[JAVA][Beginning Java 8 Games Development]

Chapter 9 ■ Controlling Your Action Figure: Implementing Java Event Handlers and Using Lambda Expressions
Next, let’s use a block copy and paste operation, and copy the .OnKeyPressed() KeyEvent handing structure
underneath itself, changing it to be an .OnKeyReleased KeyEvent handling structure, with false values instead of true.
Creating the KeyPressed KeyEvent Handling Structure
The next thing that we will need to do is to create the polar opposite of the OnKeyPressed structure, and create the
OnKeyReleased structure. This will use the same code structure, except that the true values will become false values,
and the .setOnKeyPressed() method call will instead be a .setOnKeyReleased() method call. The easiest way to do this
is to select the .setOnKeyPressed() structure, and copy and paste it underneath itself. The Java code, which is shown in
Figure 9-12, should look like this Java structure:
scene.setOnKeyReleased(KeyEvent event) -> {
switch (event.getCode()) {
case UP: up = false; break;
case DOWN: down = false; break;
case LEFT: left = false; break;
case RIGHT: right = false; break;
}
});
Figure 9-12. Use a block copy and paste operation to create .setOnKeyReleased() code block, using .setOnKeyPressed()
One of the interesting things that using lambda expressions does by “implicitly” declaring and using classes, such
as the EventHandler class in the instances in this chapter, is that it reduces the number of import statements in the
top of your class code. This is because if a class is not specifically used (its name written) in your code, the import
statement for that class does not have to be in place at the top of your code with the other import statements.
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