Youtube 封面

獲取影片封面!

您需要先安裝使用者腳本管理器擴展,如 TampermonkeyGreasemonkeyViolentmonkey 之後才能安裝該腳本。

You will need to install an extension such as Tampermonkey to install this script.

您需要先安裝使用者腳本管理器擴充功能,如 TampermonkeyViolentmonkey 後才能安裝該腳本。

您需要先安裝使用者腳本管理器擴充功能,如 TampermonkeyUserscripts 後才能安裝該腳本。

你需要先安裝一款使用者腳本管理器擴展,比如 Tampermonkey,才能安裝此腳本

您需要先安裝使用者腳本管理器擴充功能後才能安裝該腳本。

(我已經安裝了使用者腳本管理器,讓我安裝!)

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

(我已經安裝了使用者樣式管理器,讓我安裝!)

// ==UserScript==
// @name               Youtube 封面
// @name:en            Youtube Cover
// @name:zh-CN         Youtube 封面
// @namespace          http://tampermonkey.net/
// @version            1.4.7
// @description        獲取影片封面!
// @description:en     Get the cover of youtube video!
// @description:zh-CN  获取视频封面!
// @author             Anong0u0
// @match              *://*.youtube.com/*
// @icon               https://www.google.com/s2/favicons?sz=64&domain=youtube.com
// @grant              GM_setValue
// @grant              GM_getValue
// @grant              GM_registerMenuCommand
// @noframes
// @license            MIT License
// ==/UserScript==


const delay = (ms = 0) => new Promise((r)=>{setTimeout(r, ms)})

const waitElementLoad = (elementSelector, selectCount = 1, tryTimes = 1, interval = 0) =>
{
    return new Promise(async (resolve, reject)=>
    {
        let t = 1, result;
        while(true)
        {
            if(selectCount != 1) {if((result = document.querySelectorAll(elementSelector)).length >= selectCount) break;}
            else {if(result = document.querySelector(elementSelector)) break;}

            if(tryTimes>0 && ++t>tryTimes) return reject(new Error("Wait Timeout"));
            await delay(interval);
        }
        resolve(result);
    })
}

if (window.trustedTypes)
{
    const policy = trustedTypes.createPolicy("ytCover", {createHTML: (string) => string,});
    Node.prototype.setHTML = function (html) {this.innerHTML = policy.createHTML(html)}
}
else Node.prototype.setHTML = function (html) {this.innerHTML = html}

Node.prototype.getXY = function ()
{
    let x = 0, y = 0, element = this;
    while (element)
    {
        x += element.offsetLeft - element.scrollLeft + element.clientLeft;
        y += element.offsetTop - element.scrollLeft + element.clientTop;
        element = element.offsetParent;
    }
    return {X: x, Y: y}
}

const checkImg = async (url) => await fetch(url, { method: "HEAD" })
                                    .then(response => response.ok)
                                    .catch(() => false)


const main = () =>
{
    const div = document.createElement("div");
    div.style.marginLeft = "3em";
    div.setHTML(`

    <!-- css -->
    <style>
        #masthead-container { z-index: 3000 !important; }

        #ytCover {
            text-decoration: none;
            font-size: 2em;
            font-weight: bold;
            font-family: Roboto, Arial, sans-serif;
            color: var(--yt-spec-text-primary);
        }

        .list {
            background-color: var(--yt-spec-brand-background-primary);
            border: 1px solid var(--yt-spec-10-percent-layer);
            padding: 0.5em 0;
            position: fixed;
            z-index: 114514;
            max-height: 40em;
            font-size: 10px
        }

        .linkBtn {
            text-decoration: none;
        }

        .list-item {
            text-align: center;
            font-size: 1.5em;
            color: var(--yt-spec-text-primary);
            background-color: var(--yt-spec-brand-background-primary);
            height: 2.5em;
            line-height: 2.5em;
        }
        .list-item:hover {
            background: #AAA;
            box-shadow: 0 4px 5px rgba(0, 0, 0, 0.2);
        }

        .slide {
            cursor: default
        }

        img#preview {
            position: fixed;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            z-index: 2999;
            max-width: 100vw;
            max-height: 65vh;
            min-width: 40vw;
            border: 3px solid #FFF;
        }

