import Playback from './playback.js'
/**
* reveal.js
* http://revealjs.com
* MIT licensed
*
* Copyright (C) 2020 Hakim El Hattab, http://hakim.se
*/
export default function() {
'use strict';
let Reveal;
// The reveal.js version
const VERSION = '4.0.0-dev';
const SLIDES_SELECTOR = '.slides section';
const HORIZONTAL_SLIDES_SELECTOR = '.slides>section';
const VERTICAL_SLIDES_SELECTOR = '.slides>section.present>section';
const HOME_SLIDE_SELECTOR = '.slides>section:first-of-type';
const UA = navigator.userAgent;
// Methods that may not be invoked via the postMessage API
const POST_MESSAGE_METHOD_BLACKLIST = /registerPlugin|registerKeyboardShortcut|addKeyBinding|addEventListener/;
// Configuration defaults, can be overridden at initialization time
let config = {
// The "normal" size of the presentation, aspect ratio will be preserved
// when the presentation is scaled to fit different resolutions
width: 960,
height: 700,
// Factor of the display size that should remain empty around the content
margin: 0.04,
// Bounds for smallest/largest possible scale to apply to content
minScale: 0.2,
maxScale: 2.0,
// Display presentation control arrows
controls: true,
// Help the user learn the controls by providing hints, for example by
// bouncing the down arrow when they first encounter a vertical slide
controlsTutorial: true,
// Determines where controls appear, "edges" or "bottom-right"
controlsLayout: 'bottom-right',
// Visibility rule for backwards navigation arrows; "faded", "hidden"
// or "visible"
controlsBackArrows: 'faded',
// Display a presentation progress bar
progress: true,
// Display the page number of the current slide
// - true: Show slide number
// - false: Hide slide number
//
// Can optionally be set as a string that specifies the number formatting:
// - "h.v": Horizontal . vertical slide number (default)
// - "h/v": Horizontal / vertical slide number
// - "c": Flattened slide number
// - "c/t": Flattened slide number / total slides
//
// Alternatively, you can provide a function that returns the slide
// number for the current slide. The function should take in a slide
// object and return an array with one string [slideNumber] or
// three strings [n1,delimiter,n2]. See #formatSlideNumber().
slideNumber: false,
// Can be used to limit the contexts in which the slide number appears
// - "all": Always show the slide number
// - "print": Only when printing to PDF
// - "speaker": Only in the speaker view
showSlideNumber: 'all',
// Use 1 based indexing for # links to match slide number (default is zero
// based)
hashOneBasedIndex: false,
// Add the current slide number to the URL hash so that reloading the
// page/copying the URL will return you to the same slide
hash: false,
// Push each slide change to the browser history. Implies `hash: true`
history: false,
// Enable keyboard shortcuts for navigation
keyboard: true,
// Optional function that blocks keyboard events when retuning false
keyboardCondition: null,
// Enable the slide overview mode
overview: true,
// Disables the default reveal.js slide layout so that you can use
// custom CSS layout
disableLayout: false,
// Vertical centering of slides
center: true,
// Enables touch navigation on devices with touch input
touch: true,
// Loop the presentation
loop: false,
// Change the presentation direction to be RTL
rtl: false,
// Changes the behavior of our navigation directions.
//
// "default"
// Left/right arrow keys step between horizontal slides, up/down
// arrow keys step between vertical slides. Space key steps through
// all slides (both horizontal and vertical).
//
// "linear"
// Removes the up/down arrows. Left/right arrows step through all
// slides (both horizontal and vertical).
//
// "grid"
// When this is enabled, stepping left/right from a vertical stack
// to an adjacent vertical stack will land you at the same vertical
// index.
//
// Consider a deck with six slides ordered in two vertical stacks:
// 1.1 2.1
// 1.2 2.2
// 1.3 2.3
//
// If you're on slide 1.3 and navigate right, you will normally move
// from 1.3 -> 2.1. If "grid" is used, the same navigation takes you
// from 1.3 -> 2.3.
navigationMode: 'default',
// Randomizes the order of slides each time the presentation loads
shuffle: false,
// Turns fragments on and off globally
fragments: true,
// Flags whether to include the current fragment in the URL,
// so that reloading brings you to the same fragment position
fragmentInURL: false,
// Flags if the presentation is running in an embedded mode,
// i.e. contained within a limited portion of the screen
embedded: false,
// Flags if we should show a help overlay when the question-mark
// key is pressed
help: true,
// Flags if it should be possible to pause the presentation (blackout)
pause: true,
// Flags if speaker notes should be visible to all viewers
showNotes: false,
// Global override for autolaying embedded media (video/audio/iframe)
// - null: Media will only autoplay if data-autoplay is present
// - true: All media will autoplay, regardless of individual setting
// - false: No media will autoplay, regardless of individual setting
autoPlayMedia: null,
// Global override for preloading lazy-loaded iframes
// - null: Iframes with data-src AND data-preload will be loaded when within
// the viewDistance, iframes with only data-src will be loaded when visible
// - true: All iframes with data-src will be loaded when within the viewDistance
// - false: All iframes with data-src will be loaded only when visible
preloadIframes: null,
// Can be used to globally disable auto-animation
autoAnimate: true,
// Optionally provide a custom element matcher that will be
// used to dictate which elements we can animate between.
autoAnimateMatcher: null,
// Default settings for our auto-animate transitions, can be
// overridden per-slide or per-element via data arguments
autoAnimateEasing: 'ease',
autoAnimateDuration: 1.0,
autoAnimateUnmatched: true,
// CSS properties that can be auto-animated. Position & scale
// is matched separately so there's no need to include styles
// like top/right/bottom/left, width/height or margin.
autoAnimateStyles: [
'opacity',
'color',
'background-color',
'padding',
'font-size',
'line-height',
'letter-spacing',
'border-width',
'border-color',
'border-radius',
'outline',
'outline-offset'
],
// Controls automatic progression to the next slide
// - 0: Auto-sliding only happens if the data-autoslide HTML attribute
// is present on the current slide or fragment
// - 1+: All slides will progress automatically at the given interval
// - false: No auto-sliding, even if data-autoslide is present
autoSlide: 0,
// Stop auto-sliding after user input
autoSlideStoppable: true,
// Use this method for navigation when auto-sliding (defaults to navigateNext)
autoSlideMethod: null,
// Specify the average time in seconds that you think you will spend
// presenting each slide. This is used to show a pacing timer in the
// speaker view
defaultTiming: null,
// Enable slide navigation via mouse wheel
mouseWheel: false,
// Opens links in an iframe preview overlay
// Add `data-preview-link` and `data-preview-link="false"` to customise each link
// individually
previewLinks: false,
// Exposes the reveal.js API through window.postMessage
postMessage: true,
// Dispatches all reveal.js events to the parent window through postMessage
postMessageEvents: false,
// Focuses body when page changes visibility to ensure keyboard shortcuts work
focusBodyOnPageVisibilityChange: true,
// Transition style
transition: 'slide', // none/fade/slide/convex/concave/zoom
// Transition speed
transitionSpeed: 'default', // default/fast/slow
// Transition style for full page slide backgrounds
backgroundTransition: 'fade', // none/fade/slide/convex/concave/zoom
// Parallax background image
parallaxBackgroundImage: '', // CSS syntax, e.g. "a.jpg"
// Parallax background size
parallaxBackgroundSize: '', // CSS syntax, e.g. "3000px 2000px"
// Parallax background repeat
parallaxBackgroundRepeat: '', // repeat/repeat-x/repeat-y/no-repeat/initial/inherit
// Parallax background position
parallaxBackgroundPosition: '', // CSS syntax, e.g. "top left"
// Amount of pixels to move the parallax background per slide step
parallaxBackgroundHorizontal: null,
parallaxBackgroundVertical: null,
// The maximum number of pages a single slide can expand onto when printing
// to PDF, unlimited by default
pdfMaxPagesPerSlide: Number.POSITIVE_INFINITY,
// Prints each fragment on a separate slide
pdfSeparateFragments: true,
// Offset used to reduce the height of content within exported PDF pages.
// This exists to account for environment differences based on how you
// print to PDF. CLI printing options, like phantomjs and wkpdf, can end
// on precisely the total height of the document whereas in-browser
// printing has to end one pixel before.
pdfPageHeightOffset: -1,
// Number of slides away from the current that are visible
viewDistance: 3,
// Number of slides away from the current that are visible on mobile
// devices. It is advisable to set this to a lower number than
// viewDistance in order to save resources.
mobileViewDistance: 2,
// The display mode that will be used to show slides
display: 'block',
// Hide cursor if inactive
hideInactiveCursor: true,
// Time before the cursor is hidden (in ms)
hideCursorTime: 5000,
// Script dependencies to load
dependencies: []
},
// Flags if Reveal.initialize() has been called
initialized = false,
// Flags if reveal.js is loaded (has dispatched the 'ready' event)
loaded = false,
// Flags if the overview mode is currently active
overview = false,
// Holds the dimensions of our overview slides, including margins
overviewSlideWidth = null,
overviewSlideHeight = null,
// The horizontal and vertical index of the currently active slide
indexh,
indexv,
// The previous and current slide HTML elements
previousSlide,
currentSlide,
previousBackground,
// Remember which directions that the user has navigated towards
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,
// CSS transform that is currently applied to the slides container,
// split into two groups
slidesTransform = { layout: '', overview: '' },
// Cached references to DOM elements
dom = {},
// A list of registered reveal.js plugins
plugins = {},
// List of asynchronously loaded reveal.js dependencies
asyncDependencies = [],
// Features supported by the browser, see #checkCapabilities()
features = {},
// Client is a mobile device, see #checkCapabilities()
isMobileDevice,
// Client is a desktop Chrome, see #checkCapabilities()
isChrome,
// Throttles mouse wheel navigation
lastMouseWheelStep = 0,
// Delays updates to the URL due to a Chrome thumbnailer bug
writeURLTimeout = 0,
// 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,
// <style> element used to apply auto-animations
autoAnimateStyleSheet,
// Counter used to generate unique IDs for auto-animated elements
autoAnimateCounter = 0,
// The current auto-slide duration
autoSlide = 0,
// Auto slide properties
autoSlidePlayer,
autoSlideTimeout = 0,
autoSlideStartTime = -1,
autoSlidePaused = false,
// Holds information about the currently ongoing touch input
touch = {
startX: 0,
startY: 0,
startCount: 0,
captured: false,
threshold: 40
},
// A key:value map of shortcut keyboard keys and descriptions of
// the actions they trigger, generated in #configure()
keyboardShortcuts = {},
// Holds custom key code mappings
registeredKeyBindings = {};
/**
* Starts up the presentation if the client is capable.
*/
function initialize( options ) {
// Make sure we only initialize once
if( initialized === true ) return;
initialized = true;
checkCapabilities();
// Cache references to key DOM elements
dom.wrapper = document.querySelector( '.reveal' );
dom.slides = document.querySelector( '.reveal .slides' );
// Force a layout when the whole page, incl fonts, has loaded
window.addEventListener( 'load', layout, false );
let query = Reveal.getQueryHash();
// Do not accept new dependencies via query config to avoid
// the potential of malicious script injection
if( typeof query['dependencies'] !== 'undefined' ) delete query['dependencies'];
// Copy options over to our config object
extend( config, options );
extend( config, query );
// Loads dependencies and continues to #start() once done
load();
}
/**
* Inspect the client to see what it's capable of, this
* should only happens once per runtime.
*/
function checkCapabilities() {
isMobileDevice = /(iphone|ipod|ipad|android)/gi.test( UA ) ||
( navigator.platform === 'MacIntel' && navigator.maxTouchPoints > 1 ); // iPadOS
isChrome = /chrome/i.test( UA ) && !/edge/i.test( UA );
let testElement = document.createElement( 'div' );
// Flags if we should use zoom instead of transform to scale
// up slides. Zoom produces crisper results but has a lot of
// xbrowser quirks so we only use it in whitelsited browsers.
features.zoom = 'zoom' in testElement.style && !isMobileDevice &&
( isChrome || /Version\/[\d\.]+.*Safari/.test( UA ) );
}
/**
* Loads the dependencies of reveal.js. Dependencies are
* defined via the configuration option 'dependencies'
* and will be loaded prior to starting/binding reveal.js.
* Some dependencies may have an 'async' flag, if so they
* will load after reveal.js has been started up.
*/
function load() {
var scripts = [],
scriptsToLoad = 0;
config.dependencies.forEach( s => {
// Load if there's no condition or the condition is truthy
if( !s.condition || s.condition() ) {
if( s.async ) {
asyncDependencies.push( s );
}
else {
scripts.push( s );
}
}
} );
if( scripts.length ) {
scriptsToLoad = scripts.length;
// Load synchronous scripts
scripts.forEach( s => {
loadScript( s.src, function() {
if( typeof s.callback === 'function' ) s.callback();
if( --scriptsToLoad === 0 ) {
initPlugins();
}
} );
} );
}
else {
initPlugins();
}
}
/**
* Initializes our plugins and waits for them to be ready
* before proceeding.
