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authorChristoph Cullmann <cullmann@kde.org>2024-04-28 17:33:09 +0200
committerChristoph Cullmann <cullmann@kde.org>2024-04-28 17:33:09 +0200
commite77051ccc4b47951bfa4fde2be436b1bb2fb113b (patch)
treef0b75ee3521da9c8cd39dac4359212348f70e4e8 /themes/blowfish/assets/lib/lite-youtube-embed
parent4b355837824ac2422d371acef790f0f4249255c7 (diff)
use https://github.com/nunocoracao/blowfish.git
Diffstat (limited to 'themes/blowfish/assets/lib/lite-youtube-embed')
-rw-r--r--themes/blowfish/assets/lib/lite-youtube-embed/lite-yt-embed.css95
-rw-r--r--themes/blowfish/assets/lib/lite-youtube-embed/lite-yt-embed.js225
2 files changed, 320 insertions, 0 deletions
diff --git a/themes/blowfish/assets/lib/lite-youtube-embed/lite-yt-embed.css b/themes/blowfish/assets/lib/lite-youtube-embed/lite-yt-embed.css
new file mode 100644
index 0000000..c96a472
--- /dev/null
+++ b/themes/blowfish/assets/lib/lite-youtube-embed/lite-yt-embed.css
@@ -0,0 +1,95 @@
+lite-youtube {
+ background-color: #000;
+ position: relative;
+ display: block;
+ contain: content;
+ background-position: center center;
+ background-size: cover;
+ cursor: pointer;
+ max-width: 720px;
+}
+
+/* gradient */
+lite-youtube::before {
+ content: attr(data-title);
+ display: block;
+ position: absolute;
+ top: 0;
+ /* Pixel-perfect port of YT's gradient PNG, using https://github.com/bluesmoon/pngtocss plus optimizations */
+ background-image: linear-gradient(180deg, rgb(0 0 0 / 67%) 0%, rgb(0 0 0 / 54%) 14%, rgb(0 0 0 / 15%) 54%, rgb(0 0 0 / 5%) 72%, rgb(0 0 0 / 0%) 94%);
+ height: 99px;
+ width: 100%;
+ font-family: "YouTube Noto",Roboto,Arial,Helvetica,sans-serif;
+ color: hsl(0deg 0% 93.33%);
+ text-shadow: 0 0 2px rgba(0,0,0,.5);
+ font-size: 18px;
+ padding: 25px 20px;
+ overflow: hidden;
+ white-space: nowrap;
+ text-overflow: ellipsis;
+ box-sizing: border-box;
+}
+
+lite-youtube:hover::before {
+ color: white;
+}
+
+/* responsive iframe with a 16:9 aspect ratio
+ thanks https://css-tricks.com/responsive-iframes/
+*/
+lite-youtube::after {
+ content: "";
+ display: block;
+ padding-bottom: calc(100% / (16 / 9));
+}
+lite-youtube > iframe {
+ width: 100%;
+ height: 100%;
+ position: absolute;
+ top: 0;
+ left: 0;
+ border: 0;
+}
+
+/* play button */
+lite-youtube > .lty-playbtn {
+ display: block;
+ /* Make the button element cover the whole area for a large hover/click target… */
+ width: 100%;
+ height: 100%;
+ /* …but visually it's still the same size */
+ background: no-repeat center/68px 48px;
+ /* YT's actual play button svg */
+ background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 68 48"><path d="M66.52 7.74c-.78-2.93-2.49-5.41-5.42-6.19C55.79.13 34 0 34 0S12.21.13 6.9 1.55c-2.93.78-4.63 3.26-5.42 6.19C.06 13.05 0 24 0 24s.06 10.95 1.48 16.26c.78 2.93 2.49 5.41 5.42 6.19C12.21 47.87 34 48 34 48s21.79-.13 27.1-1.55c2.93-.78 4.64-3.26 5.42-6.19C67.94 34.95 68 24 68 24s-.06-10.95-1.48-16.26z" fill="red"/><path d="M45 24 27 14v20" fill="white"/></svg>');
+ position: absolute;
+ cursor: pointer;
+ z-index: 1;
+ filter: grayscale(100%);
+ transition: filter .1s cubic-bezier(0, 0, 0.2, 1);
+ border: 0;
+}
+
+lite-youtube:hover > .lty-playbtn,
+lite-youtube .lty-playbtn:focus {
+ filter: none;
+}
+
+/* Post-click styles */
+lite-youtube.lyt-activated {
+ cursor: unset;
+}
+lite-youtube.lyt-activated::before,
+lite-youtube.lyt-activated > .lty-playbtn {
+ opacity: 0;
+ pointer-events: none;
+}
+
+.lyt-visually-hidden {
+ clip: rect(0 0 0 0);
+ clip-path: inset(50%);
+ height: 1px;
+ overflow: hidden;
+ position: absolute;
+ white-space: nowrap;
+ width: 1px;
+ }
diff --git a/themes/blowfish/assets/lib/lite-youtube-embed/lite-yt-embed.js b/themes/blowfish/assets/lib/lite-youtube-embed/lite-yt-embed.js
new file mode 100644
index 0000000..49db80e
--- /dev/null
+++ b/themes/blowfish/assets/lib/lite-youtube-embed/lite-yt-embed.js
@@ -0,0 +1,225 @@
+/**
+ * A lightweight youtube embed. Still should feel the same to the user, just MUCH faster to initialize and paint.
