/*

* Copyright (c) 2008-2008 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:  Interfaces of Finite State Machine (.

*

*/

#ifndef M_FINITESTATEMACHINE_H

#define M_FINITESTATEMACHINE_H

#include <e32def.h>

#include <e32cmn.h> 

#include <e32des8.h>

typedef TInt TFSMState;

class MFSMState;

/**

 *  Finite State Machine's body interface. 

 *

 *  This callback interface has to be implemented by FSM body

 *  implementation class.

 *  @code

 *   ?good_class_usage_example(s)

 *  @endcode

 *

 *  @lib AccServer.exe

 *  @since S60 5.1

 */

NONSHARABLE_CLASS( MFSMBody )

    {

public:

    virtual ~MFSMBody() {} // Destructor needed for ownership transfer

    /**

     * Function is called by host object to indicate that FSM can proceed to 

     * initial state and make necessary initialization actions.

     * 

     * @since S60 5.1

     * @param none. 

     * @return void.

     */

    virtual void Start() = 0;

    /**

     * Function is called by  current state to indicate that FSM has to change

     * its state. Pervious state has performed necessary exit actions if any.

     *

     * @since S60 5.1

     * @param aNextState Next state where to transit. 

     * @return TBool True is transition valid. False if nextstate value invalid.

     */

    virtual TBool Transit( TFSMState aNextState ) = 0;

    /**

     * Get the id of current state.

     *

     * @since S60 5.1

     * @param none. 

     * @return TFSMState Current state identification.

     */

    virtual TFSMState CurrentStateID() = 0;

    /**

     * Function is called whenever an event that might have impact 

     * on the state machine occurs.

     *

     * @since S60 5.1

     * @param none. 

     * @return none.

     */

    virtual void Input() = 0;

    /**

     * Get the pointer of current state object.

     *

     * @since S60 5.1

     * @param none. 

     * @return MFSMState* Current state's interface pointer.

     */

    virtual  MFSMState* CurrentState() = 0;

    /**

     * Get the name of current state.

     *

     * @since S60 5.1

     * @param none. 

     * @return TPtrC Name of the current state.

     */

    virtual TPtrC CurrentStateName() = 0;

    };

/**

 *  FSM's State interface. 

 *

 *  This callback interface has to be implemented by FSM state

 *  implementation class.

 *  @code

 *   ?good_class_usage_example(s)

 *  @endcode

 *

 *  @lib AccServer.exe

 *  @since S60 5.1

 */

class MFSMState

    {

public:

    virtual ~MFSMState() {} // Destructor needed for ownership transfer

    /**

     * Function is called when entering the state. State can perform

     * necessary entry actions if any.

     *

     * @since S60 5.1

     * @param none. 

     * @return void.

     */

    virtual void Enter() = 0;

    /**

     * Function is called by FSM Body whenever an event that might have 

     * impact on the state has been fired. Implementation has to found

     * out what event has occurred and decide whether it enforces

     * transition to another state.

     *

     * @since S60 5.1

     * @param none. 

     * @return none.

     */

    virtual void Input() = 0;

    /**

     * Function returns state's identification.

     *

     * @since S60 5.1

     * @param none. 

     * @return TFSMState State's identification.

     */

    virtual TFSMState Id() = 0;

    /**

     * Function returns state's name.

     *

     * @since S60 5.1

     * @param none. 

     * @return TPtrC Name of the state.

     */

    virtual TPtrC Name() = 0;

    };

#endif // M_FINITESTATEMACHINE_H