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/* 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";
this.EXPORTED_SYMBOLS = ["HiddenFrame"];
const { classes: Cc, interfaces: Ci, utils: Cu } = Components;
Cu.import("resource://gre/modules/PromiseUtils.jsm");
Cu.import("resource://gre/modules/Services.jsm");
Cu.import("resource://gre/modules/Timer.jsm");
const HTML_NS = "http://www.w3.org/1999/xhtml";
const XUL_PAGE = "data:application/vnd.mozilla.xul+xml;charset=utf-8,<window%20id='win'/>";
/**
* An hidden frame object. It takes care of creating an IFRAME and attaching it the
* |hiddenDOMWindow|.
*/
function HiddenFrame() {}
HiddenFrame.prototype = {
_frame: null,
_deferred: null,
_retryTimerId: null,
get hiddenDOMDocument() {
return Services.appShell.hiddenDOMWindow.document;
},
get isReady() {
return this.hiddenDOMDocument.readyState === "complete";
},
/**
* Gets the |contentWindow| of the hidden frame. Creates the frame if needed.
* @returns Promise Returns a promise which is resolved when the hidden frame has finished
* loading.
*/
get: function () {
if (!this._deferred) {
this._deferred = PromiseUtils.defer();
this._create();
}
return this._deferred.promise;
},
destroy: function () {
clearTimeout(this._retryTimerId);
if (this._frame) {
if (!Cu.isDeadWrapper(this._frame)) {
this._frame.removeEventListener("load", this, true);
this._frame.remove();
}
this._frame = null;
this._deferred = null;
}
},
handleEvent: function () {
let contentWindow = this._frame.contentWindow;
if (contentWindow.location.href === XUL_PAGE) {
this._frame.removeEventListener("load", this, true);
this._deferred.resolve(contentWindow);
} else {
contentWindow.location = XUL_PAGE;
}
},
_create: function () {
if (this.isReady) {
let doc = this.hiddenDOMDocument;
this._frame = doc.createElementNS(HTML_NS, "iframe");
this._frame.addEventListener("load", this, true);
doc.documentElement.appendChild(this._frame);
} else {
// Check again if |hiddenDOMDocument| is ready as soon as possible.
this._retryTimerId = setTimeout(this._create.bind(this), 0);
}
}
};