Auto Complete Combo Boxes?

Question

Does anyone know of auto-completing combo boxes written in Java? I have a dirty hack that sort of works, but if you type too fast the caret jumps to the end of the text it thinks you are typing instead of selecting the characters that you haven't typed yet.
Any help would be greatly appreciated.

Answer 1

Jrabi,
Below is the code for KComboBoxes. Please be aware that this code comes with NO guarantee. It works for me, but that doesn't necessarily mean that it will work for you. If you have any questions about the code I will be happy to answer them. Make sure that once you create an instance of KComboBox that you set it as editable or the auto complete function won't work.
package pubprint; //make this package whatever your package is
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
* Title: <BR>
* Description: <BR>
* Copyright: Copyright (c) 2002<BR>
* Company: <BR>
* @author Kevin J. Keen
* @version 0.5
public class KComboBox extends JComboBox implements KeyListener {
private ComboBoxModel myModel;
private KeySelectionManager myKeyManager;
private ComboBoxEditor myEditor;
private JTextField txtEditor;
private long timeOfLastEvent = 0;
//Constructors
public KComboBox() {
super();
myModel = super.getModel();
myKeyManager = super.getKeySelectionManager();
myEditor = super.getEditor();
txtEditor = (JTextField)myEditor.getEditorComponent();
txtEditor.addKeyListener(this);
public KComboBox(ComboBoxModel daModel) {
super(daModel);
myModel = super.getModel();
myKeyManager = super.getKeySelectionManager();
myEditor = super.getEditor();
txtEditor = (JTextField)myEditor.getEditorComponent();
txtEditor.addKeyListener(this);
public KComboBox(Object[] items) {
super(items);
myModel = super.getModel();
myKeyManager = super.getKeySelectionManager();
myEditor = super.getEditor();
txtEditor = (JTextField)myEditor.getEditorComponent();
txtEditor.addKeyListener(this);
public KComboBox(Vector items) {
super(items);
myModel = super.getModel();
myKeyManager = super.getKeySelectionManager();
myEditor = super.getEditor();
txtEditor = (JTextField)myEditor.getEditorComponent();
txtEditor.addKeyListener(this);
//Key listener methods
public synchronized void keyReleased(KeyEvent e) {
if(e.getKeyCode() == KeyEvent.VK_SHIFT || e.getKeyCode() == KeyEvent.VK_TAB) {
return;
//This IF/ELSE is necessary because without it
//you can out-type the auto complete and get
//really weird behavior.
if((e.getWhen() - timeOfLastEvent) < 100) {
return;
else {
timeOfLastEvent = e.getWhen();
String temp = txtEditor.getText();
int hashCode = temp.hashCode();
for(int i = 0; i < myModel.getSize(); i++) {
String contents = (String)myModel.getElementAt(i);
if(contents.startsWith(temp)) {
int selectionStart = txtEditor.getCaretPosition();
int selectionEnd = (contents.length());
//Check to make sure that the value in the text field hasn't changed
if(txtEditor.getText().hashCode() == hashCode) {
setSelectedItem(contents);
selectedItemChanged();
txtEditor.setSelectionStart(selectionStart);
txtEditor.setSelectionEnd(selectionEnd);
return;
else {
return;
public void keyPressed(KeyEvent e) {}
public void keyTyped(KeyEvent e) {}
}