Continuación de https://extensions.gnome.org/extension/1601/youtube-popup-web-browser-extention/ que es continuación de https://extensions.gnome.org/extension/1095/float-youtube-preview/ funcionando en Pop OS 20.04

extension.js

// Copyright (c) Ulisses 2019
// License: MIT
// Modified by @juusechec
const Meta = imports.gi.Meta;
const Lang = imports.lang;
const Main = imports.ui.main;


function init(em) {
  return new HoppingWindow(em);
}

function HoppingWindow(em) {
  this.corner = 2;
}

HoppingWindow.prototype = {
  enable: function () {
    this.workspaceSwitchSignal = global.workspace_manager.connect("workspace-switched", Lang.bind(this, this.try_spawn))
  },
  disable: function () {
    this.despawn_window();
    global.workspace_manager.disconnect(this.workspaceSwitchSignal)
  },
  try_spawn: function () {
    this.despawn_window();
    let target = this.find_window("YouTube") ||
                 this.find_window("Anime") ||
                 this.find_window("Online");
    if (target) {
      this.spawn_window(target);
    }
  },
  find_window: function (title) {
    let workspaces_count = global.workspace_manager.n_workspaces;
    // global.log('workspaces_count', workspaces_count);

    let active_workspace_index = global.workspace_manager.get_active_workspace_index();
    // global.log('active_workspace_index', active_workspace_index);

    for (let i = 0; i < workspaces_count; i++) {
      if (i != active_workspace_index) {
        let workspace = global.workspace_manager.get_workspace_by_index(i);

        const window = this.find_window_in_workspace(workspace, title);
        if (window) {
          return window;
        }
      }
    }
  },
  find_window_in_workspace: function (workspace, title) {
    let windows = workspace.list_windows();
    // global.log('windows.length', windows.length);
    for (let i in windows) {
      // global.log('windows[i]', windows[i], windows[i].get_title());
      if (windows[i].get_title().search(title) > -1) {
        return windows[i];
      }
    }
  },
  despawn_window: function () {
    if (!this.preview) {
      return;
    }

    this.preview.destroy();
    this.preview = null;
  },
  spawn_window: function (win) {
    this.despawn_window();

    this.preview = new imports.gi.St.Button({
      style_class: "youtube-preview"
    });
    let th = this.generate_texture(win, 350);
    this.preview.add_actor(th);

    function increment(i) {
      return i + 1;
    }

    let event = Lang.bind(this, _ => this.switchCorner(increment));
    this.preview.connect("enter-event", event);
    this.switchCorner();

    Main.layoutManager.addChrome(this.preview);
  },
  generate_texture: function (win, size) {
    let mutw = win.get_compositor_private();

    if (!mutw) {
      return;
    }
    
    let framerect = win.get_frame_rect();
    let width = framerect.width;
    let height = framerect.height;
    let scale = Math.min(1.0, size / width, size / height);

    let th = new imports.gi.Clutter.Clone({
      source: mutw,
      reactive: true,
      width: width * scale,
      height: height * scale
    });

    return th;
  }
}

HoppingWindow.prototype.switchCorner = function (increment) {
  if (typeof increment == 'function') {
    this.corner = increment(this.corner) % 4
  }

  let g = Main.layoutManager.getWorkAreaForMonitor(0);

  let border_size = 0;

  let drawable_rect = [
    g.x, g.y, g.x + g.width - this.preview.get_width(), g.y + g.height - this.preview.get_height(),
  ];

  let points = [
    [
      drawable_rect[0], drawable_rect[1],
    ],
    [
      drawable_rect[0], drawable_rect[3],
    ],
    [
      drawable_rect[2] - 0, 0,
    ],
    [
      drawable_rect[2], drawable_rect[3],
    ],
  ];

  // global.log("corner: " + this.corner);

  this.posX = points[this.corner][0];
  this.posY = points[this.corner][1];

  // global.log("position_x: " + this.posX + ", position_y: " + this.posY);

  this.preview.set_position(this.posX, this.posY);
};