/*

 * 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 MCLFCONTENTLISTINGENGINE_H

 #define MCLFCONTENTLISTINGENGINE_H

 //  INCLUDES

 #include <CLFContentListing.h>

 #include <e32std.h>

 // FORWARD DECLARATIONS

 class MCLFContentListingEngineExt;

 class MCLFChangedItemObserver;

 class MCLFItemListModel;

 class MCLFOperationObserver;

 class TResourceReader;

 class MCLFProcessObserver;

 // CLASS DECLARATION

 /**

 *  Content Listing Engine.

 *  With Content Listing Engine, client can create item list models,

 *  add an observer to get notifications of changed items and

 *  send update notifications to server.

 *  Client can create an instance this class with ContentListingFactory.<br><br>

 *  Usage:

 *

 *  @code

 *

 *  // Create a new instance with Content Listing Factory

 *  MCLFContentListingEngine* engine =

 *                    ContentListingFactory::NewContentListingEngineLC();

 *

 *  // Add changed item observer

 *  engine->AddChangedItemObserverL( *myObserver );

 *

 *  // Send update notification when item is changed.

 *  engine->UpdateItemsL();

 *

 *  // Remember to remove the observer, when it is deleted

 *  engine->RemoveChangedItemObserver( *myObserver );

 *

 *  @endcode

 *

 *  @lib ContentListingFramework.lib

 *  @since S60 3.1

 */

 class MCLFContentListingEngine

     {

     public: // Constructors and destructor

         /**

         * Destructor.

         */

         virtual ~MCLFContentListingEngine() {}

     public: // New functions

         /**

         * Create a new instance of the Item List Model.

         * @since S60 3.1

         * @param aObserver Reference to an Operation Observer

         * @return New instance of the Item List Model.

         *         Ownership is transfered to the client application.

         */

         virtual MCLFItemListModel* CreateListModelLC(

                         MCLFOperationObserver& aObserver ) = 0;

         /**

         * Create a new instance of Item List Model from the application

         * resource.

         * @since S60 3.1

         * @param aObserver Reference to an Operation Observer.

         * @param aResource Resource reader to list model resource.

         *                  Use resource struct CLF_LIST_MODEL. See

         *                  CLFContentListing.rh

         * @return New instance of Item List Model.

         *         Ownership is transfered to the client application.

         */

         virtual MCLFItemListModel* CreateListModelLC(

                         MCLFOperationObserver& aObserver,

                         TResourceReader& aResource ) = 0;

         /**

         * Add a changed item observer to the Engine.

         * Changed item observer will notify you when items are changed, added

         * or removed. Remember to remove the observer before you delete

         * observer object.

         * @since S60 3.1

         * @param aObserver Changed item observer to be added

         */

         virtual void AddChangedItemObserverL(

                         MCLFChangedItemObserver& aObserver ) = 0;

         /**

         * Remove a changed item observer from the Engine.

         * @since S60 3.1

         * @param aObserver Changed item observer to be removed

         */

         virtual void RemoveChangedItemObserver(

                         MCLFChangedItemObserver& aObserver ) = 0;

         /**

         * Add CLF process observer.

         * Remember to remove the observer before delete the observer object.

         * @since S60 3.1

         * @param aObserver Process observer to be added

         */

         virtual void AddCLFProcessObserverL(

                         MCLFProcessObserver& aObserver ) = 0;

         /**

         * Remove CLF process observer.

         * @since S60 3.1

         * @param aObserver Process observer to be removed

         */

         virtual void RemoveCLFProcessObserver(

                         MCLFProcessObserver& aObserver ) = 0;

         /**

         * Send item update notification.

         * Client must use this method when media item(s) is changed or deleted.

         * This method call will request the CLF server to update its list

         * of items. Unneccesary update notifications should be avoided because

         * they generate load to the system!

         * @since S60 3.1

         */

         virtual void UpdateItemsL() = 0;

         /**

         * Send item update notification.

         * Client must use this method when media item(s) is changed or deleted.

         * This method call will request the CLF server to update items that are

         * defined in the TArray.

         * @since S60 3.1

         * @param aItemIDArray List of Item IDs of modified items

         */

         virtual void UpdateItemsL(

                         const TArray<TCLFItemId>& aItemIDArray ) = 0;

         /**

         * Send item update notification.

         * Client must use this method when media item(s) is changed or deleted.

         * @param aSemanticId Sematic ID is transfered to server plugins

         * @param aOpaqueData Opaque data is transfered to server plugins

         * @since S60 3.1

         */

         virtual void UpdateItemsL(

                         TInt aSemanticId,

                         const TDesC8& aOpaqueData ) = 0;

     private: // Extension interface

         /**

         * This member is internal and not intended for use.

         */

         virtual MCLFContentListingEngineExt* Extension() { return NULL; }

     };

 #endif      // MCLFCONTENTLISTINGENGINE_H

 // End of File