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Hakim El Hattab authoredHakim El Hattab authored
reveal.js 95.31 KiB
import SlideContent from './controllers/slidecontent.js'
import SlideNumber from './controllers/slidenumber.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 Plugins from './controllers/plugins.js'
import Touch from './controllers/touch.js'
import Playback from './components/playback.js'
import defaultConfig from './config.js'
import { isMobile, isChrome, isAndroid, supportsZoom } from './utils/device.js'
import { colorToRgb, colorBrightness } from './utils/color.js'
import {
SLIDES_SELECTOR,
HORIZONTAL_SLIDES_SELECTOR,
VERTICAL_SLIDES_SELECTOR,
POST_MESSAGE_METHOD_BLACKLIST
} from './utils/constants.js'
import {
extend,
toArray,
distanceBetween,
deserialize,
transformElement,
createSingletonNode,
createStyleSheet,
closestParent,
enterFullscreen,
getQueryHash
} from './utils/util.js'
/**
* reveal.js
* http://revealjs.com
* MIT licensed
*
* Copyright (C) 2020 Hakim El Hattab, https://hakim.se
*/
export default function( revealElement, options ) {
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,
previousBackground,
// Remember which directions that the user has navigated towards
hasNavigatedHorizontally = false,
hasNavigatedVertically = false,
// Slides may hold a data-state attribute which we pick up and apply
// as a class to the body. This list contains the combined state of
// all current slides.
state = [],
// The current scale of the presentation (see width/height config)
scale = 1,
// Controls loading and playback of slide content
slideContent = new SlideContent( Reveal ),
// Controls the optional slide number display
slideNumber = new SlideNumber( Reveal ),
// Controls auto-animations between slides
autoAnimate = new AutoAnimate( Reveal ),
// Controls navigation between slide fragments
fragments = new Fragments( Reveal ),
// Controls the birds-eye overview of slides
overview = new Overview( Reveal ),
// Controls all keyboard interactions
keyboard = new Keyboard( Reveal ),
// Controls the current location/URL
location = new Location( Reveal ),
// Controller for plugin loading
plugins = new Plugins(),
// Controls touch/swipe navigation for our deck
touch = new Touch( Reveal ),
// CSS transform that is currently applied to the slides container,
// split into two groups
slidesTransform = { layout: '', overview: '' },
// Cached references to DOM elements
dom = {},
// List of asynchronously loaded reveal.js dependencies
asyncDependencies = [],
// Throttles mouse wheel navigation
lastMouseWheelStep = 0,
// Is the mouse pointer currently hidden from view
cursorHidden = false,
// Timeout used to determine when the cursor is inactive
cursorInactiveTimeout = 0,
// Flags if the interaction event listeners are bound
eventsAreBound = false,
// The current auto-slide duration
autoSlide = 0,
// Auto slide properties
autoSlidePlayer,
autoSlideTimeout = 0,
autoSlideStartTime = -1,
autoSlidePaused = false;
/**
* Starts up the presentation if the client is capable.
*/
function initialize() {
if( !revealElement ) {
console.warn( 'reveal.js can not initialize without a valid .reveal element.' );
return; }
// Cache references to key DOM elements
dom.wrapper = revealElement;
dom.slides = revealElement.querySelector( '.slides' );
// Force a layout when the whole page, incl fonts, has loaded
window.addEventListener( 'load', layout, false );
// Copy options over to our config object
config = { ...defaultConfig, ...options, ...getQueryHash() };
// Load plugins then move on to #start()
plugins.load( config.dependencies ).then( start )
return new Promise( resolve => Reveal.addEventListener( 'ready', resolve ) );
}
/**
* 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();
// Update all backgrounds
updateBackground( true );
// Notify listeners that the presentation is ready but use a 1ms
// timeout to ensure it's not fired synchronously after #initialize()
setTimeout( () => {
// Enable transitions now that we're loaded
dom.slides.classList.remove( 'no-transition' );
dom.wrapper.classList.add( 'ready' );
dispatchEvent( 'ready', {
'indexh': indexh,
'indexv': indexv,
'currentSlide': currentSlide
} );
}, 1 );
// Special setup and config is required when printing to PDF
if( isPrintingPDF() ) {
removeEventListeners();
// The document needs to have loaded for the PDF layout
// measurements to be accurate
if( document.readyState === 'complete' ) { setupPDF();
}
else {
window.addEventListener( 'load', setupPDF );
}
}
}
/**
* Finds and stores references to DOM elements which are
* required by the presentation. If a required element is
* not found, it is created.
*/
function setupDOM() {
// Prevent transitions while we're loading
dom.slides.classList.add( 'no-transition' );
if( isMobile ) {
dom.wrapper.classList.add( 'no-hover' );
}
else {
dom.wrapper.classList.remove( 'no-hover' );
}
// Background element
dom.background = createSingletonNode( dom.wrapper, 'div', 'backgrounds', null );
// Progress bar
dom.progress = createSingletonNode( dom.wrapper, 'div', 'progress', '<span></span>' );
dom.progressbar = dom.progress.querySelector( 'span' );
// Arrow controls
dom.controls = createSingletonNode( dom.wrapper, 'aside', 'controls',
`<button class="navigate-left" aria-label="${ config.rtl ? 'next slide' : 'previous slide' }"><div class="controls-arrow"></div></button>
<button class="navigate-right" aria-label="${ config.rtl ? 'previous slide' : 'next slide' }"><div class="controls-arrow"></div></button>
<button class="navigate-up" aria-label="above slide"><div class="controls-arrow"></div></button>
<button class="navigate-down" aria-label="below slide"><div class="controls-arrow"></div></button>` );
// Slide number
slideNumber.createElement();
// Element containing notes that are visible to the audience
dom.speakerNotes = createSingletonNode( dom.wrapper, 'div', 'speaker-notes', null );
dom.speakerNotes.setAttribute( 'data-prevent-swipe', '' );
dom.speakerNotes.setAttribute( 'tabindex', '0' );
// Overlay graphic which is displayed during the paused mode
dom.pauseOverlay = createSingletonNode( dom.wrapper, 'div', 'pause-overlay', config.controls ? '<button class="resume-button">Resume presentation</button>' : null );
dom.wrapper.setAttribute( 'role', 'application' );
// There can be multiple instances of controls throughout the page
dom.controlsLeft = toArray( dom.wrapper.querySelectorAll( '.navigate-left' ) );
dom.controlsRight = toArray( dom.wrapper.querySelectorAll( '.navigate-right' ) );
dom.controlsUp = toArray( dom.wrapper.querySelectorAll( '.navigate-up' ) );
dom.controlsDown = toArray( dom.wrapper.querySelectorAll( '.navigate-down' ) );
dom.controlsPrev = toArray( dom.wrapper.querySelectorAll( '.navigate-prev' ) );
dom.controlsNext = toArray( dom.wrapper.querySelectorAll( '.navigate-next' ) );
// The left, right and down arrows in the standard reveal.js controls
dom.controlsRightArrow = dom.controls.querySelector( '.navigate-right' );
dom.controlsLeftArrow = dom.controls.querySelector( '.navigate-left' );
dom.controlsDownArrow = dom.controls.querySelector( '.navigate-down' );
dom.statusElement = createStatusElement();
}
/** * 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 ) {
toArray( node.childNodes ).forEach( child => {
text += getStatusText( child );
} );
}
}
text = text.trim();
return text === '' ? '' : text + ' ';
}
/**
* Configures the presentation for printing to a static * PDF.
