chrome/browser/resources/hotword/keep_alive.js

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 cr.define('hotword', function() {
   6   'use strict';
   7
   8   /**
   9    * Class used to keep this extension alive. When started, this calls an
  10    * extension API on a regular basis which resets the event page keep-alive
  11    * timer.
  12    * @constructor
  13    */
  14   function KeepAlive() {
  15     this.timeoutId_ = null;
  16   }
  17
  18   KeepAlive.prototype = {
  19     /**
  20      * Start the keep alive process. Safe to call multiple times.
  21      */
  22     start: function() {
  23       if (this.timeoutId_ == null)
  24         this.timeoutId_ = setTimeout(this.handleTimeout_.bind(this), 1000);
  25     },
  26
  27     /**
  28      * Stops the keep alive process. Safe to call multiple times.
  29      */
  30     stop: function() {
  31       if (this.timeoutId_ != null) {
  32         clearTimeout(this.timeoutId_);
  33         this.timeoutId_ = null;
  34       }
  35     },
  36
  37     /**
  38      * Handle the timer timeout. Calls an extension API and schedules the next
  39      * timeout.
  40      * @private
  41      */
  42     handleTimeout_: function() {
  43       // Dummy extensions API call used to keep this event page alive by
  44       // resetting the shutdown timer.
  45       chrome.runtime.getPlatformInfo(function(info) {});
  46
  47       this.timeoutId_ = setTimeout(this.handleTimeout_.bind(this), 1000);
  48     }
  49   };
  50
  51   return {
  52     KeepAlive: KeepAlive
  53   };
  54 });