/*

* 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:    Media and attribute fetch context

*

*/

#ifndef M_GLXFETCHCONTEXT_H

#define M_GLXFETCHCONTEXT_H

#include <e32base.h>

#include "glxmediaid.h"

#include <mpxattributespecs.h>

class MGlxMediaList;

class TMPXAttribute;

/**

 *  MGlxFetchContext

 *

 *  Interface that allows clients to define which media items should be 

 *  retrieved and which properties for them

 *

 *  @lib none

 */

class MGlxFetchContext 

    {

public:

    /**

     * Specifies which attributes should be fetched for a particular item

     * in the list.

     * @param aList the list for which the request relates to

     * @return in aItemIndices the list indices for which the attributes should be requested for

     *         if no items requiring attributes, returns an empty array.

     *         Caller should make sure the array is empty before calling.

     * @return in aAttributes the attributes that should be retrieved

     * @return in aDetailedSpecs a new detailed specification object 

     *		   regarding the attributes or NULL. Caller must set the 

     *		   parameter to NULL.

     * @return TInt number of items with outstanding requests.

     *     KErrGeneral if there are no more requests but there are outstanding errors.

     */

    virtual TInt AttributeRequestL(const MGlxMediaList* aList, RArray<TInt>& aItemIndices, 

    	RArray<TMPXAttribute>& aAttributes, CMPXAttributeSpecs*& aDetailedSpecs) const = 0;

    /**

     * Lists all attributes that a required for a particular item in the list.

     * Ignores whether the attributes have been loaded or not. This function 

     * is used for garbage collection, in order to know if an attribute is 

     * still in use. 

     * @param aList the list for which the call relates to

     * @param aListIndex the index in the list of the particular item

     * @return in aAttributes all attributes that this context requires.

     *		   if no attributes are required, returns the array as empty.

     *	       Caller must make sure the array is empty before calling.

     */

    virtual void AllAttributesL(const MGlxMediaList* aList, TInt aListIndex, 

    	RArray<TMPXAttribute>& aAttributes) const = 0;

    /**

     * Provides the number of items with currently outstanding requests

     *

     * @param aList the list for which the call relates to

     * @return TInt number of items with outstanding requests.

     *     KErrGeneral if there are no more requests but there are outstanding errors.

     */

    virtual TInt RequestCountL(const MGlxMediaList* aList) const = 0;

    };

#endif // M_GLXFETCHCONTEXT_H