зеркало из https://github.com/mozilla/gecko-dev.git
87 строки
2.3 KiB
JavaScript
87 строки
2.3 KiB
JavaScript
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this file,
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* You can obtain one at http://mozilla.org/MPL/2.0/. */
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"use strict";
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this.EXPORTED_SYMBOLS = ["HiddenFrame"];
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const { classes: Cc, interfaces: Ci, utils: Cu } = Components;
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Cu.import("resource://gre/modules/PromiseUtils.jsm");
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Cu.import("resource://gre/modules/Services.jsm");
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Cu.import("resource://gre/modules/Timer.jsm");
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const HTML_NS = "http://www.w3.org/1999/xhtml";
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const XUL_PAGE = "data:application/vnd.mozilla.xul+xml;charset=utf-8,<window%20id='win'/>";
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/**
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* An hidden frame object. It takes care of creating an IFRAME and attaching it the
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* |hiddenDOMWindow|.
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*/
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function HiddenFrame() {}
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HiddenFrame.prototype = {
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_frame: null,
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_deferred: null,
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_retryTimerId: null,
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get hiddenDOMDocument() {
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return Services.appShell.hiddenDOMWindow.document;
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},
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get isReady() {
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return this.hiddenDOMDocument.readyState === "complete";
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},
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/**
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* Gets the |contentWindow| of the hidden frame. Creates the frame if needed.
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* @returns Promise Returns a promise which is resolved when the hidden frame has finished
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* loading.
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*/
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get() {
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if (!this._deferred) {
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this._deferred = PromiseUtils.defer();
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this._create();
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}
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return this._deferred.promise;
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},
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destroy() {
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clearTimeout(this._retryTimerId);
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if (this._frame) {
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if (!Cu.isDeadWrapper(this._frame)) {
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this._frame.removeEventListener("load", this, true);
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this._frame.remove();
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}
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this._frame = null;
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this._deferred = null;
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}
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},
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handleEvent() {
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let contentWindow = this._frame.contentWindow;
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if (contentWindow.location.href === XUL_PAGE) {
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this._frame.removeEventListener("load", this, true);
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this._deferred.resolve(contentWindow);
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} else {
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contentWindow.location = XUL_PAGE;
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}
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},
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_create() {
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if (this.isReady) {
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let doc = this.hiddenDOMDocument;
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this._frame = doc.createElementNS(HTML_NS, "iframe");
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this._frame.addEventListener("load", this, true);
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doc.documentElement.appendChild(this._frame);
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} else {
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// Check again if |hiddenDOMDocument| is ready as soon as possible.
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this._retryTimerId = setTimeout(this._create.bind(this), 0);
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}
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}
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};
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