/*

* Copyright (c) 2008-2009 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: Definition of the Data Source Mixin Class.

*

*/

#ifndef _MGLXDATASOURCE_H_

#define _MGLXDATASOURCE_H_

// INCLUDES

#include <e32cmn.h>

#include "mglxdatasourceupdateobserver.h"

#include "mglxdatasourcerequestobserver.h"

// FORWARD DECLARATIONS

class CGlxRequest;

// CONSTANTS

// CLASS DECLARATION

/**

 *  MGlxDataSource class 

 *

 *  Data Source  collates Data Source information.

 *  @lib GlxDataSource.lib

 *	@ingroup collection_component_design

 *  @internal reviewed 11/07/2007 by Dave Schofield

 */

class MGlxDataSource 

	{

public:

	/**

	 * Asynchronous call to retrieve 

	 * 

	 * @param aListId list for this query relates to

	 * @return error code

	 */

	virtual void DataSourceRequestL(CGlxRequest* aRequest, MGlxDataSourceRequestObserver& aObserver) = 0;

	/**

	 * Cancel asynchronous request call

	 * as each requestor can only have one active request the observer is sufficient to cancel the request.

	 * 

	 */

	virtual void CancelRequest(MGlxDataSourceRequestObserver& aObserver) = 0;

public:

	/**

	 * Since there should be only one data source manager for a server,

	 * clients can use this function to either create the instance or 

	 * return the pointer if the instance already exists.

	 *

	 * The pointers are reference counter, and the instance is deleted after

	 * there are no more clients. It is, therefore, necessary

	 * to release the instance by calling Close() when no longer needed.

	 *

	 * @returns a pointer to a new or existing list manager instance

	 */

	IMPORT_C static MGlxDataSource* OpenDataSourceL(const TUid& aDataSource, MGlxDataSourceUpdateObserver& aObserver);

	/**

	 * Decrements the reference count of the data source manager. Deletes the 

	 * data source manager if there are no more references.

	 */

	virtual void Close(MGlxDataSourceUpdateObserver& aObserver)=0;

	};

#endif //_MGLXDATASOURCE_H_