pbr/2023-11-14/js/controllers/scrollview.js
Robert Bendun ea3ac6953a pres
2023-11-05 20:52:39 +01:00

889 lines
25 KiB
JavaScript

import { HORIZONTAL_SLIDES_SELECTOR } from '../utils/constants.js'
import { queryAll } from '../utils/util.js'
const HIDE_SCROLLBAR_TIMEOUT = 500;
const MAX_PROGRESS_SPACING = 4;
const MIN_PROGRESS_SEGMENT_HEIGHT = 6;
const MIN_PLAYHEAD_HEIGHT = 8;
/**
* The scroll view lets you read a reveal.js presentation
* as a linear scrollable page.
*/
export default class ScrollView {
constructor( Reveal ) {
this.Reveal = Reveal;
this.active = false;
this.activatedCallbacks = [];
this.onScroll = this.onScroll.bind( this );
}
/**
* Activates the scroll view. This rearranges the presentation DOM
* by—among other things—wrapping each slide in a page element.
*/
activate() {
if( this.active ) return;
const stateBeforeActivation = this.Reveal.getState();
this.active = true;
// Store the full presentation HTML so that we can restore it
// when/if the scroll view is deactivated
this.slideHTMLBeforeActivation = this.Reveal.getSlidesElement().innerHTML;
const horizontalSlides = queryAll( this.Reveal.getRevealElement(), HORIZONTAL_SLIDES_SELECTOR );
this.viewportElement.classList.add( 'loading-scroll-mode', 'reveal-scroll' );
let presentationBackground;
const viewportStyles = window.getComputedStyle( this.viewportElement );
if( viewportStyles && viewportStyles.background ) {
presentationBackground = viewportStyles.background;
}
const pageElements = [];
const pageContainer = horizontalSlides[0].parentNode;
let previousSlide;
// Creates a new page element and appends the given slide/bg
// to it.
const createPageElement = ( slide, h, v ) => {
let contentContainer;
// If this slide is part of an auto-animation sequence, we
// group it under the same page element as the previous slide
if( previousSlide && this.Reveal.shouldAutoAnimateBetween( previousSlide, slide ) ) {
contentContainer = document.createElement( 'div' );
contentContainer.className = 'scroll-page-content scroll-auto-animate-page';
contentContainer.style.display = 'none';
previousSlide.closest( '.scroll-page-content' ).parentNode.appendChild( contentContainer );
}
else {
// Wrap the slide in a page element and hide its overflow
// so that no page ever flows onto another
const page = document.createElement( 'div' );
page.className = 'scroll-page';
pageElements.push( page );
// Copy the presentation-wide background to each page
if( presentationBackground ) {
page.style.background = presentationBackground;
}
const stickyContainer = document.createElement( 'div' );
stickyContainer.className = 'scroll-page-sticky';
page.appendChild( stickyContainer );
contentContainer = document.createElement( 'div' );
contentContainer.className = 'scroll-page-content';
stickyContainer.appendChild( contentContainer );
}
contentContainer.appendChild( slide );
slide.classList.remove( 'past', 'future' );
slide.setAttribute( 'data-index-h', h );
slide.setAttribute( 'data-index-v', v );
if( slide.slideBackgroundElement ) {
slide.slideBackgroundElement.remove( 'past', 'future' );
contentContainer.insertBefore( slide.slideBackgroundElement, slide );
}
previousSlide = slide;
}
// Slide and slide background layout
horizontalSlides.forEach( ( horizontalSlide, h ) => {
if( this.Reveal.isVerticalStack( horizontalSlide ) ) {
horizontalSlide.querySelectorAll( 'section' ).forEach( ( verticalSlide, v ) => {
createPageElement( verticalSlide, h, v );
});
}
else {
createPageElement( horizontalSlide, h, 0 );
}
}, this );
this.createProgressBar();
// Remove leftover stacks
queryAll( this.Reveal.getRevealElement(), '.stack' ).forEach( stack => stack.remove() );
// Add our newly created pages to the DOM
pageElements.forEach( page => pageContainer.appendChild( page ) );
// Re-run JS-based content layout after the slide is added to page DOM
this.Reveal.slideContent.layout( this.Reveal.getSlidesElement() );
this.Reveal.layout();
this.Reveal.setState( stateBeforeActivation );
this.activatedCallbacks.forEach( callback => callback() );
this.activatedCallbacks = [];
this.restoreScrollPosition();
this.viewportElement.classList.remove( 'loading-scroll-mode' );
this.viewportElement.addEventListener( 'scroll', this.onScroll, { passive: true } );
}
/**
* Deactivates the scroll view and restores the standard slide-based
* presentation.
