[JAVA][Beginning Java 8 Games Development]

Chapter 9 ■ Controlling Your Action Figure: Implementing Java Event Handlers and Using Lambda Expressions
It is important to note that you do not have to use lambda expressions to replace traditional Java methods! In
fact, if you want your code to be compatible with Java 7, for instance, if you want your code to also work in Android
5.0, which uses Java 7, you do not have to utilize lambda expressions. However, since this is specifically a Java 8 game
development title, and since lambda expressions are the major new feature of Java 8, and since NetBeans will convert
your Java methods to lambda expressions for you, as you are about to see, I have decided to utilize them in this book.
Let’s take a closer look at the work process for getting NetBeans to convert your Java methods into lambda
expressions for you. As you can see in Figure 9-5, you currently have wavy yellow warning highlights in your code.
Figure 9-5. Mouse-over wavy yellow warning highlight, and reveal a “inner class can be turned into a lambda” pop-up
When you mouse-over these, they will give you a “This anonymous inner class creation can be turned into a
lambda expression,” message. This lets you know that NetBeans 8.0 may be willing to write some lambda expression
code for you, which is really nifty.
To find out, you’ll need to leverage your trusty Alt-Enter work process, and as you can see there is a lambda
expression option that will have NetBeans rewrite the code as a lambda expression. The original code looked like this:
gameButton.setOnAction(new EventHandler() {
@Override public void handle(ActionEvent event) {
splashScreenBackplate.setVisible(false);
splashScreenTextArea.setVisible(false);
}
});
192
The lambda expression that NetBeans codes is much more compact and looks like the following Java 8 code:
gameButton.setOnAction((ActionEvent event) -> {
splashScreenBackplate.setVisible(false);
splashScreenTextArea.setVisible(false);
});
www.it-ebooks.info