Adding ChromeVox as a component extensions (enabled only for ChromeOS, for no...

chrome/browser/resources/access_chromevox/audio/background/extension_tts_engine.js

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @fileoverview Sends Text-To-Speech commands to a separate Chrome extension.
+ */
+
+// Substituted by package.py
+var ttsExtensionId = 'jhfhnnjfmmflacfniolmefnflomjcbdf';
+
+goog.provide('cvox.ChromeVoxExtensionTtsEngine');
+
+goog.require('cvox.AbstractTts');
+
+/**
+ * @constructor
+ * @extends {cvox.AbstractTts}
+ */
+cvox.ChromeVoxExtensionTtsEngine = function() {
+  //Inherit AbstractTts
+  cvox.AbstractTts.call(this);
+
+  this.ttsExtensionPort = chrome.extension.connect(ttsExtensionId);
+};
+goog.inherits(cvox.ChromeVoxExtensionTtsEngine, cvox.AbstractTts);
+
+/**
+ * @return {string} The human-readable name of the speech engine.
+ */
+cvox.ChromeVoxExtensionTtsEngine.prototype.getName = function() {
+  return 'Native Client Pico Speech';
+};
+
+/**
+ * Speaks the given string using the specified queueMode and properties.
+ * @param {string} textString The string of text to be spoken.
+ * @param {number=} queueMode The queue mode: AbstractTts.QUEUE_MODE_FLUSH
+ *        for flush, AbstractTts.QUEUE_MODE_QUEUE for adding to queue.
+ * @param {Object=} properties Speech properties to use for this utterance.
+ */
+cvox.ChromeVoxExtensionTtsEngine.prototype.speak = function(
+    textString, queueMode, properties) {
+  cvox.ChromeVoxExtensionTtsEngine.superClass_.speak.call(this, textString,
+      queueMode, properties);
+  // TODO: the TTS extension should handle queueMode directly.
+  if (queueMode == cvox.AbstractTts.QUEUE_MODE_FLUSH) {
+    this.stop();
+  }
+
+  this.ttsExtensionPort.postMessage(
+    {'action': 'speak',
+     'text': textString,
+     'queueMode': queueMode,
+     'properties': properties});
+};
+
+/**
+ * Returns true if the TTS is currently speaking.
+ * @return {boolean} True if the TTS is speaking.
+ */
+cvox.ChromeVoxExtensionTtsEngine.prototype.isSpeaking = function() {
+  cvox.ChromeVoxExtensionTtsEngine.superClass_.isSpeaking.call(this);
+  // TODO: Fix this.
+  return false;
+};
+
+/**
+ * Stops speech.
+ */
+cvox.ChromeVoxExtensionTtsEngine.prototype.stop = function() {
+  cvox.ChromeVoxExtensionTtsEngine.superClass_.stop.call(this);
+  this.ttsExtensionPort.postMessage(
+    {'action': 'stop'});
+};