text: /*
   * Copyright (C) 2013 Apple Inc. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
   * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
   * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "modules/speech/SpeechSynthesis.h"
  
  #include "core/dom/ExecutionContext.h"
  #include "modules/speech/SpeechSynthesisEvent.h"
  #include "platform/speech/PlatformSpeechSynthesisVoice.h"
  #include "wtf/CurrentTime.h"
  
  namespace blink {
  
  SpeechSynthesis* SpeechSynthesis::create(ExecutionContext* context) {
    return new SpeechSynthesis(context);
  }
  
  SpeechSynthesis::SpeechSynthesis(ExecutionContext* context)
      : ContextClient(context),
        m_platformSpeechSynthesizer(PlatformSpeechSynthesizer::create(this)),
        m_isPaused(false) {}
  
  void SpeechSynthesis::setPlatformSynthesizer(
      PlatformSpeechSynthesizer* synthesizer) {
    m_platformSpeechSynthesizer = synthesizer;
  }
  
  void SpeechSynthesis::voicesDidChange() {
    m_voiceList.clear();
    if (getExecutionContext())
      dispatchEvent(Event::create(EventTypeNames::voiceschanged));
  }
  
  const HeapVector<Member<SpeechSynthesisVoice>>& SpeechSynthesis::getVoices() {
    if (m_voiceList.size())
      return m_voiceList;
  
    // If the voiceList is empty, that's the cue to get the voices from the
    // platform again.
    const Vector<RefPtr<PlatformSpeechSynthesisVoice>>& platformVoices =
        m_platformSpeechSynthesizer->voiceList();
    size_t voiceCount = platformVoices.size();
    for (size_t k = 0; k < voiceCount; k++)
      m_voiceList.push_back(SpeechSynthesisVoice::create(platformVoices[k]));
  
    return m_voiceList;
  }
  
  bool SpeechSynthesis::speaking() const {
    // If we have a current speech utterance, then that means we're assumed to be
    // in a speaking state. This state is independent of whether the utterance
    // happens to be paused.
    return currentSpeechUtterance();
  }
  
  bool SpeechSynthesis::pending() const {
    // This is true if there are any utterances that have not started.
    // That means there will be more than one in the queue.
    return m_utteranceQueue.size() > 1;
  }
  
  bool SpeechSynthesis::paused() const {
    return m_isPaused;
  }
  
  void SpeechSynthesis::startSpeakingImmediately() {
    SpeechSynthesisUtterance* utterance = currentSpeechUtterance();
    ASSERT(utterance);
  
    utterance->setStartTime(monotonicallyIncreasingTime());
    m_isPaused = false;
    m_platformSpeechSynthesizer->speak(utterance->platformUtterance());
  }
  
  void SpeechSynthesis::speak(SpeechSynthesisUtterance* utterance) {
    ASSERT(utterance);
  
    m_utteranceQueue.append(utterance);
  
    // If the queue was empty, speak this immediately.
    if (m_utteranceQueue.size() == 1)
      startSpeakingImmediately();
  }
  
  void SpeechSynthesis::cancel() {
    // Remove all the items from the utterance queue. The platform
    // may still have references to some of these utterances and may
    // fire events on them asynchronously.
    m_utteranceQueue.clear();
    m_platformSpeechSynthesizer->cancel();
  }
  
  void SpeechSynthesis::pause() {
    if (!m_isPaused)
      m_platformSpeechSynthesizer->pause();
  }
  
  void SpeechSynthesis::resume() {
    if (!currentSpeechUtterance())
      return;
    m_platformSpeechSynthesizer->resume();
  }
  
  void SpeechSynthesis::fireEvent(const AtomicString& type,
                                  SpeechSynthesisUtterance* utterance,
                                  unsigned long charIndex,
                                  const String& name) {
    if (!getExecutionContext())
      return;
  
    double elapsedTimeMillis =
        (monotonicallyIncreasingTime() - utterance->startTime()) * 1000.0;
    utterance->dispatchEvent(SpeechSynthesisEvent::create(
        type, utterance, charIndex, elapsedTimeMillis, name));
  }
  
  void SpeechSynthesis::handleSpeakingCompleted(
      SpeechSynthesisUtterance* utterance,
      bool errorOccurred) {
    ASSERT(utterance);
  
    bool shouldStartSpeaking = false;
    // If the utterance that completed was the one we're currently speaking,
    // remove it from the queue and start speaking the next one.
    if (utterance == currentSpeechUtterance()) {
      m_utteranceQueue.removeFirst();
      shouldStartSpeaking = !!m_utteranceQueue.size();
    }
  
