Graphical User Interfaces - Building Java Programs: A Back to Basics Approach - page 874

66 public void setVisible( boolean visible) {
67 frame.setVisible(visible);
68 }
69
70 // used for timer that repeatedly repaints screen
71 public void actionPerformed(ActionEvent e) {
72 panel.repaint();
73 }
74
75 // draws status bar text when mouse moves
76 public void mouseMoved(MouseEvent e) {
77 statusBar.setText("(" + e.getX() + ", " +
78 e.getY() + ")");
79 }
80 }

This version of the code can be used to draw any of the example programs from
Supplement 3G. For example, the following screenshot shows the output when the
Pyramids case study from Supplement 3G is run using the DrawingPanel we have
just implemented:

Chapter Summary

A graphical user interface (GUI) has a window frame that
contains buttons, text input fields, and other onscreen
components.

Some of the most common graphical components are but-
tons ( JButton objects), text input fields ( JTextField
objects), and text labels ( JLabel objects).

The JOptionPane class is a simple GUI class that can be
used to display messages and prompt a user to input val-
ues, enabling graphical output and input.

All graphical components in Java belong to a common
inheritance hierarchy, so they share a common set of
methods that can be used to get and set properties such as
background color, size, and font.