1 /*

     2 * Copyright (c) 2007 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:  Class declaration for MStateMachineObserver

    15 *

    16 */

    17 

    18 

    19 #ifndef DIAGENGINESTATEMACHINEOBSERVER_H

    20 #define DIAGENGINESTATEMACHINEOBSERVER_H

    21 

    22 // system include

    23 

    24 // user include

    25 #include "diagenginestates.h"   // DiagFwInternal::TState

    26 #include "diagengineevents.h"   // DiagFwInternal::TEvent

    27 

    28 namespace DiagFwInternal

    29     {

    30 // forward declaration

    31 class CEventBasic;

    32 

    33 /**

    34  *  Diagnostics Framework Engine State Machine Observer

    35  *

    36  *  This interface is called by CDiagEngineStateMachine to notify

    37  *  its client of state changes and events.

    38  *

    39  *  @since S60 v5.0

    40  */

    41 class MStateMachineObserver

    42     {

    43 public:

    44     /**

    45     * Notify state machine client that state machine has entered a new state.

    46     *

    47     * @param aPreviousState     Previous state.

    48     * @param aCurrentState      Current state. (new state.)

    49     * @param aEventPreview  Event that caused state change. Note that

    50     *   this is just a preview.  HandleEventL() will be called with the same

    51     *   event later on.

    52     */

    53     virtual void HandleStateChangedL( TState aPreviousState, 

    54                                       TState aCurrentState,

    55                                       const CEventBasic& aEventPreview ) = 0;

    56 

    57     /**

    58     * Notify state machine client that a new event is received.

    59     *

    60     * @param aEvent        New event.

    61     */

    62     virtual void HandleEventL( CEventBasic& aEvent ) = 0;

    63 

    64     /**

    65     * Notify state machine client that an abnormal error has occured.

    66     * Client can handle the error and return appropriate error state.

    67     *

    68     * @param aCurrentState Current state.

    69     * @param aError        Error number.

    70     * @return TState       New state to go to.

    71     */

    72     virtual TState HandleError( TState aCurrentState, TInt aError ) = 0;

    73     };

    74     } // end of namespace DiagFwInternal

    75     

    76 #endif // DIAGENGINESTATEMACHINEOBSERVER_H

    77 

    78 // End of File

    79