From d283f7e661e14d6ae1881fe803e5b4f1ed0689ff Mon Sep 17 00:00:00 2001 From: David Thompson Date: Mon, 24 Jun 2024 13:49:08 -0400 Subject: Add 2024 Guix social talk. --- .../reveal.js/js/controllers/autoanimate.js | 643 ++++++++++++++ .../reveal.js/js/controllers/backgrounds.js | 468 +++++++++++ .../reveal.js/js/controllers/controls.js | 279 +++++++ .../reveal.js/js/controllers/focus.js | 103 +++ .../reveal.js/js/controllers/fragments.js | 375 +++++++++ .../reveal.js/js/controllers/jumptoslide.js | 197 +++++ .../reveal.js/js/controllers/keyboard.js | 400 +++++++++ .../reveal.js/js/controllers/location.js | 247 ++++++ .../reveal.js/js/controllers/notes.js | 126 +++ .../reveal.js/js/controllers/overview.js | 255 ++++++ .../reveal.js/js/controllers/plugins.js | 254 ++++++ .../reveal.js/js/controllers/pointer.js | 126 +++ .../reveal.js/js/controllers/printview.js | 239 ++++++ .../reveal.js/js/controllers/progress.js | 110 +++ .../reveal.js/js/controllers/scrollview.js | 919 +++++++++++++++++++++ .../reveal.js/js/controllers/slidecontent.js | 489 +++++++++++ .../reveal.js/js/controllers/slidenumber.js | 139 ++++ .../reveal.js/js/controllers/touch.js | 265 ++++++ 18 files changed, 5634 insertions(+) create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/autoanimate.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/backgrounds.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/controls.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/focus.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/fragments.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/jumptoslide.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/keyboard.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/location.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/notes.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/overview.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/plugins.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/pointer.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/printview.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/progress.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/scrollview.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/slidecontent.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/slidenumber.js create mode 100644 2024-06-18-guix-social/reveal.js/js/controllers/touch.js (limited to '2024-06-18-guix-social/reveal.js/js/controllers') diff --git a/2024-06-18-guix-social/reveal.js/js/controllers/autoanimate.js b/2024-06-18-guix-social/reveal.js/js/controllers/autoanimate.js new file mode 100644 index 0000000..5da88fa --- /dev/null +++ b/2024-06-18-guix-social/reveal.js/js/controllers/autoanimate.js @@ -0,0 +1,643 @@ +import { queryAll, extend, createStyleSheet, matches, closest } from '../utils/util.js' +import { FRAGMENT_STYLE_REGEX } from '../utils/constants.js' + +// Counter used to generate unique IDs for auto-animated elements +let autoAnimateCounter = 0; + +/** + * Automatically animates matching elements across + * slides with the [data-auto-animate] attribute. + */ +export default class AutoAnimate { + + constructor( Reveal ) { + + this.Reveal = Reveal; + + } + + /** + * Runs an auto-animation between the given slides. + * + * @param {HTMLElement} fromSlide + * @param {HTMLElement} toSlide + */ + run( fromSlide, toSlide ) { + + // Clean up after prior animations + this.reset(); + + let allSlides = this.Reveal.getSlides(); + let toSlideIndex = allSlides.indexOf( toSlide ); + let fromSlideIndex = allSlides.indexOf( fromSlide ); + + // Ensure that; + // 1. Both slides exist. + // 2. Both slides are auto-animate targets with the same + // data-auto-animate-id value (including null if absent on both). + // 3. data-auto-animate-restart isn't set on the physically latter + // slide (independent of slide direction). + if( fromSlide && toSlide && fromSlide.hasAttribute( 'data-auto-animate' ) && toSlide.hasAttribute( 'data-auto-animate' ) + && fromSlide.getAttribute( 'data-auto-animate-id' ) === toSlide.getAttribute( 'data-auto-animate-id' ) + && !