Graphical User Interfaces - Building Java Programs: A Back to Basics Approach - page 861

5 import javax.swing.*;
6 import javax.swing.event.*;
7
8 public class MousePointGUI extends MouseInputAdapter {
9 public static void main(String[] args) {
10 MousePointGUI gui = new MousePointGUI();
11 }
12
13 // fields
14 private JFrame frame;

15 private JLabel label;

16
17 // sets up the GUI, components, and events
18 public MousePointGUI() {
19 label = new JLabel();
20 label.setText("Move the mouse over me!");
21
22 // listen for mouse events
23 label.addMouseListener( this );
24 label.addMouseMotionListener( this );
25
26 frame = new JFrame();
27 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
28 frame.setSize( new Dimension(200, 100));
29 frame.setTitle("A frame");
30 frame.add(label);
31 frame.setVisible( true );
32 }
33
34 // responds to mouse movement events
35 public void mouseMoved(MouseEvent event) {
36 label.setText("(" + event.getX() + ", " +
37 event.getY() + ")");
38 }
39 }

The program produces the following graphical output, shown after the user moves
the mouse onto a few different points on the label: