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 #include "cxestatemachinebase.h"

    19 #include "cxutils.h"

    20 #include "cxestate.h"

    21 

    22 CxeStateMachineBase::CxeStateMachineBase(const char *stateMachineName) :

    23     mStateBitsUsed(0), mStateId(0), mName(stateMachineName)

    24 {

    25 }

    26 

    27 CxeStateMachineBase::~CxeStateMachineBase()

    28 {

    29     qDeleteAll(mStates);

    30     mStates.clear();

    31 }

    32 

    33 bool CxeStateMachineBase::addState(CxeState *state)

    34 {

    35     bool success( state // non-null state object

    36                && state->stateId() // state id is not zero

    37                && !(mStateBitsUsed & state->stateId()) // no overlapping bits

    38                 );

    39 

    40     // if no errors

    41     if (success) {

    42         mStateBitsUsed |= state->stateId();

    43         mStates[state->stateId()] = state; // state is now owned by the state machine

    44     }

    45 

    46     return success;

    47 }

    48 

    49 bool CxeStateMachineBase::setState(int stateId, CxeError::Id error)

    50 {

    51     bool success = true;

    52 

    53     if (stateId == mStateId) {

    54         // No transition, nothing needs to be done

    55         return success;

    56     }

    57 

    58     if (mStates.contains(stateId)) {

    59         // New state name known, print it

    60         CX_DEBUG(("%s::setState(%s, %d)", mName.toAscii().constData(),

    61                 mStates[stateId]->name().toAscii().constData(), error));

    62     } else {

    63         // Unknown state...

    64         CX_DEBUG(("%s::setState(UNKNOWN[%d], %d)", mName.toAscii().constData(),

    65                 stateId, error));

    66     }

    67 

    68     // State state machine does not use the error parameter itself.

    69     // It is only forwarded to handleStateChanged to be passed

    70     // on as a parameter in the stateChanged() signal.

    71 

    72     // setStateId itself will never return an error.

    73     // If an illegal state or state change is detected, it will panic the application (because it is a design error).

    74 

    75     success = verifyStateChange(stateId);

    76 

    77     if (success) {

    78         mStateId = stateId;

    79         handleStateChanged(mStateId, error);

    80     }

    81 

    82     return success;

    83 }

    84 

    85 bool CxeStateMachineBase::setInitialState(int stateId)

    86 {

    87     bool success = mStates.contains(stateId);

    88 

    89     if (success) {

    90         // New state name known, print it

    91         CX_DEBUG(("%s::setInitialState(%s)", mName.toAscii().constData(),

    92                 mStates[stateId]->name().toAscii().constData()));

    93     } else {

    94         // Unknown state...

    95         CX_DEBUG(("%s::setInitialState(UNKNOWN[%d])", mName.toAscii().constData(),

    96                 stateId));

    97     }

    98 

    99     // check that state changes have not been made

   100     // and this is the one and only setInitialState call

   101     success = (success && mStateId == 0);

   102 

   103     if (success) {

   104         mStateId = stateId;

   105     } else {

   106         CX_DEBUG(("%s state has already been set", mName.toAscii().constData()));

   107     }

   108     return success;

   109 }

   110 

   111 int CxeStateMachineBase::stateId() const

   112 {

   113     return mStateId;

   114 }

   115 

   116 bool CxeStateMachineBase::verifyStateChange(int newStateId)

   117 {

   118     bool allowStateChange = false;

   119 

   120     // Check that current state can be found in the state chart

   121     if ( mStates.contains(stateId()) ) {

   122         // Check that current state allows change to the new state

   123         CxeState *currentState = mStates[stateId()];

   124         allowStateChange = (currentState->allowedNextStates() & newStateId);

   125     }

   126 

   127     return allowStateChange;

   128 }