root/chrome/browser/speech/tts_controller.cc

DEFINITIONS

1. TrimLanguageCode
2. IsFinalTtsEventType
3. volume
4. native
5. finished_
6. OnTtsEvent
7. Finish
8. set_options
9. GetInstance
10. platform_impl_
11. SpeakOrEnqueue
12. SpeakNow
13. Stop
14. Pause
15. Resume
16. OnTtsEvent
17. GetVoices
18. IsSpeaking
19. FinishCurrentUtterance
20. SpeakNextUtterance
21. RetrySpeakingQueuedUtterances
22. ClearUtteranceQueue
23. SetPlatformImpl
24. QueueSize
25. GetPlatformImpl
26. GetMatchingVoice
27. VoicesChanged
28. AddVoicesChangedDelegate
29. RemoveVoicesChangedDelegate

// 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.

#include "chrome/browser/speech/tts_controller.h"

#include <string>
#include <vector>

#include "base/float_util.h"
#include "base/values.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/speech/extension_api/tts_engine_extension_api.h"
#include "chrome/browser/speech/extension_api/tts_extension_api.h"
#include "chrome/browser/speech/tts_platform.h"
#include "chrome/common/extensions/api/speech/tts_engine_manifest_handler.h"
#include "extensions/browser/extension_system.h"
#include "extensions/common/extension.h"

namespace {
// A value to be used to indicate that there is no char index available.
const int kInvalidCharIndex = -1;

// Given a language/region code of the form 'fr-FR', returns just the basic
// language portion, e.g. 'fr'.
std::string TrimLanguageCode(std::string lang) {
  if (lang.size() >= 5 && lang[2] == '-')
    return lang.substr(0, 2);
  else
    return lang;
}

}  // namespace

bool IsFinalTtsEventType(TtsEventType event_type) {
  return (event_type == TTS_EVENT_END ||
          event_type == TTS_EVENT_INTERRUPTED ||
          event_type == TTS_EVENT_CANCELLED ||
          event_type == TTS_EVENT_ERROR);
}

//
// UtteranceContinuousParameters
//


UtteranceContinuousParameters::UtteranceContinuousParameters()
    : rate(-1),
      pitch(-1),
      volume(-1) {}


//
// VoiceData
//


VoiceData::VoiceData()
    : gender(TTS_GENDER_NONE),
      remote(false),
      native(false) {}

VoiceData::~VoiceData() {}


//
// Utterance
//

// static
int Utterance::next_utterance_id_ = 0;

Utterance::Utterance(Profile* profile)
    : profile_(profile),
      id_(next_utterance_id_++),
      src_id_(-1),
      gender_(TTS_GENDER_NONE),
      can_enqueue_(false),
      char_index_(0),
      finished_(false) {
  options_.reset(new base::DictionaryValue());
}

Utterance::~Utterance() {
  DCHECK(finished_);
}

void Utterance::OnTtsEvent(TtsEventType event_type,
                           int char_index,
                           const std::string& error_message) {
  if (char_index >= 0)
    char_index_ = char_index;
  if (IsFinalTtsEventType(event_type))
    finished_ = true;

  if (event_delegate_)
    event_delegate_->OnTtsEvent(this, event_type, char_index, error_message);
  if (finished_)
    event_delegate_.reset();
}

void Utterance::Finish() {
  finished_ = true;
}

void Utterance::set_options(const base::Value* options) {
  options_.reset(options->DeepCopy());
}

//
// TtsController
//

// static
TtsController* TtsController::GetInstance() {
  return Singleton<TtsController>::get();
}

TtsController::TtsController()
    : current_utterance_(NULL),
      paused_(false),
      platform_impl_(NULL) {
}

TtsController::~TtsController() {
  if (current_utterance_) {
    current_utterance_->Finish();
    delete current_utterance_;
  }

  // Clear any queued utterances too.
  ClearUtteranceQueue(false);  // Don't sent events.
}

void TtsController::SpeakOrEnqueue(Utterance* utterance) {
  // If we're paused and we get an utterance that can't be queued,
  // flush the queue but stay in the paused state.
  if (paused_ && !utterance->can_enqueue()) {
    Stop();
    paused_ = true;
    return;
  }

  if (paused_ || (IsSpeaking() && utterance->can_enqueue())) {
    utterance_queue_.push(utterance);
  } else {
    Stop();
    SpeakNow(utterance);
  }
}

void TtsController::SpeakNow(Utterance* utterance) {
  // Get all available voices and try to find a matching voice.
  std::vector<VoiceData> voices;
  GetVoices(utterance->profile(), &voices);
  int index = GetMatchingVoice(utterance, voices);

