tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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local-tab-commands-factory.js (2300B)

      1 /* This Source Code Form is subject to the terms of the Mozilla Public
      2 * License, v. 2.0. If a copy of the MPL was not distributed with this
      3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      4 
      5 "use strict";
      6 
      7 loader.lazyRequireGetter(
      8  this,
      9  "CommandsFactory",
     10  "resource://devtools/shared/commands/commands-factory.js",
     11  true
     12 );
     13 
     14 // Map of existing Commands objects, keyed by XULTab.
     15 const commandsMap = new WeakMap();
     16 
     17 /**
     18 * Functions for creating unique Commands for Local Tabs.
     19 */
     20 exports.LocalTabCommandsFactory = {
     21  /**
     22   * Create a unique commands object for the given tab.
     23   *
     24   * If a commands was already created by this factory for the provided tab,
     25   * it will be returned and no new commands created.
     26   *
     27   * Otherwise, this will automatically:
     28   * - spawn a DevToolsServer in the parent process,
     29   * - create a DevToolsClient
     30   * - connect the DevToolsClient to the DevToolsServer
     31   * - call RootActor's `getTab` request to retrieve the WindowGlobalTargetActor's form
     32   *
     33   * @param {XULTab} tab
     34   *        The tab to use in creating a new commands.
     35   *
     36   * @return {Commands object} The commands object for the provided tab.
     37   */
     38  async createCommandsForTab(tab) {
     39    let commands = commandsMap.get(tab);
     40    if (commands) {
     41      // Keep in mind that commands can be either a promise
     42      // or a commands object.
     43      return commands;
     44    }
     45 
     46    const promise = CommandsFactory.forTab(tab);
     47    // Immediately set the commands's promise in cache to prevent race
     48    commandsMap.set(tab, promise);
     49    commands = await promise;
     50    // Then replace the promise with the commands object
     51    commandsMap.set(tab, commands);
     52 
     53    commands.descriptorFront.once("descriptor-destroyed", () => {
     54      commandsMap.delete(tab);
     55    });
     56    return commands;
     57  },
     58 
     59  /**
     60   * Retrieve an existing commands created by this factory for the provided
     61   * tab. Returns null if no commands was created yet.
     62   *
     63   * @param {XULTab} tab
     64   *        The tab for which the commands should be retrieved
     65   */
     66  async getCommandsForTab(tab) {
     67    // commandsMap.get(tab) can either return an initialized commands, a promise
     68    // which will resolve a commands, or null if no commands was ever created
     69    // for this tab.
     70    return commandsMap.get(tab);
     71  },
     72 };