w.addValueChangeHandler( new ValueChangeHandler<OperatorSelection>() {
public void onValueChange( ValueChangeEvent<OperatorSelection> event ) {
setModified( true );
final OperatorSelection selection = event.getValue();
final String selected = selection.getValue();
final String selectedText = selection.getDisplayText();
//Prevent recursion once operator change has been applied
if ( selectedText.equals( c.getOperator() ) ) {
return;
}