tts.js revision cedac228d2dd51db4b79ea1e72c7f249408ee061 
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 Bridge that sends TTS messages from content scripts or
7 * other pages to the main background page.
8 *
9 */
10
11goog.provide('cvox.ChromeTts');
12
13goog.require('cvox.ChromeTtsBase');
14goog.require('cvox.HostFactory');
15
16/**
17 * @constructor
18 * @extends {cvox.ChromeTtsBase}
19 */
20cvox.ChromeTts = function() {
21  goog.base(this);
22
23  this.addBridgeListener();
24};
25goog.inherits(cvox.ChromeTts, cvox.ChromeTtsBase);
26
27/**
28 * Current call id, used for matching callback functions.
29 * @type {number}
30 */
31cvox.ChromeTts.callId = 1;
32
33/**
34 * Maps call ids to callback functions.
35 * @type {Object.<number, Function>}
36 */
37cvox.ChromeTts.functionMap = new Object();
38
39/** @override */
40cvox.ChromeTts.prototype.speak = function(textString, queueMode, properties) {
41  if (!properties) {
42    properties = {};
43  }
44
45  goog.base(this, 'speak', textString, queueMode, properties);
46
47  cvox.ExtensionBridge.send(
48      this.createMessageForProperties_(textString, queueMode, properties));
49};
50
51/** @override */
52cvox.ChromeTts.prototype.isSpeaking = function() {
53  cvox.ChromeTts.superClass_.isSpeaking.call(this);
54  return false;
55};
56
57/** @override */
58cvox.ChromeTts.prototype.stop = function() {
59  cvox.ChromeTts.superClass_.stop.call(this);
60  cvox.ExtensionBridge.send(
61      {'target': 'TTS',
62       'action': 'stop'});
63};
64
65/** @override */
66cvox.ChromeTts.prototype.increaseOrDecreaseProperty =
67    function(propertyName, increase) {
68  cvox.ExtensionBridge.send(
69      {'target': 'TTS',
70       'action': 'increaseOrDecrease',
71       'property': propertyName,
72       'increase': increase});
73};
74
75/**
76 * Increases a TTS speech property.
77 * @param {string} property_name The name of the property to increase.
78 * @param {boolean} announce Whether to announce that the property is
79 * changing.
80 */
81cvox.ChromeTts.prototype.increaseProperty = function(property_name, announce) {
82  goog.base(this, 'increaseProperty', property_name, announce);
83  cvox.ExtensionBridge.send(
84      {'target': 'TTS',
85       'action': 'increase' + property_name,
86       'announce': announce});
87};
88
89/**
90 * Listens for TTS_COMPLETED message and executes the callback function.
91 */
92cvox.ChromeTts.prototype.addBridgeListener = function() {
93  cvox.ExtensionBridge.addMessageListener(
94      function(msg, port) {
95        var message = msg['message'];
96        if (message == 'TTS_CALLBACK') {
97          var id = msg['id'];
98          var func = cvox.ChromeTts.functionMap[id];
99          if (func != undefined) {
100            func();
101            delete cvox.ChromeTts.functionMap[id];
102          }
103        }
104      });
105};
106
107/**
108 * Creates a message suitable for sending as a speak action to background tts.
109 * @param {string} textString The string of text to be spoken.
110 * @param {number=} queueMode The queue mode: cvox.AbstractTts.QUEUE_MODE_FLUSH,
111 *        for flush, cvox.AbstractTts.QUEUE_MODE_QUEUE for adding to queue.
112 * @param {Object=} properties Speech properties to use for this utterance.
113 * @return {Object} A message.
114 * @private
115 */
116cvox.ChromeTts.prototype.createMessageForProperties_ =
117    function(textString, queueMode, properties) {
118  var message = {'target': 'TTS',
119                 'action': 'speak',
120                 'text': textString,
121                 'queueMode': queueMode,
122                 'properties': properties};
123
124  if (properties['startCallback'] != undefined) {
125    cvox.ChromeTts.functionMap[cvox.ChromeTts.callId] =
126        properties['startCallback'];
127    message['startCallbackId'] = cvox.ChromeTts.callId++;
128  }
129  if (properties['endCallback'] != undefined) {
130    cvox.ChromeTts.functionMap[cvox.ChromeTts.callId] =
131        properties['endCallback'];
132    message['endCallbackId'] = cvox.ChromeTts.callId++;
133  }
134  return message;
135    };
136
137cvox.HostFactory.ttsConstructor = cvox.ChromeTts;
138