--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/calendarui/globaldata/inc/calendbchangenotifier.h	Wed Apr 14 15:55:57 2010 +0300
@@ -0,0 +1,152 @@
+/*
+* Copyright (c) 2006 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:   Notifies observers of external changes to the calendar database
+*
+*/
+
+
+#ifndef __CALENDBCHANGENOTIFIER_H
+#define __CALENDBCHANGENOTIFIER_H
+
+//  INCLUDES
+#include <e32base.h>
+
+#include <calchangecallback.h>      //MCalChangeCallBack
+
+// FORWARD DECLARATIONS
+class CCalSession;                  //Calendar session
+class CCalenGlobalData;             //Calendar global data
+
+// CLASS DECLARATION
+
+/**
+* Observer class for database changes.  Forwards callback from 
+* MCalChangeCallBack2
+*/
+class MCalenDBChangeObserver
+    {
+    public:
+        virtual void HandleDBChangeL() = 0;
+    };
+
+/**
+*  CCalenDbChangeNotifier buffers notifications from MCalChangeCallBack2 and 
+*  only notifies its observers after a set period has elapsed.  This prevents
+*  Calendar views refreshing more often than necessary during a sync operation
+*/
+NONSHARABLE_CLASS(CCalenDbChangeNotifier) : public CActive,
+                                                                  public MCalChangeCallBack2
+    {
+    public:  // Constructors and destructor
+        /**
+        * Constructor.
+        * @param aGlobalData global data reference
+        * @return a pointer to the new CCalenDbChangeNotifier instance
+        */
+        static CCalenDbChangeNotifier* NewL( CCalSession& aSession );
+
+       /**
+        * Destructor.
+        */
+        ~CCalenDbChangeNotifier();
+        
+    public:
+        /**
+        * Allow CCalenViews to register for database change notifications
+        * @param aDBObserver Observer to register
+        */
+        void RegisterObserverL( MCalenDBChangeObserver& aDBObserver );
+        
+        /**
+        * Allow CCalenViews to deregister for database change notifications
+        * @param aDBObserver Observer to deregister
+        */
+        void DeRegisterObserverL( MCalenDBChangeObserver& aDBObserver );
+        
+        /**
+        * Returns the time of the last call to MCalChangeCallBack2::CalChangeNotification
+        * This is not necessarily the same time as the last notification issued by 
+        * this class
+        * @return Time of the last database modification as TTime
+        */
+        TTime LastDBModificationTime() const;
+        
+    public: 
+        /**
+        * From MCalChangeCallBack2
+        * Called when the calendar database is changed through another
+        * CCalSession
+        * @param aChangeItems array of database items changed 
+        */
+        void CalChangeNotification( RArray<TCalChangeEntry>& aChangeItems );
+
+    private:
+        /**
+        * C++ default constructor.
+        * @param aGlobalData global data reference
+        */
+        CCalenDbChangeNotifier( CCalSession& aSession );
+
+        /**
+        * By default Symbian 2nd phase constructor is private.
+        * Performs any construction which may leave
+        */
+        void ConstructL();
+
+        /**
+        * From CActive
+        * Called when outstanding asynchronous request completes
+        * This will be called when iNotificationTimer either completes
+        * or is cancelled
+        */
+        void RunL();
+        
+        /**
+        * From CActive
+        * Called by the active scheduler if RunL leaves
+        * Ensures we are ready to receive the next database event
+        * @param aError System wide error code
+        */
+        TInt RunError( TInt aError );
+
+        /**
+        * From CActive
+        * Implements cancellation of outstanding asynchronous requests
+        * Cancels iNotificationTimer if started
+        */
+        void DoCancel();
+
+    private:    // Data
+
+        //Database change observer filter
+        CCalChangeNotificationFilter* iCalChangeFilter;      
+        
+        //Observer array
+        RPointerArray<MCalenDBChangeObserver> iDBObservers;
+        
+        //Timer to limit the amount of notifications issued by this class
+        RTimer iNotificationTimer;
+        
+        //The time of the last received notification
+        TTime iLastDbChangeNotification;
+        
+        //Flag to restart the timer after cancelling last tiemr request
+        TBool iRestartTimer;
+        
+        CCalSession& iSession;
+    };
+
+#endif      // __CALENDBCHANGENOTIFIER_H
+
+// End of File