( toSlideIndex > fromSlideIndex ? toSlide : fromSlide ).hasAttribute( 'data-auto-animate-restart' ) ) { + + // Create a new auto-animate sheet + this.autoAnimateStyleSheet = this.autoAnimateStyleSheet || createStyleSheet(); + + let animationOptions = this.getAutoAnimateOptions( toSlide ); + + // Set our starting state + fromSlide.dataset.autoAnimate = 'pending'; + toSlide.dataset.autoAnimate = 'pending'; + + // Flag the navigation direction, needed for fragment buildup + animationOptions.slideDirection = toSlideIndex > fromSlideIndex ? 'forward' : 'backward'; + + // If the from-slide is hidden because it has moved outside + // the view distance, we need to temporarily show it while + // measuring + let fromSlideIsHidden = fromSlide.style.display === 'none'; + if( fromSlideIsHidden ) fromSlide.style.display = this.Reveal.getConfig().display; + + // Inject our auto-animate styles for this transition + let css = this.getAutoAnimatableElements( fromSlide, toSlide ).map( elements => { + return this.autoAnimateElements( elements.from, elements.to, elements.options || {}, animationOptions, autoAnimateCounter++ ); + } ); + + if( fromSlideIsHidden ) fromSlide.style.display = 'none'; + + // Animate unmatched elements, if enabled + if( toSlide.dataset.autoAnimateUnmatched !== 'false' && this.Reveal.getConfig().autoAnimateUnmatched === true ) { + + // Our default timings for unmatched elements + let defaultUnmatchedDuration = animationOptions.duration * 0.8, + defaultUnmatchedDelay = animationOptions.duration * 0.2; + + this.getUnmatchedAutoAnimateElements( toSlide ).forEach( unmatchedElement => { + + let unmatchedOptions = this.getAutoAnimateOptions( unmatchedElement, animationOptions ); + let id = 'unmatched'; + + // If there is a duration or delay set specifically for this + // element our unmatched elements should adhere to those + if( unmatchedOptions.duration !== animationOptions.duration || unmatchedOptions.delay !== animationOptions.delay ) { + id = 'unmatched-' + autoAnimateCounter++; + css.push( `[data-auto-animate="running"] [data-auto-animate-target="${id}"] { transition: opacity ${unmatchedOptions.duration}s ease ${unmatchedOptions.delay}s; }` ); + } + + unmatchedElement.dataset.autoAnimateTarget = id; + + }, this ); + + // Our default transition for unmatched elements + css.push( `[data-auto-animate="running"] [data-auto-animate-target="unmatched"] { transition: opacity ${defaultUnmatchedDuration}s ease ${defaultUnmatchedDelay}s; }` ); + + } + + // Setting the whole chunk of CSS at once is the most + // efficient way to do this. Using sheet.insertRule + // is multiple factors slower. + this.autoAnimateStyleSheet.innerHTML = css.join( '' ); + + // Start the animation next cycle + requestAnimationFrame( () => { + if( this.autoAnimateStyleSheet ) { + // This forces our newly injected styles to be applied in Firefox + getComputedStyle( this.autoAnimateStyleSheet ).fontWeight; + + toSlide.dataset.autoAnimate = 'running'; + } + } ); + + this.Reveal.dispatchEvent({ + type: 'autoanimate', + data: { + fromSlide, + toSlide, + sheet: this.autoAnimateStyleSheet + } + }); + + } + + } + + /** + * Rolls back all changes that we've made to the DOM so + * that as part of animating. + */ + reset() { + + // Reset slides + queryAll( this.Reveal.getRevealElement(), '[data-auto-animate]:not([data-auto-animate=""])' ).forEach( element => { + element.dataset.autoAnimate = ''; + } ); + + // Reset elements + queryAll( this.Reveal.getRevealElement(), '[data-auto-animate-target]' ).forEach( element => { + delete element.dataset.autoAnimateTarget; + } ); + + // Remove the animation sheet + if( this.autoAnimateStyleSheet && this.autoAnimateStyleSheet.parentNode ) { + this.autoAnimateStyleSheet.parentNode.removeChild( this.autoAnimateStyleSheet ); + this.autoAnimateStyleSheet = null; + } + + } + + /** + * Creates a FLIP animation where the `to` element starts out + * in the `from` element position and animates to its original + * 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 + */ + autoAnimateElements( 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 = this.