taken from field

The editable property is used to specify whether user input is able to be typed into the Spinner editor. If editable is true, user input will be received once the user types and presses the Enter key. At this point the input is passed to the SpinnerValueFactory converter javafx.util.StringConverter.fromString(String) method. The returned value from this call (of type T) is then sent to the SpinnerValueFactory.setValue(Object) method. If the value is valid, it will remain as the value. If it is invalid, the value factory will need to react accordingly and back out this change.