Swing Menus and Toolbars - The Definitive Guide to Java Swing - page 202

Listing 6-8. The ToolBarSample Class Definition
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ToolBarSample {
private static final int COLOR_POSITION = 0;
private static final int STRING_POSITION = 1;
static Object buttonColors[][] = {
{Color.RED, "RED"},
{Color.BLUE, "BLUE"},
{Color.GREEN, "GREEN"},
{Color.BLACK, "BLACK"},
null, // separator
{Color.CYAN, "CYAN"}
};
public static class TheActionListener implements ActionListener {
public void actionPerformed (ActionEvent actionEvent) {
System.out.println(actionEvent.getActionCommand());
}
};
public static void main(final String args[]) {
Runnable runner = new Runnable() {
public void run() {
JFrame frame = new JFrame("JToolBar Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
ActionListener actionListener = new TheActionListener();
JToolBar toolbar = new JToolBar();
toolbar.setRollover(true);
for (Object[] color: buttonColors) {
if (color == null) {
toolbar.addSeparator();
} else {
Icon icon = new DiamondIcon((Color)color[COLOR_POSITION], true, 20, 20);
JButton button = new JButton(icon);
button.setActionCommand((String)color[STRING_POSITION]);
button.addActionListener(actionListener);
toolbar.add(button);
}
}