JavaFX: How can I best place a Label centered in a Shape?

Question

Let's say I already have a Shape on the screen. For example:

Circle circle = new Circle(x, y, radius);
circle.setFill(Color.YELLOW);
root.getChildren().add(circle);

I would like to create a Label "over" that Circle such that the Label is centered in the Circle, the font size is maximized to fit inside the Circle, etc.

I can see how this could be accomplished via binding, but that seems needlessly complicated if the position/size of these things will never change during runtime.

Thank you in advance for your help! I'm very new to JavaFX and not all that experienced at programming in the first place, so I apologize if I should've been able to find this out via my research.

Answer 1

Use a StackPane to automatically center the text on top of the shape.

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.*;
import javafx.scene.layout.StackPane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.text.*;
import javafx.stage.Stage;

// java 8 code.
public class Circular extends Application {
    public static void main(String[] args) throws Exception {
        launch(args);
    }

    @Override
    public void start(final Stage stage) throws Exception {
        Text   text   = createText("Xyzzy");
        Circle circle = encircle(text);

        StackPane layout = new StackPane();
        layout.getChildren().addAll(
                circle,
                text
        );
        layout.setPadding(new Insets(20));

        stage.setScene(new Scene(layout));
        stage.show();
    }

    private Text createText(String string) {
        Text text = new Text(string);
        text.setBoundsType(TextBoundsType.VISUAL);
        text.setStyle(
                "-fx-font-family: \"Times New Roman\";" +
                "-fx-font-style: italic;" +
                "-fx-font-size: 48px;"
        );

        return text;
    }

    private Circle encircle(Text text) {
        Circle circle = new Circle();
        circle.setFill(Color.ORCHID);
        final double PADDING = 10;
        circle.setRadius(getWidth(text) / 2 + PADDING);

        return circle;
    }

    private double getWidth(Text text) {
        new Scene(new Group(text));
        text.applyCss();

        return text.getLayoutBounds().getWidth();
    }
}

Related

• how to put a text into a circle object to display it from circle's center?

The answer to the related question discusses different bounds types for text (such as Visual bounds), in case you need that.

Answer 2

StackPane stackPane = new StackPane();
Circle circle = new Circle();
Label label = new Label("Hi");
circle.setFill(Color.GOLD);
circle.setStroke(Color.GRAY);
circle.radiusProperty().bind(label.widthProperty());
stackPane.getChildren().addAll(circle, label);