*/
function initPlugins() {
let pluginsToInitialize = Object.keys( plugins ).length;
// If there are no plugins, skip this step
if( pluginsToInitialize === 0 ) {
loadAsyncDependencies();
}
// ... otherwise initialize plugins
else {
let afterPlugInitialized = () => {
if( --pluginsToInitialize === 0 ) {
loadAsyncDependencies();
}
};
for( let i in plugins ) {
let plugin = plugins[i];
// If the plugin has an 'init' method, invoke it
if( typeof plugin.init === 'function' ) {
let callback = plugin.init();
// If the plugin returned a Promise, wait for it
if( callback && typeof callback.then === 'function' ) {
callback.then( afterPlugInitialized );
}
else {
afterPlugInitialized();
}
}
else {
afterPlugInitialized();
}
}
}
}
/**
* Loads all async reveal.js dependencies.
*/
function loadAsyncDependencies() {
if( asyncDependencies.length ) {
asyncDependencies.forEach( s => {
loadScript( s.src, s.callback );
} );
}
start();
}
/**
* Loads a JavaScript file from the given URL and executes it.
*
* @param {string} url Address of the .js file to load
* @param {function} callback Method to invoke when the script
* has loaded and executed
*/
function loadScript( url, callback ) {
const script = document.createElement( 'script' );
script.type = 'text/javascript';
script.async = false;
script.defer = false;
script.src = url;
if( callback ) {
// Success callback
script.onload = script.onreadystatechange = event => {
if( event.type === 'load' || /loaded|complete/.test( script.readyState ) ) {
// Kill event listeners
script.onload = script.onreadystatechange = script.onerror = null;
callback();
}
};
// Error callback
script.onerror = err => {
// Kill event listeners
script.onload = script.onreadystatechange = script.onerror = null;
callback( new Error( 'Failed loading script: ' + script.src + '\n' + err ) );
};
}
// Append the script at the end of <head>
const head = document.querySelector( 'head' );
head.insertBefore( script, head.lastChild );
}
/**
* Starts up reveal.js by binding input events and navigating
* to the current URL deeplink if there is one.
*/
function start() {
loaded = true;
// Make sure we've got all the DOM elements we need
setupDOM();
// Listen to messages posted to this window
setupPostMessage();
// Prevent the slides from being scrolled out of view
setupScrollPrevention();
// Resets all vertical slides so that only the first is visible
resetVerticalSlides();
// Updates the presentation to match the current configuration values
configure();
// Read the initial hash
readURL();
// Update all backgrounds
updateBackground( true );
// Notify listeners that the presentation is ready but use a 1ms
// timeout to ensure it's not fired synchronously after #initialize()
setTimeout( () => {
// Enable transitions now that we're loaded
dom.slides.classList.remove( 'no-transition' );
dom.wrapper.classList.add( 'ready' );
dispatchEvent( 'ready', {
'indexh': indexh,
'indexv': indexv,
'currentSlide': currentSlide
} );
}, 1 );
// Special setup and config is required when printing to PDF
if( isPrintingPDF() ) {
removeEventListeners();
// The document needs to have loaded for the PDF layout
// measurements to be accurate
if( document.readyState === 'complete' ) {
setupPDF();
}
else {
window.addEventListener( 'load', setupPDF );
}
}
}
/**
* Finds and stores references to DOM elements which are
* required by the presentation. If a required element is
* not found, it is created.
*/
function setupDOM() {
// Prevent transitions while we're loading
dom.slides.classList.add( 'no-transition' );
if( isMobileDevice ) {
dom.wrapper.classList.add( 'no-hover' );
}
else {
dom.wrapper.classList.remove( 'no-hover' );
}
if( /iphone/gi.test( UA ) ) {
dom.wrapper.classList.add( 'ua-iphone' );
}
else {
dom.wrapper.classList.remove( 'ua-iphone' );
}
// Background element
dom.background = createSingletonNode( dom.wrapper, 'div', 'backgrounds', null );
// Progress bar
dom.progress = createSingletonNode( dom.wrapper, 'div', 'progress', '<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
dom.slideNumber = createSingletonNode( dom.wrapper, 'div', 'slide-number', '' );
// Element containing notes that are visible to the audience
dom.speakerNotes = createSingletonNode( dom.wrapper, 'div', 'speaker-notes', null );
dom.speakerNotes.setAttribute( 'data-prevent-swipe', '' );
dom.speakerNotes.setAttribute( 'tabindex', '0' );
// Overlay graphic which is displayed during the paused mode
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( document.querySelectorAll( '.navigate-left' ) );
dom.controlsRight = toArray( document.querySelectorAll( '.navigate-right' ) );
dom.controlsUp = toArray( document.querySelectorAll( '.navigate-up' ) );
dom.controlsDown = toArray( document.querySelectorAll( '.navigate-down' ) );
dom.controlsPrev = toArray( document.querySelectorAll( '.navigate-prev' ) );
dom.controlsNext = toArray( document.querySelectorAll( '.navigate-next' ) );
// The 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.statusDiv = createStatusDiv();
}
/**
* Creates a hidden div with role aria-live to announce the
* current slide content. Hide the div off-screen to make it
* available only to Assistive Technologies.
*
* @return {HTMLElement}
*/
function createStatusDiv() {
let statusDiv = document.getElementById( 'aria-status-div' );
if( !statusDiv ) {
statusDiv = document.createElement( 'div' );
statusDiv.style.position = 'absolute';
statusDiv.style.height = '1px';
statusDiv.style.width = '1px';
statusDiv.style.overflow = 'hidden';
statusDiv.style.clip = 'rect( 1px, 1px, 1px, 1px )';
statusDiv.setAttribute( 'id', 'aria-status-div' );
statusDiv.setAttribute( 'aria-live', 'polite' );
statusDiv.setAttribute( 'aria-atomic','true' );
dom.wrapper.appendChild( statusDiv );
}
return statusDiv;
}
/**
* Converts the given HTML element into a string of text
* that can be announced to a screen reader. Hidden
* elements are excluded.
*/
function getStatusText( node ) {
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 );
} );
}
}
return text.trim();
}
/**
* Configures the presentation for printing to a static
* PDF.
*/
function setupPDF() {
var slideSize = getComputedSlideSize( window.innerWidth, window.innerHeight );
// Dimensions of the PDF pages
var pageWidth = Math.floor( slideSize.width * ( 1 + config.margin ) ),
pageHeight = Math.floor( slideSize.height * ( 1 + config.margin ) );
// Dimensions of slides within the pages
var slideWidth = slideSize.width,
slideHeight = slideSize.height;
// Let the browser know what page size we want to print
injectStyleSheet( '@page{size:'+ pageWidth +'px '+ pageHeight +'px; margin: 0px;}' );
// Limit the size of certain elements to the dimensions of the slide
injectStyleSheet( '.reveal section>img, .reveal section>video, .reveal section>iframe{max-width: '+ slideWidth +'px; max-height:'+ slideHeight +'px}' );
document.body.classList.add( 'print-pdf' );
document.body.style.width = pageWidth + 'px';
document.body.style.height = pageHeight + 'px';
// Make sure stretch elements fit on slide
layoutSlideContents( slideWidth, slideHeight );
// Compute slide numbers now, before we start duplicating slides
var doingSlideNumbers = config.slideNumber && /all|print/i.test( config.showSlideNumber );
toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR ) ).forEach( function( slide ) {
slide.setAttribute( 'data-slide-number', 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
var left = ( pageWidth - slideWidth ) / 2,
top = ( pageHeight - slideHeight ) / 2;
var contentHeight = slide.scrollHeight;
var numberOfPages = Math.max( Math.ceil( contentHeight / pageHeight ), 1 );
// Adhere to configured pages per slide limit
numberOfPages = Math.min( numberOfPages, config.pdfMaxPagesPerSlide );
// Center slides vertically
if( numberOfPages === 1 && config.center || slide.classList.contains( 'center' ) ) {
top = Math.max( ( pageHeight - contentHeight ) / 2, 0 );
}
// Wrap the slide in a page element and hide its overflow
// so that no page ever flows onto another
var page = document.createElement( 'div' );
page.className = 'pdf-page';
page.style.height = ( ( pageHeight + config.pdfPageHeightOffset ) * numberOfPages ) + 'px';
slide.parentNode.insertBefore( page, slide );
page.appendChild( slide );
// Position the slide inside of the page
slide.style.left = left + 'px';
slide.style.top = top + 'px';
slide.style.width = slideWidth + 'px';
if( slide.slideBackgroundElement ) {
page.insertBefore( slide.slideBackgroundElement, slide );
}
// Inject notes if `showNotes` is enabled
if( config.showNotes ) {
// Are there notes for this slide?
var notes = getSlideNotes( slide );
if( notes ) {
var notesSpacing = 8;
var notesLayout = typeof config.showNotes === 'string' ? config.showNotes : 'inline';
var notesElement = document.createElement( 'div' );
notesElement.classList.add( 'speaker-notes' );
notesElement.classList.add( 'speaker-notes-pdf' );
notesElement.setAttribute( 'data-layout', notesLayout );
notesElement.innerHTML = notes;
if( notesLayout === 'separate-page' ) {
page.parentNode.insertBefore( notesElement, page.nextSibling );
}
else {
notesElement.style.left = notesSpacing + 'px';
notesElement.style.bottom = notesSpacing + 'px';
notesElement.style.width = ( pageWidth - notesSpacing*2 ) + 'px';
page.appendChild( notesElement );
}
}
}
// Inject slide numbers if `slideNumbers` are enabled
if( doingSlideNumbers ) {
var 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.
var fragmentGroups = sortFragments( page.querySelectorAll( '.fragment' ), true );
var previousFragmentStep;
var 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
var 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 an HTML element and returns a reference to it.
* If the element already exists the existing instance will
* be returned.
*
* @param {HTMLElement} container
* @param {string} tagname
* @param {string} classname
* @param {string} innerHTML
*
* @return {HTMLElement}
*/
function createSingletonNode( container, tagname, classname, innerHTML='' ) {
// Find all nodes matching the description
let nodes = container.querySelectorAll( '.' + classname );
// Check all matches to find one which is a direct child of
// the specified container
for( let i = 0; i < nodes.length; i++ ) {
let testNode = nodes[i];
if( testNode.parentNode === container ) {
return testNode;
}
}
// If no node was found, create it now
let node = document.createElement( tagname );
node.className = classname;
node.innerHTML = innerHTML;
container.appendChild( node );
return node;
}
/**
* Creates the slide background elements and appends them
* to the background container. One element is created per
* slide no matter if the given slide has visible background.
*/
function createBackgrounds() {
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 => {
const 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 ) {
var 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 loading
// finishes
if( loaded === false ) return;
const numberOfSlides = dom.wrapper.querySelectorAll( SLIDES_SELECTOR ).length;
// Remove the previously configured transition class
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 auto animated elements
toArray( dom.slides.querySelectorAll( '[data-auto-animate]:not([data-auto-animate=""])' ) ).forEach( function( element ) {
element.dataset.autoAnimate = '';
} );
removeEphemeralAutoAnimateAttributes();
if( autoAnimateStyleSheet && autoAnimateStyleSheet.parentNode ) {
autoAnimateStyleSheet.parentNode.removeChild( autoAnimateStyleSheet );
autoAnimateStyleSheet = null;
}
// 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 ) {
toArray( dom.slides.querySelectorAll( '.fragment' ) ).forEach( element => {
element.classList.add( 'visible' );
element.classList.remove( 'current-fragment' );
} );
}
// Slide numbers
let slideNumberDisplay = 'none';
if( config.slideNumber && !isPrintingPDF() ) {
if( config.showSlideNumber === 'all' ) {
slideNumberDisplay = 'block';
}
else if( config.showSlideNumber === 'speaker' && isSpeakerNotes() ) {
slideNumberDisplay = 'block';
}
}
dom.slideNumber.style.display = slideNumberDisplay;
// 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' );
}
// Define our contextual list of keyboard shortcuts
if( config.navigationMode === 'linear' ) {
keyboardShortcuts['→ , ↓ , SPACE , N , L , J'] = 'Next slide';
keyboardShortcuts['← , ↑ , P , H , K'] = 'Previous slide';
}
else {
keyboardShortcuts['N , SPACE'] = 'Next slide';
keyboardShortcuts['P'] = 'Previous slide';
keyboardShortcuts['← , H'] = 'Navigate left';
keyboardShortcuts['→ , L'] = 'Navigate right';
keyboardShortcuts['↑ , K'] = 'Navigate up';
keyboardShortcuts['↓ , J'] = 'Navigate down';
}
keyboardShortcuts['Home , Shift ←'] = 'First slide';
keyboardShortcuts['End , Shift →'] = 'Last slide';
keyboardShortcuts['B , .'] = 'Pause';
keyboardShortcuts['F'] = 'Fullscreen';
keyboardShortcuts['ESC, O'] = 'Slide overview';
sync();
}
/**
* Binds all event listeners.
