The Tor Browser / file revision

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 "use strict";

 module.metadata = {

   "stability": "unstable"

 };

 const { Trait } = require("../deprecated/light-traits");

 const { EventEmitterTrait: EventEmitter } = require("../deprecated/events");

 const { DOMEventAssembler } = require("../deprecated/events/assembler");

 const { browserWindowIterator } = require('../deprecated/window-utils');

 const { isBrowser } = require('../window/utils');

 const { observer: windowObserver } = require("../windows/observer");

 // Event emitter objects used to register listeners and emit events on them

 // when they occur.

 const observer = Trait.compose(DOMEventAssembler, EventEmitter).create({

   /**

    * Method is implemented by `EventEmitter` and is used just for emitting

    * events on registered listeners.

    */

   _emit: Trait.required,

   /**

    * Events that are supported and emitted by the module.

    */

   supportedEventsTypes: [ "keydown", "keyup", "keypress" ],

   /**

    * Function handles all the supported events on all the windows that are

    * observed. Method is used to proxy events to the listeners registered on

    * this event emitter.

    * @param {Event} event

    *    Keyboard event being emitted.

    */

   handleEvent: function handleEvent(event) {

     this._emit(event.type, event, event.target.ownerDocument.defaultView);

   }

 });

 // Adding each opened window to a list of observed windows.

 windowObserver.on("open", function onOpen(window) {

   if (isBrowser(window))

     observer.observe(window);

 });

 // Removing each closed window form the list of observed windows.

 windowObserver.on("close", function onClose(window) {

   if (isBrowser(window))

     observer.ignore(window);

 });

 // Making observer aware of already opened windows.

 for each (let window in browserWindowIterator())

   observer.observe(window);

 exports.observer = observer;