*/
deactivate() {
if( !this.active ) return;
const stateBeforeDeactivation = this.Reveal.getState();
this.active = false;
this.viewportElement.removeEventListener( 'scroll', this.onScroll );
this.viewportElement.classList.remove( 'reveal-scroll' );
this.removeProgressBar();
this.Reveal.getSlidesElement().innerHTML = this.slideHTMLBeforeActivation;
this.Reveal.sync();
this.Reveal.setState( stateBeforeDeactivation );
this.slideHTMLBeforeActivation = null;
}
toggle( override ) {
if( typeof override === 'boolean' ) {
override ? this.activate() : this.deactivate();
}
else {
this.isActive() ? this.deactivate() : this.activate();
}
}
/**
* Checks if the scroll view is currently active.
*/
isActive() {
return this.active;
}
/**
* Renders the progress bar component.
*/
createProgressBar() {
this.progressBar = document.createElement( 'div' );
this.progressBar.className = 'scrollbar';
this.progressBarInner = document.createElement( 'div' );
this.progressBarInner.className = 'scrollbar-inner';
this.progressBar.appendChild( this.progressBarInner );
this.progressBarPlayhead = document.createElement( 'div' );
this.progressBarPlayhead.className = 'scrollbar-playhead';
this.progressBarInner.appendChild( this.progressBarPlayhead );
this.viewportElement.insertBefore( this.progressBar, this.viewportElement.firstChild );
const handleDocumentMouseMove = ( event ) => {
let progress = ( event.clientY - this.progressBarInner.getBoundingClientRect().top ) / this.progressBarHeight;
progress = Math.max( Math.min( progress, 1 ), 0 );
this.viewportElement.scrollTop = progress * ( this.viewportElement.scrollHeight - this.viewportElement.offsetHeight );
};
const handleDocumentMouseUp = ( event ) => {
this.draggingProgressBar = false;
this.showProgressBar();
document.removeEventListener( 'mousemove', handleDocumentMouseMove );
document.removeEventListener( 'mouseup', handleDocumentMouseUp );
};
const handleMouseDown = ( event ) => {
event.preventDefault();
this.draggingProgressBar = true;
document.addEventListener( 'mousemove', handleDocumentMouseMove );
document.addEventListener( 'mouseup', handleDocumentMouseUp );
handleDocumentMouseMove( event );
};
this.progressBarInner.addEventListener( 'mousedown', handleMouseDown );
}
removeProgressBar() {
if( this.progressBar ) {
this.progressBar.remove();
this.progressBar = null;
}
}
layout() {
if( this.isActive() ) {
this.syncPages();
this.syncScrollPosition();
}
}
/**
* Updates our pages to match the latest configuration and
* presentation size.