*/
function addEventListeners() {
eventsAreBound = true;
window.addEventListener( 'hashchange', onWindowHashChange, false );
window.addEventListener( 'resize', onWindowResize, false );
if( config.touch ) {
if( 'onpointerdown' in window ) {
// Use W3C pointer events
dom.wrapper.addEventListener( 'pointerdown', onPointerDown, false );
dom.wrapper.addEventListener( 'pointermove', onPointerMove, false );
dom.wrapper.addEventListener( 'pointerup', onPointerUp, false );
}
else if( window.navigator.msPointerEnabled ) {
// IE 10 uses prefixed version of pointer events
dom.wrapper.addEventListener( 'MSPointerDown', onPointerDown, false );
dom.wrapper.addEventListener( 'MSPointerMove', onPointerMove, false );
dom.wrapper.addEventListener( 'MSPointerUp', onPointerUp, false );
}
else {
// Fall back to touch events
dom.wrapper.addEventListener( 'touchstart', onTouchStart, false );
dom.wrapper.addEventListener( 'touchmove', onTouchMove, false );
dom.wrapper.addEventListener( 'touchend', onTouchEnd, false );
}
}
if( config.keyboard ) {
document.addEventListener( 'keydown', onDocumentKeyDown, false );
document.addEventListener( 'keypress', onDocumentKeyPress, false );
}
if( config.progress && dom.progress ) {
dom.progress.addEventListener( 'click', onProgressClicked, false );
}
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( UA.match( /android/gi ) ) {
pointerEvents = [ 'touchstart' ];
}
pointerEvents.forEach( function( eventName ) {
dom.controlsLeft.forEach( function( el ) { el.addEventListener( eventName, onNavigateLeftClicked, false ); } );
dom.controlsRight.forEach( function( el ) { el.addEventListener( eventName, onNavigateRightClicked, false ); } );
dom.controlsUp.forEach( function( el ) { el.addEventListener( eventName, onNavigateUpClicked, false ); } );
dom.controlsDown.forEach( function( el ) { el.addEventListener( eventName, onNavigateDownClicked, false ); } );
dom.controlsPrev.forEach( function( el ) { el.addEventListener( eventName, onNavigatePrevClicked, false ); } );
dom.controlsNext.forEach( function( el ) { el.addEventListener( eventName, onNavigateNextClicked, false ); } );
} );
}
/**
* Unbinds all event listeners.
*/
function removeEventListeners() {
eventsAreBound = false;
document.removeEventListener( 'keydown', onDocumentKeyDown, false );
document.removeEventListener( 'keypress', onDocumentKeyPress, false );
window.removeEventListener( 'hashchange', onWindowHashChange, false );
window.removeEventListener( 'resize', onWindowResize, false );
dom.wrapper.removeEventListener( 'pointerdown', onPointerDown, false );
dom.wrapper.removeEventListener( 'pointermove', onPointerMove, false );
dom.wrapper.removeEventListener( 'pointerup', onPointerUp, false );
dom.wrapper.removeEventListener( 'MSPointerDown', onPointerDown, false );
dom.wrapper.removeEventListener( 'MSPointerMove', onPointerMove, false );
dom.wrapper.removeEventListener( 'MSPointerUp', onPointerUp, false );
dom.wrapper.removeEventListener( 'touchstart', onTouchStart, false );
dom.wrapper.removeEventListener( 'touchmove', onTouchMove, false );
dom.wrapper.removeEventListener( 'touchend', onTouchEnd, false );
dom.pauseOverlay.removeEventListener( 'click', resume, false );
if ( config.progress && dom.progress ) {
dom.progress.removeEventListener( 'click', onProgressClicked, false );
}
[ 'touchstart', 'click' ].forEach( function( eventName ) {
dom.controlsLeft.forEach( function( el ) { el.removeEventListener( eventName, onNavigateLeftClicked, false ); } );
dom.controlsRight.forEach( function( el ) { el.removeEventListener( eventName, onNavigateRightClicked, false ); } );
dom.controlsUp.forEach( function( el ) { el.removeEventListener( eventName, onNavigateUpClicked, false ); } );
dom.controlsDown.forEach( function( el ) { el.removeEventListener( eventName, onNavigateDownClicked, false ); } );
dom.controlsPrev.forEach( function( el ) { el.removeEventListener( eventName, onNavigatePrevClicked, false ); } );
dom.controlsNext.forEach( function( el ) { el.removeEventListener( eventName, onNavigateNextClicked, false ); } );
} );
}
/**
* Registers a new plugin with this reveal.js instance.
*
* reveal.js waits for all regisered plugins to initialize
* before considering itself ready, as long as the plugin
* is registered before calling `Reveal.initialize()`.
*/
function registerPlugin( id, plugin ) {
if( plugins[id] === undefined ) {
plugins[id] = plugin;
// If a plugin is registered after reveal.js is loaded,
// initialize it right away
if( loaded && typeof plugin.init === 'function' ) {
plugin.init();
}
}
else {
console.warn( 'reveal.js: "'+ id +'" plugin has already been registered' );
}
}
/**
* Checks if a specific plugin has been registered.
*
* @param {String} id Unique plugin identifier
*/
function hasPlugin( id ) {
return !!plugins[id];
}
/**
* Returns the specific plugin instance, if a plugin
* with the given ID has been registered.
*
* @param {String} id Unique plugin identifier
*/
function getPlugin( id ) {
return plugins[id];
}
/**
* Add a custom key binding with optional description to
* be added to the help screen.
*/
function addKeyBinding( binding, callback ) {
if( typeof binding === 'object' && binding.keyCode ) {
registeredKeyBindings[binding.keyCode] = {
callback: callback,
key: binding.key,
description: binding.description
};
}
else {
registeredKeyBindings[binding] = {
callback: callback,
key: null,
description: null
};
}
}
/**
* Removes the specified custom key binding.
*/
function removeKeyBinding( keyCode ) {
delete registeredKeyBindings[keyCode];
}
/**
* Extend object a with the properties of object b.
* If there's a conflict, object b takes precedence.
*
* @param {object} a
* @param {object} b
*/
function extend( a, b ) {
for( var i in b ) {
a[ i ] = b[ i ];
}
return a;
}
/**
* Converts the target object to an array.
*
* @param {object} o
* @return {object[]}
*/
function toArray( o ) {
return Array.prototype.slice.call( o );
}
/**
* Utility for deserializing a value.
*
* @param {*} value
* @return {*}
*/
function deserialize( value ) {
if( typeof value === 'string' ) {
if( value === 'null' ) return null;
else if( value === 'true' ) return true;
else if( value === 'false' ) return false;
else if( value.match( /^-?[\d\.]+$/ ) ) return parseFloat( value );
}
return value;
}
/**
* Measures the distance in pixels between point a
* and point b.
*
* @param {object} a point with x/y properties
* @param {object} b point with x/y properties
*
* @return {number}
*/
function distanceBetween( a, b ) {
var dx = a.x - b.x,
dy = a.y - b.y;
return Math.sqrt( dx*dx + dy*dy );
}
/**
* Applies a CSS transform to the target element.
*
* @param {HTMLElement} element
* @param {string} transform
*/
function transformElement( element, transform ) {
element.style.transform = transform;
}
/**
* Applies CSS transforms to the slides container. The container
* is transformed from two separate sources: layout and the overview
* mode.
*
* @param {object} transforms
*/
function transformSlides( transforms ) {
// Pick up new transforms from arguments
if( typeof transforms.layout === 'string' ) slidesTransform.layout = transforms.layout;
if( typeof transforms.overview === 'string' ) slidesTransform.overview = transforms.overview;
// Apply the transforms to the slides container
if( slidesTransform.layout ) {
transformElement( dom.slides, slidesTransform.layout + ' ' + slidesTransform.overview );
}
else {
transformElement( dom.slides, slidesTransform.overview );
}
}
/**
* Injects the given CSS styles into the DOM.
*
* @param {string} value
*/
function injectStyleSheet( value ) {
let tag = document.createElement( 'style' );
tag.type = 'text/css';
if( tag.styleSheet ) {
tag.styleSheet.cssText = value;
}
else {
tag.appendChild( document.createTextNode( value ) );
}
document.getElementsByTagName( 'head' )[0].appendChild( tag );
}
/**
* Find the closest parent that matches the given
* selector.
*
* @param {HTMLElement} target The child element
* @param {String} selector The CSS selector to match
* the parents against
*
* @return {HTMLElement} The matched parent or null
* if no matching parent was found
*/
function closestParent( target, selector ) {
let parent = target.parentNode;
while( parent ) {
// There's some overhead doing this each time, we don't
// want to rewrite the element prototype but should still
// be enough to feature detect once at startup...
let matchesMethod = parent.matches || parent.matchesSelector || parent.msMatchesSelector;
// If we find a match, we're all set
if( matchesMethod && matchesMethod.call( parent, selector ) ) {
return parent;
}
// Keep searching
parent = parent.parentNode;
}
return null;
}
/**
* Converts various color input formats to an {r:0,g:0,b:0} object.
*
* @param {string} color The string representation of a color
* @example
* colorToRgb('#000');
* @example
* colorToRgb('#000000');
* @example
* colorToRgb('rgb(0,0,0)');
* @example
* colorToRgb('rgba(0,0,0)');
*
* @return {{r: number, g: number, b: number, [a]: number}|null}
*/
function colorToRgb( color ) {
let hex3 = color.match( /^#([0-9a-f]{3})$/i );
if( hex3 && hex3[1] ) {
hex3 = hex3[1];
return {
r: parseInt( hex3.charAt( 0 ), 16 ) * 0x11,
g: parseInt( hex3.charAt( 1 ), 16 ) * 0x11,
b: parseInt( hex3.charAt( 2 ), 16 ) * 0x11
};
}
let hex6 = color.match( /^#([0-9a-f]{6})$/i );
if( hex6 && hex6[1] ) {
hex6 = hex6[1];
return {
r: parseInt( hex6.substr( 0, 2 ), 16 ),
g: parseInt( hex6.substr( 2, 2 ), 16 ),
b: parseInt( hex6.substr( 4, 2 ), 16 )
};
}
let rgb = color.match( /^rgb\s*\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*\)$/i );
if( rgb ) {
return {
r: parseInt( rgb[1], 10 ),
g: parseInt( rgb[2], 10 ),
b: parseInt( rgb[3], 10 )
};
}
let rgba = color.match( /^rgba\s*\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*\,\s*([\d]+|[\d]*.[\d]+)\s*\)$/i );
if( rgba ) {
return {
r: parseInt( rgba[1], 10 ),
g: parseInt( rgba[2], 10 ),
b: parseInt( rgba[3], 10 ),
a: parseFloat( rgba[4] )
};
}
return null;
}
/**
* Calculates brightness on a scale of 0-255.
*
* @param {string} color See colorToRgb for supported formats.
* @see {@link colorToRgb}
*/
function colorBrightness( color ) {
if( typeof color === 'string' ) color = colorToRgb( color );
if( color ) {
return ( color.r * 299 + color.g * 587 + color.b * 114 ) / 1000;
}
return null;
}
/**
* Returns the remaining height within the parent of the
* target element.
*
* remaining height = [ configured parent height ] - [ current parent height ]
*
* @param {HTMLElement} element
* @param {number} [height]
*/
function getRemainingHeight( element, height = 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( document.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( document.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="${url}"></iframe>
<small class="viewport-inner">
<span class="x-frame-error">Unable to load iframe. This is likely due to the site's policy (x-frame-options).</span>
</small>
</div>`;
dom.overlay.querySelector( 'iframe' ).addEventListener( 'load', event => {
dom.overlay.classList.add( 'loaded' );
}, false );
dom.overlay.querySelector( '.close' ).addEventListener( 'click', event => {
closeOverlay();
event.preventDefault();
}, false );
dom.overlay.querySelector( '.external' ).addEventListener( 'click', event => {
closeOverlay();
}, false );
}
/**
* Open or close help overlay window.
*
* @param {Boolean} [override] Flag which overrides the
* toggle logic and forcibly sets the desired state. True means
* help is open, false means it's closed.
*/
function toggleHelp( override ){
if( typeof override === 'boolean' ) {
override ? showHelp() : closeOverlay();
}
else {
if( dom.overlay ) {
closeOverlay();
}
else {
showHelp();
}
}
}
/**
* Opens an overlay window with help material.
*/
function showHelp() {
if( config.help ) {
closeOverlay();
dom.overlay = document.createElement( 'div' );
dom.overlay.classList.add( 'overlay' );
dom.overlay.classList.add( 'overlay-help' );
dom.wrapper.appendChild( dom.overlay );
let html = '<p class="title">Keyboard Shortcuts</p><br/>';
html += '<table><th>KEY</th><th>ACTION</th>';
for( var key in keyboardShortcuts ) {
html += `<tr><td>${key}</td><td>${keyboardShortcuts[ key ]}</td></tr>`;
}
// Add custom key bindings that have associated descriptions
for( var binding in registeredKeyBindings ) {
if( registeredKeyBindings[binding].key && registeredKeyBindings[binding].description ) {
html += `<tr><td>${registeredKeyBindings[binding].key}</td><td>${registeredKeyBindings[binding].description}</td></tr>`;
}
}
html += '</table>';
dom.overlay.innerHTML = `
<header>
<a class="close" href="#"><span class="icon"></span></a>
</header>
<div class="viewport">
<div class="viewport-inner">${html}</div>
</div>
`;
dom.overlay.querySelector( '.close' ).addEventListener( 'click', function( event ) {
closeOverlay();
event.preventDefault();
}, false );
}
}
/**
* Closes any currently open overlay.
*/
function closeOverlay() {
if( dom.overlay ) {
dom.overlay.parentNode.removeChild( dom.overlay );
dom.overlay = null;
}
}
/**
* Applies JavaScript-controlled layout rules to the
* presentation.
