protected override bool OnExposeEvent(Gdk.EventExpose evnt) { if (base.IsDrawable) { Gdk.Color color = base.Style.Background(Gtk.StateType.Normal); Gdk.GC gc = GtkHelper.GetDarkenedGC(base.GdkWindow, color, 3); base.GdkWindow.DrawLine(gc, Allocation.X, Allocation.Y + Allocation.Height - 1, Allocation.X + Allocation.Width, Allocation.Y + Allocation.Height - 1); } return(base.OnExposeEvent(evnt)); }