remoting/webapp/base/js/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 /** @suppress {duplicate} */
  16 var remoting = remoting || {};
  17
  18 (function () {
  19
  20 'use strict';
  21
  22 /**
  23  * @constructor
  24  * @param {remoting.ConnectingDialog} connectingDialog
  25  * @param {function()} reconnectCallback
  26  * @param {function()} disconnectCallback
  27  * @param {remoting.ClientSession} clientSession This represents the current
  28  *    remote desktop connection.  It is used to monitor the changes in
  29  *    connection state.
  30  * @implements {base.Disposable}
  31  */
  32 remoting.SmartReconnector = function(connectingDialog, reconnectCallback,
  33                                      disconnectCallback, clientSession) {
  34   /** @private */
  35   this.reconnectCallback_ = reconnectCallback;
  36
  37   /** @private */
  38   this.disconnectCallback_ = disconnectCallback;
  39
  40   /** @private */
  41   this.clientSession_ = clientSession;
  42
  43   /**
  44    * Placeholder of any pending reconnect operations, e.g. Waiting for online,
  45    * or a timeout to reconnect.
  46    *
  47    * @private {base.Disposable}
  48    */
  49   this.pending_ = null;
  50
  51   /** @private */
  52   this.connectingDialog_ = connectingDialog;
  53
  54   var Events = remoting.ClientSession.Events;
  55   /** @private */
  56   this.eventHook_ =
  57       new base.EventHook(clientSession, Events.videoChannelStateChanged,
  58                          this.videoChannelStateChanged_.bind(this));
  59 };
  60
  61 // The online event only means the network adapter is enabled, but
  62 // it doesn't necessarily mean that we have a working internet connection.
  63 // Therefore, delay the connection by |RECONNECT_DELAY_MS| to allow for the
  64 // network to connect.
  65 var RECONNECT_DELAY_MS = 2000;
  66
  67 // If the video channel is inactive for 10 seconds reconnect the session.
  68 var CONNECTION_TIMEOUT_MS = 10000;
  69
  70 remoting.SmartReconnector.prototype.reconnect_ = function() {
  71   this.cancelPending_();
  72   this.disconnectCallback_();
  73   this.reconnectCallback_();
  74 };
  75
  76 remoting.SmartReconnector.prototype.reconnectAsync_ = function() {
  77   this.cancelPending_();
  78   this.connectingDialog_.show();
  79   this.pending_ =
  80       new base.OneShotTimer(this.reconnect_.bind(this), RECONNECT_DELAY_MS);
  81 };
  82
  83 /**
  84  * @param {!remoting.Error} reason
  85  */
  86 remoting.SmartReconnector.prototype.onConnectionDropped = function(reason) {
  87   this.cancelPending_();
  88   if (navigator.onLine) {
  89     this.reconnect_();
  90   } else {
  91     this.pending_ = new base.DomEventHook(
  92         window, 'online', this.reconnectAsync_.bind(this), false);
  93   }
  94 };
  95
  96 /**
  97  * @param {boolean=} active  True if the video channel is active.
  98  */
  99 remoting.SmartReconnector.prototype.videoChannelStateChanged_ =
 100     function (active) {
 101   this.cancelPending_();
 102   if (!active) {
 103     this.pending_ = new base.DomEventHook(
 104         window, 'online', this.startReconnectTimeout_.bind(this), false);
 105   }
 106 };
 107
 108 remoting.SmartReconnector.prototype.startReconnectTimeout_ = function() {
 109   this.cancelPending_();
 110   this.pending_ =
 111       new base.OneShotTimer(this.reconnect_.bind(this), CONNECTION_TIMEOUT_MS);
 112 };
 113
 114 /** @private */
 115 remoting.SmartReconnector.prototype.cancelPending_ = function() {
 116   base.dispose(this.pending_);
 117   this.pending_ = null;
 118 };
 119
 120 remoting.SmartReconnector.prototype.dispose = function() {
 121   this.cancelPending_();
 122   base.dispose(this.eventHook_);
 123   this.eventHook_ = null;
 124 };
 125
 126 })();