*/
function setupPDF() {
let slideSize = getComputedSlideSize( window.innerWidth, window.innerHeight );
// Dimensions of the PDF pages
let pageWidth = Math.floor( slideSize.width * ( 1 + config.margin ) ),
pageHeight = Math.floor( slideSize.height * ( 1 + config.margin ) );
// Dimensions of slides within the pages
let slideWidth = slideSize.width,
slideHeight = slideSize.height;
// Let the browser know what page size we want to print
createStyleSheet( '@page{size:'+ pageWidth +'px '+ pageHeight +'px; margin: 0px;}' );
// Limit the size of certain elements to the dimensions of the slide
createStyleSheet( '.reveal section>img, .reveal section>video, .reveal section>iframe{max-width: '+ slideWidth +'px; max-height:'+ slideHeight +'px}' );
document.body.classList.add( 'print-pdf' );
document.body.style.width = pageWidth + 'px';
document.body.style.height = pageHeight + 'px';
// Make sure stretch elements fit on slide
layoutSlideContents( slideWidth, slideHeight );
// Compute slide numbers now, before we start duplicating slides
let doingSlideNumbers = config.slideNumber && /all|print/i.test( config.showSlideNumber );
toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR ) ).forEach( function( slide ) {
slide.setAttribute( 'data-slide-number', slideNumber.getSlideNumber( slide ) );
} );
// Slide and slide background layout
toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR ) ).forEach( function( slide ) {
// Vertical stacks are not centred since their section
// children will be
if( slide.classList.contains( 'stack' ) === false ) {
// Center the slide inside of the page, giving the slide some margin
let left = ( pageWidth - slideWidth ) / 2,
top = ( pageHeight - slideHeight ) / 2;
let contentHeight = slide.scrollHeight;
let numberOfPages = Math.max( Math.ceil( contentHeight / pageHeight ), 1 );
// Adhere to configured pages per slide limit
numberOfPages = Math.min( numberOfPages, config.pdfMaxPagesPerSlide );
// Center slides vertically
if( numberOfPages === 1 && config.center || slide.classList.contains( 'center' ) ) {
top = Math.max( ( pageHeight - contentHeight ) / 2, 0 );
}
// Wrap the slide in a page element and hide its overflow
// so that no page ever flows onto another
let page = document.createElement( 'div' );
page.className = 'pdf-page';
page.style.height = ( ( pageHeight + config.pdfPageHeightOffset ) * numberOfPages ) + 'px';
slide.parentNode.insertBefore( page, slide );
page.appendChild( slide );
// Position the slide inside of the page
slide.style.left = left + 'px';
slide.style.top = top + 'px';
slide.style.width = slideWidth + 'px';
if( slide.slideBackgroundElement ) {
page.insertBefore( slide.slideBackgroundElement, slide );
}
// Inject notes if `showNotes` is enabled
if( config.showNotes ) {
// Are there notes for this slide?
let notes = getSlideNotes( slide );
if( notes ) {
let notesSpacing = 8;
let notesLayout = typeof config.showNotes === 'string' ? config.showNotes : 'inline';
let notesElement = document.createElement( 'div' );
notesElement.classList.add( 'speaker-notes' );
notesElement.classList.add( 'speaker-notes-pdf' );
notesElement.setAttribute( 'data-layout', notesLayout );
notesElement.innerHTML = notes;
if( notesLayout === 'separate-page' ) {
page.parentNode.insertBefore( notesElement, page.nextSibling );
}
else {
notesElement.style.left = notesSpacing + 'px';
notesElement.style.bottom = notesSpacing + 'px';
notesElement.style.width = ( pageWidth - notesSpacing*2 ) + 'px';
page.appendChild( notesElement );
}
}
}
// Inject slide numbers if `slideNumbers` are enabled
if( doingSlideNumbers ) {
let numberElement = document.createElement( 'div' );
numberElement.classList.add( 'slide-number' );
numberElement.classList.add( 'slide-number-pdf' );
numberElement.innerHTML = slide.getAttribute( 'data-slide-number' );
page.appendChild( numberElement );
}
// Copy page and show fragments one after another
if( config.pdfSeparateFragments ) {
// Each fragment 'group' is an array containing one or more
// fragments. Multiple fragments that appear at the same time
// are part of the same group.
let fragmentGroups = fragments.sort( page.querySelectorAll( '.fragment' ), true );
let previousFragmentStep;
let previousPage;
fragmentGroups.forEach( function( fragments ) {
// Remove 'current-fragment' from the previous group
if( previousFragmentStep ) {
previousFragmentStep.forEach( function( fragment ) {
fragment.classList.remove( 'current-fragment' );
} );
}
// Show the fragments for the current index
fragments.forEach( function( fragment ) {
fragment.classList.add( 'visible', 'current-fragment' );
} );
// Create a separate page for the current fragment state
let clonedPage = page.cloneNode( true );
page.parentNode.insertBefore( clonedPage, ( previousPage || page ).nextSibling );
previousFragmentStep = fragments;
previousPage = clonedPage;
} );
// Reset the first/original page so that all fragments are hidden
fragmentGroups.forEach( function( fragments ) {
fragments.forEach( function( fragment ) {
fragment.classList.remove( 'visible', 'current-fragment' );
} );
} );
}
// Show all fragments
else {
toArray( page.querySelectorAll( '.fragment:not(.fade-out)' ) ).forEach( function( fragment ) {
fragment.classList.add( 'visible' );
} );
}
}
} );
// Notify subscribers that the PDF layout is good to go
dispatchEvent( 'pdf-ready' );
}
/**
* This is an unfortunate necessity. Some actions – such as
* an input field being focused in an iframe or using the
* keyboard to expand text selection beyond the bounds of
* a slide – can trigger our content to be pushed out of view.
