Embeds offline voice recognizer plugin and its manager to app-list start page.

chrome/browser/resources/app_list/speech_recognition_manager.js

+// Copyright 2013 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 The manager of speech recognition.
+ */
+
+cr.define('speech', function() {
+  'use strict';
+
+  /**
+   * @constructor
+   */
+  function SpeechRecognitionManager(delegate) {
+    this.isActive = true;
+    this.delegate_ = delegate;
+
+    this.recognizer_ = new window.webkitSpeechRecognition();
+    this.recognizer_.continuous = true;
+    this.recognizer_.interimResults = true;
+    // TODO(mukai): should switch to the user's UI language.
+    this.recognizer_.lang = 'en_US';
+
+    this.recognizer_.onresult = this.onRecognizerResult_.bind(this);
+  }
+
+  /**
+   * Called when new speech recognition results arrive.
+   *
+   * @param {Event} speech_event The event to contain the recognition results.
+   * @private
+   */
+  SpeechRecognitionManager.prototype.onRecognizerResult_ = function(
+      speech_event) {
+    // Do not collect interim result for now.
+    var result = '';
+    var isFinal = false;
+    for (var i = 0; i < speech_event.results.length; i++) {
+      if (speech_event.results[i].isFinal)
+        isFinal = true;
+      result += speech_event.results[i][0].transcript;
+    }
+    if (this.delegate_)
+      this.delegate_.onSpeechRecognized(result, isFinal);
+  };
+
+  /**
+   * Starts the speech recognition through webkitSpeechRecognition.
+   */
+  SpeechRecognitionManager.prototype.start = function() {
+    if (this.delegate_) {
+      this.recognizer_.onstart =
+          this.delegate_.onSpeechRecognitionStarted.bind(this.delegate_);
+      this.recognizer_.onend =
+          this.delegate_.onSpeechRecognitionEnded.bind(this.delegate_);
+      this.recognizer_.onerror =
+          this.delegate_.onSpeechRecognitionError.bind(this.delegate_);

[xiyuan, 2013/10/29 18:10:07]

nit: move these into constructor so that we have one place for hooking up
this.recognizer_ events.

[Jun Mukai, 2013/10/30 01:01:32]

Done.

+    }
+    this.recognizer_.start();
+  };
+
+  /**
+   * Stops the ongoing speech recognition.
+   */
+  SpeechRecognitionManager.prototype.stop = function() {
+    this.recognizer_.abort();
+  };
+
+  return {
+    SpeechRecognitionManager: SpeechRecognitionManager
+  };
+});