[JAVA][Beginning Java 8 Games Development]

Chapter 13 ■ Animating Your Action Figure States: Setting the Image States Based on KeyEvent Processing
To accomplish this, we need to use the Java Unary Exclamation Point ! operator. This reverses the Boolean
value, so in our case, a false value from one of these method calls would be represented by a !invinciBagel.isUp()
construct, for instance. To find out if more than one value is false at the same time, we’ll need to implement the Java
Conditional AND operator, which uses two consecutive ampersand characters, like this && so; in this case, we will
be using three of these && Conditional AND operators, to tell the Java compiler that we want Right AND Left AND
Down AND Up to all be false. All of this logic will go inside of the if() evaluation area (inside of the parenthesis). Inside
of the curly braces, where the statements go if the if() evaluation area is met (if up, down, left and right are all false),
we will set the spriteFrame ImageView object equal to the first Image object in the imageStates List object
using the .setImage() method call. Inside of that method call, we will use the .get() method call on the imageStates
List object, to get the first Image reference imageStates(0) from the List object. This is the “waiting”
sprite cel for the InvinciBagel, which shows him waiting impatiently to be moved (animated). The Java code for the
construct would look like the following Java programming structure (I have indented this for easier readability and
learning purposes):
if( !invinciBagel.isRight() &&
!invinciBagel.isLeft() &&
!invinciBagel.isDown() &&
!invinciBagel.isUp() ) {
spriteFrame.setImage(imageStates.get(0)); }
As is seen in Figure 13-2, this first if() statement, representing “if none of the arrow keys are being pressed,” is
error-free. If you use the Run ➤ Project work process, and test this code, you’ll get the same result as you did in the
previous chapter! To see if this code works we must first make the InvinciBagel run, so that when we stop moving him
using the arrow keys, we get this impatient “waiting” state, which actually makes it a lot more effective (funny), when
this wait is in the context of all this animated movement we’re about to implement during the course of the chapter!
Figure 13-2. Add a conditional if() statement that checks for no movement, and sets the wait sprite image state (zero)
Next let’s start to implement some of the other character image cels to try and get our character animating!
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