*/
function layout() {
if( dom.wrapper && !isPrintingPDF() ) {
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( isMobileDevice ) {
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 && features.zoom && 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( var 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( isOverview() ) {
updateOverview();
}
}
}
/**
* Applies layout logic to the contents of all slides in
* the presentation.
*
* @param {string|number} width
* @param {string|number} height
*/
function layoutSlideContents( width, height ) {
// Handle sizing of elements with the 'stretch' class
toArray( dom.slides.querySelectorAll( 'section > .stretch' ) ).forEach( element => {
// Determine how much vertical space we can use
var remainingHeight = getRemainingHeight( element, height );
// Consider the aspect ratio of media elements
if( /(img|video)/gi.test( element.nodeName ) ) {
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;
}
/**
* Displays the overview of slides (quick nav) by scaling
* down and arranging all slide elements.
*/
function activateOverview() {
// Only proceed if enabled in config
if( config.overview && !isOverview() ) {
overview = true;
dom.wrapper.classList.add( 'overview' );
// Don't auto-slide while in overview mode
cancelAutoSlide();
// Move the backgrounds element into the slide container to
// that the same scaling is applied
dom.slides.appendChild( dom.background );
// Clicking on an overview slide navigates to it
toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR ) ).forEach( slide => {
if( !slide.classList.contains( 'stack' ) ) {
slide.addEventListener( 'click', onOverviewSlideClicked, true );
}
} );
// Calculate slide sizes
const margin = 70;
const slideSize = getComputedSlideSize();
overviewSlideWidth = slideSize.width + margin;
overviewSlideHeight = slideSize.height + margin;
// Reverse in RTL mode
if( config.rtl ) {
overviewSlideWidth = -overviewSlideWidth;
}
updateSlidesVisibility();
layoutOverview();
updateOverview();
layout();
// Notify observers of the overview showing
dispatchEvent( 'overviewshown', {
'indexh': indexh,
'indexv': indexv,
'currentSlide': currentSlide
} );
}
}
/**
* Uses CSS transforms to position all slides in a grid for
* display inside of the overview mode.
*/
function layoutOverview() {
// Layout slides
toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) ).forEach( ( hslide, h ) => {
hslide.setAttribute( 'data-index-h', h );
transformElement( hslide, 'translate3d(' + ( h * overviewSlideWidth ) + 'px, 0, 0)' );
if( hslide.classList.contains( 'stack' ) ) {
toArray( hslide.querySelectorAll( 'section' ) ).forEach( ( vslide, v ) => {
vslide.setAttribute( 'data-index-h', h );
vslide.setAttribute( 'data-index-v', v );
transformElement( vslide, 'translate3d(0, ' + ( v * overviewSlideHeight ) + 'px, 0)' );
} );
}
} );
// Layout slide backgrounds
toArray( dom.background.childNodes ).forEach( ( hbackground, h ) => {
transformElement( hbackground, 'translate3d(' + ( h * overviewSlideWidth ) + 'px, 0, 0)' );
toArray( hbackground.querySelectorAll( '.slide-background' ) ).forEach( ( vbackground, v ) => {
transformElement( vbackground, 'translate3d(0, ' + ( v * overviewSlideHeight ) + 'px, 0)' );
} );
} );
}
/**
* Moves the overview viewport to the current slides.
* Called each time the current slide changes.
*/
function updateOverview() {
const vmin = Math.min( window.innerWidth, window.innerHeight );
const scale = Math.max( vmin / 5, 150 ) / vmin;
transformSlides( {
overview: [
'scale('+ scale +')',
'translateX('+ ( -indexh * overviewSlideWidth ) +'px)',
'translateY('+ ( -indexv * overviewSlideHeight ) +'px)'
].join( ' ' )
} );
}
/**
* Exits the slide overview and enters the currently
* active slide.
*/
function deactivateOverview() {
// Only proceed if enabled in config
if( config.overview ) {
overview = false;
dom.wrapper.classList.remove( 'overview' );
// Temporarily add a class so that transitions can do different things
// depending on whether they are exiting/entering overview, or just
// moving from slide to slide
dom.wrapper.classList.add( 'overview-deactivating' );
setTimeout( () => {
dom.wrapper.classList.remove( 'overview-deactivating' );
}, 1 );
// Move the background element back out
dom.wrapper.appendChild( dom.background );
// Clean up changes made to slides
toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR ) ).forEach( slide => {
transformElement( slide, '' );
slide.removeEventListener( 'click', onOverviewSlideClicked, true );
} );
// Clean up changes made to backgrounds
toArray( dom.background.querySelectorAll( '.slide-background' ) ).forEach( background => {
transformElement( background, '' );
} );
transformSlides( { overview: '' } );
slide( indexh, indexv );
layout();
cueAutoSlide();
// Notify observers of the overview hiding
dispatchEvent( 'overviewhidden', {
'indexh': indexh,
'indexv': indexv,
'currentSlide': currentSlide
} );
}
}
/**
* Toggles the slide overview mode on and off.
*
* @param {Boolean} [override] Flag which overrides the
* toggle logic and forcibly sets the desired state. True means
* overview is open, false means it's closed.
*/
function toggleOverview( override ) {
if( typeof override === 'boolean' ) {
override ? activateOverview() : deactivateOverview();
}
else {
isOverview() ? deactivateOverview() : activateOverview();
}
}
/**
* Checks if the overview is currently active.
*
* @return {Boolean} true if the overview is active,
* false otherwise
*/
function isOverview() {
return overview;
}
/**
* Return a hash URL that will resolve to the given slide location.
*
* @param {HTMLElement} [slide=currentSlide] The slide to link to
*/
function locationHash( slide ) {
let url = '/';
// Attempt to create a named link based on the slide's ID
let s = slide || currentSlide;
let id = s ? s.getAttribute( 'id' ) : null;
if( id ) {
id = encodeURIComponent( id );
}
let index = getIndices( slide );
if( !config.fragmentInURL ) {
index.f = undefined;
}
// If the current slide has an ID, use that as a named link,
// but we don't support named links with a fragment index
if( typeof id === 'string' && id.length && index.f === undefined ) {
url = '/' + id;
}
// Otherwise use the /h/v index
else {
let hashIndexBase = config.hashOneBasedIndex ? 1 : 0;
if( index.h > 0 || index.v > 0 || index.f !== undefined ) url += index.h + hashIndexBase;
if( index.v > 0 || index.f !== undefined ) url += '/' + (index.v + hashIndexBase );
if( index.f !== undefined ) url += '/' + index.f;
}
return url;
}
/**
* 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 );
}
/**
* Handling the fullscreen functionality via the fullscreen API
*
* @see http://fullscreen.spec.whatwg.org/
* @see https://developer.mozilla.org/en-US/docs/DOM/Using_fullscreen_mode
*/
function enterFullscreen() {
let element = document.documentElement;
// Check which implementation is available
let requestMethod = element.requestFullscreen ||
element.webkitRequestFullscreen ||
element.webkitRequestFullScreen ||
element.mozRequestFullScreen ||
element.msRequestFullscreen;
if( requestMethod ) {
requestMethod.apply( element );
}
}
/**
* 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 && !isOverview() ) {
v = getPreviousVerticalIndex( horizontalSlides[ h ] );
}
// If we were on a vertical stack, remember what vertical index
// it was on so we can resume at the same position when returning
if( previousSlide && previousSlide.parentNode && previousSlide.parentNode.classList.contains( 'stack' ) ) {
setPreviousVerticalIndex( previousSlide.parentNode, indexv );
}
// Remember the state before this slide
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( isOverview() ) {
updateOverview();
}
// 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' ) {
navigateFragment( 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( Reveal.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 ) {
stopEmbeddedContent( previousSlide );
startEmbeddedContent( currentSlide );
}
// Announce the current slide contents, for screen readers
dom.statusDiv.textContent = getStatusText( currentSlide );
updateControls();
updateProgress();
updateBackground();
updateParallax();
updateSlideNumber();
updateNotes();
updateFragments();
// Update the URL hash
writeURL();
cueAutoSlide();
// Auto-animation
if( slideChanged && previousSlide && currentSlide && !isOverview() ) {
// 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( 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
writeURL();
sortAllFragments();
updateControls();
updateProgress();
updateSlideNumber();
updateSlidesVisibility();
updateBackground( true );
updateNotesVisibility();
updateNotes();
formatEmbeddedContent();
// Start or stop embedded content depending on global config
if( config.autoPlayMedia === false ) {
stopEmbeddedContent( currentSlide, { unloadIframes: false } );
}
else {
startEmbeddedContent( currentSlide );
}
if( isOverview() ) {
layoutOverview();
}
}
/**
* 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 );
loadSlide( 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 sortFragments( slide.querySelectorAll( '.fragment' ) );
}
/**
* Resets all vertical slides so that only the first
* is visible.
*/
function resetVerticalSlides() {
getHorizontalSlides().forEach( function( 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' );
}
} );
} );
}
/**
* Sorts and formats all of fragments in the
* presentation.
*/
function sortAllFragments() {
getHorizontalSlides().forEach( horizontalSlide => {
let verticalSlides = toArray( horizontalSlide.querySelectorAll( 'section' ) );
verticalSlides.forEach( ( verticalSlide, y ) => {
sortFragments( verticalSlide.querySelectorAll( '.fragment' ) );
} );
if( verticalSlides.length === 0 ) sortFragments( horizontalSlide.querySelectorAll( '.fragment' ) );
} );
}
/**
* 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 = isOverview() ? 10 : config.viewDistance;
// Shorten the view distance on devices that typically have
// less resources
if( isMobileDevice ) {
viewDistance = isOverview() ? 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 ) {
loadSlide( horizontalSlide );
}
else {
unloadSlide( 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 ) {
loadSlide( verticalSlide );
}
else {
unloadSlide( 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 slide number to match the current slide.
*/
function updateSlideNumber() {
// Update slide number if enabled
if( config.slideNumber && dom.slideNumber ) {
dom.slideNumber.innerHTML = getSlideNumber();
}
}
/**
* Returns the HTML string corresponding to the current slide number,
* including formatting.
*/
function getSlideNumber( slide = currentSlide ) {
let value;
let format = 'h.v';
if ( typeof config.slideNumber === 'function' ) {
value = config.slideNumber( slide );
} else {
// Check if a custom number format is available
if( typeof config.slideNumber === 'string' ) {
format = config.slideNumber;
}
// If there are ONLY vertical slides in this deck, always use
// a flattened slide number
if( !/c/.test( format ) && dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ).length === 1 ) {
format = 'c';
}
value = [];
switch( format ) {
case 'c':
value.push( getSlidePastCount( slide ) + 1 );
break;
case 'c/t':
value.push( getSlidePastCount( slide ) + 1, '/', getTotalSlides() );
break;
default:
let indices = getIndices( slide );
value.push( indices.h + 1 );
let sep = format === 'h/v' ? '/' : '.';
if( isVerticalSlide( slide ) ) value.push( sep, indices.v + 1 );
}
}
let url = '#' + locationHash( slide );
return formatSlideNumber( value[0], value[1], value[2], url );
}
/**
* Applies HTML formatting to a slide number before it's
* written to the DOM.
*
* @param {number} a Current slide
* @param {string} delimiter Character to separate slide numbers
* @param {(number|*)} b Total slides
* @param {HTMLElement} [url='#'+locationHash()] The url to link to
* @return {string} HTML string fragment
*/
function formatSlideNumber( a, delimiter, b, url = '#' + locationHash() ) {
if( typeof b === 'number' && !isNaN( b ) ) {
return `<a href="${url}">
<span class="slide-number-a">${a}</span>
<span class="slide-number-delimiter">${delimiter}</span>
<span class="slide-number-b">${b}</span>
</a>`;
}
else {
return `<a href="${url}">
<span class="slide-number-a">${a}</span>
</a>`;
}
}
/**
* Updates the state of all control/navigation arrows.
*/
function updateControls() {
let routes = availableRoutes();
let fragments = availableFragments();
// 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( fragments.prev ) dom.controlsPrev.forEach( el => { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
if( fragments.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( fragments.prev ) dom.controlsUp.forEach( el => { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
if( fragments.next ) dom.controlsDown.forEach( el => { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
}
else {
if( fragments.prev ) dom.controlsLeft.forEach( el => { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
if( fragments.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 ) {
stopEmbeddedContent( previousBackground, { unloadIframes: !shouldPreload( previousBackground ) } );
}
// Start content in the current background
if( currentBackground ) {
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';
}
}
/**
* Runs an auto-animation between the given slides.