  VoiceData voice;
  if (index != -1) {
    // Select the matching voice.
    voice = voices[index];
  } else {
    // However, if no match was found on a platform without native tts voices,
    // attempt to get a voice based only on the current locale without respect
    // to any supplied voice names.
    std::vector<VoiceData> native_voices;

    if (GetPlatformImpl()->PlatformImplAvailable())
      GetPlatformImpl()->GetVoices(&native_voices);

    if (native_voices.empty() && !voices.empty()) {
      // TODO(dtseng): Notify extension caller of an error.
      utterance->set_voice_name("");
      utterance->set_lang(g_browser_process->GetApplicationLocale());
      index = GetMatchingVoice(utterance, voices);

      // If even that fails, just take the first available voice.
      if (index == -1)
        index = 0;
      voice = voices[index];
    } else {
      // Otherwise, simply give native voices a chance to handle this utterance.
      voice.native = true;
    }
  }

  GetPlatformImpl()->WillSpeakUtteranceWithVoice(utterance, voice);

  if (!voice.native) {
#if !defined(OS_ANDROID)
    DCHECK(!voice.extension_id.empty());
    current_utterance_ = utterance;
    utterance->set_extension_id(voice.extension_id);
    ExtensionTtsEngineSpeak(utterance, voice);
    bool sends_end_event =
        voice.events.find(TTS_EVENT_END) != voice.events.end();
    if (!sends_end_event) {
      utterance->Finish();
      delete utterance;
      current_utterance_ = NULL;
      SpeakNextUtterance();
    }
#endif
  } else {
    // It's possible for certain platforms to send start events immediately
    // during |speak|.
    current_utterance_ = utterance;
    GetPlatformImpl()->clear_error();
    bool success = GetPlatformImpl()->Speak(
        utterance->id(),
        utterance->text(),
        utterance->lang(),
        voice,
        utterance->continuous_parameters());
    if (!success)
      current_utterance_ = NULL;

    // If the native voice wasn't able to process this speech, see if
    // the browser has built-in TTS that isn't loaded yet.
    if (!success &&
        GetPlatformImpl()->LoadBuiltInTtsExtension(utterance->profile())) {
      utterance_queue_.push(utterance);
      return;
    }

    if (!success) {
      utterance->OnTtsEvent(TTS_EVENT_ERROR, kInvalidCharIndex,
                            GetPlatformImpl()->error());
      delete utterance;
      return;
    }
  }
}

void TtsController::Stop() {
  paused_ = false;
  if (current_utterance_ && !current_utterance_->extension_id().empty()) {
#if !defined(OS_ANDROID)
    ExtensionTtsEngineStop(current_utterance_);
#endif
  } else {
    GetPlatformImpl()->clear_error();
    GetPlatformImpl()->StopSpeaking();
  }

  if (current_utterance_)
    current_utterance_->OnTtsEvent(TTS_EVENT_INTERRUPTED, kInvalidCharIndex,
                                   std::string());
  FinishCurrentUtterance();
  ClearUtteranceQueue(true);  // Send events.
}

void TtsController::Pause() {
  paused_ = true;
  if (current_utterance_ && !current_utterance_->extension_id().empty()) {
#if !defined(OS_ANDROID)
    ExtensionTtsEnginePause(current_utterance_);
#endif
  } else if (current_utterance_) {
    GetPlatformImpl()->clear_error();
    GetPlatformImpl()->Pause();
  }
}

void TtsController::Resume() {
  paused_ = false;
  if (current_utterance_ && !current_utterance_->extension_id().empty()) {
#if !defined(OS_ANDROID)
    ExtensionTtsEngineResume(current_utterance_);
#endif
  } else if (current_utterance_) {
    GetPlatformImpl()->clear_error();
    GetPlatformImpl()->Resume();
  } else {
    SpeakNextUtterance();
  }
}

void TtsController::OnTtsEvent(int utterance_id,
                                        TtsEventType event_type,
                                        int char_index,
                                        const std::string& error_message) {
  // We may sometimes receive completion callbacks "late", after we've
  // already finished the utterance (for example because another utterance
  // interrupted or we got a call to Stop). This is normal and we can
  // safely just ignore these events.
  if (!current_utterance_ || utterance_id != current_utterance_->id()) {
    return;
  }
  current_utterance_->OnTtsEvent(event_type, char_index, error_message);
  if (current_utterance_->finished()) {
    FinishCurrentUtterance();
    SpeakNextUtterance();
  }
}

void TtsController::GetVoices(Profile* profile,
                              std::vector<VoiceData>* out_voices) {
#if !defined(OS_ANDROID)
  if (profile)
    GetExtensionVoices(profile, out_voices);
#endif

