import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Countdown implements ActionListener
{
        private JFrame f;
        private JPanel p1, p2;

        private JLabel hrs, mins, sec,debug; //
        private JTextField tHrs, tMins, tSec;
        private JButton bStart, bStop, bBack;

        public Countdown()
        {
                f = new JFrame("Countdown");

                p1 = new JPanel();
                p2 = new JPanel();

                hrs = new JLabel("hrs: ");
                mins = new JLabel("mins: ");
                sec = new JLabel("sec: ");

                tHrs = new JTextField("0",2);
                tMins = new JTextField("0",2);
                tSec = new JTextField("0",2);

                bStart = new JButton("START");
                bStop = new JButton("STOP");
                bBack = new JButton("BACK");

                debug = new JLabel("-"); //
        }

        public void launchFrame()
        {
                p1.setLayout(new FlowLayout());

                p1.add(hrs);
                p1.add(tHrs);
                p1.add(mins);
                p1.add(tMins);
                p1.add(sec);
                p1.add(tSec);

                p2.setLayout(new FlowLayout());

                p2.add(bStart);
                p2.add(bStop);
                p2.add(bBack);

                f.setLayout(new GridLayout(3,1)); //
                f.add(p1);
                f.add(p2);
                f.add(debug);//

                f.pack();
                f.setVisible(true);

                bStart.addActionListener(this);
                bStop.addActionListener(this);
                bBack.addActionListener(this);

                f.addWindowListener(new MyCloseEventHandler());
        }
      Count cnt = new Count();
        public void actionPerformed(ActionEvent ae)
        {
                //Count cnt = new Count();
                Thread t1 = new Thread(cnt);
                Object source = ae.getSource();
                if (source == bStart)
                {
                        t1.start();
                }
                else if (source == bStop)
                {
                        cnt.stopRunning();
                }
                else if (source == bBack)
                {
                        f.setVisible(false);
                }
        }

        class Count implements Runnable
        {
                private volatile boolean timeToQuit=false;

                public void run()
                {
                        while(!timeToQuit)
                        {
                                int h = Integer.parseInt(tHrs.getText());
                                int m = Integer.parseInt(tMins.getText());
                                int s = Integer.parseInt(tSec.getText());
                                if(h!=0 || m!=0 || s!=0)
                                {
                                        while( s>=0 && !timeToQuit)
                                        {
                                                try
                                                {
                                                        Thread.sleep(1000);
                                                }
                                                catch(InterruptedException ie){}

                                                if(s == 0)
                                                {
                                                        m--;
                                                        s=60;
                                                        if(m == -1)
                                                        {
                                                                h--;
                                                                m=59;
                                                                tHrs.setText(Integer.toString(h));
                                                        }
                                                        tMins.setText(Integer.toString(m));
                                                }
                                                s--;
                                                tSec.setText(Integer.toString(s));
                                        }
                                }
                                else
                                {
                                        timeToQuit = true;
                                        //debug.setText("Stopped");
                                }
                        }

                        tHrs.setText("0");
                        tMins.setText("0");
                        tSec.setText("0");
                }

                public void stopRunning()
                {
                        timeToQuit = true;

                        debug.setText("Stopped");
                }
        }


        private class MyCloseEventHandler extends WindowAdapter
        {
                public void windowClosing(WindowEvent we)
                {
                        System.exit(0);
                }
        }

        public static void main(String args[])
        {
                Countdown c = new Countdown();
                c.launchFrame();
        }
}