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 = this.getAutoAnimatableProperties( 'from', from, elementOptions ), + toProps = this.getAutoAnimatableProperties( 'to', to, elementOptions ); + + // Maintain fragment visibility for matching elements when + // we're navigating forwards, this way the viewer won't need + // to step through the same fragments twice + if( to.classList.contains( 'fragment' ) ) { + + // Don't auto-animate the opacity of fragments to avoid + // conflicts with fragment animations + delete toProps.styles['opacity']; + + if( from.classList.contains( 'fragment' ) ) { + + let fromFragmentStyle = ( from.className.match( FRAGMENT_STYLE_REGEX ) || [''] )[0]; + let toFragmentStyle = ( to.className.match( FRAGMENT_STYLE_REGEX ) || [''] )[0]; + + // Only skip the fragment if the fragment animation style + // remains unchanged + if( fromFragmentStyle === toFragmentStyle && animationOptions.slideDirection === 'forward' ) { + to.classList.add( 'visible', 'disabled' ); + } + + } + + } + + // 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 = this.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( propertyName => { + return propertyName + ': ' + fromProps.styles[propertyName] + ' !important;'; + } ).join( '' ); + + let toCSS = Object.keys( toProps.styles ).map( 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 + */ + getAutoAnimateOptions( element, inheritedOptions ) { + + let options = { + easing: this.Reveal.getConfig().autoAnimateEasing, + duration: this.Reveal.getConfig().autoAnimateDuration, + delay: 0 + }; + + options = extend( options, inheritedOptions ); + + // Inherit options from parent elements + if( element.parentNode ) { + let autoAnimatedParent = closest( element.parentNode, '[data-auto-animate-target]' ); + if( autoAnimatedParent ) { + options = this.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' + */ + getAutoAnimatableProperties( direction, element, elementOptions ) { + + let config = this.Reveal.getConfig(); + + 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 { + if( config.center ) { + // More precise, but breaks when used in combination + // with zoom for scaling the deck ¯\_(ツ)_/¯ + bounds = element.getBoundingClientRect(); + } + else { + let scale = this.Reveal.getScale(); + bounds = { + x: element.offsetLeft * scale, + y: element.offsetTop * scale, + width: element.offsetWidth * scale, + height: element.offsetHeight * scale + }; + } + } + + 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 { + // Use a unitless value for line-height so that it inherits properly + if( style.property === 'line-height' ) { + value = parseFloat( computedStyles['line-height'] ) / parseFloat( computedStyles['font-size'] ); + } + + if( isNaN(value) ) { + 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 + */ + getAutoAnimatableElements( fromSlide, toSlide ) { + + let matcher = typeof this.Reveal.getConfig().autoAnimateMatcher === 'function' ? this.Reveal.getConfig().autoAnimateMatcher : this.getAutoAnimatePairs; + + let pairs = matcher.call( this, 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. + */ + getAutoAnimatePairs( fromSlide, toSlide ) { + + let pairs = []; + + const codeNodes = 'pre'; + const textNodes = 'h1, h2, h3, h4, h5, h6, p, li'; + const mediaNodes = 'img, video, iframe'; + + // Explicit matches via data-id + this.findAutoAnimateMatches( pairs, fromSlide, toSlide, '[data-id]', node => { + return node.nodeName + ':::' + node.getAttribute( 'data-id' ); + } ); + + // Text + this.findAutoAnimateMatches( pairs, fromSlide, toSlide, textNodes, node => { + return node.nodeName + ':::' + node.innerText; + } ); + + // Media + this.findAutoAnimateMatches( pairs, fromSlide, toSlide, mediaNodes, node => { + return node.nodeName + ':::' + ( node.getAttribute( 'src' ) || node.getAttribute( 'data-src' ) ); + } ); + + // Code + this.findAutoAnimateMatches( pairs, fromSlide, toSlide, codeNodes, node => { + return node.nodeName + ':::' + node.innerText; + } ); + + pairs.forEach( pair => { + // Disable scale transformations on text nodes, we transition + // each individual text property instead + if( matches( pair.from, textNodes ) ) { + pair.options = { scale: false }; + } + // Animate individual lines of code + else if( matches( pair.from, 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 + this.findAutoAnimateMatches( pairs, pair.from, pair.to, '.hljs .hljs-ln-code', node => { + return node.textContent; + }, { + scale: false, + styles: [], + measure: this.getLocalBoundingBox.bind( this ) + } ); + + // Line numbers + this.findAutoAnimateMatches( pairs, pair.from, pair.to, '.hljs .hljs-ln-numbers[data-line-number]', node => { + return node.getAttribute( 'data-line-number' ); + }, { + scale: false, + styles: [ 'width' ], + measure: this.getLocalBoundingBox.bind( this ) + } ); + + } + + }, this ); + + 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 + */ + getLocalBoundingBox( element ) { + + const presentationScale = this.