fa23-si/js/reveal.js
2022-10-17 09:46:41 +02:00

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JavaScript
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This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

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 = '4.4.0';
/**
* reveal.js
* https://revealjs.com
* MIT licensed
*
* Copyright (C) 2011-2022 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 ) {
if( !revealElement ) throw 'Unable to find presentation root (<div class="reveal">).';
// Cache references to key DOM elements
dom.wrapper = revealElement;
dom.slides = revealElement.querySelector( '.slides' );
if( !dom.slides ) throw 'Unable to find slides container (<div class="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();
// Adds bindings for fullscreen mode
setupFullscreen();
// 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 );
}
/**
* After entering fullscreen we need to force a layout to
* get our presentations to scale correctly. This behavior
* is inconsistent across browsers but a force layout seems
* to normalize it.
*/
function setupFullscreen() {
document.addEventListener( 'fullscreenchange', onFullscreenChange );
document.addEventListener( 'webkitfullscreenchange', onFullscreenChange );
}
/**
* 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', onPostMessage, 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( 'click', onSlidesClicked, false );
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( 'click', onSlidesClicked, false );
dom.slides.removeEventListener( 'transitionend', onTransitionEnd, false );
dom.pauseOverlay.removeEventListener( 'click', resume, false );
}
/**
* Uninitializes reveal.js by undoing changes made to the
* DOM and removing all event listeners.
*/
function destroy() {
removeEventListeners();
cancelAutoSlide();
disablePreviewLinks();
// Destroy controllers
notes.destroy();
focus.destroy();
plugins.destroy();
pointer.destroy();
controls.destroy();
progress.destroy();
backgrounds.destroy();
slideNumber.destroy();
// Remove event listeners
document.removeEventListener( 'fullscreenchange', onFullscreenChange );
document.removeEventListener( 'webkitfullscreenchange', onFullscreenChange );
document.removeEventListener( 'visibilitychange', onPageVisibilityChange, false );
window.removeEventListener( 'message', onPostMessage, false );
window.removeEventListener( 'load', layout, false );
// Undo DOM changes
if( dom.pauseOverlay ) dom.pauseOverlay.remove();
if( dom.statusElement ) dom.statusElement.remove();
document.documentElement.classList.remove( 'reveal-full-page' );
dom.wrapper.classList.remove( 'ready', 'center', 'has-horizontal-slides', 'has-vertical-slides' );
dom.wrapper.removeAttribute( 'data-transition-speed' );
dom.wrapper.removeAttribute( 'data-background-transition' );
dom.viewport.classList.remove( 'reveal-viewport' );
dom.viewport.style.removeProperty( '--slide-width' );
dom.viewport.style.removeProperty( '--slide-height' );
dom.slides.style.removeProperty( 'width' );
dom.slides.style.removeProperty( 'height' );
dom.slides.style.removeProperty( 'zoom' );
dom.slides.style.removeProperty( 'left' );
dom.slides.style.removeProperty( 'top' );
dom.slides.style.removeProperty( 'bottom' );
dom.slides.style.removeProperty( 'right' );
dom.slides.style.removeProperty( 'transform' );
Array.from( dom.wrapper.querySelectorAll( SLIDES_SELECTOR ) ).forEach( slide => {
slide.style.removeProperty( 'display' );
slide.style.removeProperty( 'top' );
slide.removeAttribute( 'hidden' );
slide.removeAttribute( 'aria-hidden' );
} );
}
/**
* 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 );
}
return event;
}
/**
* 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 {
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
}
});
}
}
dom.viewport.style.setProperty( '--slide-scale', scale );
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} [origin] Origin for use in multimaster environments
*/
function slide( h, v, f, origin ) {
// Dispatch an event before hte slide
const slidechange = dispatchEvent({
type: 'beforeslidechange',
data: {
indexh: h === undefined ? indexh : h,
indexv: v === undefined ? indexv : v,
origin
}
});
// Abort if this slide change was prevented by an event listener
if( slidechange.defaultPrevented ) return;
// 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' )
&& previousSlide.getAttribute( 'data-auto-animate-id' ) === currentSlide.getAttribute( 'data-auto-animate-id' )
&& !( ( indexh > indexhBefore || indexv > indexvBefore ) ? currentSlide : previousSlide ).hasAttribute( 'data-auto-animate-restart' ) ) {
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
}
});
}
// Handle embedded content
if( slideChanged || !previousSlide ) {
slideContent.stopEmbeddedContent( previousSlide );
slideContent.startEmbeddedContent( currentSlide );
}
// Announce the current slide contents to screen readers
// Use animation frame to prevent getComputedStyle in getStatusText
// from triggering layout mid-frame
requestAnimationFrame( () => {
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();
let loopedForwards = false;
let loopedBackwards = false;
if( slidesLength ) {
// Should the index loop?
if( config.loop ) {
if( index >= slidesLength ) loopedForwards = true;
index %= slidesLength;
if( index < 0 ) {
index = slidesLength + index;
loopedBackwards = true;
}
}
// 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
showFragmentsIn( element );
}
}
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
hideFragmentsIn( element );
}
}
// Update the visibility of fragments when a presentation loops
// in either direction
else if( i === index && config.fragments ) {
if( loopedForwards ) {
hideFragmentsIn( element );
}
else if( loopedBackwards ) {
showFragmentsIn( element );
}
}
}
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;
}
/**
* Shows all fragment elements within the given contaienr.
