/*

* 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 the License "Symbian Foundation License v1.0" to Symbian Foundation members and "Symbian Foundation End User License Agreement v1.0" to non-members

* which accompanies this distribution, and is available

* at the URL "http://www.symbianfoundation.org/legal/licencesv10.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