JavaFX isn't hard to learn, and with the right IDE and a complete JavaFX tutorial to teach the core concepts, you'll be an expert in no time.

The counterProperty() method follows the JavaFX pattern for returning a property so that a client can bind to the property, install a change listener, and so on.

Get to know the JavaFX 2 libraries by way of a practical exercise: refactoring a Swing-based text editor into one that leverages the rich UI features of JavaFX (Part 2).