[JAVA][Beginning Java 8 Games Development]

Chapter 7 ■ The Foundation of Game Play Loop: The JavaFX Pulse System and the Game Processing Architecture
Figure 7-19. Current invincibagel package, class, and object hierarchy, after addition of the GamePlayLoop
Next, , before moving on to the GamePlayLoop AnimationTimer class and object, you are going to place some
relatively simple Java code inside the currently empty .handle() method. You will do this to make sure that the pulse
engine is processing and to see just how fast 60FPS is! (I have to admit, my curiosity is getting the best of me!).
Testing the GamePlayLoop: Animating the UI Container
Let’s move one of the existing Scene Graph nodes, for example, the HBox layout container parent (branch) node,
which contains the four UI Button control elements, counterclockwise around the InvinciBagel splash screen. You will
do this by using a simple if-else Java loop control programming structure to read (using a .get() method) and control
(using a .set() method) Pos constants that control (in this case) the corner of the screen placement.
First, declare a Pos object named location at the top of the GamePlayLoop class. Then, click on the error message
highlighting, press Alt+Enter, and select the Import Pos class option so that NetBeans will write your import
statement for you. Next, inside the .handle() method, add an if-else conditional statement that evaluates this Pos
object named location and compares it with the four Pos class constants that represent the four corners of the display
screen, including BOTTOM_LEFT, BOTTOM_RIGHT, TOP_RIGHT, and TOP_LEFT. Your Java code should look like
the following if-else conditional statement Java program structure (see also Figure 7-20):
Pos location;
@Override
public void handle(long now) {
location = InvinciBagel.buttonContainer.getAlignment();
if (location == Pos.BOTTOM_LEFT) {
InvinciBagel.buttonContainer.setAlignment(Pos.BOTTOM_RIGHT);
} else if (location == Pos.BOTTOM_RIGHT) {
InvinciBagel.buttonContainer.setAlignment(Pos.TOP_RIGHT);
} else if (location == Pos.TOP_RIGHT) {
InvinciBagel.buttonContainer.setAlignment(Pos.TOP_LEFT);
} else if (location == Pos.TOP_LEFT) {
InvinciBagel.buttonContainer.setAlignment(Pos.BOTTOM_LEFT);
}
}
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