code: def _onMenuItemSelected(self, evt):
          
          current = self._menu.IsChecked(evt.GetId())
          if current:
              new = False
          else:
              new = True
          self._menu.Check(evt.GetId(), new)
          # Lines above would be deleted based on svn tracker ID 2841525;
          # not clear whether this matters or not.
          self._toolbar.set_active(self.getActiveAxes())
          evt.Skip()
docs: Called whenever one of the specific axis menu items is selected