{
    if (selection instanceof IStructuredSelection)
    {
      Object object = ((IStructuredSelection)selection).getFirstElement();
      if (object instanceof EClass)
      {
        eClass = (EClass)object;

        action.setEnabled(!eClass.isAbstract());
        return;
      }
    }
    eClass = null;
    action.setEnabled(false);
  }