[JAVA][Beginning Java 8 Games Development]

Chapter 11 ■ Moving Your Action Figure in 2D: Controlling the X and Y Display Screen Coordinates
You could also, later on, create a method for Image sprite List object loading. This would pass the
ArrayList as a parameter, instead of a comma-delimited List. Note that if you did this, you would also need to change
your Actor abstract class constructor to take in an ArrayList object, instead of an Image... List of Image objects.
Next, let’s take a look at how we add our newly created iBagel object into our game’s Scene Graph object, which is
currently a Stackpane object named root.
Adding Your iBagel to the Scene Graph: .addGameActorNodes()
One of the steps that JavaFX application developers often forget is to add their objects that will need to be displayed
in the Scene (and on the Stage that the Scene object is attached to) to the root object of the Scene Graph. In our case,
this is a StackPane object named root. We will need to use the same root.getChildren().add() method call chain
that we did in Chapter 6, when we started developing our Splashscreen, to add our iBagel object ImageView, which
is referenced using iBagel.spriteFrame, to the Scene Graph root object. I am going to add a method at this stage that
will ensure that we never forget this important add to Scene Graph step in our work process. I am going to specifically
address this stage in the Actor creation work process by making it into its own method, which I am going to call
.addGameActorNodes(). The creation of this method body, and our first add Actor to Scene Graph programming
statement, would be accomplished using the following Java code, which is also shown (highlighted) in Figure 11-7:
private void addGameActorNodes() {
root.getChildren().add(iBagel.spriteFrame);
}
Figure 11-7. Create a private void addGameActorNodes() method; .add() iBagel.spriteFrame ImageView to root object
It is important to note that I am calling this .addGameActorNodes() method, at the top of the InvinciBagel class,
inside of the .start() method, before I call the .addNodesToStackPane() method. There is a very good reason for doing
this, and it goes back to what you learned about JavaFX in Chapter 4. Remember the objects that you add to the
StackPane layer management object are displayed using a Z-index (or Z-order), which means that they are “stacked”
on top of each other. If any of these layers do not have an alpha channel, which we learned about in Chapter 5, then
nothing behind them will be able to show through! For this reason, the easiest way to get our Splashscreen to overlay
our game at any point in time that a player clicks the INSTRUCTIONS Button control object is to add these assets last.
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