gecko-dev/content/media/webaudio/AudioNode.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef AudioNode_h_
#define AudioNode_h_

#include "nsCycleCollectionParticipant.h"
#include "mozilla/Attributes.h"
#include "EnableWebAudioCheck.h"
#include "nsAutoPtr.h"
#include "nsTArray.h"
#include "AudioContext.h"

struct JSContext;

namespace mozilla {

class ErrorResult;

namespace dom {

class AudioNode : public nsISupports,
                  public EnableWebAudioCheck
{
public:
  explicit AudioNode(AudioContext* aContext);
  virtual ~AudioNode();

  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  NS_DECL_CYCLE_COLLECTION_CLASS(AudioNode)

  AudioContext* GetParentObject() const
  {
    return mContext;
  }

  AudioContext* Context() const
  {
    return mContext;
  }

  void Connect(AudioNode& aDestination, uint32_t aOutput,
               uint32_t aInput, ErrorResult& aRv);

  void Disconnect(uint32_t aOutput, ErrorResult& aRv);

  // The following two virtual methods must be implemented by each node type
  // to provide their number of input and output ports. These numbers are
  // constant for the lifetime of the node. Both default to 1.
  virtual uint32_t NumberOfInputs() const { return 1; }
  virtual uint32_t NumberOfOutputs() const { return 1; }

  struct InputNode {
    // Strong reference.
    // May be null if the source node has gone away.
    nsRefPtr<AudioNode> mInputNode;
    // The index of the input port this node feeds into.
    uint32_t mInputPort;
    // The index of the output port this node comes out of.
    uint32_t mOutputPort;
  };

private:
  nsRefPtr<AudioContext> mContext;

  // For every InputNode, there is a corresponding entry in mOutputNodes of the
  // InputNode's mInputNode.
  nsTArray<InputNode> mInputNodes;
  // For every mOutputNode entry, there is a corresponding entry in mInputNodes
  // of the mOutputNode entry. We won't necessarily be able to identify the
  // exact matching entry, since mOutputNodes doesn't include the port
  // identifiers and the same node could be connected on multiple ports.
  nsTArray<nsRefPtr<AudioNode> > mOutputNodes;
};

}
}

#endif