chrome/browser/speech/tts_chromeos.cc

   1 // Copyright (c) 2012 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 #include "base/bind_helpers.h"
   6 #include "base/logging.h"
   7 #include "base/prefs/scoped_user_pref_update.h"
   8 #include "chrome/browser/profiles/profile.h"
   9 #include "chrome/browser/speech/tts_platform.h"
  10 #include "chrome/common/extensions/extension_constants.h"
  11 #include "chrome/common/pref_names.h"
  12
  13 namespace {
  14
  15 // Trigger installing high-quality speech after this many utterances
  16 // have been spoken in one session.
  17 const int kHighQualitySpeechUtteranceThreshold = 100;
  18
  19 }  // anonymous namespace
  20
  21 // Chrome OS doesn't have native TTS, instead it includes a built-in
  22 // component extension that provides speech synthesis. This class monitors
  23 // use of this component extension and triggers installing a higher-quality
  24 // speech synthesis extension if a certain number of utterances are spoken
  25 // in a single session.
  26 class TtsPlatformImplChromeOs
  27     : public TtsPlatformImpl {
  28  public:
  29   // TtsPlatformImpl overrides:
  30   virtual bool PlatformImplAvailable() OVERRIDE {
  31     return false;
  32   }
  33
  34   virtual bool Speak(
  35       int utterance_id,
  36       const std::string& utterance,
  37       const std::string& lang,
  38       const VoiceData& voice,
  39       const UtteranceContinuousParameters& params) OVERRIDE {
  40     return false;
  41   }
  42
  43   virtual bool StopSpeaking() OVERRIDE { return false; }
  44   virtual void Pause() OVERRIDE {}
  45   virtual void Resume() OVERRIDE {}
  46   virtual bool IsSpeaking() OVERRIDE { return false; }
  47   virtual void GetVoices(std::vector<VoiceData>* out_voices) OVERRIDE {}
  48
  49   virtual void WillSpeakUtteranceWithVoice(
  50       const Utterance* utterance,
  51       const VoiceData& voice_data) OVERRIDE;
  52
  53   // Get the single instance of this class.
  54   static TtsPlatformImplChromeOs* GetInstance();
  55
  56  private:
  57   TtsPlatformImplChromeOs();
  58   virtual ~TtsPlatformImplChromeOs() {}
  59
  60   friend struct DefaultSingletonTraits<TtsPlatformImplChromeOs>;
  61
  62   // A count of the number of utterances spoken for each language
  63   // using the built-in speech synthesis. When enough utterances have
  64   // been spoken in a single session, automatically enable install
  65   // the high-quality speech synthesis extension for that language.
  66   base::hash_map<std::string, int> lang_utterance_count_;
  67
  68   DISALLOW_COPY_AND_ASSIGN(TtsPlatformImplChromeOs);
  69 };
  70
  71 TtsPlatformImplChromeOs::TtsPlatformImplChromeOs() {
  72 }
  73
  74 void TtsPlatformImplChromeOs::WillSpeakUtteranceWithVoice(
  75     const Utterance* utterance,
  76     const VoiceData& voice_data) {
  77   CHECK(utterance);
  78   CHECK(utterance->profile());
  79
  80   if (utterance->profile()->IsOffTheRecord())
  81     return;
  82
  83   if (voice_data.extension_id != extension_misc::kSpeechSynthesisExtensionId)
  84     return;
  85
  86   lang_utterance_count_[voice_data.lang]++;
  87   if (lang_utterance_count_[voice_data.lang] !=
  88           kHighQualitySpeechUtteranceThreshold) {
  89     return;
  90   }
  91
  92   // Add this language to the list that are allowed to install a
  93   // component extension for high-quality speech synthesis, overriding
  94   // the lower-quality one.
  95   ListPrefUpdate updater(utterance->profile()->GetPrefs(),
  96                          prefs::kHighQualitySpeechSynthesisLanguages);
  97   updater->AppendIfNotPresent(new base::StringValue(voice_data.lang));
  98 }
  99
 100 // static
 101 TtsPlatformImpl* TtsPlatformImpl::GetInstance() {
 102   return TtsPlatformImplChromeOs::GetInstance();
 103 }
 104
 105 // static
 106 TtsPlatformImplChromeOs*
 107 TtsPlatformImplChromeOs::GetInstance() {
 108   return Singleton<TtsPlatformImplChromeOs>::get();
 109 }