text: /*
   * Copyright (C) 2013 Apple Computer, 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.
   */
  
  #ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_SPEECH_PLATFORM_SPEECH_SYNTHESIZER_H_
  #define THIRD_PARTY_BLINK_RENDERER_PLATFORM_SPEECH_PLATFORM_SPEECH_SYNTHESIZER_H_
  
  #include <memory>
  
  #include "base/macros.h"
  #include "third_party/blink/renderer/platform/heap/handle.h"
  #include "third_party/blink/renderer/platform/platform_export.h"
  #include "third_party/blink/renderer/platform/speech/platform_speech_synthesis_voice.h"
  #include "third_party/blink/renderer/platform/wtf/vector.h"
  
  namespace blink {
  
  enum SpeechBoundary { kSpeechWordBoundary, kSpeechSentenceBoundary };
  
  class PlatformSpeechSynthesisUtterance;
  class WebSpeechSynthesizer;
  class WebSpeechSynthesizerClientImpl;
  
  class PLATFORM_EXPORT PlatformSpeechSynthesizerClient
      : public GarbageCollectedMixin {
   public:
    virtual void DidStartSpeaking(PlatformSpeechSynthesisUtterance*) = 0;
    virtual void DidFinishSpeaking(PlatformSpeechSynthesisUtterance*) = 0;
    virtual void DidPauseSpeaking(PlatformSpeechSynthesisUtterance*) = 0;
    virtual void DidResumeSpeaking(PlatformSpeechSynthesisUtterance*) = 0;
    virtual void SpeakingErrorOccurred(PlatformSpeechSynthesisUtterance*) = 0;
    virtual void BoundaryEventOccurred(PlatformSpeechSynthesisUtterance*,
                                       SpeechBoundary,
                                       unsigned char_index) = 0;
    virtual void VoicesDidChange() = 0;
  
   protected:
    virtual ~PlatformSpeechSynthesizerClient() = default;
  };
  
  class PLATFORM_EXPORT PlatformSpeechSynthesizer
      : public GarbageCollectedFinalized<PlatformSpeechSynthesizer> {
   public:
    static PlatformSpeechSynthesizer* Create(PlatformSpeechSynthesizerClient*);
  
    virtual ~PlatformSpeechSynthesizer();
  
    virtual void Speak(PlatformSpeechSynthesisUtterance*);
    virtual void Pause();
    virtual void Resume();
    virtual void Cancel();
  
    PlatformSpeechSynthesizerClient* Client() const {
      return speech_synthesizer_client_;
    }
  
    const Vector<scoped_refptr<PlatformSpeechSynthesisVoice>>& GetVoiceList();
  
    void SetVoiceList(Vector<scoped_refptr<PlatformSpeechSynthesisVoice>>&);
  
    // Eager finalization is required to promptly release the owned
    // WebSpeechSynthesizer.
    //
    // If not and delayed until lazily swept, m_webSpeechSynthesizerClient may end
    // up being lazily swept first (i.e., before this PlatformSpeechSynthesizer),
    // leaving m_webSpeechSynthesizer with a dangling pointer to a finalized
    // object -- WebSpeechSynthesizer embedder implementations calling
    // notification methods in the other directions by way of
    // m_webSpeechSynthesizerClient. Eagerly releasing WebSpeechSynthesizer
    // prevents such unsafe accesses.
    EAGERLY_FINALIZE();
    virtual void Trace(blink::Visitor*);
  
   protected:
    explicit PlatformSpeechSynthesizer(PlatformSpeechSynthesizerClient*);
  
    virtual void InitializeVoiceList();
  
    Vector<scoped_refptr<PlatformSpeechSynthesisVoice>> voice_list_;
    bool voices_initialized_ = false;
  
   private:
    void MaybeInitializeVoiceList();
  
    Member<PlatformSpeechSynthesizerClient> speech_synthesizer_client_;
  
    std::unique_ptr<WebSpeechSynthesizer> web_speech_synthesizer_;
    Member<WebSpeechSynthesizerClientImpl> web_speech_synthesizer_client_;
  
    DISALLOW_COPY_AND_ASSIGN(PlatformSpeechSynthesizer);
  };
  
  }  // namespace blink
  
  #endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_SPEECH_PLATFORM_SPEECH_SYNTHESIZER_H_
  