LRESULT wmCommandChild(long /*int*/ wParam, long /*int*/ lParam) {
   if ((style & SWT.CHECK) != 0) {
     setSelection(!getSelection());
   } else {
     if ((style & SWT.RADIO) != 0) {
       if ((parent.getStyle() & SWT.NO_RADIO_GROUP) != 0) {
         setSelection(!getSelection());
       } else {
         selectRadio();
       }
     }
   }
   sendSelectionEvent(SWT.Selection);
   return null;
 }