import java.awt.*;
import java.awt.event.*;

public class Timer implements Runnable {
    Thread timer;
    int counter = 0;
    TextField text;
    
    public Timer() {
	Frame f = new Frame("Timer demo");
	f.setLayout(new GridLayout(2,0));	
        f.setResizable(false);
	// Create three event listening objects, private class
	Command startCmd = new Command(Command.START, this);
	Command stopCmd = new Command(Command.STOP, this);
	Command resetCmd = new Command(Command.RESET, this);
	// Assign a listener to the frame (window)
        f.addWindowListener(stopCmd);
        Panel p = new Panel();
	Button b;
	// Create three buttons, assigning each a listener
	p.add(b = new Button("Start"));
	b.addActionListener(startCmd);
	p.add(b = new Button("Stop"));
	b.addActionListener(stopCmd);
	p.add(b = new Button("Reset"));
	b.addActionListener(resetCmd);
        f.add(p);
	// Set up a TextField for displaying results
        text = new TextField(" 00 ", 4);
        text.setEditable(false);
        text.setFont(new Font("Helvetica", Font.BOLD, 40));
        f.add(text);
	f.pack();
	f.show();
    }

    public void Do (int id) {
        switch (id) {
            case Command.START:
                timer.resume();
                break;
            case Command.STOP:
                timer.suspend();
                break;
            case Command.RESET:
                counter = 0;
                text.setText(" 00 ");
                break;
        }
    }

    public void run() { 
        while (true) {
            try {Thread.sleep(500);} // Should be 1000 
                catch (InterruptedException e) {};
            counter += 1;
            if (counter == 100) counter = 0;
	    // Trick way to format string as two digits
            text.setText(" " + counter/10 + counter%10 + " ");
        }
    }

    static public void main(String args[]) {
	Timer app = new Timer();
        app.timer = new Thread(app);
        app.timer.start();
    }

}

class Command extends WindowAdapter 
    implements ActionListener  {

    static final int START = 0;
    static final int STOP = 1;
    static final int RESET = 2;
    int id;
    Timer s;

    public Command(int id, Timer s) {
	this.id = id;
	this.s = s;
    }

    public void actionPerformed(ActionEvent e) {
        s.Do(id);
    }

    public void windowClosing(WindowEvent e) {
        System.exit(0);
    }
}