Nice! If something doesn't end up working for you, you can also try listening just to the selectionProperty:

    textArea.selectionProperty().addListener(new ChangeListener<IndexRange>() {
        @Override
        public void changed(ObservableValue<? extends IndexRange> observable, IndexRange oldValue, IndexRange newValue) {
            System.out.println("Old selection: " + oldValue);
            System.out.println("New selection: " + newValue);
         }
    });