* This scrolling can not be prevented by hiding overflow in
* CSS (we already do) so we have to resort to repeatedly
* checking if the slides have been offset :(
*/
function setupScrollPrevention() {
setInterval( () => {
if( dom.wrapper.scrollTop !== 0 || dom.wrapper.scrollLeft !== 0 ) {
dom.wrapper.scrollTop = 0;
dom.wrapper.scrollLeft = 0;
}
}, 1000 );
}
/**
* Creates the slide background elements and appends them
* to the background container. One element is created per
* slide no matter if the given slide has visible background.
*/
function createBackgrounds() {
let printMode = isPrintingPDF();
// Clear prior backgrounds
dom.background.innerHTML = '';
dom.background.classList.add( 'no-transition' );
// Iterate over all horizontal slides
toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) ).forEach( slideh => {
let backgroundStack = createBackground( slideh, dom.background );
// Iterate over all vertical slides
toArray( slideh.querySelectorAll( 'section' ) ).forEach( slidev => {
createBackground( slidev, backgroundStack );
backgroundStack.classList.add( 'stack' );
} );
} );
// Add parallax background if specified
if( config.parallaxBackgroundImage ) {
dom.background.style.backgroundImage = 'url("' + config.parallaxBackgroundImage + '")';
dom.background.style.backgroundSize = config.parallaxBackgroundSize;
dom.background.style.backgroundRepeat = config.parallaxBackgroundRepeat;
dom.background.style.backgroundPosition = config.parallaxBackgroundPosition;
// Make sure the below properties are set on the element - these properties are
// needed for proper transitions to be set on the element via CSS. To remove
// annoying background slide-in effect when the presentation starts, apply
// these properties after short time delay
setTimeout( () => {
dom.wrapper.classList.add( 'has-parallax-background' );
}, 1 );
}
else {
dom.background.style.backgroundImage = '';
dom.wrapper.classList.remove( 'has-parallax-background' );
}
}
/**
* Creates a background for the given slide.
*
* @param {HTMLElement} slide
* @param {HTMLElement} container The element that the background
* should be appended to
* @return {HTMLElement} New background div
*/
function createBackground( slide, container ) {
// Main slide background element
let element = document.createElement( 'div' );
element.className = 'slide-background ' + slide.className.replace( /present|past|future/, '' );
// Inner background element that wraps images/videos/iframes
let contentElement = document.createElement( 'div' );
contentElement.className = 'slide-background-content';
element.appendChild( contentElement );
container.appendChild( element );
slide.slideBackgroundElement = element;
slide.slideBackgroundContentElement = contentElement;
// Syncs the background to reflect all current background settings
syncBackground( slide );
return element;
}
/**
* Renders all of the visual properties of a slide background
* based on the various background attributes.
*
* @param {HTMLElement} slide
*/
function syncBackground( slide ) {
let element = slide.slideBackgroundElement,
contentElement = slide.slideBackgroundContentElement;
// Reset the prior background state in case this is not the
// initial sync
slide.classList.remove( 'has-dark-background' );
slide.classList.remove( 'has-light-background' );
element.removeAttribute( 'data-loaded' );
element.removeAttribute( 'data-background-hash' );
element.removeAttribute( 'data-background-size' );
element.removeAttribute( 'data-background-transition' );
element.style.backgroundColor = '';
contentElement.style.backgroundSize = '';
contentElement.style.backgroundRepeat = '';
contentElement.style.backgroundPosition = '';
contentElement.style.backgroundImage = '';
contentElement.style.opacity = '';
contentElement.innerHTML = '';
let data = {
background: slide.getAttribute( 'data-background' ),
backgroundSize: slide.getAttribute( 'data-background-size' ),
backgroundImage: slide.getAttribute( 'data-background-image' ),
backgroundVideo: slide.getAttribute( 'data-background-video' ),
backgroundIframe: slide.getAttribute( 'data-background-iframe' ),
backgroundColor: slide.getAttribute( 'data-background-color' ),
backgroundRepeat: slide.getAttribute( 'data-background-repeat' ),
backgroundPosition: slide.getAttribute( 'data-background-position' ),
backgroundTransition: slide.getAttribute( 'data-background-transition' ),
backgroundOpacity: slide.getAttribute( 'data-background-opacity' )
};
if( data.background ) {
// Auto-wrap image urls in url(...)
if( /^(http|file|\/\/)/gi.test( data.background ) || /\.(svg|png|jpg|jpeg|gif|bmp)([?#\s]|$)/gi.test( data.background ) ) {
slide.setAttribute( 'data-background-image', data.background );
}
else {
element.style.background = data.background;
}
}
// Create a hash for this combination of background settings.
// This is used to determine when two slide backgrounds are
// the same.
