Android implementation of text-to-speech code for Web Speech Synthesis API

chrome/browser/speech/tts_controller.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_SPEECH_TTS_CONTROLLER_H_
 #define CHROME_BROWSER_SPEECH_TTS_CONTROLLER_H_
 
 #include <queue>
 #include <set>
 #include <string>
@@ skipping 62 matching lines @@
 // Class that wants to receive events on utterances.
 class UtteranceEventDelegate {
  public:
   virtual ~UtteranceEventDelegate() {}
   virtual void OnTtsEvent(Utterance* utterance,
                           TtsEventType event_type,
                           int char_index,
                           const std::string& error_message) = 0;
 };
 
+// Class that wants to be notified when the set of
+// voices has changed.
+class VoicesChangedDelegate {
+ public:
+  virtual ~VoicesChangedDelegate() {}
+  virtual void OnVoicesChanged() = 0;
+};
+
 // One speech utterance.
 class Utterance {
  public:
   // Construct an utterance given a profile and a completion task to call
   // when the utterance is done speaking. Before speaking this utterance,
   // its other parameters like text, rate, pitch, etc. should all be set.
   explicit Utterance(Profile* profile);
   ~Utterance();
 
   // Sends an event to the delegate. If the event type is TTS_EVENT_END
@@ skipping 163 matching lines @@
                   const std::string& error_message);
 
   // Return a list of all available voices, including the native voice,
   // if supported, and all voices registered by extensions.
   void GetVoices(Profile* profile, std::vector<VoiceData>* out_voices);
 
   // Called by TtsExtensionLoaderChromeOs::LoadTtsExtension when it
   // finishes loading the built-in TTS component extension.
   void RetrySpeakingQueuedUtterances();
 
+  // Called by the extension system or platform implementation when the
+  // list of voices may have changed and should be re-queried.
+  void VoicesChanged();
+
+  // Add a delegate that wants to be notified when the set of voices changes.
+  void AddVoicesChangedDelegate(VoicesChangedDelegate* delegate);
+
+  // Remove delegate that wants to be notified when the set of voices changes.
+  void RemoveVoicesChangedDelegate(VoicesChangedDelegate* delegate);
+
   // For unit testing.
   void SetPlatformImpl(TtsPlatformImpl* platform_impl);
   int QueueSize();
 
  protected:
   TtsController();
   virtual ~TtsController();
 
  private:
   // Get the platform TTS implementation (or injected mock).
@@ skipping 19 matching lines @@
                        std::vector<VoiceData>& voices);
 
   friend struct DefaultSingletonTraits<TtsController>;
 
   // The current utterance being spoken.
   Utterance* current_utterance_;
 
   // A queue of utterances to speak after the current one finishes.
   std::queue<Utterance*> utterance_queue_;
 
+  // A set of delegates that want to be notified when the voices change.
+  std::set<VoicesChangedDelegate*> voices_changed_delegates_;
+
   // A pointer to the platform implementation of text-to-speech, for
   // dependency injection.
   TtsPlatformImpl* platform_impl_;
 
   DISALLOW_COPY_AND_ASSIGN(TtsController);
 };
 
 #endif  // CHROME_BROWSER_SPEECH_TTS_CONTROLLER_H_