*/
syncPages() {
const config = this.Reveal.getConfig();
const slideSize = this.Reveal.getComputedSlideSize( window.innerWidth, window.innerHeight );
const scale = this.Reveal.getScale();
const useCompactLayout = config.scrollLayout === 'compact';
const viewportHeight = this.viewportElement.offsetHeight;
const compactHeight = slideSize.height * scale;
const pageHeight = useCompactLayout ? compactHeight : viewportHeight;
// The height that needs to be scrolled between scroll triggers
const scrollTriggerHeight = useCompactLayout ? compactHeight : viewportHeight;
this.viewportElement.style.setProperty( '--page-height', pageHeight + 'px' );
this.viewportElement.style.scrollSnapType = typeof config.scrollSnap === 'string' ? `y ${config.scrollSnap}` : '';
// This will hold all scroll triggers used to show/hide slides
this.slideTriggers = [];
const pageElements = Array.from( this.Reveal.getRevealElement().querySelectorAll( '.scroll-page' ) );
this.pages = pageElements.map( pageElement => {
const page = this.createPage({
pageElement,
slideElement: pageElement.querySelector( 'section' ),
stickyElement: pageElement.querySelector( '.scroll-page-sticky' ),
contentElement: pageElement.querySelector( '.scroll-page-content' ),
backgroundElement: pageElement.querySelector( '.slide-background' ),
autoAnimateElements: pageElement.querySelectorAll( '.scroll-auto-animate-page' ),
autoAnimatePages: []
});
page.pageElement.style.setProperty( '--slide-height', config.center === true ? 'auto' : slideSize.height + 'px' );
this.slideTriggers.push({
page: page,
activate: () => this.activatePage( page ),
deactivate: () => this.deactivatePage( page )
});
// Create scroll triggers that show/hide fragments
this.createFragmentTriggersForPage( page );
// Create scroll triggers for triggering auto-animate steps
if( page.autoAnimateElements.length > 0 ) {
this.createAutoAnimateTriggersForPage( page );
}
let totalScrollTriggerCount = Math.max( page.scrollTriggers.length - 1, 0 );
// Each auto-animate step may include its own scroll triggers
// for fragments, ensure we count those as well
totalScrollTriggerCount += page.autoAnimatePages.reduce( ( total, page ) => {
return total + Math.max( page.scrollTriggers.length - 1, 0 );
}, page.autoAnimatePages.length );
// Clean up from previous renders
page.pageElement.querySelectorAll( '.scroll-snap-point' ).forEach( el => el.remove() );
// Create snap points for all scroll triggers
// - Can't be absolute in FF
// - Can't be 0-height in Safari
// - Can't use snap-align on parent in Safari because then
// inner triggers won't work
for( let i = 0; i < totalScrollTriggerCount + 1; i++ ) {
const triggerStick = document.createElement( 'div' );
triggerStick.className = 'scroll-snap-point';
triggerStick.style.height = scrollTriggerHeight + 'px';
triggerStick.style.scrollSnapAlign = useCompactLayout ? 'center' : 'start';
page.pageElement.appendChild( triggerStick );
if( i === 0 ) {
triggerStick.style.marginTop = -scrollTriggerHeight + 'px';
}
}
// In the compact layout, only slides with scroll triggers cover the
// full viewport height. This helps avoid empty gaps before or after
// a sticky slide.
if( useCompactLayout && page.scrollTriggers.length > 0 ) {
page.pageHeight = viewportHeight;
page.pageElement.style.setProperty( '--page-height', viewportHeight + 'px' );
}
else {
page.pageHeight = pageHeight;
page.pageElement.style.removeProperty( '--page-height' );
}
// Add scroll padding based on how many scroll triggers we have
page.scrollPadding = scrollTriggerHeight * totalScrollTriggerCount;
// The total height including scrollable space
page.totalHeight = page.pageHeight + page.scrollPadding;
// This is used to pad the height of our page in CSS
page.pageElement.style.setProperty( '--page-scroll-padding', page.scrollPadding + 'px' );
// If this is a sticky page, stick it to the vertical center
if( totalScrollTriggerCount > 0 ) {
page.stickyElement.style.position = 'sticky';
page.stickyElement.style.top = Math.max( ( viewportHeight - page.pageHeight ) / 2, 0 ) + 'px';
}
else {
page.stickyElement.style.position = 'relative';
page.pageElement.style.scrollSnapAlign = page.pageHeight < viewportHeight ? 'center' : 'start';
}
return page;
} );
this.setTriggerRanges();
/*
console.log(this.slideTriggers.map( t => {
return {
range: `${t.range[0].toFixed(2)}-${t.range[1].toFixed(2)}`,
triggers: t.page.scrollTriggers.map( t => {
return `${t.range[0].toFixed(2)}-${t.range[1].toFixed(2)}`
}).join( ', ' ),
}
}))
*/
this.viewportElement.setAttribute( 'data-scrollbar', config.scrollProgress );
if( config.scrollProgress && this.totalScrollTriggerCount > 1 ) {
// Create the progress bar if it doesn't already exist
if( !this.progressBar ) this.createProgressBar();
this.syncProgressBar();
}
else {
this.removeProgressBar();
}
}
/**
* Calculates and sets the scroll range for all of our scroll
* triggers.
