1 /*

     2 * Copyright (c) 2009-2010 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:

    15 *

    16 */

    17 

    18 #ifndef CXESTATEMACHINE_H

    19 #define CXESTATEMACHINE_H

    20 

    21 #include "cxestatemachinebase.h"

    22 

    23 class CxeState;

    24 

    25 /**

    26  * CxeStateMachine extends CxeStateMachineBase functionality. All methods call base class

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

    28  *

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

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

    31  *

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

    33 */

    34 class CxeStateMachine : public CxeStateMachineBase

    35 {

    36 public:

    37     /**

    38     * CxeStateMachine constructor. After construction, the derived class should

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

    40     *

    41     * @sa addState setInitialState

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

    43     */

    44     CxeStateMachine(const char *stateMachineName);

    45     virtual ~CxeStateMachine();

    46 

    47 protected:

    48     /**

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

    50      * panic, if new state id is incorrect.

    51      *

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

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

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

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

    56      */

    57     bool addState(CxeState *state);

    58 

    59     /**

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

    61      * transition is invalid, this function will panic.

    62      *

    63      * @param stateId State ID of the new state

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

    65      */

    66     bool setState(int stateId, CxeError::Id error = CxeError::None);

    67 

    68     /**

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

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

    71      * state has already been set.

    72      *

    73      * @param stateId State ID for the initial state.

    74      */

    75     bool setInitialState(int stateId);

    76 

    77     /**

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

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

    80      *

    81      * @param newStateId State ID for the new state

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

    83      */

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

    85 

    86 private:

    87 

    88 };

    89 

    90 #endif // CXESTATEMACHINE_H