        .list > button {
            border: none;
            padding: unset;
            width: inherit;
            cursor: pointer;
        }

    </style>

    <!-- html -->
    <div>
        <div class="slide" id="ytCover"></div>

        <div class="list" id="ytListHead" style="border-top: none; top: 4.8em; left: 19em;" hidden>

            <div class="list-item slide">1280x720+
                <div class="list" style="border-left: none; width: 11.5em" hidden>
                    <a class="linkBtn" imgTag="maxresdefault"><div class="list-item">maxresdefault</div></a>
                    <a class="linkBtn" imgTag="maxres1"><div class="list-item">maxres1</div></a>
                    <a class="linkBtn" imgTag="maxres2"><div class="list-item">maxres2</div></a>
                    <a class="linkBtn" imgTag="maxres3"><div class="list-item">maxres3</div></a>
                </div>
            </div>

            <div class="list-item slide">640x480
                <div class="list" style="border-left: none; width: 8.5em" hidden>
                    <a class="linkBtn" imgTag="sddefault"><div class="list-item">sddefault</div></a>
                    <a class="linkBtn" imgTag="sd1"><div class="list-item">sd1</div></a>
                    <a class="linkBtn" imgTag="sd2"><div class="list-item">sd2</div></a>
                    <a class="linkBtn" imgTag="sd3"><div class="list-item">sd3</div></a>
                </div>
            </div>

            <div class="list-item slide">480x360
                <div class="list" style="border-left: none; width: 8.5em" hidden>
                    <a class="linkBtn" imgTag="hqdefault"><div class="list-item">hqdefault</div></a>
                    <a class="linkBtn" imgTag="hq1"><div class="list-item">hq1</div></a>
                    <a class="linkBtn" imgTag="hq2"><div class="list-item">hq2</div></a>
                    <a class="linkBtn" imgTag="hq3"><div class="list-item">hq3</div></a>
                </div>
            </div>

            <div class="list-item slide">320x180
                <div class="list" style="border-left: none; width: 8.5em" hidden>
                    <a class="linkBtn" imgTag="mqdefault"><div class="list-item">mqdefault</div></a>
                    <a class="linkBtn" imgTag="mq1"><div class="list-item">mq1</div></a>
                    <a class="linkBtn" imgTag="mq2"><div class="list-item">mq2</div></a>
                    <a class="linkBtn" imgTag="mq3"><div class="list-item">mq3</div></a>
                </div>
            </div>

            <div class="list-item slide">120x90
                <div class="list" style="border-left: none; width: 6.5em" hidden>
                    <a class="linkBtn" imgTag="default"><div class="list-item">default</div></a>
                    <a class="linkBtn" imgTag="1"><div class="list-item">1</div></a>
                    <a class="linkBtn" imgTag="2"><div class="list-item">2</div></a>
                    <a class="linkBtn" imgTag="3"><div class="list-item">3</div></a>
                </div>
            </div>

            <button class="list-item">: <span id="previewSpan" style="font-weight: bold;">On</span></button>
        </div>
    </div>`)
    const insertDiv = () =>
    {
        if (GM_getValue("switchButton")) document.querySelector("#end").insertAdjacentElement("afterbegin", div);
        else document.querySelector("#start").append(div);
    }
    insertDiv();

    const ytC = document.querySelector("#ytCover");
    const ytLH = document.querySelector("#ytListHead");
    const Lang = { cover: {en:"Cover", tc:"封面", sc:"封面"},
               preview: {en:"Preview", tc:"圖片預覽", sc:"图片预览"},
                    on: {en:"On", tc:"開", sc:"开"},
                   off: {en:"Off", tc:"關", sc:"关"},
          switchButton: {en:"Switch Button Position", tc:"切換按鈕位置", sc:"切换按钮位置"}};
    const usedLang = document.documentElement.lang.match(/zh/i) ?
                        (document.documentElement.lang.match(/cn/i) ? "sc":"tc") : "en"