*/
setTriggerRanges() {
// Calculate the total number of scroll triggers
this.totalScrollTriggerCount = this.slideTriggers.reduce( ( total, trigger ) => {
return total + Math.max( trigger.page.scrollTriggers.length, 1 );
}, 0 );
let rangeStart = 0;
// Calculate the scroll range of each scroll trigger on a scale
// of 0-1
this.slideTriggers.forEach( ( trigger, i ) => {
trigger.range = [
rangeStart,
rangeStart + Math.max( trigger.page.scrollTriggers.length, 1 ) / this.totalScrollTriggerCount
];
const scrollTriggerSegmentSize = ( trigger.range[1] - trigger.range[0] ) / trigger.page.scrollTriggers.length;
// Set the range for each inner scroll trigger
trigger.page.scrollTriggers.forEach( ( scrollTrigger, i ) => {
scrollTrigger.range = [
rangeStart + i * scrollTriggerSegmentSize,
rangeStart + ( i + 1 ) * scrollTriggerSegmentSize
];
} );
rangeStart = trigger.range[1];
} );
}
/**
* Creates one scroll trigger for each fragments in the given page.
*
* @param {*} page
*/
createFragmentTriggersForPage( page, slideElement ) {
slideElement = slideElement || page.slideElement;
// 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.
const fragmentGroups = this.Reveal.fragments.sort( slideElement.querySelectorAll( '.fragment' ), true );
// Create scroll triggers that show/hide fragments
if( fragmentGroups.length ) {
page.fragments = this.Reveal.fragments.sort( slideElement.querySelectorAll( '.fragment:not(.disabled)' ) );
page.scrollTriggers.push(
// Trigger for the initial state with no fragments visible
{
activate: () => {
this.Reveal.fragments.update( -1, page.fragments, slideElement );
}
},
// Triggers for each fragment group
...fragmentGroups.map( ( fragments, i ) => ({
activate: () => {
this.Reveal.fragments.update( i, page.fragments, slideElement );
}
})
)
);
}
return page.scrollTriggers.length;
}
/**
* Creates scroll triggers for the auto-animate steps in the
* given page.
*
* @param {*} page
*/
createAutoAnimateTriggersForPage( page ) {
if( page.autoAnimateElements.length > 0 ) {
// Triggers for each subsequent auto-animate slide
this.slideTriggers.push( ...Array.from( page.autoAnimateElements ).map( ( autoAnimateElement, i ) => {
let autoAnimatePage = this.createPage({
slideElement: autoAnimateElement.querySelector( 'section' ),
contentElement: autoAnimateElement,
backgroundElement: autoAnimateElement.querySelector( '.slide-background' )
});
// Create fragment scroll triggers for the auto-animate slide
this.createFragmentTriggersForPage( autoAnimatePage, autoAnimatePage.slideElement );
page.autoAnimatePages.push( autoAnimatePage );
// Return our slide trigger
return {
page: autoAnimatePage,
activate: () => this.activatePage( autoAnimatePage ),
deactivate: () => this.deactivatePage( autoAnimatePage )
};
}));
}
}
/**
* Helper method for creating a page definition and adding
* required fields. A "page" is a slide or auto-animate step.
*/
createPage( page ) {
page.scrollTriggers = [];
page.indexh = parseInt( page.slideElement.getAttribute( 'data-index-h' ), 10 );
page.indexv = parseInt( page.slideElement.getAttribute( 'data-index-v' ), 10 );
return page;
}
/**
* Rerenders progress bar segments so that they match the current
* reveal.js config and size.
