🚀 go-pugleaf

"Matthew Sweet" <matthew.sweet@sed.redstone.army.mil> wrote in message
news:3fdf4cd0$1@newsgroups.borland.com...
> I think I figured it out. I had "ColorChooser colorChooserDlg = new
> ColorChooser( (Frame) SwingUtilities.windowForComponent(this));" in
the
> initialization section of my containor class. I moved it to the mouse
> adapter class. Dont' really understand why unless I needed to call
> colorChooserDlg.show() somewhere else.

Check what you get back from windowForComponent in each case.  I suspect
that in the original code you were getting a null return value.

That method walks up the component tree from parent to parent until it
finds one that's a Window.  If your panel hasn't yet been added to its
parent, then it won't be able to find the frame.  In other words,
suppose you had something like this:

    JPanel myPanel = new MyPanel();
    // dialog created and windowForComponent called in the constructor
    frame.getContentPane().add(myPanel);

Then at the time windowForComponent is called, myPanel doesn't have a
parent.  It doesn't get a parent until it's added to the frame's content
pane.  So when windowForComponent searches for an ancestor that's a
Window, it can't find one, because there aren't any ancestors at all,
let alone a Window.

By putting it in the even handler, you've changed the sequence to
something like this:

    JPanel myPanel = new MyPanel();
    frame.getContentPane().add(myPanel);
    // ...
    // dialog created and windowForComponent called in an event handler

-- 
Gillmer J. Derge (TeamB)