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 + */ + 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 primaryIndex = 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][ primaryIndex ] ) { + fromElement = fromMatches[key][ primaryIndex ]; + fromMatches[key][ primaryIndex ] = 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 considered + * unmatched since fading them would break the auto-animation. + * + * @param {HTMLElement} rootElement + * @return {Array} + */ + 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( this.getUnmatchedAutoAnimateElements( element ) ); + } + + return result; + + }, [] ); + + } + +} diff --git a/2024-06-18-guix-social/reveal.js/js/controllers/backgrounds.js b/2024-06-18-guix-social/reveal.js/js/controllers/backgrounds.js new file mode 100644 index 0000000..e7ca644 --- /dev/null +++ b/2024-06-18-guix-social/reveal.js/js/controllers/backgrounds.js @@ -0,0 +1,468 @@ +import { queryAll } from '../utils/util.js' +import { colorToRgb, colorBrightness } from '../utils/color.js' + +/** + * Creates and updates slide backgrounds. + */ +export default class Backgrounds { + + constructor( Reveal ) { + + this.Reveal = Reveal; + + } + + render() { + + this.element = document.createElement( 'div' ); + this.element.className = 'backgrounds'; + this.Reveal.getRevealElement().appendChild( this.element ); + + } + + /** + * 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. + */ + create() { + + // Clear prior backgrounds + this.element.innerHTML = ''; + this.element.classList.add( 'no-transition' ); + + // Iterate over all horizontal slides + this.Reveal.getHorizontalSlides().forEach( slideh => { + + let backgroundStack = this.createBackground( slideh, this.element ); + + // Iterate over all vertical slides + queryAll( slideh, 'section' ).forEach( slidev => { + + this.createBackground( slidev, backgroundStack ); + + backgroundStack.classList.add( 'stack' ); + + } ); + + } ); + + // Add parallax background if specified + if( this.Reveal.getConfig().parallaxBackgroundImage ) { + + this.element.style.backgroundImage = 'url("' + this.Reveal.getConfig().parallaxBackgroundImage + '")'; + this.element.style.backgroundSize = this.Reveal.getConfig().parallaxBackgroundSize; + this.element.style.backgroundRepeat = this.Reveal.getConfig().parallaxBackgroundRepeat; + this.element.style.backgroundPosition = this.Reveal.getConfig().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( () => { + this.Reveal.getRevealElement().classList.add( 'has-parallax-background' ); + }, 1 ); + + } + else { + + this.element.style.backgroundImage = ''; + this.Reveal.getRevealElement().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 + */ + 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 + this.sync( slide ); + + return element; + + } + + /** + * Renders all of the visual properties of a slide background + * based on the various background attributes. + * + * @param {HTMLElement} slide + */ + sync( slide ) { + + const element = slide.slideBackgroundElement, + contentElement = slide.slideBackgroundContentElement; + + const 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' ), + backgroundGradient: slide.getAttribute( 'data-background-gradient' ), + backgroundRepeat: slide.getAttribute( 'data-background-repeat' ), + backgroundPosition: slide.getAttribute( 'data-background-position' ), + backgroundTransition: slide.getAttribute( 'data-background-transition' ), + backgroundOpacity: slide.getAttribute( 'data-background-opacity' ), + }; + + const dataPreload = slide.hasAttribute( 'data-preload' ); + + // 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 = ''; + + if( data.background ) { + // Auto-wrap image urls in url(...) + if( /^(http|file|\/\/)/gi.test( data.background ) || /\.