Introduce a new method to the JavaFX property API:

    public interface ReadOnlyProperty<T> extends ObservableValue<T> {
        Class<?> getDeclaringClass();
    }

In addition, add the following interface:

    public interface AttachedProperty {
        Class<?> getTargetClass();
    }

The new API allows applications, frameworks, and tools to inspect the declaring class of a property instance, and to detect attached properties (via instanceof AttachedProperty) and discover their target class. This naturally complements the existing property metadata API (getBean() and getName()).