satengine/SatServer/Engine/inc/TSatEventMediator.h
changeset 46 2fa1fa551b0b
parent 42 35488577e233
child 48 78df25012fda
equal deleted inserted replaced
42:35488577e233 46:2fa1fa551b0b
     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:  Provides way to notify events and register observers
       
    15 *                for events
       
    16 *
       
    17 */
       
    18 
       
    19 
       
    20 
       
    21 #ifndef TSATEVENTMEDIATOR_H
       
    22 #define TSATEVENTMEDIATOR_H
       
    23 
       
    24 //  INCLUDES
       
    25 #include <e32base.h>
       
    26 
       
    27 // FORWARD DECLARATIONS
       
    28 class MSatEventObserver;
       
    29 class TSatEventsObserver;
       
    30 
       
    31 // CLASS DECLARATION
       
    32 
       
    33 /**
       
    34 *  Provides way to notify events and register observers for events.
       
    35 *  Observers are not owned by this class and therefore observers are
       
    36 *  not deleted when TSatEventMediator instance is destroyed.
       
    37 *
       
    38 *  @lib SatEngine.dll
       
    39 *  @since Series 60 3.0
       
    40 */
       
    41 class TSatEventMediator
       
    42     {
       
    43     public:  // Constructors and destructor
       
    44 
       
    45         /**
       
    46         * C++ default constructor.
       
    47         */
       
    48         TSatEventMediator();
       
    49 
       
    50     public: // New functions
       
    51 
       
    52         /**
       
    53         * Notifies possible observers who are observing the event.
       
    54         * @param aEvent Integer identifying the event.
       
    55         * @return None
       
    56         */
       
    57         void Notify( TInt aEvent );
       
    58 
       
    59         /**
       
    60         * Registers observer for event. Same observer will not be added
       
    61         * more than once for one event.
       
    62         * @param aObserver Pointer of observer instance. Panic will occur if
       
    63         * aObserver is NULL.
       
    64         * @param aEvent Event, which will cause the notification of observer.
       
    65         * @return None
       
    66         */
       
    67         void RegisterL( MSatEventObserver* aObserver, TInt aEvent );
       
    68 
       
    69         /**
       
    70         * Unregisters the notification of single event.
       
    71         * @param aObserver Observer, whom event registeration will be
       
    72         * unregistered.
       
    73         * @param aEvent Event, which will be unregistered.
       
    74         * @return None
       
    75         */
       
    76         void Unregister( const MSatEventObserver* aObserver, TInt aEvent );
       
    77 
       
    78         /**
       
    79         * Unregisters the event observer.
       
    80         * @param aObserver Observer, whom event registeration will be
       
    81         * unregistered.
       
    82         */
       
    83         void Unregister( const MSatEventObserver* aObserver );
       
    84 
       
    85         /**
       
    86         * Resets the list of event observers. Used instead of destructor
       
    87         */
       
    88         void Reset();
       
    89 
       
    90     private:  // New functions
       
    91 
       
    92         /**
       
    93         * Checks if aObserver is already in the list of observers.
       
    94         * @param aObserver Observer that is checked from the list.
       
    95         * @return Pointer of the observer, where aObserver is registered.
       
    96         * Contains NULL pointer if aObserver is not already registered.
       
    97         */
       
    98         TSatEventsObserver* HasObserverInstance(
       
    99             const MSatEventObserver* aObserver ) const;
       
   100 
       
   101         /**
       
   102         * Deletes all observers marked as deleted during notify loop
       
   103         */
       
   104         void DeleteMarkedObservers();
       
   105 
       
   106     private:
       
   107 
       
   108         // Prohibit copy constructor if not deriving from CBase.
       
   109         TSatEventMediator( const TSatEventMediator& );
       
   110 
       
   111         // Prohibit assigment operator if not deriving from CBase.
       
   112         TSatEventMediator& operator=( const TSatEventMediator& );
       
   113 
       
   114     private:    // Data
       
   115 
       
   116         // event observers.
       
   117         RPointerArray<TSatEventsObserver> iEventsObservers;
       
   118 
       
   119         // Indicates are we notifying observers. If this flag is on,
       
   120         // observers cannot be removed from iEventsObservers. After
       
   121         // notify loop is done, observers can be replaced again
       
   122         TBool iIsNotifying;
       
   123 
       
   124         // Indicates are there any observers marked as deleted during
       
   125         // Notify loop
       
   126         TBool iDeletionsMarked;
       
   127     };
       
   128 
       
   129 #endif      // TSATEVENTMEDIATOR_H
       
   130 
       
   131 // End of File