diff --git a/src/components/media-carousel.ts b/src/components/media-carousel.ts index c2177937..f4a7f36d 100644 --- a/src/components/media-carousel.ts +++ b/src/components/media-carousel.ts @@ -18,21 +18,6 @@ const getEmptyImageSrc = (width: number, height: number) => `data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 ${width} ${height}"%3E%3C/svg%3E`; export const IMG_EMPTY = getEmptyImageSrc(16, 9); -/** - * A note on carousel reinitialization: - * - The carousel needs to be reinitialized when slide sizes change, and slide - * sizes change when content is loaded (lazily or otherwise). Reinitializing - * the carousel when it's moving causes a jarring 'reset', so complexity is - * required here to reinitialize only when the carousel is stable (including - * on first media load, which may be after first carousel initialization). - * - When the carousel is dragged, it can be reinitialized via the settle event. - * - On very first load, or when the user has configured no slide transition - * effect it can be reinitialized on the media load itself as long as - * clickAllowed() confirms the carousel is otherwise stable. - * - Example bug when this reinitialization is not performed: - * https://github.com/dermotduffy/frigate-hass-card/issues/651 - */ - @customElement('frigate-card-media-carousel') export class FrigateCardMediaCarousel extends FrigateCardCarousel { // A "map" from slide number to MediaShowInfo object. @@ -47,10 +32,14 @@ export class FrigateCardMediaCarousel extends FrigateCardCarousel { // fullscreen, etc. Always call the adaptive height handler when the size // changes. protected _resizeObserver: ResizeObserver; + protected _intersectionObserver: IntersectionObserver; constructor() { super(); this._resizeObserver = new ResizeObserver(this._adaptiveHeightHandler.bind(this)); + this._intersectionObserver = new IntersectionObserver( + this._intersectionHandler.bind(this), + ); } /** @@ -105,6 +94,7 @@ export class FrigateCardMediaCarousel extends FrigateCardCarousel { this.addEventListener('frigate-card:media-show', this._adaptiveHeightHandler); this.addEventListener('frigate-card:media-show', this._titleHandler); this._resizeObserver.observe(this); + this._intersectionObserver.observe(this); } /** @@ -117,6 +107,39 @@ export class FrigateCardMediaCarousel extends FrigateCardCarousel { this.removeEventListener('frigate-card:media-show', this._adaptiveHeightHandler); this.removeEventListener('frigate-card:media-show', this._titleHandler); this._resizeObserver.disconnect(); + this._intersectionObserver.disconnect(); + } + + /** + * Called when the carousel intersects with the viewport. + * @param entries The IntersectionObserverEntry entries (should be only 1). + */ + protected _intersectionHandler(entries: IntersectionObserverEntry[]): void { + /** + * - If the DOM that contains this carousel changes such that it causes + * slides to entirely appear/disappear (e.g. `display: none` or hidden), + * then the displayed slide sizes will significantly change and the + * carousel will need to be reinitialized. Without this, odd bugs may + * occur for some users in some circumstances causing the carousel to + * appear 'stuck'. + * - Example bug when this reinitialization is not performed: + * https://github.com/dermotduffy/frigate-hass-card/issues/651 + */ + + const reinit = (): void => { + this._carousel?.reInit(); + }; + + if (entries.some((entry) => entry.isIntersecting)) { + // For performance, run the reinit in idle cycles if the browser supports + // it, but only give it 400ms before running as it may otherwise be + // noticeable to the user. + if (window.requestIdleCallback !== undefined) { + window.requestIdleCallback(reinit, { timeout: 400 }); + } else { + reinit(); + } + } } protected _destroyCarousel(): void { @@ -150,22 +173,6 @@ export class FrigateCardMediaCarousel extends FrigateCardCarousel { // Dispatch MediaShow events as the carousel is moved. carousel?.on('init', this._selectSlideMediaShowHandler.bind(this)); carousel?.on('select', this._selectSlideMediaShowHandler.bind(this)); - - carousel?.on('settle', this._reinitIfNecessary.bind(this)); - } - - /** - * Reinitialize the carousel if necessary. See 'A note on carousel - * reinitialization' above. - */ - protected _reinitIfNecessary(): void { - if (this._needReInit) { - // The original options are included here, although this should not be - // necessary (without including them, Safari ends up not having a looping - // live carousel). - this._carousel?.reInit(this._getOptions()); - this._needReInit = false; - } } /** @@ -269,15 +276,6 @@ export class FrigateCardMediaCarousel extends FrigateCardCarousel { // isValidMediaShowInfo is used to prevent saving media info that will be // rejected upstream (empty 1x1 images will be rejected here). if (mediaShowInfo && isValidMediaShowInfo(mediaShowInfo)) { - // If this is the first media load for this slide, the carousel needs to - // reinitialized as the slide size has changed. See 'A note on carousel - // reinitialization' above. - if (!(slideIndex in this._mediaShowInfo)) { - this._needReInit = true; - if (this._carousel?.clickAllowed()) { - this._reinitIfNecessary(); - } - } this._mediaShowInfo[slideIndex] = mediaShowInfo; if (this._carousel && this._carousel?.selectedScrollSnap() === slideIndex) { dispatchExistingMediaShowInfoAsEvent(this, mediaShowInfo);