YouTube Preview

A userscript to play youtube videos by hovering over their thumbnails.

您需要先安装一个扩展,例如 篡改猴Greasemonkey暴力猴,之后才能安装此脚本。

您需要先安装一个扩展,例如 篡改猴暴力猴,之后才能安装此脚本。

您需要先安装一个扩展,例如 篡改猴暴力猴,之后才能安装此脚本。

您需要先安装一个扩展,例如 篡改猴Userscripts ,之后才能安装此脚本。

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey,才能安装此脚本。

您需要先安装用户脚本管理器扩展后才能安装此脚本。

(我已经安装了用户脚本管理器,让我安装!)

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

(我已经安装了用户样式管理器,让我安装!)

// ==UserScript==
// @name         YouTube Preview
// @author       sooqua
// @namespace    https://github.com/sooqua/
// @version      0.9
// @description  A userscript to play youtube videos by hovering over their thumbnails.
// @match        *://*.youtube.com/*
// @run-at       document-end
// @grant        none
// ==/UserScript==

var APIready = new Promise(function(resolve) {
    window.onYouTubeIframeAPIReady = resolve;
});

(function() {
    'use strict';

    function init() {
        // requesting api
        var scriptTag = document.createElement('script');
        scriptTag.src = "https://www.youtube.com/iframe_api";
        var firstScriptTag = document.getElementsByTagName('script')[0];
        firstScriptTag.parentNode.insertBefore(scriptTag, firstScriptTag);

        addGlobalStyle(
            ".watch-sidebar-section { " +
            "z-index: auto !important; " +
            "} " +

            ".yt-lockup-thumbnail:not(.yt-pl-thumb),.thumb-wrapper { " +
            "-webkit-transition: all 200ms ease-in !important; " +
            "-webkit-transform: scale(1) !important; " +
            "-moz-transition: all 200ms ease-in !important; " +
            "-moz-transform: scale(1) !important; " +
            "transition: all 200ms ease-in !important; " +
            "transform: scale(1) !important; " +
            "} " +

            ".yt-lockup-thumbnail:not(.yt-pl-thumb):hover,.thumb-wrapper:hover { " +
            "z-index: 9999999999 !important; " +
            "box-shadow: 0px 0px 100px #000000 !important; " +
            "-webkit-transition: all 200ms ease-in !important; " +
            "-webkit-transform: scale(2.0) !important; " +
            "-moz-transition: all 200ms ease-in !important; " +
            "-moz-transform: scale(2.0) !important; " +
            "transition: all 200ms ease-in !important; " +
            "transform: scale(2.0) !important; " +
            "} " +

            ".yt-thumb.video-thumb, .yt-uix-simple-thumb-wrap.yt-uix-simple-thumb-related { " +
            "background-color: black !important; " +
            "} " +

            ".xspinner { " +
            "pointer-events: none; " +
            "position: absolute; " +
            "top: 0; " +
            "right: 0; " +
            "bottom: 0; " +
            "left: 0; " +
            "background: rgba(255,255,255,0.5); " +
            "font-size: 14px; " +
            "text-align: center; " +
            "line-height: 2; " +
            "color: rgb(0,0,0); " +
            "font-weight: bold; " +
            "} ");

        initOn(document);
        var mo = new MutationObserver(function(muts) {
            muts.forEach(function(mut) {
                [].forEach.call(mut.addedNodes, function(node) {
                    if (node instanceof HTMLElement) {
                        initOn(node);
                    }
                });
            });
        });
        mo.observe(document.body, {childList: true, subtree: true});
    }

    function initOn(base) {
        [].forEach.call(base.querySelectorAll('.yt-lockup-thumbnail:not(.yt-pl-thumb) a[href^="/watch"], .thumb-wrapper a[href^="/watch"]'), function(thumbnail) {

            thumbnail.parentNode.addEventListener('mouseover', function() {
                if(thumbnail.overlocker) return;
                thumbnail.overlocker = new Promise(function (unlock) {
                    var rect = thumbnail.parentElement.getBoundingClientRect();
                    var farRight = (rect.right + thumbnail.parentElement.clientWidth/2.0) > window.innerWidth;
                    var farDown = (rect.bottom + thumbnail.parentElement.clientHeight/2.0) > window.innerHeight;
                    var farLeft = (rect.left - thumbnail.parentElement.clientWidth/2.0) < 0;
                    var farUp = (rect.top - thumbnail.parentElement.clientHeight/2.0) < 0;
                    if(farRight || farDown || farLeft || farUp) {
                        var transformOrig = (farRight ? 'right ':'') + (farDown ? 'bottom ':'') + (farLeft ? 'left ':'') + (farUp ? 'top ':'');
                        thumbnail.parentElement.style.webkitTransformOrigin = transformOrig;
                        thumbnail.parentElement.style.mozTransformOrigin = transformOrig;
                        thumbnail.parentElement.style.transformOrigin = transformOrig;
                    }

