Many hand rolled properties in JavaFX could benefit from using this base class (it may have been added later).

A typical pattern is that a super class of ReadOnly*PropertyBase is extended (ReadOnly*Property for example), and that all of the methods offered by the base subclass are implemented again (the base class offers implementations for the add and remove listener methods).

An example from Node:

    private static abstract class LazyTransformProperty
            extends ReadOnlyObjectProperty<Transform> {

        private ExpressionHelper<Transform> helper;

        @Override
        public void addListener(InvalidationListener listener) {
            helper = ExpressionHelper.addListener(helper, this, listener);
        }

        @Override
        public void removeListener(InvalidationListener listener) {
            helper = ExpressionHelper.removeListener(helper, listener);
        }

        @Override
        public void addListener(ChangeListener<? super Transform> listener) {
            helper = ExpressionHelper.addListener(helper, this, listener);
        }

        @Override
        public void removeListener(ChangeListener<? super Transform> listener) {
            helper = ExpressionHelper.removeListener(helper, listener);
        }

        public void invalidate() {
            if (valid != INVALID) {
                valid = INVALID;
                ExpressionHelper.fireValueChangedEvent(helper);
            }
        }

This would become:

    private static abstract class LazyTransformProperty
            extends ReadOnlyObjectPropertyBase<Transform> {

        public void invalidate() {
            if (valid != INVALID) {
                valid = INVALID;
                fireValueChangedEvent();
            }
        }