JCombo box focus problem in WinNT/2000

Question

Hi,
We have made use of JCombobox component in our application and we have implemented autocomplete feature for that (Written our own logic). For testing we tried to run our application in Windows NT O/S. As and when user types any value in the JCombobox and if ENTER key is pressed or tries to move out by pressing tab key, then the existence of that value is checked in Registry (User profile ? Part of Autocomplete feature). If the same value does not exists, then the value will be stored in the registry. Here our problem is, user is unable to move out of JCombobox and it goes to infinite loop. To come out of the problem, user will have to terminate the application. However, if we comment part of the code i.e. focusLost part which (Setup Method in below pasted code) has logic to put the user entered value into the JCombobox in the same session of panel, then application works with one limitation i.e. user will have to press the tab key twice to move out of JCombobox.
However, none of the above problem were reported when the application is running in Windows2000 O/S with local admin rights to logon user.
Is this a bug with Swings? Or a limitation with Windows2000 O/s to run the SWING based application.
If somebody has any solution, please forward.
Thanks,
Regards,
Raj.
Code: ===============================================================
package com.tial.tial.ws.util.autocomplete;
import com.tial.tial.ws.model.SelectableFieldModel;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import javax.swing.ComboBoxEditor;
import javax.swing.ComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JTextField;
/** AutoCompleteCombo is used when normal combo Box requires Auto - complete feature.
* * @version 1.0
*modified on 26th March, 03 to solve case problem
*modified on 27th March, 03 to put the user entered value into the combo
public final class AutoCompleteCombo extends JComboBox{
private SelectableFieldModel m_myModel;
private ComboBoxEditor m_myEditor;
private JTextField m_txtEditor;
private int SIZEOFSELECTBOX = 20;
private boolean m_isTextSelected = false;
/** this is dictionary which has the data from the registry and also those entered by the user in the perticular session.
protected AutoCompleteDictionary m_dict;
//Constructors
/** Constructor for this class. Sets up the dictionary received and listners to the present instance.
* @param dict the dictionary received from the panel that uses AutoCompleteCombo.
public AutoCompleteCombo(AutoCompleteDictionary dict, SelectableFieldModel fldModel) {
super();
m_myModel = fldModel;
m_myEditor = super.getEditor();
m_txtEditor = (JTextField)m_myEditor.getEditorComponent();
setUp();
setDictionary(dict);
public AutoCompleteCombo(AutoCompleteDictionary dict) {
super();
m_myModel = null;
m_myEditor = super.getEditor();
m_txtEditor = (JTextField)m_myEditor.getEditorComponent();
setUp();
setDictionary(dict);
/** sets the dictionary received from the panel to the instance of AutoCompleteCombo.
* @param dict dictionary received in the constructor from the panel
public void setDictionary(AutoCompleteDictionary dict) {
m_dict = dict;
/** sets the focus and key listners to the AutoCompleteCombo.
protected void setUp() {
m_txtEditor.addFocusListener(new FocusAdapter() {
//Saves the field value in the dictionary when the focus of the field is lost,
//this is especially made to take care of commonly used TAB to move frm 1 fld to another.
// Comment from below to work atleast with pressing tab key twice.
public void focusLost(FocusEvent e) {
if(m_dict.size() == SIZEOFSELECTBOX){
m_dict.removeEntry(m_dict.last().toString());
m_dict.addEntry(m_txtEditor.getText().toUpperCase());
//to put the user entered value into the combo in the same session of panel
if (null != m_myModel) {
String dictList = m_dict.getElementsList();
String[] dictArray = dictList.split("~");
String enteredTxt = m_txtEditor.getText();
m_myModel.removeAll();
//so that initially the screen gets displayed with this field blank
//System.out.println("1 txt----------->" +m_txtEditor.getText());
m_myModel.addElement("");
//System.out.println("2 txt----------->" +m_txtEditor.getText());
for (int i=0; i<dictArray.length; i++) {
if (dictArray[i] != "" ) {
m_myModel.addElement(dictArray);
m_myModel.setSelectedItem(enteredTxt);
} // Comment till above to work atleast with pressing tab key twice.
m_txtEditor.addKeyListener( new KeyAdapter() {
public void keyPressed(KeyEvent e) {
m_isTextSelected = m_txtEditor.getSelectionStart() != m_txtEditor.getSelectionEnd();
public void keyReleased(KeyEvent e) {
char charPressed = e.getKeyChar();
int charCodePressed = e.getKeyCode();
if (charPressed == KeyEvent.CHAR_UNDEFINED) {
return;
if (charCodePressed == KeyEvent.VK_ENTER) {
//This is 2 restrict the dictionary lenght 2 the given limit
//remove this -1 if in SavePreference, def is "" instead of " "
//if (m_dict.size() - 1 == SIZEOFSELECTBOX) {
if (m_dict.size() == SIZEOFSELECTBOX) {
m_dict.removeEntry(m_dict.last().toString());
m_dict.addEntry(m_txtEditor.getText().toUpperCase());
//to put the user entered value into the combo in the same session of panel
if (null != m_myModel) {
String dictList = m_dict.getElementsList();
String[] dictArray = dictList.split("~");
m_myModel.removeAll();
//so that initially the screen gets displayed with this field blank
m_myModel.addElement("");
for (int i=0; i<dictArray.length; i++) {
if (dictArray[i] != "" ) {
m_myModel.addElement(dictArray[i]);
if (charCodePressed == KeyEvent.VK_DELETE) {
m_dict.removeEntry(m_txtEditor.getText());
//getSelectionStart() gives 0, as for a moment when Enter is pressed, the entire txt is selected.
//hence getCaretPosition is used
// if (m_txtEditor.getSelectionStart() != m_txtEditor.getSelectionEnd() && m_txtEditor.getSelectionEnd() != m_txtEditor.getCaretPosition()) {
// m_txtEditor.setText(m_txtEditor.getText().substring(0, m_txtEditor.getSelectionStart()));
if (m_txtEditor.getCaretPosition() != m_txtEditor.getSelectionEnd()) {
m_txtEditor.setText(m_txtEditor.getText().substring(0, m_txtEditor.getCaretPosition()));
String input = m_txtEditor.getText();
if (lookup(input) != null) {
m_txtEditor.setText(lookup(input));
m_txtEditor.setSelectionStart(input.length());
m_txtEditor.setSelectionEnd(m_txtEditor.getText().length());
m_isTextSelected = true;
else {
m_isTextSelected = false;
if (charCodePressed == KeyEvent.VK_BACK_SPACE
&& m_isTextSelected && input.length() > 0) {
m_txtEditor.setText(input.substring(0, input.length()));
/** used to search for the entered string in the dictionary list.
* @param str the string that is to be searched in the dictionary.
* @return the string from the dictionary that matches with the received str.
protected String lookup(String str) {
if (m_dict != null) {
return m_dict.lookup(str);
return null;

Answer 1

Can you post common part of the stack trace when Java goes into infinite loop?