tb.setValue( numericValue == null ? "" : numericValue.toString() );
// Wire up update handler
tb.setEnabled( !isReadOnly );
if ( !isReadOnly ) {
tb.addValueChangeHandler( new ValueChangeHandler<String>() {
public void onValueChange(ValueChangeEvent<String> event) {
try {
value.setNumericValue( new BigInteger( event.getValue() ) );
}