/*

 * 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:  location triggering server client interface

 *

 */

 #ifndef LBTTRIGGERCHANGEEVENTNOTIFIER_H

 #define LBTTRIGGERCHANGEEVENTNOTIFIER_H

 #include <lbt.h>

 #include <lbttriggerchangeeventobserver.h>

 /**

  * Helper class to receive trigger change event 

  * through observer interface. 

  *

  * @see RLbt::NotifyTriggerChangeEvent

  *

  * @lib lbt.lib

  *

  * @since S60 5.1

  */

 class CLbtTriggerChangeEventNotifier : public CActive

     {

 public:

     /**

      * Construct a trigger change event notifier object. 

      *

      * When the object is constructed. The trigger change 

      * notification request is not issued to the

      * Location Triggering Server. Client shall call 

      * CLbtTriggerChangeEventNotifier::Start() to start

      * notification.

      *

      * @param[in] aLbt A reference to RLbt object. The subsession 

      * must be opened. Otherwise a panic is raised.

      * @param[in] aObserver A reference to the 

      * observer object to receive trigger change event.

      * @param[in] aPriority An integer specifying the 

      * priority of this active object. CActive::TPriority 

      * defines a standard set of priorities. 

      *

      * @panic LocTriggering ELbtServerBadHandle If the 

      * subsession of aLbt is not opened.

      */

     IMPORT_C static CLbtTriggerChangeEventNotifier* NewL( 

         RLbt& aLbt,

         MLbtTriggerChangeEventObserver& aObserver,

         TInt aPriority = CActive::EPriorityStandard );

     /**

      * Destructor. 

      *

      * If the notification is started, the 

      * destructor will cancel the notification.

      */

     IMPORT_C ~CLbtTriggerChangeEventNotifier();

     /**

      * Start trigger change event notification. 

      *

      * After this function is called, when any 

      * trigger is changed in Location Trigger Server, the

      * client will be notified from the observer interface.

      * 

      * Client shall call Cancel() function to stop the

      * trigger change event notification.

      */

     IMPORT_C void Start();

 private:

     //Derived from CActive

     void RunL();

     TInt RunError( TInt aError );

     void DoCancel();

 private:

     /**

      * C++ default constructor

      */

     CLbtTriggerChangeEventNotifier(

         RLbt& aLbt,

         MLbtTriggerChangeEventObserver& aObserver,

         TInt aPriority = CActive::EPriorityStandard );

     /**

      * Symbian 2nd phase constructor 

      */

     void ConstructL();

 private:

     /**

      * Trigger change event object.

      */

     TLbtTriggerChangeEvent iChangeEvent;

     /** 

      * Reference to Lbt subsession.

      */

     RLbt& iLbt;

     /**

      * Reference to trigger change event observer.

      */

     MLbtTriggerChangeEventObserver& iObserver;

     };

 #endif // LBTTRIGGERCHANGEEVENTNOTIFIER_H