Disabled foreground color in JComboBox

Question

what's the correct way to set the disabled foreground color of a jcombobox? i don't want to set the disabled color for the entire ui to the same color, but for one jcombobox specifically. i searched the web and found many posts with the same question, but no real solution. this one has been giving me nightmares and i thought i'd share what i've found. the solution seems to be quite simple: wrap the combobox label in a panel. that way the panel gets the disabled colors, but the coloring of the label of the combobox remains. here's the solution in short in case others need it:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.DefaultListCellRenderer;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.ListCellRenderer;
public class MyComboBox extends JComboBox {
  public MyComboBox() {
    super();
    setRenderer( new ColorCellRenderer());
  public static void main(String s[]) {
    JFrame frame = new JFrame("ComboBox Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    final JComboBox cb = new MyComboBox();
    cb.addItem( "ComboBox Item 1");
    cb.addItem( "ComboBox Item 2");
    cb.addItem( "ComboBox Item 3");
    cb.setForeground( Color.blue);
    final JButton bt = new JButton ("disable");
    bt.addActionListener( new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent e) {
        cb.setEnabled( !cb.isEnabled());
        if( !cb.isEnabled()) {
          cb.setForeground( Color.red);
          bt.setText( "enable");
        } else {
          cb.setForeground( Color.blue);
          bt.setText( "disable");
    frame.getContentPane().setLayout( new FlowLayout());
    frame.getContentPane().add( bt);
    frame.getContentPane().add( cb);
    frame.pack();
    frame.setVisible(true);
  class ColorCellRenderer implements ListCellRenderer {
    protected DefaultListCellRenderer defaultRenderer = new DefaultListCellRenderer();
    public Component getListCellRendererComponent(JList list, Object value,
        int index, boolean isSelected, boolean cellHasFocus) {
      JLabel label = (JLabel) defaultRenderer
          .getListCellRendererComponent(list, value, index,
              isSelected, cellHasFocus);
      JPanel wrapper = new JPanel();
      wrapper.setLayout( new BorderLayout());
      wrapper.add( label, BorderLayout.CENTER);
      return wrapper;
}if anyone knows a way to remove the dropdown button of a disabled combobox without leaving a blank space when you simply hide the button, feel free to extend this :-)
Edited by: Lofi on Mar 20, 2010 10:46 PM

Answer 1

i thought i'd share what i've found. the solution seems to be quite simple: wrap the combobox label in a panel.Brilliant! I'm sure this will be useful to others who find this solution here.
Your code does have some unnecessary overheads though, like constructing a new JPanel in every call to getListCellRendererComponent, and holding a separate renderer as a field. I've attempted to clean it up for brevity and efficiency.import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.DefaultListCellRenderer;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class DisabledForegroundListCellRenderer extends DefaultListCellRenderer {
  private final JPanel wrapper = new JPanel(new BorderLayout());
  public DisabledForegroundListCellRenderer() {
    wrapper.add(this);
  @Override
  public Component getListCellRendererComponent(JList list, Object value,
          int index, boolean isSelected, boolean cellHasFocus) {
    super.getListCellRendererComponent(list, value,
            index, isSelected, cellHasFocus);
    return wrapper;
  // Test rig
  public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
      @Override
      public void run() {
        new DisabledForegroundListCellRenderer().makeUI();
  public void makeUI() {
    String[] data = {"One", "Two", "Three"};
    final JComboBox combo = new JComboBox(data);
    combo.setRenderer(new DisabledForegroundListCellRenderer());
    final JCheckBox check = new JCheckBox("Combo enabled");
    check.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent e) {
        boolean selected = check.isSelected();
        combo.setForeground(selected ? Color.BLUE : Color.RED);
        combo.setEnabled(selected);
    check.doClick();
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setLocationRelativeTo(null);
    frame.add(check, BorderLayout.NORTH);
    frame.add(combo, BorderLayout.SOUTH);
    frame.pack();
    frame.setVisible(true);
}I've also changed the class name, as to me "ColorCellRenderer" would rather imply something that renders either the foreground or the background (or both) on the basis of the value parameter.
if anyone knows a way to remove the dropdown button of a disabled combobox without leaving a blank space when you simply hide the buttonThat would require a custom UI delegate, not a custom renderer. And really, I wouldn't bother -- I would just use a JComboBox and a disabled (or maybe uneditable) JTextField, held in a CardLayout, and swap them instead of disabling the combo.
Shall take a look at how the combo UIs reserve space for the button though :)
luck, db
Edited by: DarrylBurke -- changed wrapper to private final, it shouldn't be static