Hiding one should expand another

[Rasmus Brosboel <xtrophy it dk>]

Hi,

Using Gtk-- i have a Gtk_HBox containing two widgets, let's call them
widget1 and widget2.

Widget1 is not set to expand, widget2 is.

While the program is running, i hide widget1 and thought that would
eather shrink the window by the size of the widget, or make widget2
expand to take over widget1's space.

This is not what happens tho. When I hide widget1 its space just goes
blank, and is not used. How can I make widget2 expand to take over this
empty space?

Thanks,
-Rasmus