// 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*/