1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/browser/modules/CustomizationTabPreloader.jsm Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,217 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this file,
1.6 + * You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +"use strict";
1.9 +
1.10 +this.EXPORTED_SYMBOLS = ["CustomizationTabPreloader"];
1.11 +
1.12 +const Cu = Components.utils;
1.13 +const Cc = Components.classes;
1.14 +const Ci = Components.interfaces;
1.15 +
1.16 +Cu.import("resource://gre/modules/Services.jsm");
1.17 +Cu.import("resource://gre/modules/Promise.jsm");
1.18 +
1.19 +const HTML_NS = "http://www.w3.org/1999/xhtml";
1.20 +const XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
1.21 +const XUL_PAGE = "data:application/vnd.mozilla.xul+xml;charset=utf-8,<window%20id='win'/>";
1.22 +const CUSTOMIZATION_URL = "about:customizing";
1.23 +
1.24 +// The interval between swapping in a preload docShell and kicking off the
1.25 +// next preload in the background.
1.26 +const PRELOADER_INTERVAL_MS = 600;
1.27 +
1.28 +function createTimer(obj, delay) {
1.29 + let timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
1.30 + timer.init(obj, delay, Ci.nsITimer.TYPE_ONE_SHOT);
1.31 + return timer;
1.32 +}
1.33 +
1.34 +function clearTimer(timer) {
1.35 + if (timer) {
1.36 + timer.cancel();
1.37 + }
1.38 + return null;
1.39 +}
1.40 +
1.41 +this.CustomizationTabPreloader = {
1.42 + uninit: function () {
1.43 + CustomizationTabPreloaderInternal.uninit();
1.44 + },
1.45 +
1.46 + newTab: function (aTab) {
1.47 + return CustomizationTabPreloaderInternal.newTab(aTab);
1.48 + },
1.49 +
1.50 + /**
1.51 + * ensurePreloading starts the preloading of the about:customizing
1.52 + * content page. This function is idempotent (until a call to uninit),
1.53 + * so multiple calls to it are fine.
1.54 + */
1.55 + ensurePreloading: function() {
1.56 + CustomizationTabPreloaderInternal.ensurePreloading();
1.57 + },
1.58 +};
1.59 +
1.60 +Object.freeze(CustomizationTabPreloader);
1.61 +
1.62 +this.CustomizationTabPreloaderInternal = {
1.63 + _browser: null,
1.64 +
1.65 + uninit: function () {
1.66 + HostFrame.destroy();
1.67 +
1.68 + if (this._browser) {
1.69 + this._browser.destroy();
1.70 + this._browser = null;
1.71 + }
1.72 + },
1.73 +
1.74 + newTab: function (aTab) {
1.75 + let win = aTab.ownerDocument.defaultView;
1.76 + if (win.gBrowser && this._browser) {
1.77 + return this._browser.swapWithNewTab(aTab);
1.78 + }
1.79 +
1.80 + return false;
1.81 + },
1.82 +
1.83 + ensurePreloading: function () {
1.84 + if (!this._browser) {
1.85 + this._browser = new HiddenBrowser();
1.86 + }
1.87 + }
1.88 +};
1.89 +
1.90 +function HiddenBrowser() {
1.91 + this._createBrowser();
1.92 +}
1.93 +
1.94 +HiddenBrowser.prototype = {
1.95 + _timer: null,
1.96 +
1.97 + get isPreloaded() {
1.98 + return this._browser &&
1.99 + this._browser.contentDocument &&
1.100 + this._browser.contentDocument.readyState === "complete" &&
1.101 + this._browser.currentURI.spec === CUSTOMIZATION_URL;
1.102 + },
1.103 +
1.104 + swapWithNewTab: function (aTab) {
1.105 + if (!this.isPreloaded || this._timer) {
1.106 + return false;
1.107 + }
1.108 +
1.109 + let win = aTab.ownerDocument.defaultView;
1.110 + let tabbrowser = win.gBrowser;
1.111 +
1.112 + if (!tabbrowser) {
1.113 + return false;
1.114 + }
1.115 +
1.116 + // Swap docShells.
