[JAVA][Beginning Java 8 Games Development]

Chapter 11 ■ Moving Your Action Figure in 2D: Controlling the X and Y Display Screen Coordinates
Figure 11-13. Add four if statements to the .update() method, one for each right, left, down, and up boolean variable
Next, let’s move an iBagel on the screen using the ImageView .setTranslateX() and .setTranslateY() methods.
Moving a Scene Graph ImageView Node: .setTranslateX( ) and .setTranslateY( )
Now that we have the conditional statements in place that will process where our InvinciBagel is supposed to be on
the screen based on what arrow keys (or ASDW keys) are being held down (or not held down) by the player, let’s add
the Java programming statements that will take this data from our InvinciBagel iX and iY variables, and pass this
sprite location information to the spriteFrame ImageView Node object, to actually have it reposition the Node on the
display screen. The .setTranslateX() and .setTranslateY() methods are part of the Node superclass’s transformation
methods. These methods also include method calls that will rotate and scale a Node object; in this case, it is the Actor
spriteFrame ImageView Node that contains one of the Image assets held in your List ArrayList object.
When we call these .setTranslate() methods, off of our iBagel object’s spriteFrame ImageView Node object, we
are referring to the spriteFrame ImageView object that we installed inside of the abstract Actor superclass. Since an
Actor superclass was used to create the Hero superclass, which was used to create the Bagel class, the spriteFrame
ImageView object can be referenced inside of the Bagel class by using a spriteFrame.setTranslateX(iX) statement, as
is shown in the following Java code for the completed .update() method, which is also shown in Figure 11-14:
public void update() {
if(right) { iX += vX }
if(left) { iX -= vX }
if(down) { iY += vY }
if(up) { iY -= vY }
spriteFrame.setTranslateX(iX);
spriteFrame.setTranslateY(iY);
}
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