// ---------------------------------------
// Restricted Focus Viewer (RFV) Program
// Version 2.1
// Language: Java 2
// March, 2000
// Copyright (C) 2000  Anthony R. Jansen 
// ---------------------------------------

// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

// ---------------------------------------
// RFV_Timer.java
//
// Class to implement a millisecond timer
// based on the system clock. It can be
// reset, paused and the elapsed time can
// be read without interrupting the timer.
// ---------------------------------------

public class RFV_Timer {

	// Variables needed
	// ----------------
	private	long		initialTime;
	private	long		elapsedTime;
	private	boolean		paused;

	// Constructor which starts the timer
	// ----------------------------------
	public RFV_Timer()
	{
		initialTime = System.currentTimeMillis();
		paused = false;
	}

	// Method to reset the timer to zero
	// ---------------------------------
	public void reset()
	{
		initialTime = System.currentTimeMillis();
		paused = false;
	}
	
	// Returns the time elapsed since timer began (in milliseconds)
	// Can be called even if timer is currently paused
	// ------------------------------------------------------------
	public long getElapsed()
	{
		if (paused)
			return elapsedTime;
		else
			return (System.currentTimeMillis() - initialTime);
	}

	// Pauses the timer without reseting it
	// ------------------------------------
	public void pause()
	{
		if (!paused) {
			elapsedTime = System.currentTimeMillis() - initialTime;
			paused = true;
		}
	}

	// Unpauses the timer
	// ------------------
	public void unpause()
	{
		if (paused) {
			initialTime = System.currentTimeMillis() - elapsedTime;
			paused = false;
		}
	}

	// Sets the timer to begin with a certain elapsed time
	// ---------------------------------------------------
	public void setElapsed(long t)
	{
		if (paused)
			elapsedTime = t;
		else
			initialTime = System.currentTimeMillis() - t;
	}

}