*
* @param {HTMLElement} fromSlide
* @param {HTMLElement} toSlide
*/
function autoAnimate( fromSlide, toSlide ) {
// Clean up after prior animations
removeEphemeralAutoAnimateAttributes();
if( autoAnimateStyleSheet && autoAnimateStyleSheet.parentNode ) {
autoAnimateStyleSheet.parentNode.removeChild( autoAnimateStyleSheet );
autoAnimateStyleSheet = null;
}
// Ensure that both slides are auto-animate targets
if( fromSlide.hasAttribute( 'data-auto-animate' ) && toSlide.hasAttribute( 'data-auto-animate' ) ) {
// Create a new auto-animate sheet
autoAnimateStyleSheet = autoAnimateStyleSheet || document.createElement( 'style' );
autoAnimateStyleSheet.type = 'text/css';
document.head.appendChild( autoAnimateStyleSheet );
let animationOptions = getAutoAnimateOptions( toSlide );
// Set our starting state
fromSlide.dataset.autoAnimate = 'pending';
toSlide.dataset.autoAnimate = 'pending';
// Inject our auto-animate styles for this transition
let css = getAutoAnimatableElements( fromSlide, toSlide ).map( function( elements ) {
return getAutoAnimateCSS( elements.from, elements.to, elements.options || {}, animationOptions, autoAnimateCounter++ );
} );
// Animate unmatched elements, if enabled
if( toSlide.dataset.autoAnimateUnmatched !== 'false' && config.autoAnimateUnmatched === true ) {
getUnmatchedAutoAnimateElements( toSlide ).forEach( function( unmatchedElement ) {
unmatchedElement.dataset.autoAnimateTarget = 'unmatched';
} );
css.push( `[data-auto-animate="running"] [data-auto-animate-target="unmatched"] { transition: opacity ${animationOptions.duration*0.8}s ease ${animationOptions.duration*0.2}s; }` );
}
// Setting the whole chunk of CSS at once is the most
// efficient way to do this. Using sheet.insertRule
// is multiple factors slower.
autoAnimateStyleSheet.innerHTML = css.join( '' );
// Start the animation next cycle
requestAnimationFrame( () => {
if( autoAnimateStyleSheet ) {
// This forces our newly injected styles to be applied in Firefox
getComputedStyle( autoAnimateStyleSheet ).fontWeight;
toSlide.dataset.autoAnimate = 'running';
}
} );
dispatchEvent( 'autoanimate', { fromSlide: fromSlide, toSlide: toSlide, sheet: autoAnimateStyleSheet } );
}
}
/**
* Removes all attributes that we temporarily add to slide
* elements in order to carry out auto-animation.
*/
function removeEphemeralAutoAnimateAttributes() {
toArray( dom.wrapper.querySelectorAll( '[data-auto-animate-target]' ) ).forEach( element => {
delete element.dataset.autoAnimateTarget;
} );
}
/**
* Auto-animates the properties of an element from their original
* values to their new state.
*
* @param {HTMLElement} from
* @param {HTMLElement} to
* @param {Object} elementOptions Options for this element pair
* @param {Object} animationOptions Options set at the slide level
* @param {String} id Unique ID that we can use to identify this
* auto-animate element in the DOM
*/
function getAutoAnimateCSS( from, to, elementOptions, animationOptions, id ) {
// 'from' elements are given a data-auto-animate-target with no value,
// 'to' elements are are given a data-auto-animate-target with an ID
from.dataset.autoAnimateTarget = '';
to.dataset.autoAnimateTarget = id;
// Each element may override any of the auto-animate options
// like transition easing, duration and delay via data-attributes
let options = getAutoAnimateOptions( to, animationOptions );
// If we're using a custom element matcher the element options
// may contain additional transition overrides
if( typeof elementOptions.delay !== 'undefined' ) options.delay = elementOptions.delay;
if( typeof elementOptions.duration !== 'undefined' ) options.duration = elementOptions.duration;
if( typeof elementOptions.easing !== 'undefined' ) options.easing = elementOptions.easing;
let fromProps = getAutoAnimatableProperties( 'from', from, elementOptions ),
toProps = getAutoAnimatableProperties( 'to', to, elementOptions );
// If translation and/or scaling are enabled, css transform
// the 'to' element so that it matches the position and size
// of the 'from' element
if( elementOptions.translate !== false || elementOptions.scale !== false ) {
let presentationScale = Reveal.getScale();
let delta = {
x: ( fromProps.x - toProps.x ) / presentationScale,
y: ( fromProps.y - toProps.y ) / presentationScale,
scaleX: fromProps.width / toProps.width,
scaleY: fromProps.height / toProps.height
};
// Limit decimal points to avoid 0.0001px blur and stutter
delta.x = Math.round( delta.x * 1000 ) / 1000;
delta.y = Math.round( delta.y * 1000 ) / 1000;
delta.scaleX = Math.round( delta.scaleX * 1000 ) / 1000;
delta.scaleX = Math.round( delta.scaleX * 1000 ) / 1000;
let translate = elementOptions.translate !== false && ( delta.x !== 0 || delta.y !== 0 ),
scale = elementOptions.scale !== false && ( delta.scaleX !== 0 || delta.scaleY !== 0 );
// No need to transform if nothing's changed
if( translate || scale ) {
let transform = [];
if( translate ) transform.push( `translate(${delta.x}px, ${delta.y}px)` );
if( scale ) transform.push( `scale(${delta.scaleX}, ${delta.scaleY})` );
fromProps.styles['transform'] = transform.join( ' ' );
fromProps.styles['transform-origin'] = 'top left';
toProps.styles['transform'] = 'none';
}
}
// Delete all unchanged 'to' styles
for( let propertyName in toProps.styles ) {
const toValue = toProps.styles[propertyName];
const fromValue = fromProps.styles[propertyName];
if( toValue === fromValue ) {
delete toProps.styles[propertyName];
}
else {
// If these property values were set via a custom matcher providing
// an explicit 'from' and/or 'to' value, we always inject those values.
if( toValue.explicitValue === true ) {
toProps.styles[propertyName] = toValue.value;
}
if( fromValue.explicitValue === true ) {
fromProps.styles[propertyName] = fromValue.value;
}
}
}
let css = '';
let toStyleProperties = Object.keys( toProps.styles );
// Only create animate this element IF at least one style
// property has changed
if( toStyleProperties.length > 0 ) {
// Instantly move to the 'from' state
fromProps.styles['transition'] = 'none';
// Animate towards the 'to' state
toProps.styles['transition'] = `all ${options.duration}s ${options.easing} ${options.delay}s`;
toProps.styles['transition-property'] = toStyleProperties.join( ', ' );
toProps.styles['will-change'] = toStyleProperties.join( ', ' );
// Build up our custom CSS. We need to override inline styles
// so we need to make our styles vErY IMPORTANT!1!!
let fromCSS = Object.keys( fromProps.styles ).map( function( propertyName ) {
return propertyName + ': ' + fromProps.styles[propertyName] + ' !important;';
} ).join( '' );
let toCSS = Object.keys( toProps.styles ).map( function( propertyName ) {
return propertyName + ': ' + toProps.styles[propertyName] + ' !important;';
} ).join( '' );
css = '[data-auto-animate-target="'+ id +'"] {'+ fromCSS +'}' +
'[data-auto-animate="running"] [data-auto-animate-target="'+ id +'"] {'+ toCSS +'}';
}
return css;
}
/**
* Returns the auto-animate options for the given element.
*
* @param {HTMLElement} element Element to pick up options
* from, either a slide or an animation target
* @param {Object} [inheritedOptions] Optional set of existing
* options
*/
function getAutoAnimateOptions( element, inheritedOptions ) {
let options = {
easing: config.autoAnimateEasing,
duration: config.autoAnimateDuration,
delay: 0
};
options = extend( options, inheritedOptions );
// Inherit options from parent elements
if( element.closest && element.parentNode ) {
let autoAnimatedParent = element.parentNode.closest( '[data-auto-animate-target]' );
if( autoAnimatedParent ) {
options = getAutoAnimateOptions( autoAnimatedParent, options );
}
}
if( element.dataset.autoAnimateEasing ) {
options.easing = element.dataset.autoAnimateEasing;
}
if( element.dataset.autoAnimateDuration ) {
options.duration = parseFloat( element.dataset.autoAnimateDuration );
}
if( element.dataset.autoAnimateDelay ) {
options.delay = parseFloat( element.dataset.autoAnimateDelay );
}
return options;
}
/**
* Returns an object containing all of the properties
* that can be auto-animated for the given element and
* their current computed values.
*
* @param {String} direction 'from' or 'to'
*/
function getAutoAnimatableProperties( direction, element, elementOptions ) {
let properties = { styles: [] };
// Position and size
if( elementOptions.translate !== false || elementOptions.scale !== false ) {
let bounds;
// Custom auto-animate may optionally return a custom tailored
// measurement function
if( typeof elementOptions.measure === 'function' ) {
bounds = elementOptions.measure( element );
}
else {
bounds = element.getBoundingClientRect();
}
properties.x = bounds.x;
properties.y = bounds.y;
properties.width = bounds.width;
properties.height = bounds.height;
}
const computedStyles = getComputedStyle( element );
// CSS styles
( elementOptions.styles || config.autoAnimateStyles ).forEach( style => {
let value;
// `style` is either the property name directly, or an object
// definition of a style property
if( typeof style === 'string' ) style = { property: style };
if( typeof style.from !== 'undefined' && direction === 'from' ) {
value = { value: style.from, explicitValue: true };
}
else if( typeof style.to !== 'undefined' && direction === 'to' ) {
value = { value: style.to, explicitValue: true };
}
else {
value = computedStyles[style.property];
}
if( value !== '' ) {
properties.styles[style.property] = value;
}
} );
return properties;
}
/**
* Get a list of all element pairs that we can animate
* between the given slides.
*
* @param {HTMLElement} fromSlide
* @param {HTMLElement} toSlide
*
* @return {Array} Each value is an array where [0] is
* the element we're animating from and [1] is the
* element we're animating to
*/
function getAutoAnimatableElements( fromSlide, toSlide ) {
let matcher = typeof config.autoAnimateMatcher === 'function' ? config.autoAnimateMatcher : getAutoAnimatePairs;
let pairs = matcher( fromSlide, toSlide );
let reserved = [];
// Remove duplicate pairs
return pairs.filter( ( pair, index ) => {
if( reserved.indexOf( pair.to ) === -1 ) {
reserved.push( pair.to );
return true;
}
} );
}
/**
* Identifies matching elements between slides.
*
* You can specify a custom matcher function by using
* the `autoAnimateMatcher` config option.
*/
function getAutoAnimatePairs( fromSlide, toSlide ) {
let pairs = [];
const codeNodes = 'pre';
const textNodes = 'h1, h2, h3, h4, h5, h6, p, li';
const mediaNodes = 'img, video, iframe';
// Eplicit matches via data-id
findAutoAnimateMatches( pairs, fromSlide, toSlide, '[data-id]', node => {
return node.nodeName + ':::' + node.getAttribute( 'data-id' );
} );
// Text
findAutoAnimateMatches( pairs, fromSlide, toSlide, textNodes, node => {
return node.nodeName + ':::' + node.innerText;
} );
// Media
findAutoAnimateMatches( pairs, fromSlide, toSlide, mediaNodes, node => {
return node.nodeName + ':::' + ( node.getAttribute( 'src' ) || node.getAttribute( 'data-src' ) );
} );
// Code
findAutoAnimateMatches( pairs, fromSlide, toSlide, codeNodes, node => {
return node.nodeName + ':::' + node.innerText;
} );
pairs.forEach( pair => {
// Disable scale transformations on text nodes, we transiition
// each individual text property instead
if( pair.from.matches( textNodes ) ) {
pair.options = { scale: false };
}
// Animate individual lines of code
else if( pair.from.matches( codeNodes ) ) {
// Transition the code block's width and height instead of scaling
// to prevent its content from being squished
pair.options = { scale: false, styles: [ 'width', 'height' ] };
// Lines of code
findAutoAnimateMatches( pairs, pair.from, pair.to, '.hljs .hljs-ln-code', node => {
return node.textContent;
}, {
scale: false,
styles: [],
measure: getLocalBoundingBox
} );
// Line numbers
findAutoAnimateMatches( pairs, pair.from, pair.to, '.hljs .hljs-ln-line[data-line-number]', node => {
return node.getAttribute( 'data-line-number' );
}, {
scale: false,
styles: [ 'width' ],
measure: getLocalBoundingBox
} );
}
} );
return pairs;
}
/**
* Helper method which returns a bounding box based on
* the given elements offset coordinates.
*
* @param {HTMLElement} element
* @return {Object} x, y, width, height
*/
function getLocalBoundingBox( element ) {
const presentationScale = Reveal.getScale();
return {
x: Math.round( ( element.offsetLeft * presentationScale ) * 100 ) / 100,
y: Math.round( ( element.offsetTop * presentationScale ) * 100 ) / 100,
width: Math.round( ( element.offsetWidth * presentationScale ) * 100 ) / 100,
height: Math.round( ( element.offsetHeight * presentationScale ) * 100 ) / 100
};
}
/**
* Finds matching elements between two slides.
