force redraw of progressbar

[Tobias Eberle <tobias eberle gmx de>]

Hello,

in my application I make some calculations that occur several seconds
and in the meantime I want to update a progressbar. Unfortunately I cant
do the calculation in a thread because OpenGL calls are done. So far I
call Gtk::Main::iteration() respectively  
while (Gtk::Main::events_pending())
{
  Gtk::Main::iteration();
}

Both have some drawbacks. The first call only executes one pending event
that mostly is not the progressbar draw event. The last executes all,
but the user is able to use the gui which can cause crashes ;-)

Is there a possibility to update only the progressbar or to execute all
draw events but no other?
An other possibility is to make all widgets insensitive. I can't be
bothered to make each widget insensitive for its own. Can I make all
widgets of a window insensitive with only one method call?

Thank you,

Tobias