Wired background loader component extension.

chrome/browser/resources/chromeos/backloader/scripts/background.js

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-function Loader(pages) {
-  this.pages_ = pages;
-  this.pages_loaded_ = false;
-  this.loaded_count_ = false;
-}
-
-// Global instance.
-Loader.instance_ = null;
-
-// static.
-Loader.getInstance = function() {
-  if (!Loader.instance_) {
-    if (!g_pages)
-      console.log('Warning: Undefined g_pages.');
-    Loader.instance_ = new Loader(g_pages);
-  }
-
-  return Loader.instance_;
-};
-
-Loader.prototype = {
-  // Alarm name.
-  ALARM_NAME: 'CrOSBkgLoaderAlarm',
-  // Initial delay.
-  DELAY_IN_MINUTES: 1,
-  // Periodic wakeup delay.
-  PERIOD_IN_MINUTES: 60,
-  // Delayed closing of the background page once when all iframes are loaded.
-  UNLOAD_DELAY_IN_MS: 10000,
-
-  // Loader start up. Kicks off alarm initialization if needed.
-  initialize: function() {
-    if (!g_pages || !g_pages.length) {
-      window.close();
-      return;
-    }
-
-    chrome.alarms.onAlarm.addListener(this.onAlarm_.bind(this));
-    // Check if this alarm already exists, if not then create it.
-    chrome.alarms.get(this.ALARM_NAME, function(alarm) {
-      if (!alarm) {
-        chrome.alarms.create(this.ALARM_NAME,
-                             {delayInMinutes: this.DELAY_IN_MINUTES,
-                              periodInMinutes: this.PERIOD_IN_MINUTES});
-        window.close();
-        return;
-      }
-    }.bind(this));
-  },
-
-  onAlarm_: function(alarm) {
-    this.loadSubPages_();
-  },
-
-  onMessage_: function(event) {
-    var msg = event.data;
-    if (msg.method == 'validate') {
-      var reply_msg = {
-          method: 'validationResults',
-          os: 'ChromeOS'
-      };
-      event.source.postMessage(reply_msg, event.origin);
-    } else {
-      console.log('#### Loader.onMessage_: unknown message');
-    }
-  },
-
-  loadSubPages_: function() {
-    if (this.pages_loaded_)
-      return;
-
-    window.addEventListener('message', this.onMessage_.bind(this), false);
-    for (i = 0; i < this.pages_.length; i++) {
-      this.loadPage_(i, this.pages_[i]);
-    }
-    this.pages_loaded_ = true;
-  },
-
-  loadPage_: function(index, pageUrl) {
-    var iframe = document.createElement('iframe');
-    iframe.onload = function() {
-      this.loaded_count_++;
-      if (this.loaded_count_ < this.pages_.length)
-        return;
-
-      // Delay closing.
-      setInterval(function() {
-        window.close();
-      }.bind(this), this.UNLOAD_DELAY_IN_MS);
-    }.bind(this);
-    iframe.src = pageUrl;
-    iframe.name = 'frame_' + index;
-    document.body.appendChild(iframe);
-  }
-};
-
-Loader.getInstance().initialize();