    // Always fire the event, because the platform may have asynchronously
    // sent an event on an utterance before it got the message that we
    // canceled it, and we should always report to the user what actually
    // happened.
    fireEvent(errorOccurred ? EventTypeNames::error : EventTypeNames::end,
              utterance, 0, String());
  
    // Start the next utterance if we just finished one and one was pending.
    if (shouldStartSpeaking && !m_utteranceQueue.isEmpty())
      startSpeakingImmediately();
  }
  
  void SpeechSynthesis::boundaryEventOccurred(
      PlatformSpeechSynthesisUtterance* utterance,
      SpeechBoundary boundary,
      unsigned charIndex) {
    DEFINE_STATIC_LOCAL(const String, wordBoundaryString, ("word"));
    DEFINE_STATIC_LOCAL(const String, sentenceBoundaryString, ("sentence"));
  
    switch (boundary) {
      case SpeechWordBoundary:
        fireEvent(EventTypeNames::boundary,
                  static_cast<SpeechSynthesisUtterance*>(utterance->client()),
                  charIndex, wordBoundaryString);
        break;
      case SpeechSentenceBoundary:
        fireEvent(EventTypeNames::boundary,
                  static_cast<SpeechSynthesisUtterance*>(utterance->client()),
                  charIndex, sentenceBoundaryString);
        break;
      default:
        ASSERT_NOT_REACHED();
    }
  }
  
  void SpeechSynthesis::didStartSpeaking(
      PlatformSpeechSynthesisUtterance* utterance) {
    if (utterance->client())
      fireEvent(EventTypeNames::start,
                static_cast<SpeechSynthesisUtterance*>(utterance->client()), 0,
                String());
  }
  
  void SpeechSynthesis::didPauseSpeaking(
      PlatformSpeechSynthesisUtterance* utterance) {
    m_isPaused = true;
    if (utterance->client())
      fireEvent(EventTypeNames::pause,
                static_cast<SpeechSynthesisUtterance*>(utterance->client()), 0,
                String());
  }
  
  void SpeechSynthesis::didResumeSpeaking(
      PlatformSpeechSynthesisUtterance* utterance) {
    m_isPaused = false;
    if (utterance->client())
      fireEvent(EventTypeNames::resume,
                static_cast<SpeechSynthesisUtterance*>(utterance->client()), 0,
                String());
  }
  
  void SpeechSynthesis::didFinishSpeaking(
      PlatformSpeechSynthesisUtterance* utterance) {
    if (utterance->client())
      handleSpeakingCompleted(
          static_cast<SpeechSynthesisUtterance*>(utterance->client()), false);
  }
  
  void SpeechSynthesis::speakingErrorOccurred(
      PlatformSpeechSynthesisUtterance* utterance) {
    if (utterance->client())
      handleSpeakingCompleted(
          static_cast<SpeechSynthesisUtterance*>(utterance->client()), true);
  }
  
  SpeechSynthesisUtterance* SpeechSynthesis::currentSpeechUtterance() const {
    if (m_utteranceQueue.isEmpty())
      return nullptr;
  
    return m_utteranceQueue.first();
  }
  
  const AtomicString& SpeechSynthesis::interfaceName() const {
    return EventTargetNames::SpeechSynthesis;
  }
  
  DEFINE_TRACE(SpeechSynthesis) {
    visitor->trace(m_platformSpeechSynthesizer);
    visitor->trace(m_voiceList);
    visitor->trace(m_utteranceQueue);
    PlatformSpeechSynthesizerClient::trace(visitor);
    ContextClient::trace(visitor);
    EventTargetWithInlineData::trace(visitor);
  }
  
  }  // namespace blink
  