Resizing GtkDrawingArea inside GtkScrolledWindow

[Gustavo Cipriano Mota Sousa <gustavomota inf ufg br>]

I have a GtkDrawingArea added to a GtkScrolledWindow using 
gtk_scrolled_window_add_with_viewport(). I am trying to resize the 
drawing area calling gtk_widget_set_size_request(), but when I do so, 
the toplevel widget (GtkWindow) also gets resized. I'd like to know how 
to resize just the drawing area, so that the scrollbars of the scrolled 
windows just get narrower instead of the toplevel window also getting 
resized.

Thanks for your attention.

Gustavo Cipriano Mota Sousa <gustavomota at inf dot ufg dot br>