*
* @param {Array} pairs List of pairs to push matches to
* @param {HTMLElement} fromScope Scope within the from element exists
* @param {HTMLElement} toScope Scope within the to element exists
* @param {String} selector CSS selector of the element to match
* @param {Function} serializer A function that accepts an element and returns
* a stringified ID based on its contents
* @param {Object} animationOptions Optional config options for this pair
*/
function findAutoAnimateMatches( pairs, fromScope, toScope, selector, serializer, animationOptions ) {
let fromMatches = {};
let toMatches = {};
[].slice.call( fromScope.querySelectorAll( selector ) ).forEach( ( element, i ) => {
const key = serializer( element );
if( typeof key === 'string' && key.length ) {
fromMatches[key] = fromMatches[key] || [];
fromMatches[key].push( element );
}
} );
[].slice.call( toScope.querySelectorAll( selector ) ).forEach( ( element, i ) => {
const key = serializer( element );
toMatches[key] = toMatches[key] || [];
toMatches[key].push( element );
let fromElement;
// Retrieve the 'from' element
if( fromMatches[key] ) {
const pimaryIndex = toMatches[key].length - 1;
const secondaryIndex = fromMatches[key].length - 1;
// If there are multiple identical from elements, retrieve
// the one at the same index as our to-element.
if( fromMatches[key][ pimaryIndex ] ) {
fromElement = fromMatches[key][ pimaryIndex ];
fromMatches[key][ pimaryIndex ] = null;
}
// If there are no matching from-elements at the same index,
// use the last one.
else if( fromMatches[key][ secondaryIndex ] ) {
fromElement = fromMatches[key][ secondaryIndex ];
fromMatches[key][ secondaryIndex ] = null;
}
}
// If we've got a matching pair, push it to the list of pairs
if( fromElement ) {
pairs.push({
from: fromElement,
to: element,
options: animationOptions
});
}
} );
}
/**
* Returns a all elements within the given scope that should
* be considered unmatched in an auto-animate transition. If
* fading of unmatched elements is turned on, these elements
* will fade when going between auto-animate slides.
*
* Note that parents of auto-animate targets are NOT considerd
* unmatched since fading them would break the auto-animation.
*
* @param {HTMLElement} rootElement
* @return {Array}
*/
function getUnmatchedAutoAnimateElements( rootElement ) {
return [].slice.call( rootElement.children ).reduce( ( result, element ) => {
const containsAnimatedElements = element.querySelector( '[data-auto-animate-target]' );
// The element is unmatched if
// - It is not an auto-animate target
// - It does not contain any auto-animate targets
if( !element.hasAttribute( 'data-auto-animate-target' ) && !containsAnimatedElements ) {
result.push( element );
}
if( element.querySelector( '[data-auto-animate-target]' ) ) {
result = result.concat( getUnmatchedAutoAnimateElements( element ) );
}
return result;
}, [] );
}
/**
* Should the given element be preloaded?
* Decides based on local element attributes and global config.
*
* @param {HTMLElement} element
*/
function shouldPreload( element ) {
// Prefer an explicit global preload setting
let preload = config.preloadIframes;
// If no global setting is available, fall back on the element's
// own preload setting
if( typeof preload !== 'boolean' ) {
preload = element.hasAttribute( 'data-preload' );
}
return preload;
}
/**
* Called when the given slide is within the configured view
* distance. Shows the slide element and loads any content
* that is set to load lazily (data-src).
*
* @param {HTMLElement} slide Slide to show
*/
function loadSlide( slide, options = {} ) {
// Show the slide element
slide.style.display = config.display;
// Media elements with data-src attributes
toArray( slide.querySelectorAll( 'img[data-src], video[data-src], audio[data-src], iframe[data-src]' ) ).forEach( element => {
if( element.tagName !== 'IFRAME' || shouldPreload( element ) ) {
element.setAttribute( 'src', element.getAttribute( 'data-src' ) );
element.setAttribute( 'data-lazy-loaded', '' );
element.removeAttribute( 'data-src' );
}
} );
// Media elements with <source> children
toArray( slide.querySelectorAll( 'video, audio' ) ).forEach( media => {
var sources = 0;
toArray( media.querySelectorAll( 'source[data-src]' ) ).forEach( source => {
source.setAttribute( 'src', source.getAttribute( 'data-src' ) );
source.removeAttribute( 'data-src' );
source.setAttribute( 'data-lazy-loaded', '' );
sources += 1;
} );
// If we rewrote sources for this video/audio element, we need
// to manually tell it to load from its new origin
if( sources > 0 ) {
media.load();
}
} );
// Show the corresponding background element
let background = slide.slideBackgroundElement;
if( background ) {
background.style.display = 'block';
let backgroundContent = slide.slideBackgroundContentElement;
let backgroundIframe = slide.getAttribute( 'data-background-iframe' );
// If the background contains media, load it
if( background.hasAttribute( 'data-loaded' ) === false ) {
background.setAttribute( 'data-loaded', 'true' );
let backgroundImage = slide.getAttribute( 'data-background-image' ),
backgroundVideo = slide.getAttribute( 'data-background-video' ),
backgroundVideoLoop = slide.hasAttribute( 'data-background-video-loop' ),
backgroundVideoMuted = slide.hasAttribute( 'data-background-video-muted' );
// Images
if( backgroundImage ) {
backgroundContent.style.backgroundImage = 'url('+ encodeURI( backgroundImage ) +')';
}
// Videos
else if ( backgroundVideo && !isSpeakerNotes() ) {
let video = document.createElement( 'video' );
if( backgroundVideoLoop ) {
video.setAttribute( 'loop', '' );
}
if( backgroundVideoMuted ) {
video.muted = true;
}
// Inline video playback works (at least in Mobile Safari) as
// long as the video is muted and the `playsinline` attribute is
// present
if( isMobileDevice ) {
video.muted = true;
video.autoplay = true;
video.setAttribute( 'playsinline', '' );
}
// Support comma separated lists of video sources
backgroundVideo.split( ',' ).forEach( source => {
video.innerHTML += '<source src="'+ source +'">';
} );
backgroundContent.appendChild( video );
}
// Iframes
else if( backgroundIframe && options.excludeIframes !== true ) {
let iframe = document.createElement( 'iframe' );
iframe.setAttribute( 'allowfullscreen', '' );
iframe.setAttribute( 'mozallowfullscreen', '' );
iframe.setAttribute( 'webkitallowfullscreen', '' );
iframe.setAttribute( 'allow', 'autoplay' );
iframe.setAttribute( 'data-src', backgroundIframe );
iframe.style.width = '100%';
iframe.style.height = '100%';
iframe.style.maxHeight = '100%';
iframe.style.maxWidth = '100%';
backgroundContent.appendChild( iframe );
}
}
// Start loading preloadable iframes
let backgroundIframeElement = backgroundContent.querySelector( 'iframe[data-src]' );
if( backgroundIframeElement ) {
// Check if this iframe is eligible to be preloaded
if( shouldPreload( background ) && !/autoplay=(1|true|yes)/gi.test( backgroundIframe ) ) {
if( backgroundIframeElement.getAttribute( 'src' ) !== backgroundIframe ) {
backgroundIframeElement.setAttribute( 'src', backgroundIframe );
}
}
}
}
}
/**
* Unloads and hides the given slide. This is called when the
* slide is moved outside of the configured view distance.
*
* @param {HTMLElement} slide
*/
function unloadSlide( slide ) {
// Hide the slide element
slide.style.display = 'none';
// Hide the corresponding background element
let background = getSlideBackground( slide );
if( background ) {
background.style.display = 'none';
// Unload any background iframes
toArray( background.querySelectorAll( 'iframe[src]' ) ).forEach( element => {
element.removeAttribute( 'src' );
} );
}
// Reset lazy-loaded media elements with src attributes
toArray( slide.querySelectorAll( 'video[data-lazy-loaded][src], audio[data-lazy-loaded][src], iframe[data-lazy-loaded][src]' ) ).forEach( element => {
element.setAttribute( 'data-src', element.getAttribute( 'src' ) );
element.removeAttribute( 'src' );
} );
// Reset lazy-loaded media elements with <source> children
toArray( slide.querySelectorAll( 'video[data-lazy-loaded] source[src], audio source[src]' ) ).forEach( source => {
source.setAttribute( 'data-src', source.getAttribute( 'src' ) );
source.removeAttribute( 'src' );
} );
}
/**
* Determine what available routes there are for navigation.
*
* @return {{left: boolean, right: boolean, up: boolean, down: boolean}}
*/
function availableRoutes() {
var horizontalSlides = dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ),
verticalSlides = dom.wrapper.querySelectorAll( VERTICAL_SLIDES_SELECTOR );
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;
}
}
// Reverse horizontal controls for rtl
if( config.rtl ) {
let left = routes.left;
routes.left = routes.right;
routes.right = left;
}
return routes;
}
/**
* Returns an object describing the available fragment
* directions.
*
* @return {{prev: boolean, next: boolean}}
*/
function availableFragments() {
if( currentSlide && config.fragments ) {
let fragments = currentSlide.querySelectorAll( '.fragment' );
let hiddenFragments = currentSlide.querySelectorAll( '.fragment:not(.visible)' );
return {
prev: fragments.length - hiddenFragments.length > 0,
next: !!hiddenFragments.length
};
}
else {
return { prev: false, next: false };
}
}
/**
* Enforces origin-specific format rules for embedded media.
*/
function formatEmbeddedContent() {
let _appendParamToIframeSource = ( sourceAttribute, sourceURL, param ) => {
toArray( dom.slides.querySelectorAll( 'iframe['+ sourceAttribute +'*="'+ sourceURL +'"]' ) ).forEach( el => {
var src = el.getAttribute( sourceAttribute );
if( src && src.indexOf( param ) === -1 ) {
el.setAttribute( sourceAttribute, src + ( !/\?/.test( src ) ? '?' : '&' ) + param );
}
});
};
// YouTube frames must include "?enablejsapi=1"
_appendParamToIframeSource( 'src', 'youtube.com/embed/', 'enablejsapi=1' );
_appendParamToIframeSource( 'data-src', 'youtube.com/embed/', 'enablejsapi=1' );
// Vimeo frames must include "?api=1"
_appendParamToIframeSource( 'src', 'player.vimeo.com/', 'api=1' );
_appendParamToIframeSource( 'data-src', 'player.vimeo.com/', 'api=1' );
}
/**
* Start playback of any embedded content inside of
* the given element.
*
* @param {HTMLElement} element
*/
function startEmbeddedContent( element ) {
if( element && !isSpeakerNotes() ) {
// Restart GIFs
toArray( element.querySelectorAll( 'img[src$=".gif"]' ) ).forEach( el => {
// Setting the same unchanged source like this was confirmed
// to work in Chrome, FF & Safari
el.setAttribute( 'src', el.getAttribute( 'src' ) );
} );
// HTML5 media elements
toArray( element.querySelectorAll( 'video, audio' ) ).forEach( el => {
if( closestParent( el, '.fragment' ) && !closestParent( el, '.fragment.visible' ) ) {
return;
}
// Prefer an explicit global autoplay setting
let autoplay = config.autoPlayMedia;
// If no global setting is available, fall back on the element's
// own autoplay setting
if( typeof autoplay !== 'boolean' ) {
autoplay = el.hasAttribute( 'data-autoplay' ) || !!closestParent( el, '.slide-background' );
}
if( autoplay && typeof el.play === 'function' ) {
// If the media is ready, start playback
if( el.readyState > 1 ) {
startEmbeddedMedia( { target: el } );
}
// Mobile devices never fire a loaded event so instead
// of waiting, we initiate playback
else if( isMobileDevice ) {
let promise = el.play();
// If autoplay does not work, ensure that the controls are visible so
// that the viewer can start the media on their own
if( promise && typeof promise.catch === 'function' && el.controls === false ) {
promise.catch( function() {
el.controls = true;
// Once the video does start playing, hide the controls again
el.addEventListener( 'play', () => {
el.controls = false;
} );
} );
}
}
// If the media isn't loaded, wait before playing
else {
el.removeEventListener( 'loadeddata', startEmbeddedMedia ); // remove first to avoid dupes
el.addEventListener( 'loadeddata', startEmbeddedMedia );
}
}
} );
// Normal iframes
toArray( element.querySelectorAll( 'iframe[src]' ) ).forEach( el => {
if( closestParent( el, '.fragment' ) && !closestParent( el, '.fragment.visible' ) ) {
return;
}
startEmbeddedIframe( { target: el } );
} );
// Lazy loading iframes
toArray( element.querySelectorAll( 'iframe[data-src]' ) ).forEach( el => {
if( closestParent( el, '.fragment' ) && !closestParent( el, '.fragment.visible' ) ) {
return;
}
if( el.getAttribute( 'src' ) !== el.getAttribute( 'data-src' ) ) {
el.removeEventListener( 'load', startEmbeddedIframe ); // remove first to avoid dupes
el.addEventListener( 'load', startEmbeddedIframe );
el.setAttribute( 'src', el.getAttribute( 'data-src' ) );
}
} );
}
}
/**
* Starts playing an embedded video/audio element after
* it has finished loading.
*
* @param {object} event
*/
function startEmbeddedMedia( event ) {
let isAttachedToDOM = !!closestParent( event.target, 'html' ),
isVisible = !!closestParent( event.target, '.present' );
if( isAttachedToDOM && isVisible ) {
event.target.currentTime = 0;
event.target.play();
}
event.target.removeEventListener( 'loadeddata', startEmbeddedMedia );
}
/**
* "Starts" the content of an embedded iframe using the
* postMessage API.