(svg|png|jpg|jpeg|gif|bmp|webp)([?#\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.backgroundGradient || data.backgroundImage || data.backgroundVideo || data.backgroundIframe ) { + element.setAttribute( 'data-background-hash', data.background + + data.backgroundSize + + data.backgroundImage + + data.backgroundVideo + + data.backgroundIframe + + data.backgroundColor + + data.backgroundGradient + + 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.backgroundGradient ) element.style.backgroundImage = data.backgroundGradient; + if( data.backgroundTransition ) element.setAttribute( 'data-background-transition', data.backgroundTransition ); + + if( dataPreload ) 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; + + const contrastClass = this.getContrastClass( slide ); + + if( typeof contrastClass === 'string' ) { + slide.classList.add( contrastClass ); + } + + } + + /** + * Returns a class name that can be applied to a slide to indicate + * if it has a light or dark background. + * + * @param {*} slide + * + * @returns {string|null} + */ + getContrastClass( slide ) { + + const element = slide.slideBackgroundElement; + + // 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 = slide.getAttribute( 'data-background-color' ); + + // If no bg color was found, or it cannot be converted by colorToRgb, check the computed background + if( !contrastColor || !colorToRgb( contrastColor ) ) { + let computedBackgroundStyle = window.getComputedStyle( element ); + if( computedBackgroundStyle && computedBackgroundStyle.backgroundColor ) { + contrastColor = computedBackgroundStyle.backgroundColor; + } + } + + if( contrastColor ) { + const 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 ) { + return 'has-dark-background'; + } + else { + return 'has-light-background'; + } + } + } + + return null; + + } + + /** + * Bubble the 'has-light-background'/'has-dark-background' classes. + */ + bubbleSlideContrastClassToElement( slide, target ) { + + [ 'has-light-background', 'has-dark-background' ].forEach( classToBubble => { + if( slide.classList.contains( classToBubble ) ) { + target.classList.add( classToBubble ); + } + else { + target.classList.remove( classToBubble ); + } + }, this ); + + } + + /** + * 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. + */ + update( includeAll = false ) { + + let config = this.Reveal.getConfig(); + let currentSlide = this.Reveal.getCurrentSlide(); + let indices = this.Reveal.getIndices(); + + 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) + Array.from( this.element.childNodes ).forEach( ( backgroundh, h ) => { + + backgroundh.classList.remove( 'past', 'present', 'future' ); + + if( h < indices.h ) { + backgroundh.classList.add( horizontalPast ); + } + else if ( h > indices.h ) { + backgroundh.classList.add( horizontalFuture ); + } + else { + backgroundh.classList.add( 'present' ); + + // Store a reference to the current background element + currentBackground = backgroundh; + } + + if( includeAll || h === indices.h ) { + queryAll( backgroundh, '.slide-background' ).forEach( ( backgroundv, v ) => { + + backgroundv.classList.remove( 'past', 'present', 'future' ); + + const indexv = typeof indices.v === 'number' ? indices.v : 0; + + 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 === indices.h ) currentBackground = backgroundv; + } + + } ); + } + + } ); + + // The previous background may refer to a DOM element that has + // been removed after a presentation is synced & bgs are recreated + if( this.previousBackground && !this.previousBackground.closest( 'body' ) ) { + this.previousBackground = null; + } + + if( currentBackground && this.previousBackground ) { + + // Don't transition between identical backgrounds. This + // prevents unwanted flicker. + let previousBackgroundHash = this.previousBackground.getAttribute( 'data-background-hash' ); + let currentBackgroundHash = currentBackground.getAttribute( 'data-background-hash' ); + + if( currentBackgroundHash && currentBackgroundHash === previousBackgroundHash && currentBackground !== this.previousBackground ) { + this.element.classList.add( 'no-transition' ); + + // If multiple slides have the same background video, carry + // the