Perceived Behaviour:

DnD of nodes doesn't work in modal dialogs. I've got a panel with a BeanTreeView and DnD enabled Nodes. DnD works when I put it in a TopComponent or a non-modal dialog. It silently fails when in a modal dialog.

Expected behaviour:

DnD should work in modal dialogs.

Workaround:

None

Usecase: 

My usecase is a custom PropertyEditor which uses an explorerview and node reordering for setting the property.

Bug Analyis:

DnD in modal Dialogs was removed in 2002:
http://netbeans.org/bugzilla/show_bug.cgi?id=22618

The reason was a bug in  JDK 1.4.0:

"DnD in modal dialogs freezes the JVM in
JDK 1.4.0.  We detect the situation, log it and don't allow DnD.  This
is a bug in JDK which has been fixed for 1.4.1."
http://netbeans.org/bugzilla/show_bug.cgi?id=25848

Since the bug has been fixed and NB requires at least JDK 1.6, could you replace these lines from ExplorerDragSupport, which prevent using DnD in modal dialogs:

Dialog d = (Dialog) SwingUtilities.getAncestorOfClass(Dialog.class, comp);

            if ((d != null) && d.isModal()) {
                exDnD.setDnDActive(false);

                return;
            } else {
                exDnD.setDnDActive(true);
                dge.startDrag(null, transferable, this);
            }

with something like:
exDnD.setDnDActive(true);
dge.startDrag(null, transferable, this);