Toggle Buttons - The Definitive Guide to Java Swing - page 125

Listing 5-3 demonstrates three valid means of creating JCheckBox components with
different icons, one using a state-aware icon. The last check box shows bad icon usage.
Listing 5-3. Sampling JCheckBox
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class IconCheckBoxSample {
private static class CheckBoxIcon implements Icon {
private ImageIcon checkedIcon = new ImageIcon("Plus.gif");
private ImageIcon uncheckedIcon = new ImageIcon("Minus.gif");
public void paintIcon(Component component, Graphics g, int x, int y) {
AbstractButton abstractButton = (AbstractButton)component;
ButtonModel buttonModel = abstractButton.getModel();
g.translate(x,y);
ImageIcon imageIcon = buttonModel.isSelected() ?
checkedIcon : uncheckedIcon;
Image image = imageIcon.getImage();
g.drawImage(image, 0, 0, component);
g.translate(-x,-y);
}
public int getIconWidth() {
return 20;
}
public int getIconHeight() {
return 20;
}
}
public static void main(String args[]) {
Runnable runner = new Runnable() {
public void run() {
JFrame frame = new JFrame("Iconizing CheckBox");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Icon checked = new DiamondIcon (Color.BLACK, true);
Icon unchecked = new DiamondIcon (Color.BLACK, false);
JCheckBox aCheckBox1 = new JCheckBox("Pizza", unchecked);
aCheckBox1.setSelectedIcon(checked);
JCheckBox aCheckBox2 = new JCheckBox("Calzone");
aCheckBox2.setIcon(unchecked);
aCheckBox2.setSelectedIcon(checked);