chrome/browser/resources/hotword/base_session_manager.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    * Base class for managing hotwording sessions.
  10    * @param {!hotword.StateManager} stateManager Manager of global hotwording
  11    *     state.
  12    * @param {!hotword.constants.SessionSource} sessionSource Source of the
  13    *     hotword session request.
  14    * @constructor
  15    */
  16   function BaseSessionManager(stateManager, sessionSource) {
  17     /**
  18      * Manager of global hotwording state.
  19      * @protected {!hotword.StateManager}
  20      */
  21     this.stateManager = stateManager;
  22
  23     /**
  24      * Source of the hotword session request.
  25      * @private {!hotword.constants.SessionSource}
  26      */
  27     this.sessionSource_ = sessionSource;
  28
  29     /**
  30      * Chrome event listeners. Saved so that they can be de-registered when
  31      * hotwording is disabled.
  32      * @private
  33      */
  34     this.sessionRequestedListener_ = this.handleSessionRequested_.bind(this);
  35     this.sessionStoppedListener_ = this.handleSessionStopped_.bind(this);
  36
  37     // Need to setup listeners on startup, otherwise events that caused the
  38     // event page to start up, will be lost.
  39     this.setupListeners_();
  40
  41     this.stateManager.onStatusChanged.addListener(function() {
  42       hotword.debug('onStatusChanged');
  43       this.updateListeners();
  44     }.bind(this));
  45   }
  46
  47   BaseSessionManager.prototype = {
  48     /**
  49      * Return whether or not this session type is enabled.
  50      * @protected
  51      * @return {boolean}
  52      */
  53     enabled: assertNotReached,
  54
  55     /**
  56      * Called when the hotwording session is stopped.
  57      * @protected
  58      */
  59     onSessionStop: function() {
  60     },
  61
  62     /**
  63      * Starts a launcher hotwording session.
  64      * @param {hotword.constants.TrainingMode=} opt_mode The mode to start the
  65      *     recognizer in.
  66      */
  67     startSession: function(opt_mode) {
  68       this.stateManager.startSession(
  69           this.sessionSource_,
  70           function() {
  71             chrome.hotwordPrivate.setHotwordSessionState(true, function() {});
  72           },
  73           this.handleHotwordTrigger.bind(this),
  74           opt_mode);
  75     },
  76
  77     /**
  78      * Stops a launcher hotwording session.
  79      * @private
  80      */
  81     stopSession_: function() {
  82       this.stateManager.stopSession(this.sessionSource_);
  83       this.onSessionStop();
  84     },
  85
  86     /**
  87      * Handles a hotword triggered event.
  88      * @param {?Object} log Audio log data, if audio logging is enabled.
  89      * @protected
  90      */
  91     handleHotwordTrigger: function(log) {
  92       hotword.debug('Hotword triggered: ' + this.sessionSource_, log);
  93       chrome.hotwordPrivate.notifyHotwordRecognition('search',
  94                                                      log,
  95                                                      function() {});
  96     },
  97
  98     /**
  99      * Handles a hotwordPrivate.onHotwordSessionRequested event.
 100      * @private
 101      */
 102     handleSessionRequested_: function() {
 103       hotword.debug('handleSessionRequested_: ' + this.sessionSource_);
 104       this.startSession();
 105     },
 106
 107     /**
 108      * Handles a hotwordPrivate.onHotwordSessionStopped event.
 109      * @private
 110      */
 111     handleSessionStopped_: function() {
 112       hotword.debug('handleSessionStopped_: ' + this.sessionSource_);
 113       this.stopSession_();
 114     },
 115
 116     /**
 117      * Set up event listeners.
 118      * @private
 119      */
 120     setupListeners_: function() {
 121       if (chrome.hotwordPrivate.onHotwordSessionRequested.hasListener(
 122               this.sessionRequestedListener_)) {
 123         return;
 124       }
 125
 126       chrome.hotwordPrivate.onHotwordSessionRequested.addListener(
 127           this.sessionRequestedListener_);
 128       chrome.hotwordPrivate.onHotwordSessionStopped.addListener(
 129           this.sessionStoppedListener_);
 130     },
 131
 132     /**
 133      * Remove event listeners.
 134      * @private
 135      */
 136     removeListeners_: function() {
 137       chrome.hotwordPrivate.onHotwordSessionRequested.removeListener(
 138           this.sessionRequestedListener_);
 139       chrome.hotwordPrivate.onHotwordSessionStopped.removeListener(
 140           this.sessionStoppedListener_);
 141     },
 142
 143     /**
 144      * Update event listeners based on the current hotwording state.
 145      * @protected
 146      */
 147     updateListeners: function() {
 148       if (this.enabled()) {
 149         this.setupListeners_();
 150       } else {
 151         this.removeListeners_();
 152         this.stopSession_();
 153       }
 154     }
 155   };
 156
 157   return {
 158     BaseSessionManager: BaseSessionManager
 159   };
 160 });