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

chrome/browser/resources/access_chromevox/audio/background/flash_gooss_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 Text-To-Speech engine powered by GooSS. This engine relies on
+ * Flash.
+ * TODO: Remove this engine once the audio tag is fixed and we can cut over
+ * to plain GooSS.
+ */
+
+goog.provide('cvox.ChromeVoxFlashGoossEngine');
+
+goog.require('cvox.AbstractTts');
+
+/**
+ * @constructor
+ * @extends {cvox.AbstractTts}
+ */
+cvox.ChromeVoxFlashGoossEngine = function() {
+  //Inherit AbstractTts
+  cvox.AbstractTts.call(this);
+
+  this.speech = null;
+  this.speaking = false;
+
+  var theScript = document.createElement('script');
+  theScript.type = 'text/javascript';
+  theScript.src =
+      'http://www.gstatic.com/speech/api/tts/google-network-tts.js';
+  document.getElementsByTagName('head')[0].appendChild(theScript);
+  var context = this;
+  theScript.onload = function() {
+    goog.tts = goog.tts || undefined;
+    context.speech = goog.tts;
+    context.speech.initialize();
+  };
+};
+goog.inherits(cvox.ChromeVoxFlashGoossEngine, cvox.AbstractTts);
+
+/**
+ * @return {string} The human-readable name of the speech engine.
+ */
+cvox.ChromeVoxFlashGoossEngine.prototype.getName = function() {
+  return 'Google Network Speech using Flash';
+};
+
+/**
+ * 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.ChromeVoxFlashGoossEngine.prototype.speak = function(textString,
+    queueMode, properties) {
+  if (!this.speech) {
+    console.log(this.getName() + ' is not initialized yet.');
+    return;
+  }
+  cvox.ChromeVoxFlashGoossEngine.superClass_.speak.call(this, textString,
+      queueMode, properties);
+  // TODO: Implement speech queue so that queued speech is possible
+  this.speaking = true;
+  var queue = (queueMode === cvox.AbstractTts.QUEUE_MODE_QUEUE);
+  this.speech.speak(textString,
+      function(event) {
+        this.isSpeaking = false;
+      }, queue, cvox.ChromeVoxFlashGoossEngine.DEFAULT_PROPERTIES_JSON);
+};
+
+/**
+ * Returns true if the TTS is currently speaking.
+ * @return {boolean} True if the TTS is speaking.
+ */
+cvox.ChromeVoxFlashGoossEngine.prototype.isSpeaking = function() {
+  cvox.ChromeVoxFlashGoossEngine.superClass_.isSpeaking.call(this);
+  return this.speaking;
+};
+
+/**
+ * Stops speech.
+ */
+cvox.ChromeVoxFlashGoossEngine.prototype.stop = function() {
+  if (!this.speech) {
+    return;
+  }
+  cvox.ChromeVoxFlashGoossEngine.superClass_.stop.call(this);
+  this.speaking = false;
+  this.speech.stopSpeaking();
+};
+
+/**
+ * The default properties array used for speaking.
+ * @type {Object}
+ */
+cvox.ChromeVoxFlashGoossEngine.DEFAULT_PROPERTIES_JSON = {'lang': 'en-US'};