1 /*

     2 * Copyright (c) 2002-2006 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 

    19 #ifndef GSPLUGINWRAPPER_H

    20 #define GSPLUGINWRAPPER_H

    21 

    22 // System includes

    23 #include <e32base.h>

    24 

    25 // Classes referenced

    26 class CGSBaseDocument;

    27 

    28 

    29 /**

    30  *  Utility class for separating ECOM plugin destruction from view-framework

    31  *  view cleanup.

    32  *

    33  *  Owned by CGSBaseDocument which has the longest lifetime during GS

    34  *  application run. This will ensure that ECOM resources are not deleted

    35  *  before view cleanup.

    36  *

    37  *  Problem/rationale:

    38  *  Before the functionality provided by this class, GS would occasionally

    39  *  crash in exit. This was caused by the dual nature of CGSPluginInterface

    40  *  class: It is both ECOM-plugin having individual dll and view-framework

    41  *  dependant CAknView owned by CCoeAppUi. When exiting GS, it was possible

    42  *  that a  plugin still had local views (CAknViews) which were owned

    43  *  by view-framework.

    44  *

    45  *  When the view framework destroys the registered views, it would cause

    46  *  the ECOM plugin dll to be unloaded. Should this happen before all the views

    47  *  owned and implemented by the plugin have been destroyed, an access

    48  *  violation would occur because the code needed to call the view's destructor

    49  *  was no longer loaded into memory within the GS process.

    50  *

    51  *  Solution:

    52  *  Purpose of CGSPluginWrapper is to move ECOM-related memory cleanup outside

    53  *  the scope of CGSPluginInterface destructor. This way view-framework can

    54  *  call destructor in an arbitrary order on all it's owned views even though

    55  *  plugins which had local views were already deleted.

    56  *

    57  */

    58 NONSHARABLE_CLASS( CGSPluginWrapper ) : public CBase

    59     {

    60     public:

    61         CGSPluginWrapper( CGSBaseDocument& aDocument );

    62         IMPORT_C ~CGSPluginWrapper();

    63 

    64     public:

    65         IMPORT_C void SetDetails( TUid aDestructorIdKey );

    66         inline CGSBaseDocument& Document() { return iDocument; }

    67 

    68     private:

    69         TUid iDestructorIdKey;

    70         CGSBaseDocument& iDocument;

    71     };

    72 

    73 

    74 

    75 

    76 #endif // GSPLUGINWRAPPER_H

    77 // End of File