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 file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: 'use strict';
michael@0: 
michael@0: const { classes: Cc, interfaces: Ci, utils: Cu } = Components;
michael@0: 
michael@0: Cu.import('resource://gre/modules/XPCOMUtils.jsm');
michael@0: Cu.import('resource://gre/modules/Services.jsm');
michael@0: 
michael@0: this.EXPORTED_SYMBOLS = ['SystemAppProxy'];
michael@0: 
michael@0: let SystemAppProxy = {
michael@0:   _frame: null,
michael@0:   _isReady: false,
michael@0:   _pendingEvents: [],
michael@0:   _pendingListeners: [],
michael@0: 
michael@0:   // To call when a new system app iframe is created
michael@0:   registerFrame: function (frame) {
michael@0:     this._isReady = false;
michael@0:     this._frame = frame;
michael@0: 
michael@0:     // Register all DOM event listeners added before we got a ref to the app iframe
michael@0:     this._pendingListeners
michael@0:         .forEach((args) =>
michael@0:                  this.addEventListener.apply(this, args));
michael@0:     this._pendingListeners = [];
michael@0:   },
michael@0: 
michael@0:   // To call when it is ready to receive events
michael@0:   setIsReady: function () {
michael@0:     if (this._isReady) {
michael@0:       Cu.reportError('SystemApp has already been declared as being ready.');
michael@0:     }
michael@0:     this._isReady = true;
michael@0: 
michael@0:     // Dispatch all events being queued while the system app was still loading
michael@0:     this._pendingEvents
michael@0:         .forEach(([type, details]) =>
michael@0:                  this._sendCustomEvent(type, details));
michael@0:     this._pendingEvents = [];
michael@0:   },
michael@0: 
michael@0:   /*
michael@0:    * Common way to send an event to the system app.
michael@0:    *
michael@0:    * // In gecko code:
michael@0:    *   SystemAppProxy.sendCustomEvent('foo', { data: 'bar' });
michael@0:    * // In system app:
michael@0:    *   window.addEventListener('foo', function (event) {
michael@0:    *     event.details == 'bar'
michael@0:    *   });
michael@0:    */
michael@0:   _sendCustomEvent: function systemApp_sendCustomEvent(type, details) {
michael@0:     let content = this._frame ? this._frame.contentWindow : null;
michael@0: 
michael@0:     // If the system app isn't ready yet,
michael@0:     // queue events until someone calls setIsLoaded
michael@0:     if (!this._isReady || !content) {
michael@0:       this._pendingEvents.push([type, details]);
michael@0:       return null;
michael@0:     }
michael@0: 
michael@0:     let event = content.document.createEvent('CustomEvent');
michael@0: 
michael@0:     let payload;
michael@0:     // If the root object already has __exposedProps__,
michael@0:     // we consider the caller already wrapped (correctly) the object.
michael@0:     if ('__exposedProps__' in details) {
michael@0:       payload = details;
michael@0:     } else {
michael@0:       payload = details ? Cu.cloneInto(details, content) : {};
michael@0:     }
michael@0: 
michael@0:     event.initCustomEvent(type, true, false, payload);
michael@0:     content.dispatchEvent(event);
michael@0: 
michael@0:     return event;
michael@0:   },
michael@0: 
michael@0:   // Now deprecated, use sendCustomEvent with a custom event name
michael@0:   dispatchEvent: function systemApp_sendChromeEvent(details) {
michael@0:     return this._sendCustomEvent('mozChromeEvent', details);
michael@0:   },
michael@0: 
michael@0:   // Listen for dom events on the system app
michael@0:   addEventListener: function systemApp_addEventListener() {
michael@0:     let content = this._frame ? this._frame.contentWindow : null;
michael@0:     if (!content) {
michael@0:       this._pendingListeners.push(arguments);
michael@0:       return false;
michael@0:     }
michael@0: 
michael@0:     content.addEventListener.apply(content, arguments);
michael@0:     return true;
michael@0:   },
michael@0: 
michael@0:   removeEventListener: function systemApp_removeEventListener(name, listener) {
michael@0:     let content = this._frame ? this._frame.contentWindow : null;
michael@0:     if (content) {
michael@0:       content.removeEventListener.apply(content, arguments);
michael@0:     } else {
michael@0:       let idx = this._pendingListeners.indexOf(listener);
michael@0:       if (idx != -1) {
michael@0:         this._pendingListeners.splice(idx, 1);
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: 
michael@0: };
michael@0: this.SystemAppProxy = SystemAppProxy;
michael@0: