ui/keyboard/resources/voice_input.js

   1 // Copyright (c) 2013 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 function VoiceInput(keyboard) {
   6   this.finaResult_ = null;
   7   this.recognizing_ = false;
   8   this.keyboard_ = keyboard;
   9   this.recognition_ = new webkitSpeechRecognition();
  10   this.recognition_.onstart = this.onStartHandler.bind(this);
  11   this.recognition_.onresult = this.onResultHandler.bind(this);
  12   this.recognition_.onerror = this.onErrorHandler.bind(this);
  13   this.recognition_.onend = this.onEndHandler.bind(this);
  14 };
  15
  16 VoiceInput.prototype = {
  17   /**
  18    * Event handler for mouse/touch down events.
  19    */
  20   onDown: function() {
  21     if (this.recognizing_) {
  22       this.recognition_.stop();
  23       return;
  24     }
  25     this.recognition_.start();
  26   },
  27
  28   /**
  29    * Speech recognition started. Change microphone key's icon.
  30    */
  31   onStartHandler: function() {
  32     this.recognizing_ = true;
  33     this.finalResult_ = '';
  34     if (!this.keyboard_.classList.contains('audio'))
  35       this.keyboard_.classList.add('audio');
  36   },
  37
  38   /**
  39    * Speech recognizer returns a result.
  40    * @param{Event} e The SpeechRecognition event that is raised each time
  41    *     there
  42    *     are any changes to interim or final results.
  43    */
  44   onResultHandler: function(e) {
  45     for (var i = e.resultIndex; i < e.results.length; i++) {
  46       if (e.results[i].isFinal)
  47         this.finalResult_ = e.results[i][0].transcript;
  48     }
  49     insertText(this.finalResult_);
  50   },
  51
  52   /**
  53    * Speech recognizer returns an error.
  54    * @param{Event} e The SpeechRecognitionError event that is raised each time
  55    *     there is an error.
  56    */
  57   onErrorHandler: function(e) {
  58     console.error('error code = ' + e.error);
  59   },
  60
  61   /**
  62    * Speech recognition ended. Reset microphone key's icon.
  63    */
  64   onEndHandler: function() {
  65     if (this.keyboard_.classList.contains('audio'))
  66       this.keyboard_.classList.remove('audio');
  67     this.recognizing_ = false;
  68   }
  69 };