Building Dynamic UI Layouts in JavaFX - JavaFX 8: A Definitive Guide to Building Desktop, Mobile, and Embedded Java Clients - page 192

Listing 5-2. Example of Centering Text in a Scene

public class CenterUsingBind extends Application {

public static void main(String[] args) {
launch(args);
}
@Override
public void start(Stage primaryStage) {
Text text = new Text("JavaFX Reversi");
text.setTextOrigin(VPos.TOP);
text.setFont(Font.font(null, FontWeight.BOLD, 18));
Scene scene = new Scene(new Group(text), 400, 100);
text.layoutXProperty().bind(scene.widthProperty().subtract(text.prefWidth(-1)).divide(2));
text.layoutYProperty().bind(scene.heightProperty().subtract(text.prefHeight(-1)).divide(2));
primaryStage.setScene(scene);
primaryStage.show();
}
}

Here are some specific points to highlight about Listing 5-2:

textOrigin property of Text is BASELINE , which aligns to the bottom
of the letters, not including descenders. We chose to use TOP instead, which makes the origin
line up with the top of the letters. This makes Text behave similarly to most other Nodes , and is
much easier to center.

• The default value for the

Text node to a Group to add it to the Scene , which expects a container
of type Parent . There are better options than using a Group , as we show in the next section,
because this disables any automatic resizing.

• We have to add the

prefWidth and prefHeight we pass in a parameter of -1 for the
counterdimension, because this does not affect the returned dimensions for Text nodes. ( Text
nodes have no content bias.)

• When getting the

Running this program produces a window where the title stays centered even if you resize the frame, as shown in
Figure 5-4 .

Figure 5-4. A Text node centered within a Scene using bind