if( data.background || data.backgroundColor || data.backgroundImage || data.backgroundVideo || data.backgroundIframe ) {
element.setAttribute( 'data-background-hash', data.background +
data.backgroundSize +
data.backgroundImage +
data.backgroundVideo +
data.backgroundIframe +
data.backgroundColor +
data.backgroundRepeat +
data.backgroundPosition +
data.backgroundTransition +
data.backgroundOpacity );
}
// Additional and optional background properties
if( data.backgroundSize ) element.setAttribute( 'data-background-size', data.backgroundSize );
if( data.backgroundColor ) element.style.backgroundColor = data.backgroundColor;
if( data.backgroundTransition ) element.setAttribute( 'data-background-transition', data.backgroundTransition );
if( slide.hasAttribute( 'data-preload' ) ) element.setAttribute( 'data-preload', '' );
// Background image options are set on the content wrapper
if( data.backgroundSize ) contentElement.style.backgroundSize = data.backgroundSize; if( data.backgroundRepeat ) contentElement.style.backgroundRepeat = data.backgroundRepeat;
if( data.backgroundPosition ) contentElement.style.backgroundPosition = data.backgroundPosition;
if( data.backgroundOpacity ) contentElement.style.opacity = data.backgroundOpacity;
// If this slide has a background color, we add a class that
// signals if it is light or dark. If the slide has no background
// color, no class will be added
let contrastColor = data.backgroundColor;
// If no bg color was found, check the computed background
if( !contrastColor ) {
let computedBackgroundStyle = window.getComputedStyle( element );
if( computedBackgroundStyle && computedBackgroundStyle.backgroundColor ) {
contrastColor = computedBackgroundStyle.backgroundColor;
}
}
if( contrastColor ) {
let rgb = colorToRgb( contrastColor );
// Ignore fully transparent backgrounds. Some browsers return
// rgba(0,0,0,0) when reading the computed background color of
// an element with no background
if( rgb && rgb.a !== 0 ) {
if( colorBrightness( contrastColor ) < 128 ) {
slide.classList.add( 'has-dark-background' );
}
else {
slide.classList.add( 'has-light-background' );
}
}
}
}
/**
* 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 oldTransition = config.transition;
// New config options may be passed when this method
// is invoked through the API after initialization
if( typeof options === 'object' ) extend( config, options );
// Abort if reveal.js hasn't finished loading, config
// changes will be applied automatically once 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( oldTransition );
dom.wrapper.classList.add( config.transition );
dom.wrapper.setAttribute( 'data-transition-speed', config.transitionSpeed );
dom.wrapper.setAttribute( 'data-background-transition', config.backgroundTransition );
dom.controls.style.display = config.controls ? 'block' : 'none';
dom.progress.style.display = config.progress ? 'block' : 'none';
dom.controls.setAttribute( 'data-controls-layout', config.controlsLayout );
dom.controls.setAttribute( 'data-controls-back-arrows', config.controlsBackArrows );
if( config.shuffle ) {
shuffle();
}
if( config.rtl ) {
dom.wrapper.classList.add( 'rtl' );
}
else {
dom.wrapper.classList.remove( 'rtl' );
}
if( config.center ) {
dom.wrapper.classList.add( 'center' );
}
else {
dom.wrapper.classList.remove( 'center' );
}
// Exit the paused mode if it was configured off
if( config.pause === false ) {
resume();
}
if( config.showNotes ) {
dom.speakerNotes.setAttribute( 'data-layout', typeof config.showNotes === 'string' ? config.showNotes : 'inline' );
}
if( config.mouseWheel ) {
document.addEventListener( 'DOMMouseScroll', onDocumentMouseScroll, false ); // FF document.addEventListener( 'mousewheel', onDocumentMouseScroll, false );
}
else {
document.removeEventListener( 'DOMMouseScroll', onDocumentMouseScroll, false ); // FF
document.removeEventListener( 'mousewheel', onDocumentMouseScroll, false );
}
// Auto-hide the mouse pointer when its inactive
if( config.hideInactiveCursor ) {
document.addEventListener( 'mousemove', onDocumentCursorActive, false );
document.addEventListener( 'mousedown', onDocumentCursorActive, false );
}
else {
showCursor();
document.removeEventListener( 'mousemove', onDocumentCursorActive, false );
document.removeEventListener( 'mousedown', onDocumentCursorActive, false );
}
// 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;
}
// When fragments are turned off they should be visible
if( config.fragments === false ) {
fragments.showAll();
}
// 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' );
}
slideNumber.refreshVisibility();
keyboard.refreshSortcuts();
sync();
}
/**
* Binds all event listeners. */
function addEventListeners() {
eventsAreBound = true;
window.addEventListener( 'hashchange', onWindowHashChange, false );
window.addEventListener( 'resize', onWindowResize, false );
if( config.touch ) {
touch.bind();
}
if( config.keyboard ) {
keyboard.bind();
}
if( config.progress && dom.progress ) {
dom.progress.addEventListener( 'click', onProgressClicked, false );
}
dom.pauseOverlay.addEventListener( 'click', resume, false );
if( config.focusBodyOnPageVisibilityChange ) {
document.addEventListener( 'visibilitychange', onPageVisibilityChange, false );
}
// Listen to both touch and click events, in case the device
// supports both
let pointerEvents = [ 'touchstart', 'click' ];
// Only support touch for Android, fixes double navigations in
// stock browser
if( isAndroid ) {
pointerEvents = [ 'touchstart' ];
}
pointerEvents.forEach( eventName => {
dom.controlsLeft.forEach( el => el.addEventListener( eventName, onNavigateLeftClicked, false ) );
dom.controlsRight.forEach( el => el.addEventListener( eventName, onNavigateRightClicked, false ) );
dom.controlsUp.forEach( el => el.addEventListener( eventName, onNavigateUpClicked, false ) );
dom.controlsDown.forEach( el => el.addEventListener( eventName, onNavigateDownClicked, false ) );
dom.controlsPrev.forEach( el => el.addEventListener( eventName, onNavigatePrevClicked, false ) );
dom.controlsNext.forEach( el => el.addEventListener( eventName, onNavigateNextClicked, false ) );
} );
}
/**
* Unbinds all event listeners.
*/
function removeEventListeners() {
eventsAreBound = false;
touch.unbind();
keyboard.unbind();
window.removeEventListener( 'hashchange', onWindowHashChange, false );
window.removeEventListener( 'resize', onWindowResize, false );
dom.pauseOverlay.removeEventListener( 'click', resume, false );
if ( config.progress && dom.progress ) {
dom.progress.removeEventListener( 'click', onProgressClicked, false );
}
[ 'touchstart', 'click' ].forEach( eventName => {
dom.controlsLeft.forEach( el => el.removeEventListener( eventName, onNavigateLeftClicked, false ) );
dom.controlsRight.forEach( el => el.removeEventListener( eventName, onNavigateRightClicked, false ) );
dom.controlsUp.forEach( el => el.removeEventListener( eventName, onNavigateUpClicked, false ) ); dom.controlsDown.forEach( el => el.removeEventListener( eventName, onNavigateDownClicked, false ) );
dom.controlsPrev.forEach( el => el.removeEventListener( eventName, onNavigatePrevClicked, false ) );
dom.controlsNext.forEach( el => el.removeEventListener( eventName, onNavigateNextClicked, false ) );
} );
}
/**
* Applies CSS transforms to the slides container. The container
* is transformed from two separate sources: layout and the overview
* mode.
*
* @param {object} transforms
*/
function transformSlides( transforms ) {
// Pick up new transforms from arguments
if( typeof transforms.layout === 'string' ) slidesTransform.layout = transforms.layout;
if( typeof transforms.overview === 'string' ) slidesTransform.overview = transforms.overview;
// Apply the transforms to the slides container
if( slidesTransform.layout ) {
transformElement( dom.slides, slidesTransform.layout + ' ' + slidesTransform.overview );
}
else {
transformElement( dom.slides, slidesTransform.overview );
}
}
/**
* Returns the remaining height within the parent of the
* target element.
