/*

* Copyright (c) 2009 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:

*

*/

#ifndef CXESTATEMACHINE_H

#define CXESTATEMACHINE_H

#include "cxestatemachinebase.h"

class CxeState;

/**

 * CxeStateMachine extends CxeStateMachineBase functionality. All methods call base class

 * implementation, and will panic if the base class return value indicates failure.

 *

 * Engine classes should derive from CxeStateMachine. CxeStateMachineBase is for situations where

 * asserts can't be used, like unit testing.

 *

 * CxeStateMachine is internal to the engine and is not visible in the engine API.

*/

class CxeStateMachine : public CxeStateMachineBase

{

public:

    /**

    * CxeStateMachine constructor. After construction, the derived class should

    * add all the defined states and call setInitialState().

    *

    * @sa addState setInitialState

    * @param stateMachineName  Name for this state machine (used for debug prints)

    */

    CxeStateMachine(const char* stateMachineName);

    virtual ~CxeStateMachine();

protected:

    /**

     * Add a new state to the machine. Takes ownership of state. This function will

     * panic, if new state id is incorrect.

     *

     * @param state A CxeState object defining a name, ID, and allowed transitions for

     * the new state. The CxeState ID must be unique and not to contain overlapping bits

     * with other state ids, since bitwise AND operator is used for the state ids.

     * @return True if adding was successful, false if adding failed

     */

    bool addState(CxeState *state);

    /**

     * Initiate a state transition from current state to a given state ID. If the state

     * transition is invalid, this function will panic.

     *

     * @param stateId State ID of the new state

     * @param error   Optional error code to be associated with the transition

     */

    bool setState(int stateId, int error = 0);

    /**

     * Set the initial state of the state machine. Can be called only once.

     * This method will panic, if initial state to be set is unknown, or initial

     * state has already been set.

     *

     * @param stateId State ID for the initial state.

     */

    bool setInitialState(int stateId);

    /**

     * Pure virtual function to be implemented by derived classes. Called when state changes.

     * The implementation should emit a signal informing interested parties of a state change.

     *

     * @param newStateId State ID for the new state

     * @param error      An error code associated with the state transition

     */

    virtual void handleStateChanged(int newStateId, CxeError::Id error) = 0;

private:

};

#endif // CXESTATEMACHINE_H