here is my code. i setmaxrowcount to 8, and it still had the same problem. if you run the program, first select a item, hit enter, and then backspace to remove all the letters. you will see that only one item is displayed. if you then click on the down-arrow, the popup menu show the right size. is there anything to do with the preferredsize of the popup menu.... thanks for your help. i am running it with jdk 1.6
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.io.Serializable;
import java.util.ArrayList;
import javax.swing.AbstractListModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.MutableComboBoxModel;
import javax.swing.SwingUtilities;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
public class LRComboBox
{
public static JComboBox createCB (Object[] items)
{
final LRComboBoxModel cbModel = new LRComboBoxModel (items);
DocumentListener documentListener = new DocumentListener() {
public void changedUpdate(DocumentEvent documentEvent) {
System.err.println ("change update");
doit (documentEvent);
}
public void insertUpdate(DocumentEvent documentEvent) {
System.err.println ("insert update");
doit (documentEvent);
}
public void removeUpdate(DocumentEvent documentEvent) {
System.err.println ("remove update");
doit (documentEvent);
}
private void doit (DocumentEvent documentEvent)
{
Document source = documentEvent.getDocument();
int length = source.getLength();
try
{
final
String pattern = source.getText(0, length);
System.err.println("pattern is " + pattern);
cbModel.filter(pattern);
}
catch (BadLocationException badLocationException)
{
System.exit(-1);
}
}
};
System.err.println ("Creating combo box..");
JComboBox bc = new JComboBox (cbModel);
bc.setEditable(true);
Component com = bc.getEditor().getEditorComponent();
JTextField tf = (JTextField) com;
tf.addKeyListener(new LRKeyStrokeListener(bc));
tf.getDocument().addDocumentListener(documentListener);
bc.setMaximumRowCount(8);
return bc;
}
public static void main (String[] args)
{
SwingUtilities.invokeLater(new Runnable () {
public void run ()
{
JFrame frame = new JFrame ("LRComboBox");
String items[] = new String[] {"1A23", "234", "456", "232", "12ACV", "12wed", "64646 23232", "134xsc", "12qas", "7646 2232", "87575 2222", "3434 43232", "23232 5343"};
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add (BorderLayout.CENTER, LRComboBox.createCB (items));
frame.setSize(500,500);
frame.pack();
frame.setVisible(true);
}
});
}
}
class LRComboBoxModel extends AbstractListModel implements MutableComboBoxModel, Serializable
{
private ArrayList<Object> immutableObjects = new ArrayList<Object> ();
private ArrayList<Object> displayedObjects = new ArrayList<Object> ();
private Object selectedObject;
private static final long serialVersionUID = -766074626262654394L;
public LRComboBoxModel(Object[] items) {
for (int i=0; i<items.length; ++i)
{
immutableObjects.add (items[i]);
displayedObjects.add (items[i]);
}
if (items.length > 0) selectedObject = displayedObjects.get (0);
}
@Override
public void addElement(Object obj) {
throw new RuntimeException ("not implemented");
}
@Override
public void insertElementAt(Object obj, int index) {
throw new RuntimeException ("not implemented");
}
@Override
public void removeElement(Object obj) {
throw new RuntimeException ("not implemented");
}
public void filter(String pattern) {
int max = 0;
setSelectedItem(pattern);
displayedObjects = new ArrayList<Object> ();
for (Object obj : immutableObjects)
{
String str = (String) obj;
String lowerStr = str.toLowerCase();
String lowerPat = pattern.toLowerCase();
if (lowerStr.indexOf(lowerPat) >= 0)
{
displayedObjects.add(str);
}
}
max = displayedObjects.size();
fireContentsChanged(this, 0, max);
}
@Override
public void removeElementAt(int index) {
throw new RuntimeException ("not implemented");
}
@Override
public Object getSelectedItem() {
return selectedObject;
}
@Override
public void setSelectedItem(Object anObject) {
if ((selectedObject != null && !selectedObject.equals( anObject )) ||
selectedObject == null && anObject != null) {
selectedObject = anObject;
fireContentsChanged(this, -1, -1);
}
}
@Override
public Object getElementAt(int index) {
if ( index >= 0 && index < displayedObjects.size() )
return displayedObjects.get(index);
else
return null;
}
@Override
public int getSize() {
return displayedObjects.size();
}
}
class LRKeyStrokeListener implements KeyListener
{
private JComboBox lrCB = null;
public LRKeyStrokeListener(JComboBox lrCB) {
this.lrCB = lrCB;
}
@Override
public void keyPressed(KeyEvent e) {
// TODO Auto-generated method stub
}
@Override
public void keyReleased(KeyEvent e) {
// TODO Auto-generated method stub
}
@Override
public void keyTyped(KeyEvent e)
{
if ((e.getKeyChar() == KeyEvent.VK_TAB) ||
(e.getKeyChar() == KeyEvent.VK_ESCAPE) ||
(e.getKeyChar() == KeyEvent.VK_ENTER))
{
lrCB.setPopupVisible(false);
}
else
{
if (!lrCB.isPopupVisible()) lrCB.setPopupVisible(true);
}
}
}
