How to make JPopupMenu pop out upwards?

Question

The title is just my problem.I add a JToolBar at BorderLayout.South of a JPanel. A popup menu will shown when I click on one button of my JToolBar. But the low part of JPopupMenu was covered by the taskbar of Windows2000. I want to make my JPopupMenu pop out upwards. How can I?

Answer 1

Assuming that the popup is triggered by the mouse click and it's screen coordinates (x, y). Since the toolbar is in the southern border, and the popup appears to the right and below from that position "(x, y)". Calculate the width and length of the popup, (say it's 60 pixels wide by 90 pixels long) subrtact the witdth value ,(60) and the length value, (90) from x and y respectively. So as to go something like this:
private void maybeShowPopup(MouseEvent e) {
     if (e.isPopupTrigger()) {
          int x = e.getX() - 60;
              int y = e.getY() - 90;
                   popup.show(e.getComponent(), x, y);
}Or something to that effect. You simply alter the coordinates(x, y) to reposition the popup starting point. I did not test the above code as this is purely a fictional example. Hope this helps. Also if you need help measuring screen pixels here is a cool little program called Calipers that will help. http://www.iconico.com/caliper/