/* -*- 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 mozilla_dom_MIDIAccess_h

#define mozilla_dom_MIDIAccess_h

#include "mozilla/Attributes.h"

#include "mozilla/DOMEventTargetHelper.h"

#include "mozilla/ErrorResult.h"

#include "mozilla/Observer.h"

#include "nsCycleCollectionParticipant.h"

#include "nsIObserver.h"

#include "nsWrapperCache.h"

struct JSContext;

namespace mozilla {

// Predeclare void_t here, as including IPCMessageUtils brings in windows.h and

// causes binding compilation problems.

struct void_t;

namespace dom {

class MIDIAccessManager;

class MIDIInputMap;

struct MIDIOptions;

class MIDIOutputMap;

class MIDIPermissionRequest;

class MIDIPort;

class MIDIPortChangeEvent;

class MIDIPortInfo;

class MIDIPortList;

class Promise;

typedef Observer<void_t> MIDIAccessDestructionObserver;

/**

 * MIDIAccess is the DOM object that is handed to the user upon MIDI permissions

 * being successfully granted. It manages access to MIDI ports, and fires events

 * for device connection and disconnection.

 *

 * New MIDIAccess objects are created every time RequestMIDIAccess is called.

 * MIDIAccess objects are managed via MIDIAccessManager.

 */

class MIDIAccess final : public DOMEventTargetHelper,

                         public Observer<MIDIPortList>

{

  // Use the Permission Request class in MIDIAccessManager for creating

  // MIDIAccess objects.

  friend class MIDIPermissionRequest;

  friend class MIDIAccessManager;

public:

  NS_DECL_ISUPPORTS_INHERITED

  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(MIDIAccess,

                                                         DOMEventTargetHelper)

public:

  virtual JSObject* WrapObject(JSContext* aCx,

                               JS::Handle<JSObject*> aGivenProto) override;

  // Return map of MIDI Input Ports

  MIDIInputMap* Inputs() const

  {

    return mInputMap;

  }

  // Return map of MIDI Output Ports

  MIDIOutputMap* Outputs() const

  {

    return mOutputMap;

  }

  // Returns true if sysex permissions were given

  bool SysexEnabled() const

  {

    return mSysexEnabled;

  }

  // Observer implementation for receiving port connection updates

  void Notify(const MIDIPortList& aEvent) override;

  // All MIDIPort objects observe destruction of the MIDIAccess object that

  // created them, as the port object receives disconnection events which then

  // must be passed up to the MIDIAccess object. If the Port object dies before

  // the MIDIAccess object, it needs to be removed from the observer list.

  void RemovePortListener(MIDIAccessDestructionObserver* aPort);

  // Fires DOM event on port connection/disconnection

  void FireConnectionEvent(MIDIPort* aPort);

  // Notify all MIDIPorts that were created by this MIDIAccess and are still

  // alive, and detach from the MIDIAccessManager.

  void Shutdown();

  IMPL_EVENT_HANDLER(statechange);

private:

  MIDIAccess(nsPIDOMWindowInner* aWindow, bool aSysexEnabled,

             Promise* aAccessPromise);

  ~MIDIAccess();

  // On receiving a connection event from MIDIAccessManager, create a

  // corresponding MIDIPort object if we don't already have one.

  void MaybeCreateMIDIPort(const MIDIPortInfo& aInfo, ErrorResult& aRv);

  // Stores all known MIDIInput Ports

  RefPtr<MIDIInputMap> mInputMap;

  // Stores all known MIDIOutput Ports

  RefPtr<MIDIOutputMap> mOutputMap;

  // List of MIDIPort observers that need to be updated on destruction.

  ObserverList<void_t> mDestructionObservers;

  // True if user gave permissions for sysex usage to this object.

  bool mSysexEnabled;

  // Promise created by RequestMIDIAccess call, to be resolved after port

  // populating is finished.

  RefPtr<Promise> mAccessPromise;

  // True if shutdown process has started, so we don't try to add more ports.

  bool mHasShutdown;

};

} // namespace dom

} // namespace mozilla

#endif // mozilla_dom_MIDIAccess_h