/** 
 * A simple stopwatch class 
 * @author Rett Bull 
 * @date January 23, 2008 
 */ 
public class StopWatch{ 
	protected long startTime; // when we started 
	private long accumulatedTime; // the time accumulated by previous runs 
	protected boolean running; // true, if we are timing 

	/** 
	 * creates a functioning Stopwatch 
	 */ 
	public StopWatch(){ 
		running = false; 
		startTime = 0; 
		accumulatedTime = 0; 
	} 

	/** 
	 * sets the time to zero 
	 */ 
	public void reset(){ 
		accumulatedTime = 0; 
	} 

	/** 
	 * starts timing 
	 */ 
	public void start(){ 
		if (!running) { 
			startTime = System.nanoTime(); 
			running = true; 
		}
	}

	/** 
	 * stops (perhaps temporarily) the timing 
	 */ 
	public void stop(){ 
		if (running) { 
			accumulatedTime += System.nanoTime() - startTime; 
			running = false; 
		}
	}

	/** 
	 * returns the elapsed time 
	 */ 
	public long getTime(){ 
		if (running){ 
			return accumulatedTime + System.nanoTime() - startTime; 
		}else{ 
			return accumulatedTime; 
		}
	}
}