Griffon/JavaFX - Adding a change listener to a text field Part 3 - reusing the closure across multiple text fields

gistfile1.groovy

import javafx.beans.value.ChangeListener
import javafx.beans.value.ObservableValue
import org.apache.commons.lang.StringUtils

// model
@FXBindable String amount1
@FXBindable String amount2

// view
textField(id: 'amount1', text: bind(model.amount1Property))
textField(id: 'amount2', text: bind(model.amount2Property))

noparent {
    amount1.textProperty().addListener(controller.restrictToNumber)
    amount2.textProperty().addListener(controller.restrictToNumber)
}

// controller
def restrictToNumber = { ObservableValue<? extends String> observable, String oldValue, String newValue ->
    try {
        if (StringUtils.isNotBlank(newValue)) {
            Integer.parseInt(newValue);
        }
    } catch (Exception e) {
        observable.setValue(oldValue);
    }
} as ChangeListener<String>