*
* remaining height = [ configured parent height ] - [ current parent height ]
*
* @param {HTMLElement} element
* @param {number} [height]
*/
function getRemainingHeight( element, height = 0 ) {
if( element ) {
let newHeight, oldHeight = element.style.height;
// Change the .stretch element height to 0 in order find the height of all
// the other elements
element.style.height = '0px';
// In Overview mode, the parent (.slide) height is set of 700px.
// Restore it temporarily to its natural height.
element.parentNode.style.height = 'auto';
newHeight = height - element.parentNode.offsetHeight;
// Restore the old height, just in case
element.style.height = oldHeight + 'px';
// Clear the parent (.slide) height. .removeProperty works in IE9+
element.parentNode.style.removeProperty('height');
return newHeight;
}
return height;
}
/**
* Checks if this instance is being used to print a PDF.
*/ function isPrintingPDF() {
return ( /print-pdf/gi ).test( window.location.search );
}
/**
* Dispatches an event of the specified type from the
* reveal DOM element.
*/
function dispatchEvent( type, args ) {
let event = document.createEvent( 'HTMLEvents', 1, 2 );
event.initEvent( type, true, true );
extend( event, args );
dom.wrapper.dispatchEvent( event );
// If we're in an iframe, post each reveal.js event to the
// parent window. Used by the notes plugin
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()
};
extend( message, data );
window.parent.postMessage( JSON.stringify( message ), '*' );
}
}
/**
* Bind preview frame links.
*
* @param {string} [selector=a] - selector for anchors
*/
function enablePreviewLinks( selector = 'a' ) {
toArray( 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' ) {
toArray( 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 && !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( 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 && 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 = toArray( 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( 'resize', {
'oldScale': oldScale,
'scale': scale,
'size': size
} );
}
}
updateProgress();
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
toArray( dom.slides.querySelectorAll( 'section > .stretch' ) ).forEach( element => {
// Determine how much vertical space we can use
let remainingHeight = 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;
}
/**
* Shows the mouse pointer after it has been hidden with
* #hideCursor.
*/
function showCursor() {
if( cursorHidden ) {
cursorHidden = false;
dom.wrapper.style.cursor = '';
}
}
/**
* Hides the mouse pointer when it's on top of the .reveal
* container.
*/
function hideCursor() {
if( cursorHidden === false ) {
cursorHidden = true;
dom.wrapper.style.cursor = 'none';
}
}
/**
* 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( 'paused' );
}
}
}
/**
* Exits from the paused mode.
*/
function resume() {
const wasPaused = dom.wrapper.classList.contains( 'paused' );
dom.wrapper.classList.remove( 'paused' );
cueAutoSlide();
if( wasPaused ) {
dispatchEvent( 'resumed' );
}
}
/**
* Toggles the paused mode on and off.
*/
function togglePause( override ) {
if( typeof override === 'boolean' ) {
override ? pause() : resume();
}
else { isPaused() ? resume() : pause();
}
}
/**
* Checks if we are currently in the paused mode.
*
* @return {Boolean}
*/
function isPaused() {
return dom.wrapper.classList.contains( 'paused' );
}
/**
* Toggles the auto slide mode on and off.
*
* @param {Boolean} [override] Flag which sets the desired state.
* True means autoplay starts, false means it stops.
*/
function toggleAutoSlide( override ) {
if( typeof override === 'boolean' ) {
override ? resumeAutoSlide() : pauseAutoSlide();
}
else {
autoSlidePaused ? resumeAutoSlide() : pauseAutoSlide();
}
}
/**
* Checks if the auto slide mode is currently on.
*
* @return {Boolean}
*/
function isAutoSliding() {
return !!( autoSlide && !autoSlidePaused );
}
/**
* Steps from the current point in the presentation to the
* slide which matches the specified horizontal and vertical
* indices.
*
* @param {number} [h=indexh] Horizontal index of the target slide
* @param {number} [v=indexv] Vertical index of the target slide
* @param {number} [f] Index of a fragment within the
* target slide to activate
* @param {number} [o] Origin for use in multimaster environments
*/
function slide( h, v, f, o ) {
// Remember where we were at before
previousSlide = currentSlide;
// Query all horizontal slides in the deck
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 );
// 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();
}
// 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;
// Show fragment, if specified
if( typeof f !== 'undefined' ) {
fragments.goto( f );
}
// Dispatch an event if the slide changed
let slideChanged = ( indexh !== indexhBefore || indexv !== indexvBefore );
if (!slideChanged) {
// Ensure that the previous slide is never the same as the current
previousSlide = null;
}
// Solves an edge case where the previous slide maintains the
// 'present' class when navigating between adjacent vertical
// stacks
if( previousSlide && previousSlide !== 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( state[i] );
}
// Clean up the remains of the previous state
while( stateBefore.length ) {
document.documentElement.classList.remove( stateBefore.pop() );
}
if( slideChanged ) {
dispatchEvent( 'slidechanged', {
'indexh': indexh,
'indexv': indexv,
'previousSlide': previousSlide,
'currentSlide': 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 ) );
updateControls();
updateProgress();
updateBackground();
updateParallax();
updateNotes();
slideNumber.update();
fragments.update();
// Update the URL hash
location.writeURL();
cueAutoSlide();
// Auto-animation
if( slideChanged && previousSlide && currentSlide && !overview.isActive() ) {
// Skip the slide transition between our two slides
// when auto-animating individual elements
if( previousSlide.hasAttribute( 'data-auto-animate' ) && currentSlide.hasAttribute( 'data-auto-animate' ) ) {
dom.slides.classList.add( 'disable-slide-transitions' );
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 the slide backgrounds
createBackgrounds();
// Write the current hash to the URL
location.writeURL();
fragments.sortAll();
updateControls();
updateProgress();
updateSlidesVisibility();
updateBackground( true );
updateNotesVisibility();
updateNotes();
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 ) {
syncBackground( slide );
syncFragments( slide );
slideContent.load( slide );
updateBackground();
updateNotes();
}
/**
* Formats the fragments on the given slide so that they have
* valid indices. Call this if fragments are changed in the DOM
* after reveal.js has already initialized.
*
* @param {HTMLElement} slide
* @return {Array} a list of the HTML fragments that were synced
*/
function syncFragments( slide = currentSlide ) {
return config.sort( slide.querySelectorAll( '.fragment' ) );
}
/**
* Resets all vertical slides so that only the first
* is visible.
