[JAVA][Beginning Java 8 Games Development]

Chapter 9 ■ Controlling Your Action Figure: Implementing Java Event Handlers and Using Lambda Expressions
Processing Your KeyEvent: Using the Switch-Case Statement
KeyEvent object processing is a perfect application for implementing Java’s highly efficient switch-case statement.
We can add a case statement for each type of KeyCode constant that is contained inside of any KeyEvent (named event)
that is passed into the .handle() method. A KeyCode can be extracted from a KeyEvent object using a .getCode()
method. This method is called on the KeyEvent object named event, inside of the switch() evaluation area. Inside of
the switch{} body, the case statements compare themselves against this extracted KeyCode constant, and if there is a
match, the statements after the colon are processed. The break; statement allows processing to exit the switch-case
evaluation, as an optimization.
This event handling switch-case structure should be implemented by using the following Java programming
structure, which is also shown highlighted in Figure 9-10:
scene.setOnKeyPressed(new EventHandler() {
@Override
public void handle(KeyEvent event) {
switch (event.getCode()) {
case UP: up = true; break;
case DOWN: down = true; break;
case LEFT: left = true; break;
case RIGHT: right = true; break;
}
}
});
Figure 9-10. Add a switch-case statement inside of the public void handle() method setting Boolean direction variables
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