1 /*

     2 * Copyright (c) 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:  header of EventNotifier class.

    15 *

    16 */

    17 

    18 

    19 

    20 #ifndef EVENTNOTIFIER_H

    21 #define EVENTNOTIFIER_H

    22 

    23 #include <e32base.h>

    24 #include <Events.h>

    25 

    26 namespace multimedia

    27     {

    28     class MControlObserver;

    29     class CEventBase;

    30     class MControl;

    31     

    32     class CObserverManager : public CBase

    33         {

    34         public:

    35             static CObserverManager* NewL();

    36             ~CObserverManager();

    37             

    38             // Adds observer to list

    39             TInt AddObserver( const MControlObserver& aObserver );

    40             // Marks observer as inactive in the list

    41             TInt RemoveObserver( const MControlObserver& aObserver );

    42             

    43             // Moves the pointer to element before the first in list

    44             void Init();

    45             // Returns true and moves pointer to next active observer.

    46             TBool Next();

    47             // aObserver will contain pointer to current observer

    48             void Observer( MControlObserver*& aObserver );

    49             

    50             // Returns the count of active observers

    51             TInt Count();

    52             // Purge inactive observers in the list

    53             void Purge();

    54             // Resets the list

    55             void Reset();

    56             

    57         private:

    58             CObserverManager();

    59             void ConstructL();

    60             

    61         private:

    62             TInt    iObserverCount;

    63             TInt    iCurrentObserverIndex;

    64             // For now we maintain 2 RPointerArray lists

    65             // better option is to merge into one data structure

    66             RPointerArray<MControlObserver> iObserversList;

    67             RArray<TInt>                    iActiveList;

    68         };

    69     

    70     class CEventQueueItem : public CBase

    71         {

    72         public:

    73             static CEventQueueItem* NewL( MControl* aControl, TUint aEvent, CEventBase* aEventObject );

    74             ~CEventQueueItem();

    75 

    76         TUint EventType();

    77         CEventBase* EventObject();

    78         MControl* ControlObject();

    79             TAny* GetInterface();

    80             

    81         private:

    82             CEventQueueItem( MControl* aControl,TUint aEvent, CEventBase* aEventObject );

    83             void ConstructL();

    84             

    85         public:

    86             // next item

    87             TSglQueLink* iLink;

    88             

    89         private:

    90             TUint  iEvent;

    91             CEventBase*       iEventObject;

    92             MControl* iControl;

    93         };

    94     

    95     class CEventNotifier : public CActive

    96         {

    97         public:

    98             static CEventNotifier* NewL();

    99             ~CEventNotifier();

   100             

   101             // Adds observer

   102             TInt AddObserver( const MControlObserver& aObserver );

   103             // Remove observer

   104             TInt RemoveObserver( const MControlObserver& aObserver );

   105             // Send notification to observers. If another event is

   106             // being processed, this will add event to pending events

   107             // and observers will be notified later.

   108             // Takes ownership of aEventObject

   109             TInt Event( MControl* aControl, TUint aEvent, CEventBase* aEventObject );

   110             

   111             // From CActive

   112             void RunL();

   113             void DoCancel();

   114             TInt RunError(TInt aError);

   115             

   116         private:

   117             CEventNotifier();

   118             void ConstructL();

   119             

   120             // Signals to continue processing.

   121             void KickSignal();

   122             // Signals the event has been notified to all observers

   123             void EventNotified();

   124             

   125             void EmptyQueue();

   126             

   127         private:

   128             // Pointer to observer manager

   129             CObserverManager* iObserverManager;

   130             // List holding events to be notified

   131             TSglQue<CEventQueueItem>* iEventQueue;

   132         };

   133     } // namespace multimedia

   134     

   135 #endif // EVENTNOTIFIER_H

   136     

   137     // End of file