michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 'use strict';
michael@0: 
michael@0: module.metadata = {
michael@0:   "stability": "unstable"
michael@0: };
michael@0: 
michael@0: const { EventEmitterTrait: EventEmitter } = require("../deprecated/events");
michael@0: const { DOMEventAssembler } = require("../deprecated/events/assembler");
michael@0: const { Trait } = require("../deprecated/light-traits");
michael@0: const { getActiveTab, getTabs, getTabContainer } = require("./utils");
michael@0: const { browserWindowIterator } = require("../deprecated/window-utils");
michael@0: const { isBrowser } = require('../window/utils');
michael@0: const { observer: windowObserver } = require("../windows/observer");
michael@0: 
michael@0: const EVENTS = {
michael@0:   "TabOpen": "open",
michael@0:   "TabClose": "close",
michael@0:   "TabSelect": "select",
michael@0:   "TabMove": "move",
michael@0:   "TabPinned": "pinned",
michael@0:   "TabUnpinned": "unpinned"
michael@0: };
michael@0: 
michael@0: 
michael@0: // Event emitter objects used to register listeners and emit events on them
michael@0: // when they occur.
michael@0: const observer = Trait.compose(DOMEventAssembler, EventEmitter).create({
michael@0:   /**
michael@0:    * Method is implemented by `EventEmitter` and is used just for emitting
michael@0:    * events on registered listeners.
michael@0:    */
michael@0:   _emit: Trait.required,
michael@0:   /**
michael@0:    * Events that are supported and emitted by the module.
michael@0:    */
michael@0:   supportedEventsTypes: Object.keys(EVENTS),
michael@0:   /**
michael@0:    * Function handles all the supported events on all the windows that are
michael@0:    * observed. Method is used to proxy events to the listeners registered on
michael@0:    * this event emitter.
michael@0:    * @param {Event} event
michael@0:    *    Keyboard event being emitted.
michael@0:    */
michael@0:   handleEvent: function handleEvent(event) {
michael@0:     this._emit(EVENTS[event.type], event.target, event);
michael@0:   }
michael@0: });
michael@0: 
michael@0: // Currently Gecko does not dispatch any event on the previously selected
michael@0: // tab before / after "TabSelect" is dispatched. In order to work around this
michael@0: // limitation we keep track of selected tab and emit "deactivate" event with
michael@0: // that before emitting "activate" on selected tab.
michael@0: var selectedTab = null;
michael@0: function onTabSelect(tab) {
michael@0:   if (selectedTab !== tab) {
michael@0:     if (selectedTab) observer._emit('deactivate', selectedTab);
michael@0:     if (tab) observer._emit('activate', selectedTab = tab);
michael@0:   }
michael@0: };
michael@0: observer.on('select', onTabSelect);
michael@0: 
michael@0: // We also observe opening / closing windows in order to add / remove it's
michael@0: // containers to the observed list.
michael@0: function onWindowOpen(chromeWindow) {
michael@0:   if (!isBrowser(chromeWindow)) return; // Ignore if it's not a browser window.
michael@0:   observer.observe(getTabContainer(chromeWindow));
michael@0: }
michael@0: windowObserver.on("open", onWindowOpen);
michael@0: 
michael@0: function onWindowClose(chromeWindow) {
michael@0:   if (!isBrowser(chromeWindow)) return; // Ignore if it's not a browser window.
michael@0:   // Bug 751546: Emit `deactivate` event on window close immediatly
michael@0:   // Otherwise we are going to face "dead object" exception on `select` event
michael@0:   if (getActiveTab(chromeWindow) == selectedTab) {
michael@0:     observer._emit("deactivate", selectedTab);
michael@0:     selectedTab = null;
michael@0:   }
michael@0:   observer.ignore(getTabContainer(chromeWindow));
michael@0: }
michael@0: windowObserver.on("close", onWindowClose);
michael@0: 
michael@0: 
michael@0: // Currently gecko does not dispatches "TabSelect" events when different
michael@0: // window gets activated. To work around this limitation we emulate "select"
michael@0: // event for this case.
michael@0: windowObserver.on("activate", function onWindowActivate(chromeWindow) {
michael@0:   if (!isBrowser(chromeWindow)) return; // Ignore if it's not a browser window.
michael@0:   observer._emit("select", getActiveTab(chromeWindow));
michael@0: });
michael@0: 
michael@0: // We should synchronize state, since probably we already have at least one
michael@0: // window open.
michael@0: for each (let window in browserWindowIterator()) onWindowOpen(window);
michael@0: 
michael@0: exports.observer = observer;