/*

* Copyright (c) 2010 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:  MDE harvester utility class

*

*/

#ifndef MDEHARVESTER_H_

#define MDEHARVESTER_H_

#include <e32def.h>

#include <e32base.h>

#include <mdesession.h>

#include <mdequery.h>

#include <mdeconstants.h>

#include <mdeobjectquery.h>

#include <mdccommon.h>

#include <mdeitem.h>

#include <mdeobject.h>

#include "mdeobjectqueuemanager.h"

class CMdeHarvester : public CActive,

                      public MMdEQueryObserver

   {

   public:

    /*

     * Construction

     * @param CMdESession* aSession valid mde session donot own

     * @param MdeMEdiaObserver* aObserver media observer for completion donot own

     * @param CMdeObjectQueueManager* aObjJobQueue object queue manager donot own

     * @return instance of mde harvester

     */

   static CMdeHarvester* NewL(CMdESession* aSession,

                              MdeMEdiaObserver* aObserver,

                              CMdeObjectQueueManager* aObjJobQueue);

   /*

    * Construction

    * @param CMdESession* aSession valid mde session

    * @param MdeMEdiaObserver* aObserver media observer for completion

    * @param CMdeObjectQueueManager* aObjJobQueue object queue manager

    * @return instance of mde harvester

    */   

   static CMdeHarvester* NewLC(CMdESession* aSession,

                               MdeMEdiaObserver* aObserver,

                               CMdeObjectQueueManager* aObjJobQueue);

   /*

    * destruction

    */

   virtual ~CMdeHarvester();

   public:

   /*

    * Callback from MMdEQueryObserver

    * @param CMdEQuery& aQuery query instance

    * @param TInt aFirstNewItemIndex

    * @param TInt aNewItemCount

    */

   void HandleQueryNewResults(CMdEQuery& aQuery,

                                          TInt aFirstNewItemIndex,

                                          TInt aNewItemCount);

   /*

    * Callback from MMdEQueryObserver

    * @param CMdEQuery& aQuery query instance

    * @param TInt aError

    */

   void HandleQueryCompleted(CMdEQuery& aQuery, TInt aError);

   /*

    * DoHarvestL start harvesting 

    * @param TDesC& aNameSpaceDef namespace definition

    */

   void DoHarvesetL(const TDesC& aNameSpaceDef);

   //from CActive

   void RunL();

   void DoCancel();

   TInt RunError();

private:

   /*

    * Second phase constructor

    * @param CMdESession* aSession valid mde session do not own

    * @param MdeMEdiaObserver* aObserver media event observer completion do notown

    * @param CMdeObjectQueueManager* aObjJobQueue job queue manager donot own

    */

   void ConstructL(CMdESession* aSession,

                   MdeMEdiaObserver* aObserver,

                   CMdeObjectQueueManager* aObjJobQueue);

   /*

    * Default constructor

    */

   CMdeHarvester();

   /*

    * Queryall media objects

    * @param TDesC& aNameSpaceDef namespace definition

    */

   void QueryAllMediaObjectsL(const TDesC& aNameSpaceDef);

   /*

    * HandleNextRequest

    */

   void HandleNextRequestL();

   /*

    * AO completion on self

    */

   void CompleteSelf();

private:

   MdeMEdiaObserver* iObserver;//Media observer for event completion    

   // session to metadata engine

   CMdESession* iSession;

   // metadata query

   CMdEObjectQuery* iQuery;

   CActiveSchedulerWait* iWait; //Nested AO wait

   CMdeObjectQueueManager* iJobQueue;//Pass the Object for Metadata processing

   TInt         iCurrentIndex; //Current index for MDE items

   };

#endif /* MDEHARVESTER_H_ */