*/
syncProgressBar() {
this.progressBarInner.querySelectorAll( '.scrollbar-slide' ).forEach( slide => slide.remove() );
const scrollHeight = this.viewportElement.scrollHeight;
const viewportHeight = this.viewportElement.offsetHeight;
const viewportHeightFactor = viewportHeight / scrollHeight;
this.progressBarHeight = this.progressBarInner.offsetHeight;
this.playheadHeight = Math.max( viewportHeightFactor * this.progressBarHeight, MIN_PLAYHEAD_HEIGHT );
this.progressBarScrollableHeight = this.progressBarHeight - this.playheadHeight;
const progressSegmentHeight = viewportHeight / scrollHeight * this.progressBarHeight;
const spacing = Math.min( progressSegmentHeight / 8, MAX_PROGRESS_SPACING );
this.progressBarPlayhead.style.height = this.playheadHeight - spacing + 'px';
// Don't show individual segments if they're too small
if( progressSegmentHeight > MIN_PROGRESS_SEGMENT_HEIGHT ) {
this.slideTriggers.forEach( slideTrigger => {
const { page } = slideTrigger;
// Visual representation of a slide
page.progressBarSlide = document.createElement( 'div' );
page.progressBarSlide.className = 'scrollbar-slide';
page.progressBarSlide.style.top = slideTrigger.range[0] * this.progressBarHeight + 'px';
page.progressBarSlide.style.height = ( slideTrigger.range[1] - slideTrigger.range[0] ) * this.progressBarHeight - spacing + 'px';
page.progressBarSlide.classList.toggle( 'has-triggers', page.scrollTriggers.length > 0 );
this.progressBarInner.appendChild( page.progressBarSlide );
// Visual representations of each scroll trigger
page.scrollTriggerElements = page.scrollTriggers.map( ( trigger, i ) => {
const triggerElement = document.createElement( 'div' );
triggerElement.className = 'scrollbar-trigger';
triggerElement.style.top = ( trigger.range[0] - slideTrigger.range[0] ) * this.progressBarHeight + 'px';
triggerElement.style.height = ( trigger.range[1] - trigger.range[0] ) * this.progressBarHeight - spacing + 'px';
page.progressBarSlide.appendChild( triggerElement );
if( i === 0 ) triggerElement.style.display = 'none';
return triggerElement;
} );
} );
}
else {
this.pages.forEach( page => page.progressBarSlide = null );
}
}
/**
* Reads the current scroll position and updates our active
* trigger states accordingly.
*/
syncScrollPosition() {
const viewportHeight = this.viewportElement.offsetHeight;
const viewportHeightFactor = viewportHeight / this.viewportElement.scrollHeight;
const scrollTop = this.viewportElement.scrollTop;
const scrollHeight = this.viewportElement.scrollHeight - viewportHeight
const scrollProgress = Math.max( Math.min( scrollTop / scrollHeight, 1 ), 0 );
const scrollProgressMid = Math.max( Math.min( ( scrollTop + viewportHeight / 2 ) / this.viewportElement.scrollHeight, 1 ), 0 );
let activePage;
this.slideTriggers.forEach( ( trigger ) => {
const { page } = trigger;
const shouldPreload = scrollProgress >= trigger.range[0] - viewportHeightFactor*2 &&
scrollProgress <= trigger.range[1] + viewportHeightFactor*2;
// Load slides that are within the preload range
if( shouldPreload && !page.loaded ) {
page.loaded = true;
this.Reveal.slideContent.load( page.slideElement );
}
else if( page.loaded ) {
page.loaded = false;
this.Reveal.slideContent.unload( page.slideElement );
}
// If we're within this trigger range, activate it
if( scrollProgress >= trigger.range[0] && scrollProgress <= trigger.range[1] ) {
this.activateTrigger( trigger );
activePage = trigger.page;
}
// .. otherwise deactivate
else if( trigger.active ) {
this.deactivateTrigger( trigger );
}
} );
// Each page can have its own scroll triggers, check if any of those
// need to be activated/deactivated
if( activePage ) {
activePage.scrollTriggers.forEach( ( trigger ) => {
if( scrollProgressMid >= trigger.range[0] && scrollProgressMid <= trigger.range[1] ) {
this.activateTrigger( trigger );
}
else if( trigger.active ) {
this.deactivateTrigger( trigger );
}
} );
}
// Update our visual progress indication
this.setProgressBarValue( scrollTop / ( this.viewportElement.scrollHeight - viewportHeight ) );
}
/**
* Moves the progress bar playhead to the specified position.
*
* @param {number} progress 0-1
*/
setProgressBarValue( progress ) {
if( this.progressBar ) {
this.progressBarPlayhead.style.transform = `translateY(${progress * this.progressBarScrollableHeight}px)`;
this.getAllPages()
.filter( page => page.progressBarSlide )
.forEach( ( page ) => {
page.progressBarSlide.classList.toggle( 'active', page.active === true );
page.scrollTriggers.forEach( ( trigger, i ) => {
page.scrollTriggerElements[i].classList.toggle( 'active', page.active === true && trigger.active === true );
} );
} );
this.showProgressBar();
}
}
/**
* Show the progress bar and, if configured, automatically hide
* it after a delay.
