElement.blur === 'function' ) { + document.activeElement.blur(); + } + document.body.focus(); + } + + } + + /** + * Handles clicks on links that are set to preview in the + * iframe overlay. + * + * @param {object} event + */ + function onPreviewLinkClicked( event ) { + + if( event.currentTarget && event.currentTarget.hasAttribute( 'href' ) ) { + let url = event.currentTarget.getAttribute( 'href' ); + if( url ) { + showPreview( url ); + event.preventDefault(); + } + } + + } + + /** + * Handles click on the auto-sliding controls element. + * + * @param {object} [event] + */ + function onAutoSlidePlayerClick( event ) { + + // Replay + if( isLastSlide() && config.loop === false ) { + slide( 0, 0 ); + resumeAutoSlide(); + } + // Resume + else if( autoSlidePaused ) { + resumeAutoSlide(); + } + // Pause + else { + pauseAutoSlide(); + } + + } + + + // --------------------------------------------------------------------// + // ------------------------------- API --------------------------------// + // --------------------------------------------------------------------// + + // The public reveal.js API + const API = { + VERSION, + + initialize, + configure, + + sync, + syncSlide, + syncFragments: fragments.sync.bind( fragments ), + + // Navigation methods + slide, + left: navigateLeft, + right: navigateRight, + up: navigateUp, + down: navigateDown, + prev: navigatePrev, + next: navigateNext, + + // Navigation aliases + navigateLeft, navigateRight, navigateUp, navigateDown, navigatePrev, navigateNext, + + // Fragment methods + navigateFragment: fragments.goto.bind( fragments ), + prevFragment: fragments.prev.bind( fragments ), + nextFragment: fragments.next.bind( fragments ), + + // Event binding + on, + off, + + // Legacy event binding methods left in for backwards compatibility + addEventListener: on, + removeEventListener: off, + + // Forces an update in slide layout + layout, + + // Randomizes the order of slides + shuffle, + + // Returns an object with the available routes as booleans (left/right/top/bottom) + availableRoutes, + + // Returns an object with the available fragments as booleans (prev/next) + availableFragments: fragments.availableRoutes.bind( fragments ), + + // Toggles a help overlay with keyboard shortcuts + toggleHelp, + + // Toggles the overview mode on/off + toggleOverview: overview.toggle.bind( overview ), + + // Toggles the "black screen" mode on/off + togglePause, + + // Toggles the auto slide mode on/off + toggleAutoSlide, + + // Slide navigation checks + isFirstSlide, + isLastSlide, + isLastVerticalSlide, + isVerticalSlide, + + // State checks + isPaused, + isAutoSliding, + isSpeakerNotes: notes.isSpeakerNotesWindow.bind( notes ), + isOverview: overview.isActive.bind( overview ), + isFocused: focus.isFocused.bind( focus ), + isPrintingPDF: print.isPrintingPDF.bind( print ), + + // Checks if reveal.js has been loaded and is ready for use + isReady: () => ready, + + // Slide preloading + loadSlide: slideContent.load.bind( slideContent ), + unloadSlide: slideContent.unload.bind( slideContent ), + + // Adds or removes all internal event listeners + addEventListeners, + removeEventListeners, + dispatchEvent, + + // Facility for persisting and restoring the presentation state + getState, + setState, + + // Presentation progress on range of 0-1 + getProgress, + + // Returns the indices of the current, or specified, slide + getIndices, + + // Returns an Array of key:value maps of the attributes of each + // slide in the deck + getSlidesAttributes, + + // Returns the number of slides that we have passed + getSlidePastCount, + + // Returns the total number of slides + getTotalSlides, + + // Returns the slide element at the specified index + getSlide, + + // Returns the previous slide element, may be null + getPreviousSlide: () => previousSlide, + + // Returns the current slide element + getCurrentSlide: () => currentSlide, + + // Returns the slide background element at the specified index + getSlideBackground, + + // Returns the speaker notes string for a slide, or null + getSlideNotes: notes.getSlideNotes.bind( notes ), + + // Returns an Array of all slides + getSlides, + + // Returns an array with all horizontal/vertical slides in the deck + getHorizontalSlides, + getVerticalSlides, + + // Checks if the presentation contains two or more horizontal + // and vertical slides + hasHorizontalSlides, + hasVerticalSlides, + + // Checks if the deck has navigated on either axis at least once + hasNavigatedHorizontally: () => navigationHistory.hasNavigatedHorizontally, + hasNavigatedVertically: () => navigationHistory.hasNavigatedVertically, + + // Adds/removes a custom key binding + addKeyBinding: keyboard.addKeyBinding.bind( keyboard ), + removeKeyBinding: keyboard.removeKeyBinding.bind( keyboard ), + + // Programmatically triggers a keyboard event + triggerKey: keyboard.triggerKey.bind( keyboard ), + + // Registers a new shortcut to include in the help overlay + registerKeyboardShortcut: keyboard.registerKeyboardShortcut.bind( keyboard ), + + getComputedSlideSize, + + // Returns the current scale of the presentation content + getScale: () => scale, + + // Returns the current configuration object + getConfig: () => config, + + // Helper method, retrieves query string as a key:value map + getQueryHash: Util.getQueryHash, + + // Returns reveal.js DOM elements + getRevealElement: () => revealElement, + getSlidesElement: () => dom.slides, + getViewportElement: () => dom.viewport, + getBackgroundsElement: () => backgrounds.element, + + // API for registering and retrieving plugins + registerPlugin: plugins.registerPlugin.bind( plugins ), + hasPlugin: plugins.hasPlugin.bind( plugins ), + getPlugin: plugins.getPlugin.bind( plugins ), + getPlugins: plugins.getRegisteredPlugins.bind( plugins ) + + }; + + // Our internal API which controllers have access to + Util.extend( Reveal, { + ...API, + + // Methods for announcing content to screen readers + announceStatus, + getStatusText, + + // Controllers + print, + focus, + progress, + controls, + location, + overview, + fragments, + slideContent, + slideNumber, + + onUserInput, + closeOverlay, + updateSlidesVisibility, + layoutSlideContents, + transformSlides, + cueAutoSlide, + cancelAutoSlide + } ); + + return API; + +}; |