Custom combobox renderer (interactive tooltip) on Vista

Question

I'm trying to add following functionality to my code:
http://www.java2s.com/Code/Java/Swing-Components/ToolTipComboBoxExample.htm
but I've found there is rendering problem on Vista. I don't know why, but following addition to original code
if (-1 < index) {
list.setToolTipText(jtUtil.getToolTip(value.toString()));
causes wrong rendering of 'selected item area' of combobox. There is white background instead of gradient. Is there any other Vista user who can confirm such behaviour or it is problem on my computer?
Is there another way how to ensure the same functionality without changes to renderer, for example addition any listener to javax.swing.plaf.basic.BasicComboPopup class? Or is there any easy way how to make own renderer without such fatal results? Thanks in advance for any tips.

Answer 1

Don't forget to use the Code Formatting Tags so the posted code retains its original formatting. That is done by selecting the code and then clicking on the "Code" button above the question input area.
I don't use Vista, but I would guess the problem is because your code is overriding the background property of the renderer. All you want to do is set the tooltip text so there is no need to change the default rendering of the renderer. Maybe something like the following will work:
  class MyComboBoxRenderer extends BasicComboBoxRenderer {
    public Component getListCellRendererComponent(JList list, Object value,
        int index, boolean isSelected, boolean cellHasFocus) {
        Component c = super.getListCellRendererComponent(
            list, value, index, isSelected, cellHasFocus);
        if (-1 < index)
          list.setToolTipText(tooltips[index]);
      return c;
  }