/*************************************************************************
 *  Compilation:  javac GUI.java
 *  Execution:    java GUI
 *
 *  A minimal Java program with a graphical user interface. The
 *  GUI prints out the number of times the user clicks a button.
 *
 *  % java GUI
 *
 *************************************************************************/

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

public class GUI extends JFrame implements ActionListener {
    private int clicks = 0;
    private JLabel label = new JLabel("Number of clicks:  0     ");

    public GUI() {

        // the clickable button
        JButton button = new JButton("Click Me");
        button.addActionListener(this);

        // layout
        JPanel  panel  = new JPanel();
        panel.setBorder(BorderFactory.createEmptyBorder(30, 30, 10, 30));
        panel.setLayout(new GridLayout(0, 1));
        panel.add(button);
        panel.add(label);
        getContentPane().add(panel, BorderLayout.CENTER);

        // finish setting up the frame, and show it
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setTitle("GUI");
        pack();
        show();
    }

    // process the button clicks
    public void actionPerformed(ActionEvent e) {
        clicks++;
        label.setText("Number of clicks:  " + clicks);
    };

    // create one Frame
    public static void main(String[] args) {
        GUI gui = new GUI();
    }
}