/*

* Copyright (c) 2007-2008 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:    Slideshow specific timer

 *

*/

#ifndef __SHWTIMER_H__

#define __SHWTIMER_H__

// INCLUDES

#include <e32std.h>

#include <e32base.h>

// Forward declarations

// CLASS DECLARATION

/**

 * CShwTimer. a Pause-able timer

 * 

 * @lib shwslideshowengine.lib

 */

NONSHARABLE_CLASS( CShwTimer ) : public CBase

	{

	public:

		/**

		 * Constructor.

		 * @param TInt aPriority - the priority of the timer.

		 */

		static CShwTimer* NewL( TInt aPriority );

		/**

		 * Destructor.

		 */

		~CShwTimer();

	public: // the API

		/**

		 * This method starts the timer.  It may be called repeatedly

		 * as the timer is always first cancelled.

		 * Note! Time is given in milliseconds

		 * 

		 * @param aDelay - milliseconds for the first callback

		 * @param aInterval - milliseconds for the successive callbacks

		 * @param aCallback - the function to call

		 */

		void Start( TInt aDelay, TInt aInterval, TCallBack aCallback );

		/**

		 * This method cancels the timer.

		 */

		void Cancel();

		/**

		 * Pauses the timer if it is active

		 */

		void Pause();

		/**

		 * Resumes the timer. If timer was paused the timer is restarted

		 * for the time left and after that for interval.

		 */

		void Resume();

		/**

		 * Method that returns whether the timer is active.

		 * @return ETrue if the timer is active, EFalse otherwise

		 */

		TBool IsActive();

	private: // Constructors

		/**

		 * C++ constructor.

		 */

		CShwTimer();

		/**

		 * 2nd stage constructor

		 */

		void ConstructL( TInt aPriority );

		/**

		 * This method returns the amount of time remaining until

		 * the timer is due to expire.

		 * @return - the time in microseconds left until the timer finishes

		 *			or 0 (whichever is greater).

		 */

		TTimeIntervalMicroSeconds32 TimeLeft();

	private:

		/// Own: the timer

		CPeriodic* iTimer;

		/// Own: the callback

		TCallBack iCallback;

		/// Own: the time left in pause

		TTimeIntervalMicroSeconds32 iTimeLeft;

		/// Own: the interval for the timer

		TTimeIntervalMicroSeconds32 iInterval;

		/// Own: state flag that tells us if we are paused

		TBool iPaused;

		/// Own: the time at which the timer is set to expire

		TTime iTimeTimerExpires;

	};

#endif // __SHWTIMER_H__