gtk-sharp 2.8.0.0 Gtk# is thread aware, but not thread safe; See the Gtk# Thread Programming for details. placement can be influenced using this enumeration. System.Enum GLib.GType(WrapperType=typeof(Gtk.WindowPositionGType)) Field Gtk.WindowPosition No influence is made on placement. Field Gtk.WindowPosition Windows should be placed in the center of the screen. Field Gtk.WindowPosition Windows should be placed at the current mouse position. Field Gtk.WindowPosition Keep window centered as it changes size, etc. Field Gtk.WindowPosition Center the window on its transient parent (see ).