JavaFX VBox and HBox layouts - layout

Question

I'm working on a JavaFX application which has a layout generated from an external data structure, composed of
displaying components that know their own aspect ratios (height as a dependent of width)
2 types of structural components that
display all children with an equal width across their page, each child up as much vertical space as needed
display all children down the page using the full width and taking as much vertical space as needed
But I'm finding things aren't displaying as I expect. I've made a simplified case that demonstrates the problem.
The code is below, and the problem is that v3 doesn't get displayed, and I can't for the life of me work out why. I guess there's some facet of VBoxes and HBoxes that I haven't understood.
I'd really appreciate any help or ideas. Thanks in advance!
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Priority;
import javafx.scene.layout.Region;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
import java.util.Random;
public class Test extends Application {
static Random rand = new Random();
public static void main(String args[]) {
Application.launch("something");
}
#Override
public void start(Stage mainStage) throws Exception {
testVBoxes(mainStage);
}
private void testVBoxes(Stage mainStage) {
VBox root = new VBox();
Scene one = new Scene(root, 800, 600, Color.WHITE);
FixedAspectRatioH h1 = new FixedAspectRatioH();
FixedAspectRatioH h2 = new FixedAspectRatioH();
FixedAspectRatioH h3 = new FixedAspectRatioH();
FixedAspectRatioV v1 = new FixedAspectRatioV();
FixedAspectRatioV v2 = new FixedAspectRatioV();
FixedAspectRatioV v3 = new FixedAspectRatioV();
h1.prefWidthProperty().bind(root.widthProperty());
h2.add(v2);
v1.add(h3);
v1.add(h2);
h1.add(v1);
h1.add(v3);
root.getChildren().add(h1);
mainStage.setScene(one);
mainStage.show();
}
private class FixedAspectRatioV extends VBox {
public FixedAspectRatioV() {
Rectangle r = new Rectangle();
r.setFill(Color.rgb(rand.nextInt(256), rand.nextInt(256), rand.nextInt(256)));
r.widthProperty().bind(widthProperty());
r.heightProperty().bind(r.widthProperty().divide(3));
getChildren().add(r);
}
public void add(Region n) {
n.prefWidthProperty().bind(widthProperty());
getChildren().add(n);
}
}
private class FixedAspectRatioH extends HBox {
public FixedAspectRatioH() {
Rectangle r = new Rectangle();
r.setFill(Color.rgb(rand.nextInt(256), rand.nextInt(256), rand.nextInt(256)));
r.widthProperty().bind(widthProperty().divide(4));
r.heightProperty().bind(r.widthProperty());
getChildren().add(r);
}
public void add(Region n) {
HBox.setHgrow(n, Priority.ALWAYS);
getChildren().add(n);
}
}
}

Answer 1

its 2 years but the solution is you forgot
Node.setPrefSize(width,height);
and also add this to your constructor Hbox.setFillHeight(true);