text: /*
   * Copyright (C) 2012, Google 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 INC. AND ITS CONTRIBUTORS ``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 INC. OR ITS 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 MediaStreamAudioDestinationNode_h
  #define MediaStreamAudioDestinationNode_h
  
  #include "modules/mediastream/MediaStream.h"
  #include "modules/webaudio/AudioBasicInspectorNode.h"
  #include "platform/audio/AudioBus.h"
  #include "wtf/OwnPtr.h"
  #include "wtf/PassRefPtr.h"
  
  namespace blink {
  
  class AbstractAudioContext;
  
  class MediaStreamAudioDestinationHandler final : public AudioBasicInspectorHandler {
  public:
      static PassRefPtr<MediaStreamAudioDestinationHandler> create(AudioNode&, size_t numberOfChannels);
      ~MediaStreamAudioDestinationHandler() override;
  
      MediaStream* stream() { return m_stream.get(); }
  
      // AudioHandler.
      void process(size_t framesToProcess) override;
      void setChannelCount(unsigned long, ExceptionState&) override;
  
      unsigned long maxChannelCount() const;
  
  private:
      MediaStreamAudioDestinationHandler(AudioNode&, size_t numberOfChannels);
      // As an audio source, we will never propagate silence.
      bool propagatesSilence() const override { return false; }
  
      // This Persistent doesn't make a reference cycle.
      Persistent<MediaStream> m_stream;
      Persistent<MediaStreamSource> m_source;
  
      // This internal mix bus is for up/down mixing the input to the actual
      // number of channels in the destination.
      RefPtr<AudioBus> m_mixBus;
  };
  
  class MediaStreamAudioDestinationNode final : public AudioBasicInspectorNode {
      DEFINE_WRAPPERTYPEINFO();
  public:
      static MediaStreamAudioDestinationNode* create(AbstractAudioContext&, size_t numberOfChannels);
      MediaStream* stream() const;
  
  private:
      MediaStreamAudioDestinationNode(AbstractAudioContext&, size_t numberOfChannels);
  };
  
  } // namespace blink
  
  #endif // MediaStreamAudioDestinationNode_h
  