1 /*

     2 * Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies). 

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

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

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:    Media and attribute fetch context

    15 *

    16 */

    17 

    18 

    19 

    20 

    21 #ifndef M_GLXFETCHCONTEXT_H

    22 #define M_GLXFETCHCONTEXT_H

    23 

    24 #include <e32base.h>

    25 #include "glxmediaid.h"

    26 

    27 #include <mpxattributespecs.h>

    28 

    29 class MGlxMediaList;

    30 class TMPXAttribute;

    31 

    32 /**

    33  *  MGlxFetchContext

    34  *

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

    36  *  retrieved and which properties for them

    37  *

    38  *  @lib none

    39  */

    40 class MGlxFetchContext 

    41     {

    42 public:

    43     /**

    44      * Specifies which attributes should be fetched for a particular item

    45      * in the list.

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

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

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

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

    50      * @return in aAttributes the attributes that should be retrieved

    51      * @return in aDetailedSpecs a new detailed specification object 

    52      *		   regarding the attributes or NULL. Caller must set the 

    53      *		   parameter to NULL.

    54      * @return TInt number of items with outstanding requests.

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

    56      */

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

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

    59     

    60     /**

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

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

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

    64      * still in use. 

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

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

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

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

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

    70      */

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

    72     	RArray<TMPXAttribute>& aAttributes) const = 0;

    73 

    74     /**

    75      * Provides the number of items with currently outstanding requests

    76      *

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

    78      * @return TInt number of items with outstanding requests.

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

    80      */

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

    82     };

    83 

    84 #endif // M_GLXFETCHCONTEXT_H