// ==UserScript==
// @name         Add YouTube Thumbnail to Video Description
// @namespace    http://tampermonkey.net/
// @version      1.0
// @description  Adds the video's thumbnail to the description of the video that you are currently watching.
// @author       Kyle Nakamura
// @match        https://www.youtube.com/watch*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=youtube.com
// @grant        none
// @license MIT
// ==/UserScript==
function awaitElement(selector) {
return new Promise(resolve => {
if (document.querySelector(selector)) {
return resolve(document.querySelector(selector));
}
const observer = new MutationObserver(mutations => {
if (document.querySelector(selector)) {
resolve(document.querySelector(selector));
observer.disconnect();
}
});
observer.observe(document.body, {
childList: true,
subtree: true
});
});
}
// On document load...
(function() {
'use strict';
// Wait for description container div to load
awaitElement('div #description').then((descriptionContainer) => {
// Wait for description contents to load
awaitElement('div #description-inner').then(_ => {
const thumbnailPreview = document.createElement('img'),
videoID = new URLSearchParams(window.location.search).get('v'),
imgSD = `https://img.youtube.com/vi/${videoID}/sddefault.jpg`,
imgHD = `https://img.youtube.com/vi/${videoID}/maxresdefault.jpg`;
descriptionContainer.style.display = 'flex';
descriptionContainer.style.flexDirection = 'row';
descriptionContainer.style.justifyContent = 'space-between';
thumbnailPreview.src = imgSD;
thumbnailPreview.style.height = '100px';
thumbnailPreview.style.cursor = 'pointer';
thumbnailPreview.onclick = _ => {
window.open(imgHD, '_blank');
};
descriptionContainer.append(thumbnailPreview);
});
});
})();