How to use

addValueChangeListener

method

in

com.vaadin.v7.ui.Field

@Override
public void addField(Field<?> field) {
  // This oddly simply connects the field to the error count
  // field itself is added to the component tree by FormBuilder
  fields.add(field);
  field.addValueChangeListener(new Property.ValueChangeListener() {
    @Override
    public void valueChange(Property.ValueChangeEvent event) {
      invalidateErrorAmount();
    }
  });
}

/**
 * Makes all fields "immediate" to trigger eager validation
 *
 * @param listener a listener that will be notified when a field in the
 *                 group has been modified
 * @return the MBeanFieldGroup that can be used for further modifications or
 * e.g. commit if buffered
 */
public MBeanFieldGroup<T> withEagerValidation(FieldGroupListener<T> listener) {
  this.listener = listener;
  for (Field<?> field : getFields()) {
    // ((AbstractComponent) field).setImmediate(true);
    field.addValueChangeListener(this);
    if (field instanceof EagerValidateable) {
      EagerValidateable ev = (EagerValidateable) field;
      ev.setEagerValidation(true);
    }
    if (field instanceof TextChangeNotifier) {
      final TextChangeNotifier abstractTextField = (TextChangeNotifier) field;
      abstractTextField.addTextChangeListener(this);
    }
  }
  return this;
}