Focus problem when JPopupMenu is shown

Question

I have compiled and ran the following 'JPopupTest.java' in JDK 1.4.1 on Windows. Kindly conduct the two tests as given below
First Test :
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The class shows an editable JComboBox and a JButton when visible. Now click the down-arrow button of the JComboBox and make the drop-down popup visible. Then click on the "OK" button while the popup is visible. The popup gets hidden and a dialog is displayed as it should be.
Second Test :
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Run the appilcation again. This time type something in the editable textfield of the JComboBox. A custom JPopupMenu with the text "Hello World" would be visible. Then click on the "OK" button while the popup is visible. The expected dialog is not shown. The custom JPopupMenu gets hidden. Now click on "OK" button again. The dialog is visible now.
My Desire :
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When I click on the "OK" button in the "Second Test" the JPopupMenu should get hidden and the dialog gets displayed (as it happens for the "First Test") in one click.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.*;
import javax.swing.event.*;
import javax.swing.plaf.basic.*;
import java.util.*;
public class JPopupTest extends JPanel implements DocumentListener, ActionListener
     JButton button;
     Vector vec;
     JComboBox jcombobox;
     JPopupMenu jpopupmenu;
     BasicComboBoxEditor _bcbe;
     JTextField jtextfield;
     public JPopupTest()
        vec = new Vector();
           vec.addElement("One");
        vec.addElement("Two");
        vec.addElement("Three");
        vec.addElement("Four");
        vec.addElement("Five");
        vec.addElement("Six");
        vec.addElement("Seven");
        vec.addElement("Eight");
        vec.addElement("Nine");
        vec.addElement("Ten");
        jcombobox = new JComboBox(vec);
        jcombobox.setEditable(true);
        _bcbe = ((BasicComboBoxEditor) jcombobox.getEditor());
        jtextfield = ((JTextField) _bcbe.getEditorComponent());
        jtextfield.getDocument().addDocumentListener(this);
        add(jcombobox);
        button = new JButton("OK");
        button.addActionListener(this);
        add(button);
        jpopupmenu = new JPopupMenu();
        jpopupmenu.add("Hello World");
     public void insertUpdate(DocumentEvent e)  {changedUpdate(e);}
     public void removeUpdate(DocumentEvent e)  {changedUpdate(e);}
        public void changedUpdate(DocumentEvent e)
        if(!jpopupmenu.isVisible())
        jpopupmenu.show(jcombobox, 0, jcombobox.getHeight());
        jtextfield.requestFocus();
     public void actionPerformed(ActionEvent e)
        JOptionPane.showMessageDialog(this, "OK button was pressed");
     public static void main(String[] args)
        JPopupTest test = new JPopupTest();
        JFrame jframe = new JFrame();
        jframe.getContentPane().add(test);
        jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jframe.setSize(200,100);
        jframe.setVisible(true);

Answer 1

See the code below with auto complete of text. When button is pressed, still TF gets focus after JOptionPane dialog is closed.
-Pratap
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.plaf.basic.*;
public class JPopupTest extends JPanel implements ActionListener {
     JButton button;
     Vector vec;
     JComboBox jcombobox;
     BasicComboBoxEditor _bcbe;
     JTextField jtextfield;
     MyComboUI comboUi = new MyComboUI();
     public JPopupTest() {
          vec = new Vector();
          vec.addElement("One");
          vec.addElement("Two");
          vec.addElement("Three");
          vec.addElement("Four");
          vec.addElement("Five");
          vec.addElement("Six");
          vec.addElement("Seven");
          vec.addElement("Eight");
          vec.addElement("Nine");
          vec.addElement("Ten");
          jcombobox = new JComboBox(vec);
          jcombobox.setEditable(true);
          jcombobox.setUI(comboUi);
          add(jcombobox);
          button = new JButton("OK");
          button.addActionListener(this);
          add(button);
          _bcbe = ((BasicComboBoxEditor) jcombobox.getEditor());
          jtextfield = ((JTextField) _bcbe.getEditorComponent());
          jtextfield.addCaretListener(new CaretListener() {
                    public void caretUpdate(CaretEvent e) {
                         if (!jcombobox.isPopupVisible() && jtextfield.isShowing() &&
                                   jtextfield.hasFocus()) {
                              jcombobox.showPopup();
                         String text = jtextfield.getText().toLowerCase();
                         int index = -1;
                         for (int i = 0; i < jcombobox.getItemCount(); i++) {
                              String item = ((String) jcombobox.getItemAt(i)).toLowerCase();
                              if (item.startsWith(text)) {
                                   index = i;
                                   break;
                         if (index != -1) {
                              comboUi.getList().setSelectedIndex(index);
                         } else {
                              comboUi.getList().clearSelection();
               jtextfield.addKeyListener(new KeyAdapter() {
                    public void keyPressed(KeyEvent e) {
                         if (e.getKeyCode() == e.VK_ENTER) {
                              Object value = comboUi.getList().getSelectedValue();
                              jcombobox.setSelectedItem(value);
                              jcombobox.hidePopup();
     public void actionPerformed(ActionEvent e) {
          JOptionPane.showMessageDialog(this,"OK button was pressed");
          jtextfield.requestFocus();
     public static void main(String[] args) {
          JPopupTest test = new JPopupTest();
          JFrame jframe = new JFrame();
          jframe.getContentPane().add(test);
          jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          jframe.setSize(200,100);
          jframe.setVisible(true);
     public class MyComboUI extends BasicComboBoxUI {
          public JList getList() {
               return listBox;