+ *
+ * Thx to these as the inspiration
+ * https://storage.googleapis.com/amp-vs-non-amp/youtube-lazy.html
+ * https://autoplay-youtube-player.glitch.me/
+ *
+ * Once built it, I also found these:
+ * https://github.com/ampproject/amphtml/blob/master/extensions/amp-youtube (👍👍)
+ * https://github.com/Daugilas/lazyYT
+ * https://github.com/vb/lazyframe
+ */
+class LiteYTEmbed extends HTMLElement {
+ connectedCallback() {
+ this.videoId = this.getAttribute('videoid');
+
+ let playBtnEl = this.querySelector('.lty-playbtn');
+ // A label for the button takes priority over a [playlabel] attribute on the custom-element
+ this.playLabel = (playBtnEl && playBtnEl.textContent.trim()) || this.getAttribute('playlabel') || 'Play';
+
+ this.dataset.title = this.getAttribute('title') || "";
+
+ /**
+ * Lo, the youtube poster image! (aka the thumbnail, image placeholder, etc)
+ *
+ * See https://github.com/paulirish/lite-youtube-embed/blob/master/youtube-thumbnail-urls.md
+ */
+ if (!this.style.backgroundImage) {
+ this.style.backgroundImage = `url("https://i.ytimg.com/vi/${this.videoId}/hqdefault.jpg")`;
+ this.upgradePosterImage();
+ }
+
+ // Set up play button, and its visually hidden label
+ if (!playBtnEl) {
+ playBtnEl = document.createElement('button');
+ playBtnEl.type = 'button';
+ playBtnEl.classList.add('lty-playbtn');
+ this.append(playBtnEl);
+ }
+ if (!playBtnEl.textContent) {
+ const playBtnLabelEl = document.createElement('span');
+ playBtnLabelEl.className = 'lyt-visually-hidden';
+ playBtnLabelEl.textContent = this.playLabel;
+ playBtnEl.append(playBtnLabelEl);
+ }
+
+ this.addNoscriptIframe();
+
+ playBtnEl.removeAttribute('href');
+
+ // On hover (or tap), warm up the TCP connections we're (likely) about to use.
+ this.addEventListener('pointerover', LiteYTEmbed.warmConnections, {once: true});
+
+ // Once the user clicks, add the real iframe and drop our play button
+ // TODO: In the future we could be like amp-youtube and silently swap in the iframe during idle time
+ // We'd want to only do this for in-viewport or near-viewport ones: https://github.com/ampproject/amphtml/pull/5003
+ this.addEventListener('click', this.activate);
+
+ // Chrome & Edge desktop have no problem with the basic YouTube Embed with ?autoplay=1
+ // However Safari desktop and most/all mobile browsers do not successfully track the user gesture of clicking through the creation/loading of the iframe,
+ // so they don't autoplay automatically. Instead we must load an additional 2 sequential JS files (1KB + 165KB) (un-br) for the YT Player API
+ // TODO: Try loading the the YT API in parallel with our iframe and then attaching/playing it. #82
+ this.needsYTApi = this.hasAttribute("js-api") || navigator.vendor.includes('Apple') || navigator.userAgent.includes('Mobi');
+ }
+
+ /**
+ * Add a <link rel={preload | preconnect} ...> to the head
+ */
+ static addPrefetch(kind, url, as) {
+ const linkEl = document.createElement('link');
+ linkEl.rel = kind;
+ linkEl.href = url;
+ if (as) {
+ linkEl.as = as;
+ }
+ document.head.append(linkEl);
+ }
+
+ /**
+ * Begin pre-connecting to warm up the iframe load
+ * Since the embed's network requests load within its iframe,
+ * preload/prefetch'ing them outside the iframe will only cause double-downloads.
+ * So, the best we can do is warm up a few connections to origins that are in the critical path.
+ *
+ * Maybe `<link rel=preload as=document>` would work, but it's unsupported: http://crbug.com/593267
+ * But TBH, I don't think it'll happen soon with Site Isolation and split caches adding serious complexity.
+ */
+ static warmConnections() {
+ if (LiteYTEmbed.preconnected) return;
+
+ // The iframe document and most of its subresources come right off youtube.com
+ LiteYTEmbed.addPrefetch('preconnect', 'https://www.youtube-nocookie.com');
+ // The botguard script is fetched off from google.com
+ LiteYTEmbed.addPrefetch('preconnect', 'https://www.google.com');
+
+ // Not certain if these ad related domains are in the critical path. Could verify with domain-specific throttling.
