The shell_widget is the pop-up shell to pop down,
and the enable_widget is the widget that was used to pop it up.
with the specified shell_widget
and then calls
to resensitize the enable_widget.
If a shell name is not given,
with the widget for which the translation is specified.
If a shell_name is specified in the translation table,
tries to find the shell by looking up the widget tree starting at the
parent of the widget in which it is invoked.
If it finds a shell with the specified name in the pop-up children
of that parent,
it pops down the shell;
otherwise, it moves up the parent chain as needed.
gets to the application top-level shell widget
and cannot find a matching shell,
it generates an error.