1 /*

     2 * Copyright (c) 2009 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 #ifndef CXESTATEMACHINE_H

    18 #define CXESTATEMACHINE_H

    19 

    20 #include "cxestatemachinebase.h"

    21 

    22 class CxeState;

    23 

    24 /**

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

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

    27  *

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

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

    30  *

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

    32 */

    33 class CxeStateMachine : public CxeStateMachineBase

    34 {

    35 public:

    36     /**

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

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

    39     *

    40     * @sa addState setInitialState

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

    42     */

    43     CxeStateMachine(const char* stateMachineName);

    44     virtual ~CxeStateMachine();

    45 

    46 protected:

    47     /**

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

    49      * panic, if new state id is incorrect.

    50      *

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

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

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

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

    55      */

    56     bool addState(CxeState *state);

    57 

    58     /**

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

    60      * transition is invalid, this function will panic.

    61      *

    62      * @param stateId State ID of the new state

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

    64      */

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

    66 

    67     /**

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

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

    70      * state has already been set.

    71      *

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

    73      */

    74     bool setInitialState(int stateId);

    75 

    76     /**

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

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

    79      *

    80      * @param newStateId State ID for the new state

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

    82      */

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

    84 

    85 private:

    86 

    87 };

    88 

    89 #endif // CXESTATEMACHINE_H

    90 

    91