Hide a toplevel window without closing the application

[Pedro Sousa <pasousa ml gmail com>]

Hi to all,

When I want to load a project from a file it takes a long time, with
window hanging in the mean time. For putting the system prettier to the
user, I want to load a dialog with the message "In process" and a status
bar increasing.  The  toplevel window should disconnect the
sensitiveness meanwhile the operation occurs.

I can create the dialog without any problem but I try to show it also
hangs the dialog. I heaven tried with creation of another thread, using
lower priority, without success.

Now I try to hide the toplevel window while the dialog is shown, but
when I do hide () to that window, the application shut down. How can I
hide the window without closing the application?

Best regards
Pedro Sousa