/*

* Copyright (c) 2006 - 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:    Sends keepalive messages to STUN Client in order to keep

*                binding in STUN Server alive

*

*/

#ifndef C_NATFWSTUNREFRESHTIMER_H

#define C_NATFWSTUNREFRESHTIMER_H

#include <e32base.h>

class MNATFWRefreshObserver;

/**

 *  Sends keepalive messages to STUN Client.

 *

 *  Sends keepalive messages to STUN Client in order to keep

 *  binding in STUN Server alive. Gets interval in microseconds from 

 *  CNATFWStunConnectionHandler.

 *

 *  @lib stunplugin.lib

 *  @since S60 v3.2

 */

class CNATFWStunRefreshTimer : public CActive

    {

public:

    /**

     * Creates a new instance of NAT FW STUN Refresh Timer.

     *

     * @since S60 v3.2

     * @param aObserver Observer for callbacks to timer's user

     * @return A new instance, ownership is transferred.

     */

    static CNATFWStunRefreshTimer* NewL( MNATFWRefreshObserver& aObserver );

    /**

     * Creates a new instance of NAT FW STUN Refresh Timer and

     * pushes it to CleanupStack.

     *

     * @since S60 v3.2

     * @param aObserver Observer for callbacks to timer's user

     * @return A new instance, ownership is transferred.

     */

    static CNATFWStunRefreshTimer* NewLC( MNATFWRefreshObserver& aObserver );

    ~CNATFWStunRefreshTimer();

    /**

     * Waits for given time (aInterval) and calls SetActive().

     * If interval is 0, timer is cancelled.

     *

     * @since S60 v3.2

     * @param aInterval Interval in microseconds

     */

    void StartStunRefresh( TUint aInterval );

    /**

     * Client can query if refresh is going on.

     *

     * @since S60 v3.2

     * @return ETrue if refreshing

     */

    TBool IsRunning() const;

protected:

    /**

     * from CActive

     */

    void RunL();

    /**

     * from CActive

     */

    void DoCancel();

private:

    CNATFWStunRefreshTimer( MNATFWRefreshObserver& aObserver );

    void ConstructL();

private: // data

    /**

     * Interval in microseconds

     */

    TUint iInterval;

    /**

     * Asynchronous timer service.

     */

    RTimer iTimer;

    /**

     * MNATFWRefreshObserver reference.

     */

    MNATFWRefreshObserver& iObserver;

    };

#endif // C_NATFWSTUNREFRESHTIMER_H