import java.awt.event.*;

public class Timer250 {
    private long period;
    private ActionListener listener;
    private Timer250Thread t2t;
    
    public Timer250(long period, ActionListener listener) {
        this.period = period;
        this.listener = listener;
        t2t = null; 
    }
    
    public void start() {
        stop();
        t2t = new Timer250Thread();
        t2t.start();
    }
    
    public void stop() {
        if (t2t != null) {t2t.halt();}
    }
    
    private class Timer250Thread extends Thread {
        private boolean going;
        private long nextTick;
        
        public Timer250Thread() {
            super();
            going = false;
        }
        
        public void run() {
            going = true;
            ActionEvent ae = new ActionEvent(Timer250.this, 0, "TickTock");
            nextTick = System.currentTimeMillis();
            while (going) {
                if (System.currentTimeMillis() >= nextTick) {
                    listener.actionPerformed(ae);
                    nextTick += period;
                }
            }
        }
        
        public void halt() {
            going = false;
        }
        
        public boolean isRunning() {return going;}
    }
    
    public static void main(String[] args) {
        if (args.length == 0) {
            System.out.println("Usage: Timer250 period");
        }
        
        int period = Integer.parseInt(args[0]);
        
        ActionListener al = 
            new ActionListener() {
                private int ct = 0;
                public void actionPerformed(ActionEvent e) {
                    ct += 1;
                    System.out.println(ct + ": " + System.currentTimeMillis());
                }
            };
            
        Timer250 t = new Timer250(period, al);
        t.start();
        long startTime = System.currentTimeMillis();
        while (System.currentTimeMillis() < startTime + 1000) {}
        t.stop();
    }
}