JList performance in JScrollPane

Question

Hi!
I've got a really odd problem with JList handling inside a JScrollPane.
What happens is that I populate the JList with elements from a vector, and it displays them allright, but when I add or remove any element after creating the jList for first time, the CPU usage goes crazy until I move the scrollbar knob of the ScrollPane it's in. After moving the knob, the elements display ok, and cpu usage goes down to normality.. I can reproduce this phenomenon every time.
At first I thought it was a performance issue, but after implementing a custom minimal cell renderer (which I actually don't use anymore) and adjusting the prototypecell and fixed size properties, this kept happening... Any ideas are welcome!
Thanks!
P.S:The code is a little large, but I'll post it if it helps!

Answer 1

Seems to work for meimport java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
public class Test2 extends JFrame {
  Vector data = new Vector(10000);
  DefaultListModel dlm = new DefaultListModel();
  JList jl = new JList();
  public Test2() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container content = getContentPane();
    for (int i=0; i<10000; i++) dlm.addElement("Stuff-"+i);
    jl.setModel(dlm);
    JButton jb = new JButton("Remove");
    content.add(jb, BorderLayout.SOUTH);
    jb.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent ae) {
        int index = jl.getSelectedIndex();
        if (index>=0) dlm.remove(index);
    content.add(new JScrollPane(jl), BorderLayout.CENTER);
    setSize(300,300);
  public static void main(String[] args) { new Test2().setVisible(true); }
}