[JAVA][Beginning Java 8 Games Development]

Chapter 4 ■ An Introduction to JavaFX 8: Exploring the Capabilities of the Java 8 Multimedia Engine
}
@Override
public void stop() {
super.stop();
}
Next, let’s investigate the JavaFX Stage class (object),which is passed into your InvinciBagel .start() method!
JavaFX Screen and Window Control: Using javafx.stage Classes
The javafx.stage package contains classes that can be considered top level, in terms of the display for your JavaFX
application (in this case, a game). This display is at the top of the resulting game play, because it shows your game’s
scenes to the end user of your application. Inside the Stage object are Scene objects, and inside these are Scene Graph
Node objects, which contain the elements that make up an application.
In contrast, the classes that are in this package could be considered fairly low level, from an OS perspective;
these are the Stage, Screen, Window, WindowEvent, PopupWindow, Popup, DirectoryChooser, and FileChooser
classes as well as the FileChooser.ExtensionFilter nested class. These classes can be used to interface with the
device’s display hardware, and the OS software’s windowing management, file management, and directory (folder)
management functionality.
To get a description of the display hardware that is being used by the device that a JavaFX application is running
on, you will want to use the Screen class. This class supports multiscreen (commonly referred to as second screen)
scenarios, using the .getScreens() method, which can access an ObservableList object that will contain a list (array)
with all the currently available screens. A primary screen is accessed using the .getPrimary() method call. You
can get the physical resolution for the primary screen hardware by using a .getDpi() method call. There are also
.getBounds() and .getVisualBounds() method calls for usable resolution.
The Window superclass, and its Stage and PopupWindow subclasses, can be used by the JavaFX end user to
interact with your application. As you saw in Chapter 3 (see Figure 3-2), this is done using the Stage object named
primaryStage, which is passed into your .start() method, or using a PopupWindow (dialog, tool tip, context menu,
notification, and so on) subclass, such as a Popup or PopupControl object.
You can use the Stage class to create secondary stages within your JavaFX application programming logic.
A primary Stage object is always constructed by the JavaFX platform, using the public void start(Stage primaryStage)
method call, as you have already seen in Chapters 2 and 3 in the bootstrap JavaFX application created by NetBeans.
All JavaFX Stage objects must be constructed using, and modified inside the primary JavaFX application thread,
which I discussed in the previous section. Because a stage equates to a window on the OS platform it is running
on, certain attributes or properties are read-only, as they need to be controlled at the OS level; these are Boolean
properties (variables): alwaysOnTop, fullScreen, iconified, and maximized.
All Stage objects have a StageStyle attribute and a Modality attribute, which can be set using constants. The
stageStyle constants are StageStyle.DECORATED, StageStyle.UNDECORATED, StageStyle.TRANSPARENT, and
StageStyle.UTILITY. The Modality constants are Modality.NONE, Modality.APPLICATION_MODAL, and Modality.
WINDOW_MODAL. In the next section, I will show you how to do something really impressive using the StageStyle
attribute and the TRANSPARENT constant that will make your JavaFX applications stand out from everyone else’s in
the marketplace.
The Popup class can be used to create custom pop-up notifications, and even custom game components, from
scratch. Alternately, you can use the PopupControl class, and its ContextMenu and Tooltip subclasses, to provide
these predefined (coded) JavaFX UI controls.
The DirectoryChooser and FileChooser classes give support for passing through the standard OS file selection
and directory navigation dialogs into your JavaFX applications. The FileChooser.ExtensionFilter nested class offers a
utility for filtering the files that will come up in the FileChooser dialog, based on file type (file extension).
Next, let’s take your current InvinciBagel Stage object to the next level and make it a windowless (floating)
application. This is one of the impressive features of JavaFX that cannot be matched by Flash or other game engines.
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