commitButton.addListener(new Button.ClickListener() {
@Override
public void buttonClick(Button.ClickEvent event) {
try {
String value = (String) rawText.getValue();
WidgetsDefinitionElement unmarshall = (WidgetsDefinitionElement) definitionLoader.unmarshall(value);
hierarchyEditor.processXml(value);
List<XmlValidationError> xmlValidationErrors = unmarshall.validate();
if (xmlValidationErrors != null && !xmlValidationErrors.isEmpty()) {
getApplication().getMainWindow().showNotification(getLocalizedMessage("validation-errors"),
joinValidationErrors(xmlValidationErrors),
Window.Notification.TYPE_ERROR_MESSAGE);
} else {