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Hakim El Hattab authoredHakim El Hattab authored
reveal.js 65.12 KiB
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 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'
/**
* 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 = {};
// The reveal.js version
const VERSION = '4.0.0-dev';
// 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 ),
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
config = { ...defaultConfig, ...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 ) {
if( revealElement.closest( '.reveal-viewport' ) === null ) {
revealElement.classList.add( 'reveal-viewport' );
}
}
// Full-page decks use the body as their viewport
else {
document.body.classList.add( 'reveal-viewport' );
document.documentElement.classList.add( 'reveal-full-page' );
}
}
/**
* Starts up reveal.js by binding input events and navigating
* to the current URL deeplink if there is one.
*/
function start() {
ready = true;
// Make sure we've got all the DOM elements we need
setupDOM();
// Listen to messages posted to this window
setupPostMessage();
// Prevent the slides from being scrolled out of view
setupScrollPrevention();
// Resets all vertical slides so that only the first is visible
resetVerticalSlides();
// Updates the presentation to match the current configuration values
configure();
// Read the initial hash
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 );
}
}
}
/**
* 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 );
if( config.shuffle ) {
shuffle();
}
if( config.rtl ) {
dom.wrapper.classList.add( 'rtl' );
} else {
dom.wrapper.classList.remove( 'rtl' );
}
if( config.center ) {
dom.wrapper.classList.add( 'center' );
}
else {
dom.wrapper.classList.remove( 'center' );
}
// Exit the paused mode if it was configured off
if( config.pause === false ) {
resume();
}
// 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 );
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();
controls.bind();
location.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();
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/>';
html += '<table><th>KEY</th><th>ACTION</th>';
for( let key in keyboard.shortcuts ) {
html += `<tr><td>${key}</td><td>${keyboard.shortcuts[ key ]}</td></tr>`;
}
// Add custom key bindings that have associated descriptions
for( let binding in keyboard.registeredKeyBindings ) {
if( keyboard.registeredKeyBindings[binding].key && keyboard.registeredKeyBindings[binding].description ) {
html += `<tr><td>${keyboard.registeredKeyBindings[binding].key}</td><td>${keyboard.registeredKeyBindings[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 ) {
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 'stretch' class
Util.queryAll( dom.slides, 'section > .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;
}
}
document.documentElement.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 ) {
document.documentElement.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() {
getHorizontalSlides().forEach( ( slide, i, slides ) => {
// Insert this slide next to another random slide. This may
// cause the slide to insert before itself but that's fine.
dom.slides.insertBefore( slide, slides[ Math.floor( Math.random() * slides.length ) ] );
} );
}
/**
* Updates one dimension of slides by showing the slide
* with the specified index.
*
* @param {string} selector A CSS selector that will fetch
* the group of slides we are working with
* @param {number} index The index of the slide that should be
* shown
*
* @return {number} The index of the slide that is now shown,
* might differ from the passed in index if it was out of
* bounds.
*/
function updateSlides( selector, index ) {
// Select all slides and convert the NodeList result to
// an array
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 );
element.classList.remove( 'past', 'present', '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() {
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;
}
// 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 ),
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,
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,
progress,
controls,
location,
overview,
fragments,
slideContent,
slideNumber,
onUserInput,
closeOverlay,
updateSlidesVisibility,
layoutSlideContents,
transformSlides,
cueAutoSlide,
cancelAutoSlide
} );
return API;
};