  TtsPlatformImpl* platform_impl = GetPlatformImpl();
  if (platform_impl && platform_impl->PlatformImplAvailable())
    platform_impl->GetVoices(out_voices);
}

bool TtsController::IsSpeaking() {
  return current_utterance_ != NULL || GetPlatformImpl()->IsSpeaking();
}

void TtsController::FinishCurrentUtterance() {
  if (current_utterance_) {
    if (!current_utterance_->finished())
      current_utterance_->OnTtsEvent(TTS_EVENT_INTERRUPTED, kInvalidCharIndex,
                                     std::string());
    delete current_utterance_;
    current_utterance_ = NULL;
  }
}

void TtsController::SpeakNextUtterance() {
  if (paused_)
    return;

  // Start speaking the next utterance in the queue.  Keep trying in case
  // one fails but there are still more in the queue to try.
  while (!utterance_queue_.empty() && !current_utterance_) {
    Utterance* utterance = utterance_queue_.front();
    utterance_queue_.pop();
    SpeakNow(utterance);
  }
}

void TtsController::RetrySpeakingQueuedUtterances() {
  if (current_utterance_ == NULL && !utterance_queue_.empty())
    SpeakNextUtterance();
}

void TtsController::ClearUtteranceQueue(bool send_events) {
  while (!utterance_queue_.empty()) {
    Utterance* utterance = utterance_queue_.front();
    utterance_queue_.pop();
    if (send_events)
      utterance->OnTtsEvent(TTS_EVENT_CANCELLED, kInvalidCharIndex,
                            std::string());
    else
      utterance->Finish();
    delete utterance;
  }
}

void TtsController::SetPlatformImpl(
    TtsPlatformImpl* platform_impl) {
  platform_impl_ = platform_impl;
}

int TtsController::QueueSize() {
  return static_cast<int>(utterance_queue_.size());
}

TtsPlatformImpl* TtsController::GetPlatformImpl() {
  if (!platform_impl_)
    platform_impl_ = TtsPlatformImpl::GetInstance();
  return platform_impl_;
}

int TtsController::GetMatchingVoice(
    const Utterance* utterance, std::vector<VoiceData>& voices) {
  // Make two passes: the first time, do strict language matching
  // ('fr-FR' does not match 'fr-CA'). The second time, do prefix
  // language matching ('fr-FR' matches 'fr' and 'fr-CA')
  for (int pass = 0; pass < 2; ++pass) {
    for (size_t i = 0; i < voices.size(); ++i) {
      const VoiceData& voice = voices[i];

      if (!utterance->extension_id().empty() &&
          utterance->extension_id() != voice.extension_id) {
        continue;
      }

      if (!voice.name.empty() &&
          !utterance->voice_name().empty() &&
          voice.name != utterance->voice_name()) {
        continue;
      }
      if (!voice.lang.empty() && !utterance->lang().empty()) {
        std::string voice_lang = voice.lang;
        std::string utterance_lang = utterance->lang();
        if (pass == 1) {
          voice_lang = TrimLanguageCode(voice_lang);
          utterance_lang = TrimLanguageCode(utterance_lang);
        }
        if (voice_lang != utterance_lang) {
          continue;
        }
      }
      if (voice.gender != TTS_GENDER_NONE &&
          utterance->gender() != TTS_GENDER_NONE &&
          voice.gender != utterance->gender()) {
        continue;
      }

      if (utterance->required_event_types().size() > 0) {
        bool has_all_required_event_types = true;
        for (std::set<TtsEventType>::const_iterator iter =
                 utterance->required_event_types().begin();
             iter != utterance->required_event_types().end();
             ++iter) {
          if (voice.events.find(*iter) == voice.events.end()) {
            has_all_required_event_types = false;
            break;
          }
        }
        if (!has_all_required_event_types)
          continue;
      }

      return static_cast<int>(i);
    }
  }

  return -1;
}

void TtsController::VoicesChanged() {
  for (std::set<VoicesChangedDelegate*>::iterator iter =
           voices_changed_delegates_.begin();
       iter != voices_changed_delegates_.end(); ++iter) {
    (*iter)->OnVoicesChanged();
  }
}

void TtsController::AddVoicesChangedDelegate(VoicesChangedDelegate* delegate) {
  voices_changed_delegates_.insert(delegate);
}

void TtsController::RemoveVoicesChangedDelegate(
    VoicesChangedDelegate* delegate) {
  voices_changed_delegates_.erase(delegate);
}