*
* @param {object} event
*/
function startEmbeddedIframe( event ) {
let iframe = event.target;
if( iframe && iframe.contentWindow ) {
let isAttachedToDOM = !!closestParent( event.target, 'html' ),
isVisible = !!closestParent( event.target, '.present' );
if( isAttachedToDOM && isVisible ) {
// Prefer an explicit global autoplay setting
let autoplay = config.autoPlayMedia;
// If no global setting is available, fall back on the element's
// own autoplay setting
if( typeof autoplay !== 'boolean' ) {
autoplay = iframe.hasAttribute( 'data-autoplay' ) || !!closestParent( iframe, '.slide-background' );
}
// YouTube postMessage API
if( /youtube\.com\/embed\//.test( iframe.getAttribute( 'src' ) ) && autoplay ) {
iframe.contentWindow.postMessage( '{"event":"command","func":"playVideo","args":""}', '*' );
}
// Vimeo postMessage API
else if( /player\.vimeo\.com\//.test( iframe.getAttribute( 'src' ) ) && autoplay ) {
iframe.contentWindow.postMessage( '{"method":"play"}', '*' );
}
// Generic postMessage API
else {
iframe.contentWindow.postMessage( 'slide:start', '*' );
}
}
}
}
/**
* Stop playback of any embedded content inside of
* the targeted slide.
*
* @param {HTMLElement} element
*/
function stopEmbeddedContent( element, options = {} ) {
options = extend( {
// Defaults
unloadIframes: true
}, options );
if( element && element.parentNode ) {
// HTML5 media elements
toArray( element.querySelectorAll( 'video, audio' ) ).forEach( el => {
if( !el.hasAttribute( 'data-ignore' ) && typeof el.pause === 'function' ) {
el.setAttribute('data-paused-by-reveal', '');
el.pause();
}
} );
// Generic postMessage API for non-lazy loaded iframes
toArray( element.querySelectorAll( 'iframe' ) ).forEach( el => {
if( el.contentWindow ) el.contentWindow.postMessage( 'slide:stop', '*' );
el.removeEventListener( 'load', startEmbeddedIframe );
});
// YouTube postMessage API
toArray( element.querySelectorAll( 'iframe[src*="youtube.com/embed/"]' ) ).forEach( el => {
if( !el.hasAttribute( 'data-ignore' ) && el.contentWindow && typeof el.contentWindow.postMessage === 'function' ) {
el.contentWindow.postMessage( '{"event":"command","func":"pauseVideo","args":""}', '*' );
}
});
// Vimeo postMessage API
toArray( element.querySelectorAll( 'iframe[src*="player.vimeo.com/"]' ) ).forEach( el => {
if( !el.hasAttribute( 'data-ignore' ) && el.contentWindow && typeof el.contentWindow.postMessage === 'function' ) {
el.contentWindow.postMessage( '{"method":"pause"}', '*' );
}
});
if( options.unloadIframes === true ) {
// Unload lazy-loaded iframes
toArray( element.querySelectorAll( 'iframe[data-src]' ) ).forEach( el => {
// Only removing the src doesn't actually unload the frame
// in all browsers (Firefox) so we set it to blank first
el.setAttribute( 'src', 'about:blank' );
el.removeAttribute( 'src' );
} );
}
}
}
/**
* Returns the number of past slides. This can be used as a global
* flattened index for slides.
*
* @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 );
}
/**
* Reads the current URL (hash) and navigates accordingly.
*/
function readURL() {
let hash = window.location.hash;
// Attempt to parse the hash as either an index or name
let bits = hash.slice( 2 ).split( '/' ),
name = hash.replace( /#|\//gi, '' );
// If the first bit is not fully numeric and there is a name we
// can assume that this is a named link
if( !/^[0-9]*$/.test( bits[0] ) && name.length ) {
let element;
// Ensure the named link is a valid HTML ID attribute
try {
element = document.getElementById( decodeURIComponent( name ) );
}
catch ( error ) { }
// Ensure that we're not already on a slide with the same name
let isSameNameAsCurrentSlide = currentSlide ? currentSlide.getAttribute( 'id' ) === name : false;
if( element ) {
// If the slide exists and is not the current slide...
if ( !isSameNameAsCurrentSlide ) {
// ...find the position of the named slide and navigate to it
let indices = Reveal.getIndices(element);
slide(indices.h, indices.v);
}
}
// If the slide doesn't exist, navigate to the current slide
else {
slide( indexh || 0, indexv || 0 );
}
}
else {
let hashIndexBase = config.hashOneBasedIndex ? 1 : 0;
// Read the index components of the hash
let h = ( parseInt( bits[0], 10 ) - hashIndexBase ) || 0,
v = ( parseInt( bits[1], 10 ) - hashIndexBase ) || 0,
f;
if( config.fragmentInURL ) {
f = parseInt( bits[2], 10 );
if( isNaN( f ) ) {
f = undefined;
}
}
if( h !== indexh || v !== indexv || f !== undefined ) {
slide( h, v, f );
}
}
}
/**
* Updates the page URL (hash) to reflect the current
* state.
*
* @param {number} delay The time in ms to wait before
* writing the hash
*/
function writeURL( delay ) {
// Make sure there's never more than one timeout running
clearTimeout( writeURLTimeout );
// If a delay is specified, timeout this call
if( typeof delay === 'number' ) {
writeURLTimeout = setTimeout( writeURL, delay );
}
else if( currentSlide ) {
// If we're configured to push to history OR the history
// API is not avaialble.
if( config.history || !window.history ) {
window.location.hash = locationHash();
}
// If we're configured to reflect the current slide in the
// URL without pushing to history.
else if( config.hash ) {
window.history.replaceState( null, null, '#' + locationHash() );
}
// If history and hash are both disabled, a hash may still
// be added to the URL by clicking on a href with a hash
// target. Counter this by always removing the hash.
else {
window.history.replaceState( null, null, window.location.pathname + window.location.search );
}
}
}
/**
* 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( function( 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: isOverview()
};
}
/**
* 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 ) );
var pausedFlag = deserialize( state.paused ),
overviewFlag = deserialize( state.overview );
if( typeof pausedFlag === 'boolean' && pausedFlag !== isPaused() ) {
togglePause( pausedFlag );
}
if( typeof overviewFlag === 'boolean' && overviewFlag !== isOverview() ) {
toggleOverview( overviewFlag );
}
}
}
/**
* Return a sorted fragments list, ordered by an increasing
* "data-fragment-index" attribute.
*
* Fragments will be revealed in the order that they are returned by
* this function, so you can use the index attributes to control the
* order of fragment appearance.
*
* To maintain a sensible default fragment order, fragments are presumed
* to be passed in document order. This function adds a "fragment-index"
* attribute to each node if such an attribute is not already present,
* and sets that attribute to an integer value which is the position of
* the fragment within the fragments list.
*
* @param {object[]|*} fragments
* @param {boolean} grouped If true the returned array will contain
* nested arrays for all fragments with the same index
* @return {object[]} sorted Sorted array of fragments
*/
function sortFragments( fragments, grouped = false ) {
fragments = toArray( fragments );
let ordered = [],
unordered = [],
sorted = [];
// Group ordered and unordered elements
fragments.forEach( fragment => {
if( fragment.hasAttribute( 'data-fragment-index' ) ) {
let index = parseInt( fragment.getAttribute( 'data-fragment-index' ), 10 );
if( !ordered[index] ) {
ordered[index] = [];
}
ordered[index].push( fragment );
}
else {
unordered.push( [ fragment ] );
}
} );
// Append fragments without explicit indices in their
// DOM order
ordered = ordered.concat( unordered );
// Manually count the index up per group to ensure there
// are no gaps
let index = 0;
// Push all fragments in their sorted order to an array,
// this flattens the groups
ordered.forEach( group => {
group.forEach( fragment => {
sorted.push( fragment );
fragment.setAttribute( 'data-fragment-index', index );
} );
index ++;
} );
return grouped === true ? ordered : sorted;
}
/**
* Refreshes the fragments on the current slide so that they
* have the appropriate classes (.visible + .current-fragment).
*
* @param {number} [index] The index of the current fragment
* @param {array} [fragments] Array containing all fragments
* in the current slide
*
* @return {{shown: array, hidden: array}}
*/
function updateFragments( index, fragments ) {
let changedFragments = {
shown: [],
hidden: []
};
if( currentSlide && config.fragments ) {
fragments = fragments || sortFragments( currentSlide.querySelectorAll( '.fragment' ) );
if( fragments.length ) {
let maxIndex = 0;
if( typeof index !== 'number' ) {
let currentFragment = sortFragments( currentSlide.querySelectorAll( '.fragment.visible' ) ).pop();
if( currentFragment ) {
index = parseInt( currentFragment.getAttribute( 'data-fragment-index' ) || 0, 10 );
}
}
toArray( fragments ).forEach( ( el, i ) => {
if( el.hasAttribute( 'data-fragment-index' ) ) {
i = parseInt( el.getAttribute( 'data-fragment-index' ), 10 );
}
maxIndex = Math.max( maxIndex, i );
// Visible fragments
if( i <= index ) {
if( !el.classList.contains( 'visible' ) ) changedFragments.shown.push( el );
el.classList.add( 'visible' );
el.classList.remove( 'current-fragment' );
// Announce the fragments one by one to the Screen Reader
dom.statusDiv.textContent = getStatusText( el );
if( i === index ) {
el.classList.add( 'current-fragment' );
startEmbeddedContent( el );
}
}
// Hidden fragments
else {
if( el.classList.contains( 'visible' ) ) changedFragments.hidden.push( el );
el.classList.remove( 'visible' );
el.classList.remove( 'current-fragment' );
}
} );
// Write the current fragment index to the slide <section>.
// This can be used by end users to apply styles based on
// the current fragment index.
index = typeof index === 'number' ? index : -1;
index = Math.max( Math.min( index, maxIndex ), -1 );
currentSlide.setAttribute( 'data-fragment', index );
}
}
return changedFragments;
}
/**
* Navigate to the specified slide fragment.
*
* @param {?number} index The index of the fragment that
* should be shown, -1 means all are invisible
* @param {number} offset Integer offset to apply to the
* fragment index
*
* @return {boolean} true if a change was made in any
* fragments visibility as part of this call
*/
function navigateFragment( index, offset = 0 ) {
if( currentSlide && config.fragments ) {
let fragments = sortFragments( currentSlide.querySelectorAll( '.fragment' ) );
if( fragments.length ) {
// If no index is specified, find the current
if( typeof index !== 'number' ) {
let lastVisibleFragment = sortFragments( currentSlide.querySelectorAll( '.fragment.visible' ) ).pop();
if( lastVisibleFragment ) {
index = parseInt( lastVisibleFragment.getAttribute( 'data-fragment-index' ) || 0, 10 );
}
else {
index = -1;
}
}
// Apply the offset if there is one
index += offset;
let changedFragments = updateFragments( index, fragments );
if( changedFragments.hidden.length ) {
dispatchEvent( 'fragmenthidden', { fragment: changedFragments.hidden[0], fragments: changedFragments.hidden } );
}
if( changedFragments.shown.length ) {
dispatchEvent( 'fragmentshown', { fragment: changedFragments.shown[0], fragments: changedFragments.shown } );
}
updateControls();
updateProgress();
if( config.fragmentInURL ) {
writeURL();
}
return !!( changedFragments.shown.length || changedFragments.hidden.length );
}
}
return false;
}
/**
* Navigate to the next slide fragment.
*
* @return {boolean} true if there was a next fragment,
* false otherwise
*/
function nextFragment() {
return navigateFragment( null, 1 );
}
/**
* Navigate to the previous slide fragment.
*
* @return {boolean} true if there was a previous fragment,
* false otherwise
*/
function prevFragment() {
return navigateFragment( null, -1 );
}
/**
* 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() && !isOverview() && ( !Reveal.isLastSlide() || availableFragments().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( ( isOverview() || nextFragment() === false ) && availableRoutes().left ) {
slide( indexh + 1, config.navigationMode === 'grid' ? indexv : undefined );
}
}
// Normal navigation
else if( ( isOverview() || prevFragment() === false ) && availableRoutes().left ) {
slide( indexh - 1, config.navigationMode === 'grid' ? indexv : undefined );
}
}
function navigateRight() {
hasNavigatedHorizontally = true;
// Reverse for RTL
if( config.rtl ) {
if( ( isOverview() || prevFragment() === false ) && availableRoutes().right ) {
slide( indexh - 1, config.navigationMode === 'grid' ? indexv : undefined );
}
}
// Normal navigation
else if( ( isOverview() || nextFragment() === false ) && availableRoutes().right ) {
slide( indexh + 1, config.navigationMode === 'grid' ? indexv : undefined );
}
}
function navigateUp() {
// Prioritize hiding fragments
if( ( isOverview() || prevFragment() === false ) && availableRoutes().up ) {
slide( indexh, indexv - 1 );
}
}
function navigateDown() {
hasNavigatedVertically = true;
// Prioritize revealing fragments
if( ( isOverview() || nextFragment() === 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( prevFragment() === 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( nextFragment() === 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 && Reveal.isLastVerticalSlide( currentSlide ) ) {
routes.down = false;
}
if( routes.down ) {
navigateDown();
}
else if( config.rtl ) {
navigateLeft();
}
else {
navigateRight();
}
}
}
/**
* Checks if the target element prevents the triggering of
* swipe navigation.
*/
function isSwipePrevented( target ) {
while( target && typeof target.hasAttribute === 'function' ) {
if( target.hasAttribute( 'data-prevent-swipe' ) ) return true;
target = target.parentNode;
}
return false;
}
// --------------------------------------------------------------------//
// ----------------------------- 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 );
}
/**
* Handler for the document level 'keypress' event.
*
* @param {object} event
*/
function onDocumentKeyPress( event ) {
// Check if the pressed key is question mark
if( event.shiftKey && event.charCode === 63 ) {
toggleHelp();
}
}
/**
* Handler for the document level 'keydown' event.
