/*

* Copyright (c) 2005-2006 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:  CPosLmOperation class

*

*/

#ifndef CPOSLMOPERATION_H

#define CPOSLMOPERATION_H

#include <e32base.h>

class CPosLmOperation;

/**

*  Executes the operation synchronously and then deletes it.

*

*  All functions which return a @ref CPosLmOperation object can be run

*  incrementally. If the client is not interested in running it

*  incrementally, it can call @ref CPosLmOperation::ExecuteL to run the

*  whole operation in one batch. This can be simplified by using

*  @ref ExecuteAndDeleteLD. It runs the operation and deletes the object

*  when it is done.

*

*  For instance, to use this function for

*  @ref CPosLandmarkDatabase::InitializeL, the client would call

*

*  ExecuteAndDeleteLD( database->InitializeL() );

*

*  The operation object should not be on the cleanup stack when this function

*  is called.

*

*  @since S60 3.0

*  @param aOperation The operation to handle. It will be deleted when the

*   function returns.

*/

inline void ExecuteAndDeleteLD( CPosLmOperation* aOperation );

/**

*  Base class for handles to landmark operations.

*

*  Long running operations in the Landmarks API returns an object of this class

*  so that the client can run it incrementally and check the progress of the

*  operation.

*

*  The operation must explicitly be run by the client. The operation can

*  be run incrementally by calling @ref NextStep until it does not return

*  the status @p KPosLmOperationNotComplete. Alternately the operation can be

*  run synchronously by calling @ref ExecuteL.

*

*  @ref ExecuteAndDeleteLD can be used to handle the operation object if

*  it is run in synchronous mode.

*

*  @lib eposlandmarks.lib

*  @since S60 3.0

*/

class CPosLmOperation : public CBase

    {

    public:

        /**

        * Destructor.

        */

        IMPORT_C virtual ~CPosLmOperation();

    public:

        /**

        * Incremental execution of the operation.

        *

        * The client should use an active object and call this function until

        * it does not complete with status @p KPosLmOperationNotComplete.

        *

        * When the operation has finished, this function will complete with

        * status @p KErrNone if the operation was successful, or an error code

        * if some error was encountered.

        *

        * This function also returns a progress of the operation. Progress is a

        * floating point number in the interval [0.0,1.0]. 0.0 indicates that

        * the operation has not started and 1.0 indicates that the operation

        * has completed.

        *

        * Note that this function is asynchronous which means that status and

        * progress may not be set when the function returns. They are only

        * guaranteed to be set when the request is completed.

        *

        * The only way to cancel an operation is to delete the operation

        * object. This will also cancel any outstanding request to

        * NextStep().

        *

        * @param[out] aStatus The request status. Upon request completion contains

        *   step status: 

        *   - @p KPosLmOperationNotComplete if the step has completed but more

        *   steps are needed before the operation will be completed. 

        *   - @p KErrNone if the operation has finished successfully. 

        *   - An error code if the operation has failed.

        * @param[out] aProgress Upon request completion is set to the progress 

        *   of the operation.

        *

        * @panic "Landmarks Client"-EPosInvalidOperationMode 

        *   The function is called when the operation is already complete.

        */

        virtual void NextStep(

            TRequestStatus& aStatus,

            TReal32& aProgress

        ) = 0;

        /**

        * Synchronous execution of the operation.

        *

        * When this function returns, the operation has finished.

        *

        * @panic "Landmarks Client"-EPosInvalidOperationMode 

        *   -# This function is called when the operation is already complete

        *   -# The operation has already been started incrementally using @ref NextStep().

        */

        virtual void ExecuteL() = 0;

    protected:

        // C++ constructor.

        IMPORT_C CPosLmOperation();

    private:

        // Prohibit copy constructor

        CPosLmOperation( const CPosLmOperation& );

        // Prohibit assigment operator

        CPosLmOperation& operator= ( const CPosLmOperation& );

    };

#include "EPos_CPosLmOperation.inl"

#endif      // CPOSLMOPERATION_H