/*

* Copyright (c) 2005 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:  Asynchronous request handlers for DS host server.

*

*/

#ifndef __NSMLDSASYNCREQUESTHANDLER_H__

#define __NSMLDSASYNCREQUESTHANDLER_H__

// INCLUDES

#include <e32base.h>

#include <nsmldsconstants.h>

#include <nsmlconstants.h>

#include "nsmldshostconstants.h"

#include "nsmldshostitem.h"

#include "nsmldsitemmodificationset.h"

// FORWARD DECLARATIONS

class CNSmlDSHostSession;

class CSmlDataStore;

struct TNSmlDSDataStoreElement;

struct TNSmlDSDataProviderElement;

class CNSmlAdapterLog;

// CLASS DECLARATION

// ------------------------------------------------------------------------------------------------

// Base class for asynchronous request handlers.

//

// @lib nsmldshostserver.lib

// ------------------------------------------------------------------------------------------------

class CNSmlDSAsyncRequestHandler : public CActive

    {

	public: // destructor

		/**

		* C++ default destructor.

		*/	

		virtual ~CNSmlDSAsyncRequestHandler();

	public:	// New functions

		/**

		* Initializes the object for asynchronous calls.

		* @return CSmlDataStore&. The asynchronous service provider for the request.

		*/

		CSmlDataStore& CallDSAsyncLC();

		/**

		* Pushes item to cleanupstack, item, which sets the request status

		* on leave CleanupStack::PopAndDestroy()

		*/

		void SetRequestStatusOnLeaveLC();  

		/**

		* Called when the item pushed in CNSmlDSAsyncCallBackForOpen::SetRequestStatusOnLeaveLC() is 

		* destroyed from the cleanupstack. Sets the request status.

		* @param aP. instance of CNSmlDSAsyncCallBackForOpen.

		*/

		static void SetRequestStatusOnLeaveCleanup( TAny* aP );

	public: // Functions from base classes

		/**

		* calls CActive::SetActive().

		*/

		void SetActive();

	protected:

		/**

		* A C++ constructor of this class. 

		* @param aPriority. The priority of the active object,

		* @param aSession. The session object of the request.

		* @param aDSItem. contains the data store, which provides the asynchronous service.

		* @param aMessage. The message associated with the request.

		*/

		CNSmlDSAsyncRequestHandler(TInt aPriority,

    		CNSmlDSHostSession* aSession, 

			TNSmlDSDataStoreElement* aDSItem, 

			const RMessagePtr2& aMessage );

		/**

		* Adds object to Active scheduler.

		*/

		void AddToSchedulerL();

	private:	//Functions from base class

		TInt RunError(TInt aError);

	public:		//Data

		CNSmlDSHostSession* iSession;		//session for request.

		TNSmlDSDataStoreElement* iDSItem;	//data store for request

		RMessagePtr2 iMessage;			//message for request.

    };

// ------------------------------------------------------------------------------------------------

// Asynchronous request handler, that calls callback method, when request finishes.

//

// @lib nsmldshostserver.lib

// ------------------------------------------------------------------------------------------------

class CNSmlDSAsyncCallBack : public CNSmlDSAsyncRequestHandler

    {

	public:	//DATA TYPES

		enum TCallBackOperation

			{

			EFinished = 0,

			ECanceled,

			EFree

			};

		typedef TInt (CNSmlDSHostSession::*RequestFinishedFunction) 

			(CNSmlDSAsyncCallBack* aDSAO, CNSmlDSAsyncCallBack::TCallBackOperation aOperation);

	public: 	//Constructors and destructors

		/**

		* A C++ constructor of this class.

		* @param aSession. The session object of the request.

		* @param aDSItem. Contains the data store, which provides the asynchronous service.

		* @param aMessage. The message associated with the request.

		* @param aReqFinishedFunc.the call back function this object calls, when request completes.

		* @param aPtr. Pointer to request specific data.