*/
function resetVerticalSlides() {
getHorizontalSlides().forEach( horizontalSlide => {
toArray( horizontalSlide.querySelectorAll( '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 = toArray( dom.wrapper.querySelectorAll( selector ) ),
slidesLength = slides.length;
let printMode = isPrintingPDF();
if( slidesLength ) {
// Should the index loop?
if( config.loop ) {
index %= slidesLength;
if( index < 0 ) {
index = slidesLength + index;
}
}
// Enforce max and minimum index bounds
index = Math.max( Math.min( index, slidesLength - 1 ), 0 );
for( 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
toArray( element.querySelectorAll( '.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 toArray( element.querySelectorAll( '.fragment.visible' ) ).forEach( fragment => {
fragment.classList.remove( 'visible', 'current-fragment' );
} );
}
}
}
// Mark the current slide as present
slides[index].classList.add( 'present' );
slides[index].removeAttribute( 'hidden' );
slides[index].removeAttribute( 'aria-hidden' );
// If this slide has a state associated with it, add it
// onto the current state of the deck
let slideState = slides[index].getAttribute( 'data-state' );
if( slideState ) {
state = state.concat( slideState.split( ' ' ) );
}
}
else {
// Since there are no slides we can't be anywhere beyond the
// zeroth index
index = 0;
}
return index;
}
/**
* Optimization method; hide all slides that are far away
* from the present slide.
*/
function updateSlidesVisibility() {
// Select all slides and convert the NodeList result to
// an array
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( isMobile ) {
viewDistance = overview.isActive() ? 6 : config.mobileViewDistance;
}
// All slides need to be visible when exporting to PDF
if( isPrintingPDF() ) {
viewDistance = Number.MAX_VALUE;
}
for( let x = 0; x < horizontalSlidesLength; x++ ) {
let horizontalSlide = horizontalSlides[x];
let verticalSlides = toArray( horizontalSlide.querySelectorAll( 'section' ) ),
verticalSlidesLength = verticalSlides.length;
// Determine how far away this slide is from the present
distanceX = Math.abs( ( indexh || 0 ) - x ) || 0;
// If the presentation is looped, distance should measure // 1 between the first and last slides
if( config.loop ) {
distanceX = Math.abs( ( ( indexh || 0 ) - x ) % ( horizontalSlidesLength - viewDistance ) ) || 0;
}
// Show the horizontal slide if it's within the view distance
if( distanceX < viewDistance ) {
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' );
}
}
}
/**
* Pick up notes from the current slide and display them
* to the viewer.
*
* @see {@link config.showNotes}
*/
function updateNotes() {
if( config.showNotes && dom.speakerNotes && currentSlide && !isPrintingPDF() ) {
dom.speakerNotes.innerHTML = getSlideNotes() || '<span class="notes-placeholder">No notes on this slide.</span>';
}
}
/** * Updates the visibility of the speaker notes sidebar that
* is used to share annotated slides. The notes sidebar is
* only visible if showNotes is true and there are notes on
* one or more slides in the deck.
*/
function updateNotesVisibility() {
if( config.showNotes && hasNotes() ) {
dom.wrapper.classList.add( 'show-notes' );
}
else {
dom.wrapper.classList.remove( 'show-notes' );
}
}
/**
* Checks if there are speaker notes for ANY slide in the
* presentation.
*/
function hasNotes() {
return dom.slides.querySelectorAll( '[data-notes], aside.notes' ).length > 0;
}
/**
* Updates the progress bar to reflect the current slide.
*/
function updateProgress() {
// Update progress if enabled
if( config.progress && dom.progressbar ) {
dom.progressbar.style.width = getProgress() * dom.wrapper.offsetWidth + 'px';
}
}
/**
* Updates the state of all control/navigation arrows.
*/
function updateControls() {
let routes = availableRoutes();
let fragmentsRoutes = fragments.availableRoutes();
// Remove the 'enabled' class from all directions
[...dom.controlsLeft, ...dom.controlsRight, ...dom.controlsUp, ...dom.controlsDown, ...dom.controlsPrev, ...dom.controlsNext].forEach( node => {
node.classList.remove( 'enabled', 'fragmented' );
// Set 'disabled' attribute on all directions
node.setAttribute( 'disabled', 'disabled' );
} );
// Add the 'enabled' class to the available routes; remove 'disabled' attribute to enable buttons
if( routes.left ) dom.controlsLeft.forEach( el => { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } );
if( routes.right ) dom.controlsRight.forEach( el => { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } );
if( routes.up ) dom.controlsUp.forEach( el => { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } );
if( routes.down ) dom.controlsDown.forEach( el => { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } );
// Prev/next buttons
if( routes.left || routes.up ) dom.controlsPrev.forEach( el => { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } );
if( routes.right || routes.down ) dom.controlsNext.forEach( el => { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } );
// Highlight fragment directions
if( currentSlide ) {
// Always apply fragment decorator to prev/next buttons if( fragmentsRoutes.prev ) dom.controlsPrev.forEach( el => { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
if( fragmentsRoutes.next ) dom.controlsNext.forEach( el => { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
// Apply fragment decorators to directional buttons based on
// what slide axis they are in
if( isVerticalSlide( currentSlide ) ) {
if( fragmentsRoutes.prev ) dom.controlsUp.forEach( el => { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
if( fragmentsRoutes.next ) dom.controlsDown.forEach( el => { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
}
else {
if( fragmentsRoutes.prev ) dom.controlsLeft.forEach( el => { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
if( fragmentsRoutes.next ) dom.controlsRight.forEach( el => { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
}
}
if( config.controlsTutorial ) {
// Highlight control arrows with an animation to ensure
// that the viewer knows how to navigate
if( !hasNavigatedVertically && routes.down ) {
dom.controlsDownArrow.classList.add( 'highlight' );
}
else {
dom.controlsDownArrow.classList.remove( 'highlight' );
if( config.rtl ) {
if( !hasNavigatedHorizontally && routes.left && indexv === 0 ) {
dom.controlsLeftArrow.classList.add( 'highlight' );
}
else {
dom.controlsLeftArrow.classList.remove( 'highlight' );
}
} else {
if( !hasNavigatedHorizontally && routes.right && indexv === 0 ) {
dom.controlsRightArrow.classList.add( 'highlight' );
}
else {
dom.controlsRightArrow.classList.remove( 'highlight' );
}
}
}
}
}
/**
* Updates the background elements to reflect the current
* slide.
*
* @param {boolean} includeAll If true, the backgrounds of
* all vertical slides (not just the present) will be updated.