+ LiteYTEmbed.addPrefetch('preconnect', 'https://googleads.g.doubleclick.net');
+ LiteYTEmbed.addPrefetch('preconnect', 'https://static.doubleclick.net');
+
+ LiteYTEmbed.preconnected = true;
+ }
+
+ fetchYTPlayerApi() {
+ if (window.YT || (window.YT && window.YT.Player)) return;
+
+ this.ytApiPromise = new Promise((res, rej) => {
+ var el = document.createElement('script');
+ el.src = 'https://www.youtube.com/iframe_api';
+ el.async = true;
+ el.onload = _ => {
+ YT.ready(res);
+ };
+ el.onerror = rej;
+ this.append(el);
+ });
+ }
+
+ /** Return the YT Player API instance. (Public L-YT-E API) */
+ async getYTPlayer() {
+ if(!this.playerPromise) {
+ await this.activate();
+ }
+
+ return this.playerPromise;
+ }
+
+ async addYTPlayerIframe() {
+ this.fetchYTPlayerApi();
+ await this.ytApiPromise;
+
+ const videoPlaceholderEl = document.createElement('div')
+ this.append(videoPlaceholderEl);
+
+ const paramsObj = Object.fromEntries(this.getParams().entries());
+
+ this.playerPromise = new Promise(resolve => {
+ let player = new YT.Player(videoPlaceholderEl, {
+ width: '100%',
+ videoId: this.videoId,
+ playerVars: paramsObj,
+ events: {
+ 'onReady': event => {
+ event.target.playVideo();
+ resolve(player);
+ }
+ }
+ });
+ });
+ }
+
+ // Add the iframe within <noscript> for indexability discoverability. See https://github.com/paulirish/lite-youtube-embed/issues/105
+ addNoscriptIframe() {
+ const iframeEl = this.createBasicIframe();
+ const noscriptEl = document.createElement('noscript');
+ // Appending into noscript isn't equivalant for mysterious reasons: https://html.spec.whatwg.org/multipage/scripting.html#the-noscript-element
+ noscriptEl.innerHTML = iframeEl.outerHTML;
+ this.append(noscriptEl);
+ }
+
+ getParams() {
+ const params = new URLSearchParams(this.getAttribute('params') || []);
+ params.append('autoplay', '1');
+ params.append('playsinline', '1');
+ return params;
+ }
+
+ async activate(){
+ if (this.classList.contains('lyt-activated')) return;
+ this.classList.add('lyt-activated');
+
+ if (this.needsYTApi) {
+ return this.addYTPlayerIframe(this.getParams());
+ }
+
+ const iframeEl = this.createBasicIframe();
+ this.append(iframeEl);
+
+ // Set focus for a11y
+ iframeEl.focus();
+ }
+
+ createBasicIframe(){
+ const iframeEl = document.createElement('iframe');
+ iframeEl.width = 560;
+ iframeEl.height = 315;
+ // No encoding necessary as [title] is safe. https://cheatsheetseries.owasp.org/cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.html#:~:text=Safe%20HTML%20Attributes%20include
+ iframeEl.title = this.playLabel;
+ iframeEl.allow = 'accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture';
+ iframeEl.allowFullscreen = true;
+ // AFAIK, the encoding here isn't necessary for XSS, but we'll do it only because this is a URL
+ // https://stackoverflow.com/q/64959723/89484
+ iframeEl.src = `https://www.youtube-nocookie.com/embed/${encodeURIComponent(this.videoId)}?${this.getParams().toString()}`;
+ return iframeEl;
+ }
+
+ /**
+ * In the spirit of the `lowsrc` attribute and progressive JPEGs, we'll upgrade the reliable
+ * poster image to a higher resolution one, if it's available.
+ * Interestingly this sddefault webp is often smaller in filesize, but we will still attempt it second
+ * because getting _an_ image in front of the user if our first priority.
+ *
+ * See https://github.com/paulirish/lite-youtube-embed/blob/master/youtube-thumbnail-urls.md for more details
+ */
+ upgradePosterImage() {
+ // Defer to reduce network contention.
+ setTimeout(() => {
+ const webpUrl = `https://i.ytimg.com/vi_webp/${this.videoId}/sddefault.webp`;
+ const img = new Image();
+ img.fetchPriority = 'low'; // low priority to reduce network contention
+ img.referrerpolicy = 'origin'; // Not 100% sure it's needed, but https://github.com/ampproject/amphtml/pull/3940
+ img.src = webpUrl;
+ img.onload = e => {
+ // A pretty ugly hack since onerror won't fire on YouTube image 404. This is (probably) due to
+ // Youtube's style of returning data even with a 404 status. That data is a 120x90 placeholder image.
+ // … per "annoying yt 404 behavior" in the .md
+ const noAvailablePoster = e.target.naturalHeight == 90 && e.target.naturalWidth == 120;
+ if (noAvailablePoster) return;
+
+ this.style.backgroundImage = `url("${webpUrl}")`;
+ }
+ }, 100);
+ }
+}
+// Register custom element
+customElements.define('lite-youtube', LiteYTEmbed);