Set Style & Font Size of Full Screen Exit Hint, JavaFX

Question

You're familiar with the "press esc to exit full screen" message.

In JavaFX, there is the method:

Stage stage = new Stage();
stage.setFullScreenExitHint("whatever you want it to say, instead of 'press esc to exit full screen.');

I'm using it to display an instructional message for the user, just because it's so easy, pre-made, well formatted, and goes away after a short time. It works great, but after maybe 15 words the text overflows:

I was thinking it could be fixed by setting the font size. In JavaFX, you do this by

Node node = new Node();
node.setStyle("-fx-font-size:___pt");//or px, rem, em.

How do you change that message's style - if at all possible?

The requested minimal reproducible example:

import javafx.application.Application;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.layout.Border;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;

import java.io.IOException;

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws IOException {
        Parent root = new BorderPane();
     
        primaryStage.setFullScreen(true);
        primaryStage.setFullScreenExitHint("""
                Welcome to Minesweeper. At left, you can alter the # of rows and columns. At right, set the # of mines. Play is bottom right.
                                
                                
                                
                                
                _
                """);

        Scene scene = new Scene(root);

        primaryStage.setScene(scene);
        primaryStage.show();


    }
    public static void main(String[] args) {
        launch(args);
    }

}

Answer 1

Trying to reuse the existing functionality is not a bad idea. But unfortunately this cannot be applied here, because you don't have any control over the message box displayed for full screen. This cannot be done even with the node lookup/traversing to find the correct node, because the message box is not part of the scene graph.

You might be wondering then how it is rendered, its the internal implementation in Scene to provide the box directly to the "Painter" to paint it over the screen.

So instead of relying on "setFullScreenExitHint" method, I would recommend to create your own message box so that you will have full control over all the parameters (display duration, location, font size, styles...).

Below is a full working demo of a custom message box shown on full screen:

import javafx.animation.FadeTransition;
import javafx.animation.PauseTransition;
import javafx.animation.SequentialTransition;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.layout.StackPane;
import javafx.stage.Popup;
import javafx.stage.Stage;
import javafx.util.Duration;

public class FullScreenStageDemo extends Application {
    @Override
    public void start(Stage primaryStage) throws Exception {
        StackPane root = new StackPane();
        // Adding a busy background, to showcase the transparency of the message box.
        root.setStyle("-fx-background-color: linear-gradient(from 41px 34px to 50px 50px, reflect, #ff7f50 30%, #faebd7 47%);");
        primaryStage.setScene(new Scene(root));
        primaryStage.setTitle("Full Screen Stage");
        primaryStage.setFullScreen(true);
        primaryStage.setFullScreenExitHint(""); // Setting empty string will not show the default message box
        primaryStage.setOnShown(e->{
            Duration displayDuration = Duration.millis(5000); // Adjust as per your need

            Label msg = new Label("Welcome to Minesweeper. At left, you can alter the # of rows and columns. At right, set the # of mines. Play is bottom right.");
            msg.setWrapText(true);
            msg.setStyle("-fx-font-size:15px;-fx-font-family:verdana;-fx-text-fill:#FFFFFF;");

            StackPane box = new StackPane(msg);
            box.setMaxWidth(500);
            box.setStyle("-fx-padding:20px;-fx-background-radius:5px,4px;-fx-background-color:#33333380,#AAAAAA60;-fx-background-insets:0,2;");

            Popup popup = new Popup();
            popup.getContent().add(box);
            popup.show(primaryStage);

            PauseTransition pause = new PauseTransition(displayDuration);
            FadeTransition fade = new FadeTransition(Duration.millis(1000), box);
            fade.setFromValue(1);
            fade.setToValue(0);

            SequentialTransition overlayTransition = new SequentialTransition();
            overlayTransition.getChildren().addAll(pause,fade);
            overlayTransition.setOnFinished(event -> popup.hide());
            overlayTransition.play();
        });
        primaryStage.show();
    }
}