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

import com.sun.java.swing.*; 

public class ProgressBarDemo extends JFrame {

    public final static int ONE_SECOND = 1000;

    JProgressBar progressBar;
    Timer timer;
    JButton startButton;
    LongTask task;

    public ProgressBarDemo() {
        super("ProgressBarDemo");
	task = new LongTask();

	//create the demo's UI
	startButton = new JButton("Start");
	startButton.setActionCommand("start");
	startButton.addActionListener(new ButtonListener());

	progressBar = new JProgressBar();
	progressBar.setMinimum(0);
	progressBar.setMaximum(task.getLengthOfTask());
	progressBar.setValue(0);

	JPanel contentPane = new JPanel();
	contentPane.add(startButton);
	contentPane.add(progressBar);
	contentPane.setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
	setContentPane(contentPane);

	//create a timer and a task
	timer = new Timer(ONE_SECOND, new TimerListener());
    }

    //the actionPerformed method in this class
    //is called each time the Timer "goes off"
    class TimerListener implements ActionListener {
        public void actionPerformed(ActionEvent evt) {
	    progressBar.setValue(task.getCurrent());
	    if (task.done()) {
		Toolkit.getDefaultToolkit().beep();
		timer.stop();
		startButton.setEnabled(true);
	    }
        }
    }

    //the actionPerformed method in this class
    //when the user presses the start button
    class ButtonListener implements ActionListener {
        public void actionPerformed(ActionEvent evt) {
	    startButton.setEnabled(false);
	    progressBar.setValue(progressBar.getMinimum());
	    task.go();
	    timer.start();
	}
    }
    
    public static void main(String[] args) {

        JFrame frame = new ProgressBarDemo();

        WindowListener l = new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        };
        frame.addWindowListener(l);

        frame.pack();
        frame.setVisible(true);
    }
}