		*/

		CNSmlDSAsyncCallBack( CNSmlDSHostSession* aSession, 

			TNSmlDSDataStoreElement* aDSItem, 

			const RMessage2& aMessage,

			RequestFinishedFunction aReqFinishedFunc = NULL,

			TAny* aPtr = NULL );

		/**

		* C++ destructor

		*/

		virtual ~CNSmlDSAsyncCallBack();

	private: // Functions from base classes

		void DoCancel();

		void RunL();

	public:

		TAny* iPtr; // request specific data.

	protected:

		RequestFinishedFunction iReqFinishedFunc;

    };

// ------------------------------------------------------------------------------------------------

// Asynchronous request handler for CSmlDataStore::Open

//

// @lib nsmldshostserver.lib

// ------------------------------------------------------------------------------------------------    

class CNSmlDSAsyncCallBackForOpen : public CNSmlDSAsyncCallBack

	{

	public: //Constructor

		/**

		* A C++ constructor of this class. 

		* @param aSession. The session object of the request.

		* @param aMessage. The message associated with the request.

		* @param aReqFinishedFunc. the call back function this object calls, when request completes.

		*/

		CNSmlDSAsyncCallBackForOpen( CNSmlDSHostSession* aSession, 

			const RMessage2& aMessage,

			RequestFinishedFunction aReqFinishedFunc = NULL );        

	public:	//Data

		TNSmlDSDataProviderElement* iDpi;	//Data provider for request

		HBufC* iServerId;

		HBufC* iRemoteDB;

	};

// ------------------------------------------------------------------------------------------------

// Asynchronous request handler for fetching all changed items.

//

// @lib nsmldshostserver.lib

// ------------------------------------------------------------------------------------------------

class CNSmlDSChangedItemsFetcher : public CNSmlDSAsyncRequestHandler

	{

	public:	//DATA TYPES

		typedef void ( CNSmlDSHostSession::*RequestFinishedFunction ) 

			( CNSmlDSChangedItemsFetcher* aDSAO );

	public:// Constructor and destructor

		/**

		* Creates new instance of the CNSmlDSChangedItemsFetcher and pushed it to the cleanup stack.

		* @param aSession. The session object of the request.

		* @param aDSItem. Contains the data store, which provides the asynchronous service.

		* @param aMessage. The message associated with the request.

		* @param aReqFinishedFunc. The call back function this object calls, when request completes.

		* @return CNSmlDSChangedItemsFetcher*. Newly created instance.

		*/

		static CNSmlDSChangedItemsFetcher* NewLC( CNSmlDSHostSession* aSession, 

			TNSmlDSDataStoreElement* aDSItem, 

			const RMessage2& aMessage,

			RequestFinishedFunction aReqFinishedFunc );

		/**

		* C++ destructor

		*/

		virtual ~CNSmlDSChangedItemsFetcher();

	public:	//New methods

		/**

		* Fetches all changed items asynchronously. Calls the call back method when done.

		*/

		void FetchAllChangedItemsL();

		/**

		* Returns the changes after they are fetched. 

		* @return RNSmlDbItemModificationSet*. Contains the requested changes.

		*/    

		const RNSmlDbItemModificationSet* ChangedItems() const;

	protected:

		/**

		* A C++ constructor of this class. 

		* @param aSession. The session object of the request.

		* @param aDSItem. Contains the data store, which provides the asynchronous service.

		* @param aMessage. The message associated with the request.

		* @param aReqFinishedFunc. The call back function this object calls, when request completes.

		*/

		CNSmlDSChangedItemsFetcher( CNSmlDSHostSession* aSession, 

			TNSmlDSDataStoreElement* aDSItem, 

			const RMessage2& aMessage,

			RequestFinishedFunction aReqFinishedFunc );

		/**        

		* Symbian 2nd phase constructor

		*/

		void ConstructL();

	private: // Functions from base classes

		virtual void DoCancel();

	public:

	protected:

		RequestFinishedFunction iReqFinishedFunc;

		TNSmlDbItemModification::TNSmlDbItemModificationType iNextModsToFetch;

		RNSmlDbItemModificationSet* iChangedItems;

	}; 

#endif //__NSMLDSASYNCREQUESTHANDLER_H__

// End of File