/*

* Copyright (c) 2008 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 execution class for LC VT plugin.

*

*/

#ifndef CLCVTACTIVEEXEC_H

#define CLCVTACTIVEEXEC_H

//  INCLUDES

#include    <e32base.h>

// FORWARD DECLARATIONS

class CLcVtActiveExec;

// CLASS DECLARATION

/**

*  Interface for asynchronous execution.

*

*  @since Series 60 2.6

*/

class MLcVtActiveExec

    {

    public: // New functions

        /**

        * Starts execution of a command.

        * @param aActiveExec active executor.

        * @param aState state based on which execution can be started.

        * @param aNextState next state.

        * @param aRequest request status, which should be used if operation is 

        *        asynchronous.

        * @return ETrue if operation was synchronous, otherwise EFalse.

        */

        virtual TBool ActiveExecExecuteL( 

            CLcVtActiveExec& aActiveExec,

            const TInt aState, 

            TInt& aNextState,

            TRequestStatus& aRequest ) = 0; 

        /**

        * Decide whether to continue or not.

        * @param aActiveExec active executor.

        * @param aState current state, should be updated to new state.

        * @param aError error code.

        * @return ETrue if continued, EFalse if stopped.

        */

        virtual TBool ActiveExecContinue(

            CLcVtActiveExec& aActiveExec,

            TInt& aState, 

            const TInt aError ) = 0;

        /**

        * Cancels operation of specific state.

        * @param aActiveExec active executor.

        * @param aState state.

        */

        virtual void ActiveExecCancel( 

            CLcVtActiveExec& aActiveExec,

            const TInt aState ) = 0;

        /**

        * Informs that operation has been finished.

        * @param aActiveExec active executor.

        * @param aInitialState initial state.

        */

        virtual void ActiveExecDone( 

            CLcVtActiveExec& aActiveExec,

            const TInt aInitialState ) = 0;

    };

/**

*  Asynchronous execution class for LC VT plugin.

*

*  @since Series 60 2.6

*/

class CLcVtActiveExec 

    : public CActive

    {

    public: // Constructors and destructor

        /**

        * Constructor.

        * @param aPriority priority of the active object.

        */

        CLcVtActiveExec(

            const TInt aPriority );

        /**

        * Destructor.

        */

        ~CLcVtActiveExec();

    public: // New functions

        /**

        * Starts execution.

        * @param aStartState initial state.

        * @param aExec executor.

        */

        void Start( 

            TInt aStartState, 

            MLcVtActiveExec& aExec );

        /**

        * Initial state of currently

        * active operation.

        *

        * @return initial state, or KErrNotFound if no operation ongoing.

        */

        TInt InitialState() const;

        /**

        * Returns request status.

        * @return request status.

        */

        TInt RequestStatus() const;

    protected: // Functions from base classes

        /**

        * @see CActive::RunL.

        */

        virtual void RunL();

        /**

        * @see CActive::DoCancel.

        */

        virtual void DoCancel();

        /**

        * @see CActive::RunError.

        */

        virtual TInt RunError( TInt aError );

    private:

        // Ref to active executor.

        MLcVtActiveExec* iActiveExec;

        // Initial state.

        TInt iInitialState;

        // Current state.

        TInt iCurrentState;

        // Next state.

        TInt iNextState;

    };

#endif // CLCVTACTIVEEXEC_H

// End of File