Question

I’m facing a frustrating issue. I have an application where the scroll wheel doesn’t work in a JDialog window (but works in a JFrame).

Here’s the code:

import javax.swing.*;
import java.awt.event.*;

public class Failtest extends JFrame {

 public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
       @Override
       public void run() {
          new Failtest();             
       }
    });

 }

 public Failtest() {
  super();
        setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
  setTitle("FRAME");
  JScrollPane sp1 = new   JScrollPane(getNewList());
  add(sp1);
  setSize(150, 150);
        setVisible(true);


  JDialog d = new JDialog(this, false);// NOT WORKING
        //JDialog d = new JDialog((JFrame)null, false); // NOT WORKING
        //JDialog d = new JDialog((JDialog)null, false);// WORKING - WHY? 

  d.setTitle("DIALOG");
        d.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
  JScrollPane sp = new JScrollPane(getNewList());

  d.add(sp);
  d.setSize(150, 150);
  d.setVisible(true);
 }

 public JList getNewList() {
  String objs[] = new String[30];
  for(int i=0; i<objs.length; i++) {
  objs[i] = "Item "+i;
 }
 JList l = new JList(objs);
  return l;
 }
}

I found a solution which is present as a comment in the java code – the constructor receiving a (JDialog)null parameter.

Can someone enlighten me?
My opinion is that this is a java bug.

Tested on Windows XP-SP3 with 1 JDK and 2 JREs:

D:\Program Files\Java\jdk1.6.0_17\bin>javac -version
javac 1.6.0_17

D:\Program Files\Java\jdk1.6.0_17\bin>java -version
java version "1.6.0_17"
Java(TM) SE Runtime Environment (build 1.6.0_17-b04)
Java HotSpot(TM) Client VM (build 14.3-b01, mixed mode, sharing)

D:\Program Files\Java\jdk1.6.0_17\bin>cd ..

D:\Program Files\Java\jdk1.6.0_17>java -version
java version "1.6.0_18"
Java(TM) SE Runtime Environment (build 1.6.0_18-b07)
Java HotSpot(TM) Client VM (build 16.0-b13, mixed mode, sharing)

Thank you in advance,

Iulian Şerbănoiu

PS: The problem is not new – the code is taken from a forum (here) where this problem was also mentioned – but no solutions to it (yet)

LATER EDIT:
The problem persists with jre/jdk_1.6.0_10, 1.6.0_16 also

LATER EDIT 2:
Back home, tested on linux (Ubuntu – lucid/lynx) – both with openjdk and sun-java from distribution repo and it works (I used the .class file compiled on Windows) !!! – so I believe I’m facing a JRE bug that happens on some Windows configurations.

Answer 1

There is something weird with your java install : your default version is not the 1.6.0_17 you show us, but an even more recent 1.6.0_18.

Anyway, using my (just a little older) 1.6.0_16 version on Windows XP, I cannot reproduce your issue, letting me think it may be a bug in J