gecko-dev/b2g/components/SystemAppProxy.jsm

123 строки
3.8 KiB
JavaScript

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