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
5function 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
16VoiceInput.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};
70