When a JDialog is popped up from a menu item, the popup cannot
be used as the component for setting the dialog location.

Specifically, I had an ActionListener to a JMenuItem that looks
like this:

   public void actionPerformed (ActionEvent e)
   {
      Component sourceComponent = null;

      if (e.getSource () instanceof Component)
         sourceComponent = (Component) e.getSource ();

      JOptionPane.showMessageDialog
         (sourceComponent,
         name + " " + versionNumber + "\n" + versionDate,
         "About " + name,
         JOptionPane.INFORMATION_MESSAGE);
   }

and the popup was always in the center of the screen.  I tracked
problem to where JDialog has a loop to find the window that
contains the component.  This logic does not allow for the
fact that JPopupMenus are not in the parent chain of their
windows.  I changed my code to the following, which worked fine.
I recommend this change to the JDialog logic.  Thank you.

New code:

   public void actionPerformed (ActionEvent e)
   {
      Component sourceWindow = null;

      if (e.getSource () instanceof Component)
         sourceWindow = getWindow ((Component) e.getSource ());

      JOptionPane.showMessageDialog
         (sourceComponent,
         name + " " + versionNumber + "\n" + versionDate,
         "About " + name,
         JOptionPane.INFORMATION_MESSAGE);
   }

   Component getWindow (Component c)
   {
      // This is copied from JDialog, except that it fixes
      // the bug caused by JPopupMenu

      boolean   trace = true;
      Component root = null;

      if (c != null)
      {
         if (c instanceof Window || c instanceof Applet)
         {
            if (trace)
               System.out.println (c.getClass ().getName ());
            root = c;
         }
         else
         {
            Component parent;
            for (parent = getParent (c);
                 parent != null ;
                 parent = getParent (parent))
            {
               if (trace && parent == null)
                  System.out.println ("null");
               else if (trace)
                  System.out.println (parent.getClass ().getName ());

               if (parent instanceof Window || parent instanceof Applet)
               {
                  root = parent;
                  break;
               }
            }
         }
      }
      else if (trace)
         System.out.println ("null");

      return root;
   }

   Component getParent (Component c)
   {
      if (c instanceof JPopupMenu)
         return ((JPopupMenu) c).getInvoker ();
      else
         return c.getParent ();
   }
(Review ID: 53237) 
======================================================================
Posted Date : 2005-11-10 13:59:58.0

See above.
======================================================================

It's possible to change JOptionPane to fix this. We need to use the invoker of the popup menu instead of popup menu itself for setting location of JOptionPane.
  xxxxx@xxxxx   2005-03-17 18:15:13 GMT
Also we should modify JOptionPane.getFrameForComponent() and JOptionPane.getWindowForComponent() methods because then we invoke JOptionPane from JPopupMenu, these methods should return frame/window not for popup menu, but for it's invoker.
  xxxxx@xxxxx   2005-07-04 19:28:48 GMT
Posted Date : 2005-07-04 19:28:48.0

See also:

Hans Muller's Blog: Dialog Diatribe
http://weblogs.java.net/blog/hansmuller/archive/2006/10/dialog_diatribe.html

This bug comes up anywhere you write a loop based on parent.getParent(). This includes these 4 methods in SwingUtilities:

Window getWindowAncestor(Component c) 
Window windowForComponent(Component c) 
Component getRoot(Component c) 
JRootPane getRootPane(Component c)

I'm sure many developers have the same kind of loop somewhere in their code. I know I do.

See the second comment to bug 6499857 for a suggested change that would fix all of these loops.