*
* @param {object} event
*/
function onDocumentKeyDown( event ) {
// If there's a condition specified and it returns false,
// ignore this event
if( typeof config.keyboardCondition === 'function' && config.keyboardCondition(event) === false ) {
return true;
}
// Shorthand
let keyCode = event.keyCode;
// Remember if auto-sliding was paused so we can toggle it
let autoSlideWasPaused = autoSlidePaused;
onUserInput( event );
// Is there a focused element that could be using the keyboard?
let activeElementIsCE = document.activeElement && document.activeElement.contentEditable !== 'inherit';
let activeElementIsInput = document.activeElement && document.activeElement.tagName && /input|textarea/i.test( document.activeElement.tagName );
let activeElementIsNotes = document.activeElement && document.activeElement.className && /speaker-notes/i.test( document.activeElement.className);
// Whitelist specific modified + keycode combinations
let prevSlideShortcut = event.shiftKey && event.keyCode === 32;
let firstSlideShortcut = event.shiftKey && keyCode === 37;
let lastSlideShortcut = event.shiftKey && keyCode === 39;
// Prevent all other events when a modifier is pressed
let unusedModifier = !prevSlideShortcut && !firstSlideShortcut && !lastSlideShortcut &&
( event.shiftKey || event.altKey || event.ctrlKey || event.metaKey );
// Disregard the event if there's a focused element or a
// keyboard modifier key is present
if( activeElementIsCE || activeElementIsInput || activeElementIsNotes || unusedModifier ) return;
// While paused only allow resume keyboard events; 'b', 'v', '.'
let resumeKeyCodes = [66,86,190,191];
let key;
// Custom key bindings for togglePause should be able to resume
if( typeof config.keyboard === 'object' ) {
for( key in config.keyboard ) {
if( config.keyboard[key] === 'togglePause' ) {
resumeKeyCodes.push( parseInt( key, 10 ) );
}
}
}
if( isPaused() && resumeKeyCodes.indexOf( keyCode ) === -1 ) {
return false;
}
// Use linear navigation if we're configured to OR if
// the presentation is one-dimensional
let useLinearMode = config.navigationMode === 'linear' || !hasHorizontalSlides() || !hasVerticalSlides();
let triggered = false;
// 1. User defined key bindings
if( typeof config.keyboard === 'object' ) {
for( key in config.keyboard ) {
// Check if this binding matches the pressed key
if( parseInt( key, 10 ) === keyCode ) {
var value = config.keyboard[ key ];
// Callback function
if( typeof value === 'function' ) {
value.apply( null, [ event ] );
}
// String shortcuts to reveal.js API
else if( typeof value === 'string' && typeof Reveal[ value ] === 'function' ) {
Reveal[ value ].call();
}
triggered = true;
}
}
}
// 2. Registered custom key bindings
if( triggered === false ) {
for( key in registeredKeyBindings ) {
// Check if this binding matches the pressed key
if( parseInt( key, 10 ) === keyCode ) {
let action = registeredKeyBindings[ key ].callback;
// Callback function
if( typeof action === 'function' ) {
action.apply( null, [ event ] );
}
// String shortcuts to reveal.js API
else if( typeof action === 'string' && typeof Reveal[ action ] === 'function' ) {
Reveal[ action ].call();
}
triggered = true;
}
}
}
// 3. System defined key bindings
if( triggered === false ) {
// Assume true and try to prove false
triggered = true;
// P, PAGE UP
if( keyCode === 80 || keyCode === 33 ) {
navigatePrev();
}
// N, PAGE DOWN
else if( keyCode === 78 || keyCode === 34 ) {
navigateNext();
}
// H, LEFT
else if( keyCode === 72 || keyCode === 37 ) {
if( firstSlideShortcut ) {
slide( 0 );
}
else if( !isOverview() && useLinearMode ) {
navigatePrev();
}
else {
navigateLeft();
}
}
// L, RIGHT
else if( keyCode === 76 || keyCode === 39 ) {
if( lastSlideShortcut ) {
slide( Number.MAX_VALUE );
}
else if( !isOverview() && useLinearMode ) {
navigateNext();
}
else {
navigateRight();
}
}
// K, UP
else if( keyCode === 75 || keyCode === 38 ) {
if( !isOverview() && useLinearMode ) {
navigatePrev();
}
else {
navigateUp();
}
}
// J, DOWN
else if( keyCode === 74 || keyCode === 40 ) {
if( !isOverview() && useLinearMode ) {
navigateNext();
}
else {
navigateDown();
}
}
// HOME
else if( keyCode === 36 ) {
slide( 0 );
}
// END
else if( keyCode === 35 ) {
slide( Number.MAX_VALUE );
}
// SPACE
else if( keyCode === 32 ) {
if( isOverview() ) {
deactivateOverview();
}
if( event.shiftKey ) {
navigatePrev();
}
else {
navigateNext();
}
}
// TWO-SPOT, SEMICOLON, B, V, PERIOD, LOGITECH PRESENTER TOOLS "BLACK SCREEN" BUTTON
else if( keyCode === 58 || keyCode === 59 || keyCode === 66 || keyCode === 86 || keyCode === 190 || keyCode === 191 ) {
togglePause();
}
// F
else if( keyCode === 70 ) {
enterFullscreen();
}
// A
else if( keyCode === 65 ) {
if ( config.autoSlideStoppable ) {
toggleAutoSlide( autoSlideWasPaused );
}
}
else {
triggered = false;
}
}
// If the input resulted in a triggered action we should prevent
// the browsers default behavior
if( triggered ) {
event.preventDefault && event.preventDefault();
}
// ESC or O key
else if( keyCode === 27 || keyCode === 79 ) {
if( dom.overlay ) {
closeOverlay();
}
else {
toggleOverview();
}
event.preventDefault && event.preventDefault();
}
// If auto-sliding is enabled we need to cue up
// another timeout
cueAutoSlide();
}
/**
* Handler for the 'touchstart' event, enables support for
* swipe and pinch gestures.
*
* @param {object} event
*/
function onTouchStart( event ) {
if( isSwipePrevented( event.target ) ) return true;
touch.startX = event.touches[0].clientX;
touch.startY = event.touches[0].clientY;
touch.startCount = event.touches.length;
}
/**
* Handler for the 'touchmove' event.
*
* @param {object} event
*/
function onTouchMove( event ) {
if( isSwipePrevented( event.target ) ) return true;
// Each touch should only trigger one action
if( !touch.captured ) {
onUserInput( event );
let currentX = event.touches[0].clientX;
let currentY = event.touches[0].clientY;
// There was only one touch point, look for a swipe
if( event.touches.length === 1 && touch.startCount !== 2 ) {
let deltaX = currentX - touch.startX,
deltaY = currentY - touch.startY;
if( deltaX > touch.threshold && Math.abs( deltaX ) > Math.abs( deltaY ) ) {
touch.captured = true;
if( config.navigationMode === 'linear' ) {
if( config.rtl ) {
navigateNext();
}
else {
navigatePrev();
}
}
else {
navigateLeft();
}
}
else if( deltaX < -touch.threshold && Math.abs( deltaX ) > Math.abs( deltaY ) ) {
touch.captured = true;
if( config.navigationMode === 'linear' ) {
if( config.rtl ) {
navigatePrev();
}
else {
navigateNext();
}
}
else {
navigateRight();
}
}
else if( deltaY > touch.threshold ) {
touch.captured = true;
if( config.navigationMode === 'linear' ) {
navigatePrev();
}
else {
navigateUp();
}
}
else if( deltaY < -touch.threshold ) {
touch.captured = true;
if( config.navigationMode === 'linear' ) {
navigateNext();
}
else {
navigateDown();
}
}
// If we're embedded, only block touch events if they have
// triggered an action
if( config.embedded ) {
if( touch.captured || isVerticalSlide( currentSlide ) ) {
event.preventDefault();
}
}
// Not embedded? Block them all to avoid needless tossing
// around of the viewport in iOS
else {
event.preventDefault();
}
}
}
// There's a bug with swiping on some Android devices unless
// the default action is always prevented
else if( UA.match( /android/gi ) ) {
event.preventDefault();
}
}
/**
* Handler for the 'touchend' event.
*
* @param {object} event
*/
function onTouchEnd( event ) {
touch.captured = false;
}
/**
* Convert pointer down to touch start.
*
* @param {object} event
*/
function onPointerDown( event ) {
if( event.pointerType === event.MSPOINTER_TYPE_TOUCH || event.pointerType === "touch" ) {
event.touches = [{ clientX: event.clientX, clientY: event.clientY }];
onTouchStart( event );
}
}
/**
* Convert pointer move to touch move.
*
* @param {object} event
*/
function onPointerMove( event ) {
if( event.pointerType === event.MSPOINTER_TYPE_TOUCH || event.pointerType === "touch" ) {
event.touches = [{ clientX: event.clientX, clientY: event.clientY }];
onTouchMove( event );
}
}
/**
* Convert pointer up to touch end.
*
* @param {object} event
*/
function onPointerUp( event ) {
if( event.pointerType === event.MSPOINTER_TYPE_TOUCH || event.pointerType === "touch" ) {
event.touches = [{ clientX: event.clientX, clientY: event.clientY }];
onTouchEnd( event );
}
}
/**
* 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 ) {
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();
}
}
/**
* Invoked when a slide is and we're in the overview.
*
* @param {object} event
*/
function onOverviewSlideClicked( event ) {
// TODO There's a bug here where the event listeners are not
// removed after deactivating the overview.
if( eventsAreBound && isOverview() ) {
event.preventDefault();
let element = event.target;
while( element && !element.nodeName.match( /section/gi ) ) {
element = element.parentNode;
}
if( element && !element.classList.contains( 'disabled' ) ) {
deactivateOverview();
if( element.nodeName.match( /section/gi ) ) {
var h = parseInt( element.getAttribute( 'data-index-h' ), 10 ),
v = parseInt( element.getAttribute( 'data-index-v' ), 10 );
slide( h, v );
}
}
}
}
/**
* 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( Reveal.isLastSlide() && config.loop === false ) {
slide( 0, 0 );
resumeAutoSlide();
}
// Resume
else if( autoSlidePaused ) {
resumeAutoSlide();
}
// Pause
else {
pauseAutoSlide();
}
}
// --------------------------------------------------------------------//
// ------------------------------- API --------------------------------//
// --------------------------------------------------------------------//
Reveal = {
VERSION: 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,
prevFragment,
nextFragment,
// 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,
// Toggles a help overlay with keyboard shortcuts
toggleHelp,
// Toggles the overview mode on/off
toggleOverview,
// Toggles the "black screen" mode on/off
togglePause,
// Toggles the auto slide mode on/off
toggleAutoSlide,
// State checks
isOverview,
isPaused,
isAutoSliding,
isSpeakerNotes,
// Slide preloading
loadSlide,
unloadSlide,
// Adds or removes all internal event listeners (such as keyboard)
addEventListeners,
removeEventListeners,
// 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,
removeKeyBinding,
// API for registering and retrieving plugins
registerPlugin,
hasPlugin,
getPlugin,
getComputedSlideSize,
// Returns the previous slide element, may be null
getPreviousSlide: () => {
return previousSlide;
},
// Returns the current slide element
getCurrentSlide: () => {
return currentSlide;
},
// Returns the current scale of the presentation content
getScale: () => {
return scale;
},
// Returns the current configuration object
getConfig: () => {
return config;
},
// Helper method, retrieves query string as a key/value hash
getQueryHash: () => {
let query = {};
location.search.replace( /[A-Z0-9]+?=([\w\.%-]*)/gi, a => {
query[ a.split( '=' ).shift() ] = a.split( '=' ).pop();
} );
// Basic deserialization
for( let i in query ) {
let value = query[ i ];
query[ i ] = deserialize( unescape( value ) );
}
return query;
},
// Returns the top-level DOM element
getRevealElement: () => {
return dom.wrapper || document.querySelector( '.reveal' );
},
// Returns a hash with all registered plugins
getPlugins: () => {
return plugins;
},
// Returns true if we're currently on the first slide
isFirstSlide: () => {
return indexh === 0 && indexv === 0;
},
// Returns true if we're currently on the last slide
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;
},
// Returns true if we're on the last slide in the current
// vertical stack
isLastVerticalSlide: () => {
if( currentSlide && isVerticalSlide( currentSlide ) ) {
// Does this slide have a next sibling?
if( currentSlide.nextElementSibling ) return false;
return true;
}
return false;
},
// Checks if reveal.js has been loaded and is ready for use
isReady: () => {
return loaded;
},
// Forward event binding to the reveal DOM element
addEventListener: ( type, listener, useCapture ) => {
if( 'addEventListener' in window ) {
Reveal.getRevealElement().addEventListener( type, listener, useCapture );
}
},
removeEventListener: ( type, listener, useCapture ) => {
if( 'addEventListener' in window ) {
Reveal.getRevealElement().removeEventListener( type, listener, useCapture );
}
},
// Programmatically triggers a keyboard event
triggerKey: keyCode => {
onDocumentKeyDown( { keyCode } );
},
// Registers a new shortcut to include in the help overlay
registerKeyboardShortcut: ( key, value ) => {
keyboardShortcuts[key] = value;
}
};
return Reveal;
};