*/
function showFragmentsIn( container ) {
Util.queryAll( container, '.fragment' ).forEach( fragment => {
fragment.classList.add( 'visible' );
fragment.classList.remove( 'current-fragment' );
} );
}
/**
* Hides all fragment elements within the given contaienr.
*/
function hideFragmentsIn( container ) {
Util.queryAll( container, '.fragment.visible' ).forEach( fragment => {
fragment.classList.remove( 'visible', 'current-fragment' );
} );
}
/**
* 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({skipFragments=false}={}) {
navigationHistory.hasNavigatedHorizontally = true;
// Reverse for RTL
if( config.rtl ) {
if( ( overview.isActive() || skipFragments || fragments.next() === false ) && availableRoutes().left ) {
slide( indexh + 1, config.navigationMode === 'grid' ? indexv : undefined );
}
}
// Normal navigation
else if( ( overview.isActive() || skipFragments || fragments.prev() === false ) && availableRoutes().left ) {
slide( indexh - 1, config.navigationMode === 'grid' ? indexv : undefined );
}
}
function navigateRight({skipFragments=false}={}) {
navigationHistory.hasNavigatedHorizontally = true;
// Reverse for RTL
if( config.rtl ) {
if( ( overview.isActive() || skipFragments || fragments.prev() === false ) && availableRoutes().right ) {
slide( indexh - 1, config.navigationMode === 'grid' ? indexv : undefined );
}
}
// Normal navigation
else if( ( overview.isActive() || skipFragments || fragments.next() === false ) && availableRoutes().right ) {
slide( indexh + 1, config.navigationMode === 'grid' ? indexv : undefined );
}
}
function navigateUp({skipFragments=false}={}) {
// Prioritize hiding fragments
if( ( overview.isActive() || skipFragments || fragments.prev() === false ) && availableRoutes().up ) {
slide( indexh, indexv - 1 );
}
}
function navigateDown({skipFragments=false}={}) {
navigationHistory.hasNavigatedVertically = true;
// Prioritize revealing fragments
if( ( overview.isActive() || skipFragments || 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({skipFragments=false}={}) {
// Prioritize revealing fragments
if( skipFragments || fragments.prev() === false ) {
if( availableRoutes().up ) {
navigateUp({skipFragments});
}
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();
}
// When going backwards and arriving on a stack we start
// at the bottom of the stack
if( previousSlide && previousSlide.classList.contains( 'stack' ) ) {
let v = ( previousSlide.querySelectorAll( 'section' ).length - 1 ) || undefined;
let h = indexh - 1;
slide( h, v );
}
else {
navigateLeft({skipFragments});
}
}
}
}
/**
* The reverse of #navigatePrev().
*/
function navigateNext({skipFragments=false}={}) {
navigationHistory.hasNavigatedHorizontally = true;
navigationHistory.hasNavigatedVertically = true;
// Prioritize revealing fragments
if( skipFragments || 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() ) {
routes.down = false;
}
if( routes.down ) {
navigateDown({skipFragments});
}
else if( config.rtl ) {
navigateLeft({skipFragments});
}
else {
navigateRight({skipFragments});
}
}
}
// --------------------------------------------------------------------//
// ----------------------------- EVENTS -------------------------------//
// --------------------------------------------------------------------//
/**
* Called by all event handlers that are based on user
* input.
*
* @param {object} [event]
*/
function onUserInput( event ) {
if( config.autoSlideStoppable ) {
pauseAutoSlide();
}
}
/**
* Listener for post message events posted to this window.
*/
function onPostMessage( 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' );
}
}
}
}
/**
* 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 }
});
}
}
/**
* A global listener for all click events inside of the
* .slides container.
*
* @param {object} [event]
*/
function onSlidesClicked( event ) {
const anchor = Util.closest( event.target, 'a[href^="#"]' );
// If a hash link is clicked, we find the target slide
// and navigate to it. We previously relied on 'hashchange'
// for links like these but that prevented media with
// audio tracks from playing in mobile browsers since it
// wasn't considered a direct interaction with the document.
if( anchor ) {
const hash = anchor.getAttribute( 'href' );
const indices = location.getIndicesFromHash( hash );
if( indices ) {
Reveal.slide( indices.h, indices.v, indices.f );
event.preventDefault();
}
}
}
/**
* 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();
}
}
/**
* Handler for the document level 'fullscreenchange' event.
*
* @param {object} [event]
*/
function onFullscreenChange( event ) {
let element = document.fullscreenElement || document.webkitFullscreenElement;
if( element === dom.wrapper ) {
event.stopImmediatePropagation();
// Timeout to avoid layout shift in Safari
setTimeout( () => {
Reveal.layout();
Reveal.focus.focus(); // focus.focus :'(
}, 1 );
}
}
/**
* 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,
destroy,
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 ),
// Preview management
showPreview,
hidePreview: closeOverlay,
// 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 the path to the current slide as represented in the URL
getSlidePath: location.getHash.bind( location ),
// 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;
};