*/
showProgressBar() {
this.progressBar.classList.add( 'visible' );
clearTimeout( this.hideProgressBarTimeout );
if( this.Reveal.getConfig().scrollProgress === 'auto' && !this.draggingProgressBar ) {
this.hideProgressBarTimeout = setTimeout( () => {
if( this.progressBar ) {
this.progressBar.classList.remove( 'visible' );
}
}, HIDE_SCROLLBAR_TIMEOUT );
}
}
/**
* Scrolls the given slide element into view.
*
* @param {HTMLElement} slideElement
*/
scrollToSlide( slideElement ) {
// If the scroll view isn't active yet, queue this action
if( !this.active ) {
this.activatedCallbacks.push( () => this.scrollToSlide( slideElement ) );
}
else {
// Find the trigger for this slide
const trigger = this.getScrollTriggerBySlide( slideElement );
if( trigger ) {
// Use the trigger's range to calculate the scroll position
this.viewportElement.scrollTop = trigger.range[0] * ( this.viewportElement.scrollHeight - this.viewportElement.offsetHeight );
}
}
}
/**
* Persists the current scroll position to session storage
* so that it can be restored.
*/
storeScrollPosition() {
clearTimeout( this.storeScrollPositionTimeout );
this.storeScrollPositionTimeout = setTimeout( () => {
sessionStorage.setItem( 'reveal-scroll-top', this.viewportElement.scrollTop );
sessionStorage.setItem( 'reveal-scroll-origin', location.origin + location.pathname );
this.storeScrollPositionTimeout = null;
}, 50 );
}
/**
* Restores the scroll position when a deck is reloader.
*/
restoreScrollPosition() {
const scrollPosition = sessionStorage.getItem( 'reveal-scroll-top' );
const scrollOrigin = sessionStorage.getItem( 'reveal-scroll-origin' );
if( scrollPosition && scrollOrigin === location.origin + location.pathname ) {
this.viewportElement.scrollTop = parseInt( scrollPosition, 10 );
}
}
/**
* Activates the given page and starts its embedded content
* if there is any.
*
* @param {object} page
*/
activatePage( page ) {
if( !page.active ) {
page.active = true;
const { slideElement, backgroundElement, contentElement, indexh, indexv } = page;
contentElement.style.display = 'block';
slideElement.classList.add( 'present' );
if( backgroundElement ) {
backgroundElement.classList.add( 'present' );
}
this.Reveal.setCurrentScrollPage( slideElement, indexh, indexv );
this.Reveal.backgrounds.bubbleSlideContrastClassToElement( slideElement, this.viewportElement );
// If this page is part of an auto-animation there will be one
// content element per auto-animated page. We need to show the
// current page and hide all others.
Array.from( contentElement.parentNode.querySelectorAll( '.scroll-page-content' ) ).forEach( sibling => {
if( sibling !== contentElement ) {
sibling.style.display = 'none';
}
});
}
}
/**
* Deactivates the page after it has been visible.
*
* @param {object} page
*/
deactivatePage( page ) {
if( page.active ) {
page.active = false;
page.slideElement.classList.remove( 'present' );
page.backgroundElement.classList.remove( 'present' );
}
}
activateTrigger( trigger ) {
if( !trigger.active ) {
trigger.active = true;
trigger.activate();
}
}
deactivateTrigger( trigger ) {
if( trigger.active ) {
trigger.active = false;
if( trigger.deactivate ) {
trigger.deactivate();
}
}
}
/**
* Retrieve a slide by its original h/v index (i.e. the indices the
* slide had before being linearized).
*
* @param {number} h
* @param {number} v
* @returns {HTMLElement}
*/
getSlideByIndices( h, v ) {
const page = this.getAllPages().find( page => {
return page.indexh === h && page.indexv === v;
} );
return page ? page.slideElement : null;
}
/**
* Retrieve a list of all scroll triggers for the given slide
* DOM element.
*
* @param {HTMLElement} slide
* @returns {Array}
*/
getScrollTriggerBySlide( slide ) {
return this.slideTriggers.find( trigger => trigger.page.slideElement === slide );
}
/**
* Get a list of all pages in the scroll view. This includes
* both top-level slides and auto-animate steps.
*
* @returns {Array}
*/
getAllPages() {
return this.pages.flatMap( page => [page, ...(page.autoAnimatePages || [])] );
}
onScroll() {
this.syncScrollPosition();
this.storeScrollPosition();
}
get viewportElement() {
return this.Reveal.getViewportElement();
}
}