javascript 允许镜像Youtube视频播放

Posted 2021-05-03

// ==UserScript==
// @name         Youtube Mirror
// @namespace    https://drjest.xyz/
// @version      1.0
// @description  Allows to mirror Youtube video playback
// @author       DrJest
// @match        https://www.youtube.com/watch*
// @grant        none
// ==/UserScript==

(function() {
  const activate = () => {
    if(document.querySelector('#yt-mirror')) {
      return;
    }
    var label = document.createElement('label');
    label.innerText = 'Mirror?';
    label.style.float = 'right';
    label.style.fontSize = '70%';
    label.style.cursor = 'pointer';
    label.id = 'yt-mirror';
    var cb = document.createElement('input');
    cb.type = 'checkbox';
    label.appendChild(cb);
    cb.addEventListener('change', function() {
        document.querySelector('#movie_player > div.html5-video-container > video').style.transform = this.checked ? 'scale(-1,1)' : '';
        sessionStorage.setItem('mirror', this.checked);
    });
    if(sessionStorage.getItem('mirror') === 'true') {
      cb.checked = true;
      document.querySelector('#movie_player > div.html5-video-container > video').style.transform = 'scale(-1,1)';
    }
    document.querySelector('.title').appendChild(label);
  };
  document.body.addEventListener('yt-page-data-updated', evt => {
    activate();
  });
})();