1.117 + tabbrowser.swapNewTabWithBrowser(aTab, this._browser);
1.118 +
1.119 + // Load all default frame scripts attached to the target window.
1.120 + let mm = aTab.linkedBrowser.messageManager;
1.121 + let scripts = win.messageManager.getDelayedFrameScripts();
1.122 + Array.forEach(scripts, ([script, runGlobal]) => mm.loadFrameScript(script, true, runGlobal));
1.123 +
1.124 + // Remove the browser, it will be recreated by a timer.
1.125 + this._removeBrowser();
1.126 +
1.127 + // Start a timer that will kick off preloading the next page.
1.128 + this._timer = createTimer(this, PRELOADER_INTERVAL_MS);
1.129 +
1.130 + // Signal that we swapped docShells.
1.131 + return true;
1.132 + },
1.133 +
1.134 + observe: function () {
1.135 + this._timer = null;
1.136 +
1.137 + // Start pre-loading the customization page.
1.138 + this._createBrowser();
1.139 + },
1.140 +
1.141 + destroy: function () {
1.142 + this._removeBrowser();
1.143 + this._timer = clearTimer(this._timer);
1.144 + },
1.145 +
1.146 + _createBrowser: function () {
1.147 + HostFrame.get().then(aFrame => {
1.148 + let doc = aFrame.document;
1.149 + this._browser = doc.createElementNS(XUL_NS, "browser");
1.150 + this._browser.setAttribute("type", "content");
1.151 + this._browser.setAttribute("src", CUSTOMIZATION_URL);
1.152 + this._browser.style.width = "400px";
1.153 + this._browser.style.height = "400px";
1.154 + doc.getElementById("win").appendChild(this._browser);
1.155 + });
1.156 + },
1.157 +
1.158 + _removeBrowser: function () {
1.159 + if (this._browser) {
1.160 + this._browser.remove();
1.161 + this._browser = null;
1.162 + }
1.163 + }
1.164 +};
1.165 +
1.166 +let HostFrame = {
1.167 + _frame: null,
1.168 + _deferred: null,
1.169 +
1.170 + get hiddenDOMDocument() {
1.171 + return Services.appShell.hiddenDOMWindow.document;
1.172 + },
1.173 +
1.174 + get isReady() {
1.175 + return this.hiddenDOMDocument.readyState === "complete";
1.176 + },
1.177 +
1.178 + get: function () {
1.179 + if (!this._deferred) {
1.180 + this._deferred = Promise.defer();
1.181 + this._create();
1.182 + }
1.183 +
1.184 + return this._deferred.promise;
1.185 + },
1.186 +
1.187 + destroy: function () {
1.188 + if (this._frame) {
1.189 + if (!Cu.isDeadWrapper(this._frame)) {
1.190 + this._frame.removeEventListener("load", this, true);
1.191 + this._frame.remove();
1.192 + }
1.193 +
1.194 + this._frame = null;
1.195 + this._deferred = null;
1.196 + }
1.197 + },
1.198 +
1.199 + handleEvent: function () {
1.200 + let contentWindow = this._frame.contentWindow;
1.201 + if (contentWindow.location.href === XUL_PAGE) {
1.202 + this._frame.removeEventListener("load", this, true);
1.203 + this._deferred.resolve(contentWindow);
1.204 + } else {
1.205 + contentWindow.location = XUL_PAGE;
1.206 + }
1.207 + },
1.208 +
1.209 + _create: function () {
1.210 + if (this.isReady) {
1.211 + let doc = this.hiddenDOMDocument;
1.212 + this._frame = doc.createElementNS(HTML_NS, "iframe");
1.213 + this._frame.addEventListener("load", this, true);
1.214 + doc.documentElement.appendChild(this._frame);
1.215 + } else {
1.216 + let flags = Ci.nsIThread.DISPATCH_NORMAL;
1.217 + Services.tm.currentThread.dispatch(() => this._create(), flags);
1.218 + }
1.219 + }
1.220 +};
