/** Fire all current {@link IValidationTextBoxListener}. */
 void fireOnFailure() {
   if (listeners != null) {
     listeners.fireOnFailure(this);
   }
 }
 public void removeValidatableTextBoxListener(IValidationTextBoxListener listener) {
   if (listeners != null) {
     listeners.remove(listener);
   }
 }
 /** Fire all current {@link IValidationTextBoxListener}. */
 void fireOnSuccess() {
   if (listeners != null) {
     listeners.fireOnSuccess(this);
   }
 }
 public void addValidatableTextBoxListener(IValidationTextBoxListener listener) {
   if (listeners == null) {
     listeners = new ValidationTextBoxListenerCollection();
   }
   listeners.add(listener);
 }