*/
function updateBackground( includeAll = false ) {
let currentBackground = null;
// Reverse past/future classes when in RTL mode
let horizontalPast = config.rtl ? 'future' : 'past',
horizontalFuture = config.rtl ? 'past' : 'future';
// Update the classes of all backgrounds to match the
// states of their slides (past/present/future)
toArray( dom.background.childNodes ).forEach( ( backgroundh, h ) => {
backgroundh.classList.remove( 'past', 'present', 'future' );
if( h < indexh ) { backgroundh.classList.add( horizontalPast );
}
else if ( h > indexh ) {
backgroundh.classList.add( horizontalFuture );
}
else {
backgroundh.classList.add( 'present' );
// Store a reference to the current background element
currentBackground = backgroundh;
}
if( includeAll || h === indexh ) {
toArray( backgroundh.querySelectorAll( '.slide-background' ) ).forEach( ( backgroundv, v ) => {
backgroundv.classList.remove( 'past', 'present', 'future' );
if( v < indexv ) {
backgroundv.classList.add( 'past' );
}
else if ( v > indexv ) {
backgroundv.classList.add( 'future' );
}
else {
backgroundv.classList.add( 'present' );
// Only if this is the present horizontal and vertical slide
if( h === indexh ) currentBackground = backgroundv;
}
} );
}
} );
// Stop content inside of previous backgrounds
if( previousBackground ) {
slideContent.stopEmbeddedContent( previousBackground, { unloadIframes: !slideContent.shouldPreload( previousBackground ) } );
}
// Start content in the current background
if( currentBackground ) {
slideContent.startEmbeddedContent( currentBackground );
let currentBackgroundContent = currentBackground.querySelector( '.slide-background-content' );
if( currentBackgroundContent ) {
let backgroundImageURL = currentBackgroundContent.style.backgroundImage || '';
// Restart GIFs (doesn't work in Firefox)
if( /\.gif/i.test( backgroundImageURL ) ) {
currentBackgroundContent.style.backgroundImage = '';
window.getComputedStyle( currentBackgroundContent ).opacity;
currentBackgroundContent.style.backgroundImage = backgroundImageURL;
}
}
// Don't transition between identical backgrounds. This
// prevents unwanted flicker.
let previousBackgroundHash = previousBackground ? previousBackground.getAttribute( 'data-background-hash' ) : null;
let currentBackgroundHash = currentBackground.getAttribute( 'data-background-hash' );
if( currentBackgroundHash && currentBackgroundHash === previousBackgroundHash && currentBackground !== previousBackground ) {
dom.background.classList.add( 'no-transition' );
}
previousBackground = currentBackground;
}
// If there's a background brightness flag for this slide,
// bubble it to the .reveal container
if( currentSlide ) {
[ 'has-light-background', 'has-dark-background' ].forEach( classToBubble => {
if( currentSlide.classList.contains( classToBubble ) ) {
dom.wrapper.classList.add( classToBubble );
}
else {
dom.wrapper.classList.remove( classToBubble );
}
} );
}
// Allow the first background to apply without transition
setTimeout( () => {
dom.background.classList.remove( 'no-transition' );
}, 1 );
}
/**
* Updates the position of the parallax background based
* on the current slide index.
*/
function updateParallax() {
if( config.parallaxBackgroundImage ) {
let horizontalSlides = getHorizontalSlides(),
verticalSlides = getVerticalSlides();
let backgroundSize = dom.background.style.backgroundSize.split( ' ' ),
backgroundWidth, backgroundHeight;
if( backgroundSize.length === 1 ) {
backgroundWidth = backgroundHeight = parseInt( backgroundSize[0], 10 );
}
else {
backgroundWidth = parseInt( backgroundSize[0], 10 );
backgroundHeight = parseInt( backgroundSize[1], 10 );
}
let slideWidth = dom.background.offsetWidth,
horizontalSlideCount = horizontalSlides.length,
horizontalOffsetMultiplier,
horizontalOffset;
if( typeof config.parallaxBackgroundHorizontal === 'number' ) {
horizontalOffsetMultiplier = config.parallaxBackgroundHorizontal;
}
else {
horizontalOffsetMultiplier = horizontalSlideCount > 1 ? ( backgroundWidth - slideWidth ) / ( horizontalSlideCount-1 ) : 0;
}
horizontalOffset = horizontalOffsetMultiplier * indexh * -1;
let slideHeight = dom.background.offsetHeight,
verticalSlideCount = verticalSlides.length,
verticalOffsetMultiplier,
verticalOffset;
if( typeof config.parallaxBackgroundVertical === 'number' ) {
verticalOffsetMultiplier = config.parallaxBackgroundVertical;
}
else {
verticalOffsetMultiplier = ( backgroundHeight - slideHeight ) / ( verticalSlideCount-1 );
}
verticalOffset = verticalSlideCount > 0 ? verticalOffsetMultiplier * indexv : 0;
dom.background.style.backgroundPosition = horizontalOffset + 'px ' + -verticalOffset + 'px';
}
}
/**
* 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 );
}
/**
* Checks if this presentation is running inside of the
* speaker notes window.
*
* @return {boolean}
*/
function isSpeakerNotes() {
return !!window.location.search.match( /receiver/gi );
}
/**
* 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 = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) );
// Now that we know which the horizontal slide is, get its index
h = Math.max( horizontalSlides.indexOf( slideh ), 0 );
// Assume we're not vertical
v = undefined;
// If this is a vertical slide, grab the vertical index
if( isVertical ) {
v = Math.max( toArray( slide.parentNode.querySelectorAll( 'section' ) ).indexOf( slide ), 0 );
}
}
if( !slide && currentSlide ) {
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 toArray( dom.wrapper.querySelectorAll( 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 toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) );
}
/**
* Returns all vertical slides that exist within this deck.
*/
function getVerticalSlides() {
return toArray( dom.wrapper.querySelectorAll( '.slides>section>section' ) );
}
/**
* Returns all vertical stacks (each stack can contain multiple slides).
