[JAVA][Beginning Java 8 Games Development]

Chapter 6 ■ The Foundation of Game Design: The JavaFX Scene Graph and the InvinciBagel Game Infrastructure
You will be using the constructor that offers unequal insets values, which would look very unprofessional if you
were framing a picture! The Java class hierarchy for the Insets class starts with the java.lang.Object master class and
uses this class to create the javafx.geometry.Insets class. As Figure 6-4 illustrates (l. 5), Insets is contained in the
JavaFX geometry package, just like the Pos class, and uses the following class hierarchy structure:
java.lang.Object
> javafx.geometry.Insets
The Insets class furnishes a set of four double offset values specifying the four sides (top, right, bottom, left)
of a rectangle, which should be specified in that order within the constructor method. You will be using the Insets
class (object) to fine-tune the position of the Button control bank, which you will be creating using the HBox layout
container. Think of these Insets objects as a way to draw a box inside another box, which shows the spacing that you
want the objects inside the rectangle to “respect” around its edges. The simple constructor for an Insets object would
use the following format:
Insets(double topRightBottomLeft)
This constructor uses a single value for all the spacing sides (topRightBottomLeft), and an overloaded
constructor allows you to specify each of these values separately, like this:
Insets(double top, double right, double bottom, double left)
These values need to be specified in this order. An easy way to remember this is by using an analog clock. A clock
has “12” at the top, “3” at the right, “6” at the bottom, and “9” at the left. So, starting at high noon (for you western
genre lovers out there), always work clockwise, the way the hands move around a clockface, and you will have a great
way to remember how to specify the Insets values in the “uneven values” constructor method. You will soon be using
the Insets class to position the Button control bank, which are initially “stuck” in the bottom-left corner of the splash
screen design, away from the left-hand side and bottom of the screen, using two of these four insets positioning
parameters.
The JavaFX HBox Class: Using a Layout Container in a Design
Because Button objects cannot be positioned easily, I will be placing the four Button objects in a layout container from
the javafx.scene.layout package called HBox, which stands for Horizontal Box. This public class arranges things in
a row, and because you want the buttons to be aligned at the bottom of the splash screen, you use the Parent node for
four Button control nodes, which will become children (leaf nodes) of this HBox branch node. This will create a bank
of UI buttons that can be positioned (moved around) together as a single unit of the splash screen design.
An HBox class is a public class that directly extends the javafx.layout.Pane superclass, which in turn extends a
javafx.layout.Region superclass. The javafx.layout.Region superclass extends a javafx.scene.parent superclass, which
in turn extends a javafx.scene.Node superclass, which extends the java.lang.Object masterclass. As Figure 6-4
shows (l. 11), HBox is contained in the javafx.scene.layout package, just like the StackPane class, and it uses the
following class hierarchy structure:
java.lang.Object
> javafx.scene.Node
> javafx.scene.Parent
> javafx.scene.layout.Region
> javafx.scene.layout.Pane
> javafx.scene.layout.HBox
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