Modal Internal Frames and JCombos

Question

Hi,
I'm trying to create a modal internal frame as suggested in Sun's TechTip:
http://developer.java.sun.com/developer/JDCTechTips/2001/tt1220.html
All I need is to block the input for the rest of the GUI, I don't care about real modality (the setVisible() call returns immediately).
I need to have a JComboBox in my internal frame. It turns out that under JDK1.4.0/1.4.1 the list for the combo is visible only with the Windows Look And Feel, while in every other JDK version it's not visible, except for the portion falling out of the internal frame.
The code to verify this follows. Does anybody know how to fix this? I've opened a bug for it, but I was wondering if someone can help in the forum...
Run the application passing "Windows" or "CDE/Motif", click on "open" and play with the combo to observe the result.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
public class Modal {
static class ModalAdapter
extends InternalFrameAdapter {
Component glass;
public ModalAdapter(Component glass) {
this.glass = glass;
// Associate dummy mouse listeners
// Otherwise mouse events pass through
MouseInputAdapter adapter =
new MouseInputAdapter(){};
glass.addMouseListener(adapter);
glass.addMouseMotionListener(adapter);
public void internalFrameClosed(
InternalFrameEvent e) {
glass.setVisible(false);
public static void main(String args[]) {
System.out.println("Installed lookAndFeels:");
UIManager.LookAndFeelInfo[] lafInfo = UIManager.getInstalledLookAndFeels();
for(int i=0; i<lafInfo.length; i++) {
System.out.println(lafInfo.getName());
String lookAndFeel = null;
if (args.length>0)
lookAndFeel = args[0];
initLookAndFeel(lookAndFeel);
final JFrame frame = new JFrame(
"Modal Internal Frame");
frame.setDefaultCloseOperation(
JFrame.EXIT_ON_CLOSE);
final JDesktopPane desktop = new JDesktopPane();
ActionListener showModal =
new ActionListener() {
public void actionPerformed(ActionEvent e) {
// Manually construct a message frame popup
JOptionPane optionPane = new JOptionPane();
optionPane.setMessage("Hello, World");
optionPane.setMessageType(
JOptionPane.INFORMATION_MESSAGE);
// JInternalFrame modal = optionPane.
// createInternalFrame(desktop, "Modal");
                    JInternalFrame modal = new JInternalFrame("test", true, true, true);
JPanel jp = (JPanel )modal.getContentPane();
          JComboBox jcb = new JComboBox(new String[]{"choice a", "choice b"});
jp.setLayout(new BorderLayout());
          jp.add(jcb,BorderLayout.NORTH);
          jp.add(new JTextArea(),BorderLayout.CENTER);
// create opaque glass pane
JPanel glass = new JPanel();
glass.setOpaque(false);
// Attach modal behavior to frame
modal.addInternalFrameListener(
new ModalAdapter(glass));
// Add modal internal frame to glass pane
glass.add(modal);
// Change glass pane to our panel
frame.setGlassPane(glass);
// Show glass pane, then modal dialog
modal.setVisible(true);
glass.setVisible(true);
System.out.println("Returns immediately");
JInternalFrame internal =
new JInternalFrame("Opener");
desktop.add(internal);
JButton button = new JButton("Open");
button.addActionListener(showModal);
Container iContent = internal.getContentPane();
iContent.add(button, BorderLayout.CENTER);
internal.setBounds(25, 25, 200, 100);
internal.setVisible(true);
Container content = frame.getContentPane();
content.add(desktop, BorderLayout.CENTER);
frame.setSize(500, 300);
frame.setVisible(true);
private static void initLookAndFeel(String lookAndFeel) {
String lookAndFeelClassName = null;
UIManager.LookAndFeelInfo[] lafInfo = UIManager.getInstalledLookAndFeels();
for(int i=0; i<lafInfo.length; i++) {
if (lafInfo[i].getName().equals(lookAndFeel)) {
lookAndFeelClassName = lafInfo[i].getClassName();
if (lookAndFeelClassName == null)
System.err.println("No class found for lookAndFeel: "+ lookAndFeel);
try {
UIManager.setLookAndFeel(lookAndFeelClassName);
} catch (ClassNotFoundException e) {
System.err.println("Couldn't find class for specified look and feel:"
+ lookAndFeel);
System.err.println("Did you include the L&F library in the class path?");
System.err.println("Using the default look and feel.");
} catch (UnsupportedLookAndFeelException e) {
System.err.println("Can't use the specified look and feel ("
+ lookAndFeel
+ ") on this platform.");
System.err.println("Using the default look and feel.");
} catch (Exception e) {
System.err.println("Couldn't get specified look and feel ("
+ lookAndFeel
+ "), for some reason.");
System.err.println("Using the default look and feel.");
e.printStackTrace();

Answer 1

Hi,
Had exactly the same problem. Seems there are plenty of similar problems all related to the glass pane, so have solved the problem here by putting the event-blocking panel onto the MODAL_LAYER of the layered pane, rather than replacing the glass pane. Otherwise pretty much the same technique - you may need a property change listener to track changes in the size of the layered pane
something like ...
layer = frame.getLayeredPane();
glass.setSize (layer.getSize()); // will need to track size
glass.add (modal);
layer.add(glass, JLayeredPane.MODAL_LAYER, 0);
I've modified the original examples so the frames can be re-used so you may have to play around with the example a bit
Hope it helps
cheers.