    GM_registerMenuCommand(Lang.switchButton[usedLang], () =>
    {
        GM_setValue("switchButton", !GM_getValue("switchButton"));
        insertDiv();
    });


    ytC.innerText = Lang.cover[usedLang];
    ytLH.style.width = usedLang=="en"?"10em":"10.4em";

    window.onresize = () =>
    {
        ytLH.style.left = (ytC.getXY().X/10-1)+"em";
        if(window.innerWidth<1350)
        {
            if(window.innerWidth>850)div.style.margin = `0 ${3*((window.innerWidth-500)/850)}em`;
            else div.style.margin = "0 1em";
        }
        else
        {div.style.margin = "0 3em"}
    }

    document.querySelectorAll(".list > .slide").forEach((e)=>
    {
        const list = e.querySelector(".list");
        e.onmouseenter = () =>
        {
            list.style.top = (e.getXY().Y/10-0.5)+"em";
            list.style.left = parseFloat(ytLH.style.left) + parseFloat(ytLH.style.width) + "em";
            list.hidden = false;
        };
        e.onmouseleave = () => {list.hidden = true}
    });

    const preview = document.createElement("img");
    preview.id = "preview";
    preview.hidden = true;
    document.body.append(preview);

    const Btns = document.querySelectorAll(".linkBtn");
    Btns.forEach((e)=>
    {
        e.onmouseenter = () =>
        {
            if(!GM_getValue("previewOn")) return;
            preview.hidden = false;
            preview.src = e.href;
        };
        e.onmouseleave = () => {preview.hidden = true}
        e.target="_blank";
    });

    const previewBtn = document.querySelector(".list > button");
    previewBtn.setHTML(Lang.preview[usedLang] + previewBtn.innerHTML);
    const previewSpan = document.querySelector("#previewSpan");
    const previewBtnChange = () =>
    {
        if (GM_getValue("previewOn"))
        {
            previewSpan.style.color = "green";
            previewSpan.innerText = Lang.on[usedLang];
        }
        else
        {
            previewSpan.style.color = "red";
            previewSpan.innerText = Lang.off[usedLang];
        }
    };
    previewBtn.onclick = () =>
    {
        GM_setValue("previewOn", !GM_getValue("previewOn"));
        previewBtnChange();
    }
    previewBtnChange();


    let hide;
    ytC.onmouseenter = () =>
    {
        hide = false;
        ytLH.hidden = false;
        window.onresize();
    };
    ytC.onmouseleave = () =>
    {
        hide = true;
        delay(500).then(()=>{ytLH.hidden = hide});
    };
    ytLH.onmouseenter = () =>
    {
        hide = false;
    };
    ytLH.onmouseleave = () =>
    {
        hide = true;
        delay(200).then(()=>{ytLH.hidden = hide});
    };

    let oldHref;
    const onPageUpdate = () =>
    {
        if (oldHref == location.href) return
        oldHref = location.href

        console.log("[Youtube Cover] detect page updated")

        const video_id = location.href.match(/(?<=v=)[^&]{11}|(?<=\/shorts\/).{11}/);
        ytC.hidden = !video_id;
        if (!video_id) return;

        document.querySelectorAll(".list-item > .list").forEach((e)=>
        {
            e.parentNode.hidden = true;
            e.querySelectorAll(".linkBtn").forEach((forEachBtn)=>
            {
                const imgSizeSpec = forEachBtn.getAttribute("imgTag") ?? forEachBtn.innerText
                checkImg(`https://i.ytimg.com/vi/${video_id}/${imgSizeSpec}.jpg`).then((notHide)=>
                {
                    forEachBtn.hidden = !notHide;
                    if(notHide) e.parentNode.hidden = false;
                });
                forEachBtn.href = `https://i.ytimg.com/vi/${video_id}/${imgSizeSpec}.jpg`
            });
        });
    }

    document.addEventListener("yt-rendererstamper-finished", onPageUpdate)
    document.addEventListener("yt-page-type-changed", onPageUpdate)
    document.addEventListener("yt-navigate-start", onPageUpdate)
    waitElementLoad("yt-page-navigation-progress",1,20,250)
        .then((e)=>{new MutationObserver(onPageUpdate).observe(e, {attributes: true})})

    console.log("[Youtube Cover] done");
}

console.log("[Youtube Cover] loading");
waitElementLoad("#start", 1, 10, 300).then(main)