/*

* Copyright (c) 2007 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:  Calendar notifier

*

*/

#ifndef CALENNOTIFIER_H

#define CALENNOTIFIER_H

// INCLUDES

#include <e32hashtab.h>                 //RHashSet

#include "calennotificationhandler.h"   // MCalenNotificationHandler

#include "calencontextchangeobserver.h" // MCalenContextChangeObserver

// FORWARD DECLARATIONS

class CEnvironmentChangeNotifier;       // Receive system event notifications

class CCalenStateMachine;

/**

 * CalenNotifier observes various system events relevent to Calendar

 * MCalenNotificationHandlers can register for notifications of specific

 * events. This minimises the number of event observers required

 * throughout the Calendar application.

 */

class CalenNotifier :  public CBase,   

                       public MCalenContextChangeObserver

    {

    public:

        /**

         * C++ default Constructor

         */

        CalenNotifier( CCalenStateMachine& aStateMachine );

        /**

         * 2nd phase of construction.

         */

        void ConstructL();

        /**

         * Destructor

         */

        virtual ~CalenNotifier();

    public:

        /**

         * Allows MCalenNotificationHandlers to register for system event

         * notifications

         * @param aHandler Handler to register

         * @param aFlag Notification of events to notify aHandler about

         */

        void RegisterForNotificationsL( MCalenNotificationHandler* aHandler,

                                                TCalenNotification aNotification );

        /**

         * Allows MCalenNotificationHandlers to register for system event

         * notifications

         * @param aHandler Handler to register

         * @param aFlags Array of notifications to  notify aHandler about

         */

        void RegisterForNotificationsL( MCalenNotificationHandler* aHandler,

                                                 RArray<TCalenNotification>& aNotifications );

        /**

         * Allows MCalenNotificationHandlers to cancel system event

         * notifications

         * @param aHandler Handler to deregister

         */

        void CancelNotifications( MCalenNotificationHandler* aHandler );

        /**

         * Notify all interested handlers about an event

         * @param aNotification Notification to broadcast

         */

        void BroadcastNotification( TCalenNotification aNotification );

        /**

         * Notify all interested handlers about an event

         * @param aNotification Notification to broadcast

         */

        void BroadcastApprovedNotification( TCalenNotification aNotification );

    public:       

        /**

         * From MCalenContextChangeObserver.

         * Called when the context changes.

         */

        void ContextChanged();

    private:    // Callback functions from observers

        /**

         * Called from CEnvironmentChangeNotifier when the

         * system environment changes

         * @param aThisPtr self pointer

         * @return EFalse

         */

        static TInt EnvChangeCallbackL( TAny* aThisPtr );

        /**

         * Broadcasts the given notification.

         * @param aNotification Notification id to be broadcasted

         */

        void DoBroadcast( TCalenNotification aNotification );  

        TInt DoEnvChange();

    private:  // Data

        // Array of handlers to notify

        class TNotificationHandler

            {  

            public:

                TNotificationHandler();

                RHashSet<TCalenNotification>  iHashSet;

                MCalenNotificationHandler* iHandler;

            };

        RArray<TNotificationHandler> iHandlers;

        RArray<TCalenNotification> iBroadcastQueue;

        TBool iBroadcastActive;

        CCalenStateMachine& iStateMachine; 

        // Notifications about locale and time changes

        CEnvironmentChangeNotifier* iEnvChangeNotifier;

        bool iIgnoreFirstLocaleChange;

    };

#endif // CALENNOTIFIER_H

// End of file