1 /*

     2 * Copyright (c) 2007-2008 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:  FreestyleEmailUi exit guardian.

    15 *

    16 */

    17 

    18 #ifndef C_EUIEXITGUARDIAN_H

    19 #define C_EUIEXITGUARDIAN_H

    20 

    21 #include <e32base.h>

    22 

    23 // FORWARD DECLARATIONS

    24 class CFreestyleEmailUiAppUi;

    25 class CIdle;

    26 

    27 /**

    28  * Application exit guardian for email UI. This is needed because some routines

    29  * in email framework create nested scheduler loops to hide asynchronity in

    30  * them. When application is shutdown these nested levels may cause crashes

    31  * as resources are freed while they are still being used on other recursion

    32  * levels.

    33  *

    34  * Usage:

    35  *

    36  * void CClass::RoutineThatMayCreatedNestedLevelL()

    37  *    {

    38  *    iExitGuardian->EnterLC();

    39  *    // call or execute code that may create nested sceduler loop

    40  *    ...

    41  *    // and finally popup and destroy cleanup item

    42  *    CleanupStack::PopAndDestroy(); // iExitGuardian->EnterLC()

    43  *    }

    44  *

    45  * @since S60 5.1

    46  */

    47 class CEUiExitGuardian : public CBase

    48   	{

    49 

    50 public:

    51 

    52     /**

    53      * Leave safe construction for CEuiExitGuardian.

    54      * @return Newly created instance of CEuiExitGuardian

    55      */

    56     static CEUiExitGuardian* NewL(CFreestyleEmailUiAppUi& aAppUi);

    57 

    58     /**

    59      * Destructor.

    60      */

    61     ~CEUiExitGuardian();

    62 

    63     /**

    64      * Called before executing code that may cause new nested level in

    65      * active scheduler. Leaves cleanup item in cleanup stack and this item

    66      * must be purged by the caller after code execution. Cleanup item is used

    67      * to make level counter leavesafe.

    68      */

    69     void EnterLC();

    70 

    71     /**

    72      * Called by the application to inform that application is ready to

    73      * exit. If there is any nested active scheduler levels (i.e. recursion),

    74      * exit execution will be delayed until every nested level has returned.

    75      *

    76      * @return KRequestPending if the exit execution is delayed because of

    77      * nesting, KErrNone otherwise.

    78      */

    79     TInt ExitApplication();

    80 

    81 private:

    82 

    83     /**

    84      * Constructor.

    85      */

    86     CEUiExitGuardian(CFreestyleEmailUiAppUi& aAppUi);

    87 

    88     /**

    89      * Pass 2 constructor, may leave.

    90      */

    91 	void ConstructL();

    92 

    93     /**

    94      * Static exit method that is given to cleanup item.

    95      */

    96     static void Exit(TAny* aPtr);

    97 

    98     /**

    99      * Non static exit method that is called from static Exit.

   100      */

   101     void DoExit();

   102 

   103     /**

   104      * Static callback method for CIdle. This is run when recursion is rewinded

   105      * and appication can be closed.

   106      */

   107     static TInt IdleCallBack(TAny* aPtr);

   108 

   109 private:

   110 

   111     // Reference to application UI

   112     CFreestyleEmailUiAppUi& iAppUi;

   113 

   114     // Recursion depth (nested level count)

   115     TInt iEnterCount;

   116 

   117     // ETrue if the application is ready to exit.

   118     TBool iExitPending;

   119 

   120     // Idle class instance to rewind final level of recursion before calling the

   121     // exit

   122     CIdle* iIdle;

   123 

   124     };

   125 

   126 #endif // C_EUIEXITGUARDIAN_H