How to get index of currently focussed element in JComboBox

Question

Hello
I have an editable JComboBox and i have the following property set on it
"JComboBox.lightweightKeyboardNavigation","Lightweight". THis enables the user to traverse using arrow keys without actually selecting each time.
In this case how do i find out which element or value is in focus because the value in focus may be different from the selected value in the combo box.
Please help!!!!!!!!
Gunjan

Answer 1

Try this:
import java.awt.event.KeyEvent;
import java.util.Vector;
import javax.swing.ComboBoxModel;
import javax.swing.JComboBox;
public class LightWeightComboBox extends JComboBox {
private int m_intSelectedIndex;
public LightWeightComboBox() {
super();
init();
public LightWeightComboBox(ComboBoxModel aModel) {
super(aModel);
init();
public LightWeightComboBox(Object[] items) {
super(items);
init();
public LightWeightComboBox(Vector items) {
super(items);
init();
private void init() {
// Enable lightweight keyboard navigation.
putClientProperty("JComboBox.lightweightKeyboardNavigation", "Lightweight"); // JDK 1.3
putClientProperty("JComboBox.isTableCellEditor", Boolean.TRUE); // JDK 1.4
public void showPopup() {
m_intSelectedIndex = getSelectedIndex();
super.showPopup();
private void updateSelectedIndex(int intKeyCode) {
if (intKeyCode == KeyEvent.VK_UP) {
m_intSelectedIndex--;
if (m_intSelectedIndex < 0) {
m_intSelectedIndex = 0;
else if (intKeyCode == KeyEvent.VK_DOWN) {
m_intSelectedIndex++;
if (m_intSelectedIndex > (getItemCount()-1)) {
m_intSelectedIndex = getItemCount()-1;
public void processKeyEvent(KeyEvent e) {
if (isPopupVisible()) {
if ( (e.getID() == KeyEvent.KEY_RELEASED) && ( (e.getKeyCode() == KeyEvent.VK_UP) || (e.getKeyCode() == KeyEvent.VK_DOWN) ) ) {
updateSelectedIndex(e.getKeyCode());
else if ( (e.getID() == KeyEvent.KEY_RELEASED) && ( (e.getKeyCode() == KeyEvent.VK_SPACE) || (e.getKeyCode() == KeyEvent.VK_ENTER) ) ) {
hidePopup();
setSelectedIndex(m_intSelectedIndex);
else if ( (e.getID() == KeyEvent.KEY_RELEASED) && ( (e.getKeyCode() == KeyEvent.VK_DOWN) || (e.getKeyCode() == KeyEvent.VK_SPACE) || (e.getKeyCode() == KeyEvent.VK_ENTER) ) ) {
showPopup();
if ( (e.getKeyCode() != KeyEvent.VK_ENTER) && (e.getKeyCode() != KeyEvent.VK_SPACE) ) {
super.processKeyEvent(e);
}