/*

* Copyright (c) 2002-2009 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: 

*

*/

#ifndef MCLFCUSTOMGROUPER_H

#define MCLFCUSTOMGROUPER_H

//  INCLUDES

#include <e32std.h>

// FORWARD DECLARATIONS

class MCLFCustomGrouperExt;

class MCLFItem;

// CLASS DECLARATION

/**

*  Custom grouper interface of Content Listing Framework.

*  With this interface, client can add own custom grouper

*  to its List Model. Custom grouper is used for grouping list model items.

*  For example, List Model of music files can be grouped by genre or artist

*  name by using this interface.

*  Use ContentListingFactory to create items for new groups (MCLFModifiableItem).

*  <br><br>

*  Example:

*  @code

*  // This grouper will overwrite the source list and add three items to model.

*  void CMyGrouper::GroupItemsL( const TArray<MCLFItem*>& aSourceList,

*                                RPointerArray<MCLFItem>& aGroupedList )

*      {

*      _LIT( KTest, "test" );

*      MCLFModifiableItem* item = ContentListingFactory::NewModifiableItemLC();

*      item->AddFieldL( ECLFFieldIdName, KTest );

*      aGroupedList.AppendL( item );

*      CleanupStack::Pop(); // item

*

*      _LIT( KTest1, "test1" );

*      item = ContentListingFactory::NewModifiableItemLC();

*      item->AddFieldL( ECLFFieldIdName, KTest1 );

*      aGroupedList.AppendL( item );

*      CleanupStack::Pop(); // item

*

*      _LIT( KTest2, "test2" );

*      item = ContentListingFactory::NewModifiableItemLC();

*      item->AddFieldL( ECLFFieldIdName, KTest2 );

*      aGroupedList.AppendL( item );

*      CleanupStack::Pop(); // item

*      }

*  @endcode

*

*  Custom grouper is activated and removed by calling method

*  MCLFItemListModel::SetCustomGrouper

*

*  @lib ContentListingFramework.lib

*  @since S60 3.1

*/

class MCLFCustomGrouper

    {

    public: // New functions

        /**

        * Abstract method for grouping Content Listing Framework items of

        * list models. This method is called when the grouping process is

        * executed by refreshing the model.

        * @since S60 3.1

        * @param aSourceList Source list. Contains all items that are in

        *        the list model when the grouping process starts.

        * @param aGroupedList Grouped/destination list. While grouping, each

        *        group should be added to this list. The list model will

        *        contain only these items when the grouping process is

        *        finished.

        */

        virtual void GroupItemsL( const TArray<MCLFItem*>& aSourceList,

                                  RPointerArray<MCLFItem>& aGroupedList ) = 0;

    protected:

        /**

        * Destructor.

        */

        virtual ~MCLFCustomGrouper() {}

    private: // Extension interface

        /**

        * This member is internal and not intended for use.

        */

        virtual MCLFCustomGrouperExt* Extension() { return NULL; }

    };

#endif      // MCLFCUSTOMGROUPER_H

// End of File