Basic Text Components - The Definitive Guide to Java Swing - page 519

In addition to calling the setDisplayedMnemonic() method, you must also call the public
void setLabelFor(Component component) method of JLabel . This configures the JLabel to
move input focus to the text field when the special mnemonic value is pressed.
Figure 15-3 shows what this sample program might look like. The complete source for the
program follows in Listing 15-2.
Figure 15-3. Connecting a JLabel and a JTextField
Listing 15-2. Connected JLabel and JTextField
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class LabelSample {
public static void main(String args[]) {
Runnable runner = new Runnable() {
public void run() {
JFrame frame = new JFrame("Label Focus Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel(new BorderLayout());
JLabel label = new JLabel("Name: ");
label.setDisplayedMnemonic(KeyEvent.VK_N);
JTextField textField = new JTextField();
label.setLabelFor(textField);
panel.add(label, BorderLayout.WEST);
panel.add(textField, BorderLayout.CENTER);
frame.add(panel, BorderLayout.NORTH);
frame.add(new JButton("Somewhere Else"), BorderLayout.SOUTH);
frame.setSize(250, 150);
frame.setVisible(true);
}
};
EventQueue.invokeLater(runner);
}
}