// Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of the License "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

 @internalComponent

 @released

*/

#ifndef STREAMAGENTRESOLVER_H

#define STREAMAGENTRESOLVER_H

#include <e32base.h>

#include <ecom/ecom.h>

#include "streamagentinfo.h"

namespace StreamAccess

	{

	class CStreamAgentInfo;

	/**

	 * Responsible for the identification of stream agent ECOM plug-in implementations and

	 * the selection of the most appropriate agent based on the key stream session description

	 * metadata and plug-in resource file information. 

	 */

	class CStreamAgentResolver : public CBase

		{

	public:

		/* Constructs a new instance of CStreamAgentResolver and pushs it onto the cleanup stack

		 * @return Pointer to the new CStreamAgentResolver object

		 */

		static CStreamAgentResolver* NewLC();

		/* Destructor

		 */

		~CStreamAgentResolver();

		/* Resolves a stream agent by the SDP (Session Description Protocol) media description

		 * of the key stream.

		 * @param aSdpKeyStream SDP media description of the key stream

		 * @return Reference to the CStreamAgentInfo instance for the chosen Stream Agent, capable

		 * of decoding the key stream. 

		 * NOTE: The lifetime of the returned reference is limited by the lifetime of the resolver. 

		 * The CStreamAgentInfo reference cannot be used after the CStreamAgentResolver object is

		 * destroyed.

		 * @leave KErrCANoAgent No stream agent can be found that supports the given SDP key management

		 * description

		 * @leave One of the system-wide error codes

		 */

		CStreamAgentInfo& ResolveSdpKeyStreamL(const CSdpMediaField& aSdpKeyStream) const;

	protected:

		/* Constructor

	 	*/

		CStreamAgentResolver();

		/* Second phase of construction for CStreamAgentResolver 

		 */

		void ConstructL();

	private:

		/* Constructs a list of information about plug-in implementations located

		 * by the ECOM framework that satisfy the stream agent interface.

		 */

		void BuildStreamAgentListL();

		/* Adds a new instance of a stream agent to the CStreamAgentInfo array

		 * @param aAgentInfo Registration data regarding the stream agent interface implementation,

		 * retrieved from the associated resource file

		 */

		void AddStreamAgentL(const CImplementationInformation& aAgentInfo);

		/* Cleanup Item Operation used when constructing the stream agent list via ECOM

		 * @param aArray Pointer to an RImplInfoPtrArray array which is used by ECOM to store 

		 * information about located stream agents implementations

		 */ 

		static void CleanAgentImplArray(TAny* aArray);

	private:

		/* Array of information regarding stream agent interface implementations located by ECOM

		 */

		RPointerArray<CStreamAgentInfo> iStreamAgentInfoArray;

		};

	} // namespace StreamAccess

#endif /*STREAMAGENTRESOLVER_H*/