code: func (v *Menu) PopupAtPointer(_ *gdk.Event) {
  	C.gtk_menu_popup(v.native(),
  		nil,
  		nil,
  		nil,
  		nil,
  		C.guint(0),
  		C.gtk_get_current_event_time())
  }
docs: // PopupAtPointer() is a wrapper for gtk_menu_popup_at_pointer(), on older versions it uses PopupAtMouseCursor