// Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

//

/**

 @file

 @publishedPartner

 @released

*/

#ifndef MAUDIOPROCESSINGUNIT_H

#define MAUDIOPROCESSINGUNIT_H

#include <e32base.h>

#include <f32file.h>

#include <mmf/common/mmfcontroller.h>

#include <a3f/a3fbase.h>

class MAudioProcessingUnitObserver;

/**

 * A generic interface for audio processing units.

 */

class MAudioProcessingUnit

	{

public:

	/**

	 * Fetches the identifier of the context in which this processing unit exists.

	 *

	 * @return TUid context instance id.

	 */

	virtual TAudioContextId ContextId() const = 0;

	/**

	 * Fetches the specified interface to this processing unit.

	 * The interface must not be deleted by the client.

	 * The processing unit must be removed once from the context using

	 * any of the retrieved processing unit interfaces.

	 * @param aTypeId the type of the interface

	 */

	virtual TAny* Interface(TUid aType)=0;

	/**

	 * Registers a processing unit observer.

	 *

	 * The observer must be unregistered before the processing unit is removed from the context.

	 * 

	 * @see MAudioProcessingUnitObserver for further inforamtion about the observer usage.

	 * @param aObserver a reference to the observer to register

	 * @return an error code. KErrNone if successful.

	 *         KErrNotSupported the processing unit does not provide support for this type of observation.

	 *         Other system wide error codes are also possible.

	 */

	virtual TInt RegisterProcessingUnitObserver(MAudioProcessingUnitObserver& aObserver)=0;

	/**

	 * Unregisters audio processing unit observer.

	 *

	 * @see RegisterProcessingUnitObserver for further information.

	 * @param aObserver a reference to the processing unit observer to unregister.

	 * @return an error code. KErrNone if successful.

	 */

	virtual void UnregisterProcessingUnitObserver(MAudioProcessingUnitObserver& aObserver)=0; 

	/**

	 * Returns the component instance id.

	 *

	 * @return TUid component instance id.

	 */

	virtual TAudioComponentId InstanceId() const = 0;

	/** 

	 * Returns if the component is the same type of the given feature Uid. 

 	 * @param aTypeId a feature Uid to compare with.

	 */

	virtual TBool IsTypeOf(TUid aTypeId) const =  0;

	};

#endif // MAUDIOPROCESSINGUNIT_H