remoting/webapp/smart_reconnector.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 /**
   6  * @fileoverview
   7  * Class handling reconnecting the session when it is disconnected due to
   8  * network failure.
   9  *
  10  * The SmartReconnector listens for changes in connection state of
  11  * |clientSession| to determine if a reconnection is needed.  It then calls into
  12  * |connector| to reconnect the session.
  13  */
  14
  15 'use strict';
  16
  17 /** @suppress {duplicate} */
  18 var remoting = remoting || {};
  19
  20 /**
  21  * @constructor
  22  * @param {remoting.SessionConnector} connector This is used to reconnect the
  23  *    the session when necessary
  24  * @param {remoting.ClientSession} clientSession This represents the current
  25  *    remote desktop connection.  It is used to monitor the changes in
  26  *    connection state.
  27  * @implements {base.Disposable}
  28  */
  29 remoting.SmartReconnector = function(connector, clientSession) {
  30   /** @private */
  31   this.connector_ = connector;
  32
  33   /** @private */
  34   this.clientSession_ = clientSession;
  35
  36   /** @private */
  37   this.reconnectTimerId_ = null;
  38
  39   /** @private */
  40   this.connectionTimeoutTimerId_ = null;
  41
  42   /** @private */
  43   this.bound_ = {
  44     reconnect: this.reconnect_.bind(this),
  45     reconnectAsync: this.reconnectAsync_.bind(this),
  46     startReconnectTimeout: this.startReconnectTimeout_.bind(this),
  47     stateChanged: this.stateChanged_.bind(this),
  48     videoChannelStateChanged: this.videoChannelStateChanged_.bind(this)
  49   };
  50
  51   clientSession.addEventListener(
  52       remoting.ClientSession.Events.stateChanged,
  53       this.bound_.stateChanged);
  54   clientSession.addEventListener(
  55       remoting.ClientSession.Events.videoChannelStateChanged,
  56       this.bound_.videoChannelStateChanged);
  57 };
  58
  59 // The online event only means the network adapter is enabled, but
  60 // it doesn't necessarily mean that we have a working internet connection.
  61 // Therefore, delay the connection by |kReconnectDelay| to allow for the network
  62 // to connect.
  63 remoting.SmartReconnector.kReconnectDelay = 2000;
  64
  65 // If the video channel is inactive for 10 seconds reconnect the session.
  66 remoting.SmartReconnector.kConnectionTimeout = 10000;
  67
  68 remoting.SmartReconnector.prototype = {
  69   reconnect_: function() {
  70     this.cancelPending_();
  71     remoting.disconnect();
  72     remoting.setMode(remoting.AppMode.CLIENT_CONNECTING);
  73     this.connector_.reconnect();
  74   },
  75
  76   reconnectAsync_: function() {
  77     this.cancelPending_();
  78     remoting.setMode(remoting.AppMode.CLIENT_CONNECTING);
  79     this.reconnectTimerId_ = window.setTimeout(
  80         this.bound_.reconnect, remoting.SmartReconnector.kReconnectDelay);
  81   },
  82
  83   /**
  84    * @param {remoting.ClientSession.StateEvent} event
  85    */
  86   stateChanged_: function(event) {
  87     var State = remoting.ClientSession.State;
  88     if (event.previous === State.CONNECTED && event.current === State.FAILED) {
  89       this.cancelPending_();
  90       if (navigator.onLine) {
  91         this.reconnect_();
  92       } else {
  93         window.addEventListener('online', this.bound_.reconnectAsync, false);
  94       }
  95     }
  96   },
  97
  98   /**
  99    * @param {boolean} active  True if the video channel is active.
 100    */
 101   videoChannelStateChanged_: function (active) {
 102     this.cancelPending_();
 103     if (!active) {
 104       window.addEventListener(
 105           'online', this.bound_.startReconnectTimeout, false);
 106     }
 107   },
 108
 109   startReconnectTimeout_: function () {
 110     this.cancelPending_();
 111     this.connectionTimeoutTimerId_ = window.setTimeout(
 112           this.bound_.reconnect, remoting.SmartReconnector.kConnectionTimeout);
 113   },
 114
 115   cancelPending_: function() {
 116     window.removeEventListener(
 117         'online', this.bound_.startReconnectTimeout, false);
 118     window.removeEventListener('online', this.bound_.reconnectAsync, false);
 119     window.clearTimeout(this.reconnectTimerId_);
 120     window.clearTimeout(this.connectionTimeoutTimerId_);
 121     this.reconnectTimerId_ = null;
 122     this.connectionTimeoutTimerId_ = null;
 123   },
 124
 125   dispose: function() {
 126     this.clientSession_.removeEventListener(
 127         remoting.ClientSession.Events.stateChanged,
 128         this.bound_.stateChanged);
 129     this.clientSession_.removeEventListener(
 130         remoting.ClientSession.Events.videoChannelStateChanged,
 131         this.bound_.videoChannelStateChanged);
 132   }
 133 };