                    var spinner = document.createElement('div');
                    spinner.className = 'xspinner';
                    spinner.textContent = 'Loading...';

                    var childThumb = thumbnail.querySelector('.yt-thumb.video-thumb, .yt-uix-simple-thumb-wrap.yt-uix-simple-thumb-related');
                    childThumb.appendChild(spinner);

                    thumbnail.watchedContainer = [];
                    for (var el = thumbnail; el; el = el.parentElement) {
                        if (el.classList.contains('watched')) {
                            thumbnail.watchedContainer.push(el);
                            el.classList.remove('watched');
                        }
                    }
                    thumbnail.watchedBadgeContainer = [];
                    [].forEach.call(thumbnail.parentNode.querySelectorAll('.watched-badge'), function (watchedBadge) {
                        thumbnail.watchedBadgeContainer.push(watchedBadge);
                        watchedBadge.style.display = 'none';
                    });
                    thumbnail.imageContainer = [];
                    [].forEach.call(thumbnail.getElementsByTagName('img'), function(img) {
                        thumbnail.imageContainer.push(img);
                        img.style.opacity = 0;
                    });

                    var vidId = thumbnail.href.split('v=')[1];
                    thumbnail.PPlayer = new Promise(function (resolve) {
                        var playerTag = document.createElement('div');
                        playerTag.id = vidId;
                        playerTag.style.pointerEvents = 'none';
                        playerTag.style.position = 'absolute';
                        childThumb.insertBefore(playerTag, childThumb.firstChild);
                        APIready.then(function () {
                            var pplayer = new YT.Player(playerTag.id, {
                                width: childThumb.offsetWidth,
                                height: childThumb.offsetHeight,
                                videoId: vidId,
                                playerVars: {
                                    'enablejsapi': 1, 'autoplay': 1, 'showinfo': 0, 'controls': 0,
                                    'modestbranding': 1, 'ps': 'docs', 'iv_load_policy': 3, 'rel': 0,
                                    'vq': 'medium'
                                },
                                events: {
                                    'onReady': function() { resolve(pplayer); }
                                }
                            });
                        });
                    });
                    thumbnail.PPlayer.then(function () {
                        childThumb.removeChild(spinner);
                        unlock();
                    });
                });
            });

            thumbnail.parentNode.addEventListener('mousemove', function(evt) {
                if (thumbnail.spinner) return;

                if(thumbnail.lastX !== evt.screenX) {
                    var offsetX = evt.offsetX || evt.layerX - thumbnail.offsetLeft;

                    if(thumbnail.PPlayer) {
                        thumbnail.PPlayer.then(function (PPlayer) {
                            try {
                                PPlayer.seekTo(PPlayer.getDuration() * offsetX / thumbnail.parentElement.offsetWidth, true);
                            } catch (e){}
                        });
                    }
                }
                thumbnail.lastX = evt.screenX;
            });

            thumbnail.parentNode.addEventListener('mouseout', function(evt) {
                if(!thumbnail.overlocker) return;
                thumbnail.overlocker.then(function () {
                    if(evt.relatedTarget) {
                        if (thumbnail.parentElement.contains(evt.relatedTarget)) return;
                        if (evt.relatedTarget.className.indexOf('yt-uix-tooltip-tip') !== -1) return;
                    }

                    if(thumbnail.watchedContainer) {
                        for (var i = 0; i < thumbnail.watchedContainer.length; i++)
                            thumbnail.watchedContainer[i].classList.add('watched');
                        thumbnail.watchedContainer = null;
                    }
                    if(thumbnail.watchedBadgeContainer) {
                        for (var i = 0; i < thumbnail.watchedBadgeContainer.length; i++)
                            thumbnail.watchedBadgeContainer[i].style.display = null;
                        thumbnail.watchedBadgeContainer = null;
                    }
                    if(thumbnail.imageContainer) {
                        for (var i = 0; i < thumbnail.imageContainer.length; i++)
                            thumbnail.imageContainer[i].style.opacity = null;
                        thumbnail.imageContainer = null;
                    }

                    if(thumbnail.PPlayer) {
                        thumbnail.PPlayer.then(function(PPlayer) {
                            if(PPlayer.a.parentNode)
                                PPlayer.a.parentNode.removeChild(PPlayer.a);
                            thumbnail.PPlayer = null;
                            thumbnail.overlocker = null;
                        });
                    }
                    else {
                        thumbnail.overlocker = null;
                    }
                });
            });

        });
    }

    function addGlobalStyle(css) {
        var head = document.getElementsByTagName('head')[0];
        if (!head) { return; }
        var style = document.createElement('style');
        style.type = 'text/css';
        style.innerHTML = css;
        head.appendChild(style);
    }

    init();
})();