*/
function getVerticalStacks() {
return toArray( dom.wrapper.querySelectorAll( 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 speaker notes from a slide. Notes can be
* defined in two ways:
* 1. As a data-notes attribute on the slide <section>
* 2. As an <aside class="notes"> inside of the slide
*
* @param {HTMLElement} [slide=currentSlide]
* @return {(string|null)}
*/
function getSlideNotes( slide = currentSlide ) {
// Notes can be specified via the data-notes attribute...
if( slide.hasAttribute( 'data-notes' ) ) {
return slide.getAttribute( 'data-notes' );
}
// ... or using an <aside class="notes"> element
let notesElement = slide.querySelector( 'aside.notes' );
if( notesElement ) {
return notesElement.innerHTML;
}
return null;
}
/**
* 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( deserialize( state.indexh ), deserialize( state.indexv ), deserialize( state.indexf ) );
let pausedFlag = deserialize( state.paused ),
overviewFlag = 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 ) {
toArray( currentSlide.querySelectorAll( '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( 'autoslidepaused' );
clearTimeout( autoSlideTimeout );
if( autoSlidePlayer ) {
autoSlidePlayer.setPlaying( false );
}
}
}
function resumeAutoSlide() {
if( autoSlide && autoSlidePaused ) {
autoSlidePaused = false;
dispatchEvent( 'autoslideresumed' );
cueAutoSlide();
}
}
function navigateLeft() {
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() {
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() {
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 = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR + '.future' ) ).pop();
}
else {
previousSlide = toArray( dom.wrapper.querySelectorAll( 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() {
hasNavigatedHorizontally = true;
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();
}
}
/**
* Called whenever there is mouse input at the document level
* to determine if the cursor is active or not.
*
* @param {object} event
*/
function onDocumentCursorActive( event ) {
showCursor();
clearTimeout( cursorInactiveTimeout );
cursorInactiveTimeout = setTimeout( hideCursor, config.hideCursorTime );
}
/**
* Handles mouse wheel scrolling, throttled to avoid skipping
* multiple slides.
*
* @param {object} event
*/
function onDocumentMouseScroll( event ) {
if( Date.now() - lastMouseWheelStep > 600 ) {
lastMouseWheelStep = Date.now();
let delta = event.detail || -event.wheelDelta;
if( delta > 0 ) {
navigateNext();
}
else if( delta < 0 ) {
navigatePrev();
}
}
}
/** * Clicking on the progress bar results in a navigation to the
* closest approximate horizontal slide using this equation:
*
* ( clickX / presentationWidth ) * numberOfSlides
*
* @param {object} event
*/
function onProgressClicked( event ) {
onUserInput( event );
event.preventDefault();
let slidesTotal = getHorizontalSlides().length;
let slideIndex = Math.floor( ( event.clientX / dom.wrapper.offsetWidth ) * slidesTotal );
if( config.rtl ) {
slideIndex = slidesTotal - slideIndex;
}
slide( slideIndex );
}
/**
* Event handler for navigation control buttons.
*/
function onNavigateLeftClicked( event ) { event.preventDefault(); onUserInput(); config.navigationMode === 'linear' ? navigatePrev() : navigateLeft(); }
function onNavigateRightClicked( event ) { event.preventDefault(); onUserInput(); config.navigationMode === 'linear' ? navigateNext() : navigateRight(); }
function onNavigateUpClicked( event ) { event.preventDefault(); onUserInput(); navigateUp(); }
function onNavigateDownClicked( event ) { event.preventDefault(); onUserInput(); navigateDown(); }
function onNavigatePrevClicked( event ) { event.preventDefault(); onUserInput(); navigatePrev(); }
function onNavigateNextClicked( event ) { event.preventDefault(); onUserInput(); navigateNext(); }
/**
* Handler for the window level 'hashchange' event.
*
* @param {object} [event]
*/
function onWindowHashChange( event ) {
location.readURL();
}
/**
* 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 --------------------------------//
// --------------------------------------------------------------------//
return extend( Reveal, {
VERSION,
initialize,
configure,
sync,
syncSlide,
syncFragments,
// Navigation methods
slide,
left: navigateLeft,
right: navigateRight,
up: navigateUp,
down: navigateDown,
prev: navigatePrev,
next: navigateNext,
// Deprecated aliases
navigateTo: slide,
navigateLeft: navigateLeft,
navigateRight: navigateRight,
navigateUp: navigateUp,
navigateDown: navigateDown,
navigatePrev: navigatePrev,
navigateNext: navigateNext,
// Fragment methods
navigateFragment: fragments.goto.bind( fragments ),
prevFragment: fragments.prev.bind( fragments ),
nextFragment: fragments.next.bind( fragments ),
// Forward event binding to the reveal DOM element
addEventListener: ( type, listener, useCapture ) => {
Reveal.getRevealElement().addEventListener( type, listener, useCapture );
},
removeEventListener: ( type, listener, useCapture ) => {
Reveal.getRevealElement().removeEventListener( type, listener, useCapture );
},
// 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
isOverview: overview.isActive.bind( overview ),
isPaused,
isAutoSliding,
isSpeakerNotes,
isPrintingPDF,
// Slide preloading
loadSlide: slideContent.load.bind( slideContent ),
unloadSlide: slideContent.unload.bind( slideContent ),
// Adds or removes all internal event listeners (such as keyboard)
addEventListeners,
removeEventListeners,
dispatchEvent,
// Facility for persisting and restoring the presentation state getState,
setState,
// Presentation progress
getSlidePastCount,
// Presentation progress on range of 0-1
getProgress,
// Returns the indices of the current, or specified, slide
getIndices,
// Returns an Array of all slides
getSlides,
// Returns an Array of objects representing the attributes on
// the slides
getSlidesAttributes,
// Returns the total number of slides
getTotalSlides,
// Returns the slide element at the specified index
getSlide,
// Returns the slide background element at the specified index
getSlideBackground,
// Returns the speaker notes string for a slide, or null
getSlideNotes,
// Returns an array with all horizontal/vertical slides in the deck
getHorizontalSlides,
getVerticalSlides,
// Checks if the presentation contains two or more
// horizontal/vertical slides
hasHorizontalSlides,
hasVerticalSlides,
// 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 ),
// 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 ),
getComputedSlideSize,
// Returns the previous slide element, may be null
getPreviousSlide: () => previousSlide,
// Returns the current slide element
getCurrentSlide: () => currentSlide,
// 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,
// Returns the top-level DOM element
getRevealElement: () => dom.wrapper || document.querySelector( '.reveal' ),
getSlidesElement: () => dom.slides,
getBackgroundsElement: () => dom.background,
// Checks if reveal.js has been loaded and is ready for use
isReady: () => ready,
// The following API methods are primarily intended for use
// by reveal.js controllers
// Methods for announcing content to screen readers
announceStatus,
getStatusText,
location,
overview,
slideContent,
onUserInput,
closeOverlay,
updateControls,
updateProgress,
updateSlidesVisibility,
transformSlides,
cueAutoSlide,
cancelAutoSlide
} );
};