Mine

    public class Clock : DrawingArea {

        public Clock () {
            expose_event += widget_exposed;
        }

        private bool widget_exposed (Widget widget, Gdk.EventExpose ev)
        {
            return false;
        }

        static int main (string[] args) {
            Gtk.init (out args);

            Window window = new Window (WindowType.TOPLEVEL);
            Clock clock = new Clock ();

            window.add (clock);
            window.destroy += Gtk.main_quit;

            window.show_all ();

            Gtk.main ();
            return 0;
        }    
    }