Automatically resizing the window based on dynamic content

Question

I am checking for a feature to automatically resize the window based on the content. I am already aware of Window.sizeToScene() method. But this is so cumbersome that I need to take care in every place to call the sizeToScene(). For example, when I add/remove nodes, when I expanded the titlePanes, etc...

Can someone let me know if it is possible to automatically adjust the window based on the content. I am looking this feature for both normal and transparent windows.

Any hints/suggestion is highly appreciated.

Please find below a quick demo of what I am looking for. Everything works as expected if I consider calling sizeToScene(). I am targeting for a way to get the same behavior without calling sizeToScene for every scenario.

import javafx.application.Application;
import javafx.application.Platform;
import javafx.beans.property.DoubleProperty;
import javafx.beans.property.SimpleDoubleProperty;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.CheckBox;
import javafx.scene.control.Label;
import javafx.scene.control.TitledPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
import javafx.stage.StageStyle;

public class TransparentWindowResizeDemo extends Application {
    @Override
    public void start(Stage stage) throws Exception {
        VBox root = new VBox();
        root.setSpacing(15);
        root.setAlignment(Pos.CENTER);

        Scene sc = new Scene(root, 300, 300);
        stage.setScene(sc);
        stage.show();

        Button showNormal = new Button("Show Normal Window");
        showNormal.setOnAction(e -> showWindow(false));

        Button showTransparent = new Button("Show Transparent Window");
        showTransparent.setOnAction(e -> showWindow(true));

        root.getChildren().addAll(showNormal, showTransparent);
    }

    private void showWindow(boolean isTransparent) {
        Stage window = new Stage();
        VBox root = new VBox();
        root.setStyle("-fx-background-color: grey; -fx-border-width:2px;-fx-border-color:black;");
        Scene scene = new Scene(root, Color.TRANSPARENT);
        window.setScene(scene);

        VBox layout = new VBox();
        layout.setSpacing(5);
        layout.setPadding(new Insets(5));

        CheckBox sizeToScene = new CheckBox("sizeToScene");
        sizeToScene.setSelected(true);

        StackPane box = new StackPane();
        box.setStyle("-fx-background-color:yellow; -fx-border-width:1px;-fx-border-color:black;");
        box.setMinSize(200, 100);
        box.setMaxSize(200, 100);

        Button add = new Button("Add Pane");
        Button remove = new Button("Remove Pane");
        remove.setDisable(true);
        add.setOnAction(e -> {
            layout.getChildren().add(box);
            add.setDisable(true);
            remove.setDisable(false);
            if (sizeToScene.isSelected()) {
                window.sizeToScene();
            }
        });
        remove.setOnAction(e -> {
            layout.getChildren().remove(box);
            add.setDisable(false);
            remove.setDisable(true);
            if (sizeToScene.isSelected()) {
                window.sizeToScene();
            }
        });
        HBox btnLayout = new HBox();
        btnLayout.setSpacing(5);
        btnLayout.getChildren().addAll(add, remove);

        StackPane tpContent = new StackPane();
        tpContent.setStyle("-fx-background-color:pink; -fx-border-width:1px;-fx-border-color:black;");
        tpContent.setMinSize(200, 100);
        tpContent.setMaxSize(200, 100);

        TitledPane tp = new TitledPane("Titled Pane", tpContent);
        tp.setAnimated(false);
        tp.expandedProperty().addListener((obs, oldVal, newVal) -> {
            if (sizeToScene.isSelected()) {
                window.sizeToScene();
            }
        });

        if (isTransparent) {
            window.initStyle(StageStyle.TRANSPARENT);

            StackPane close = new StackPane();
            close.setMaxWidth(30);
            close.setStyle("-fx-background-color:red;");
            close.getChildren().add(new Label("X"));
            close.setOnMouseClicked(e -> window.hide());

            DoubleProperty x = new SimpleDoubleProperty();
            DoubleProperty y = new SimpleDoubleProperty();
            StackPane header = new StackPane();
            header.setOnMousePressed(e -> {
                x.set(e.getSceneX());
                y.set(e.getSceneY());
            });
            header.setOnMouseDragged(e -> {
                window.setX(e.getScreenX() - x.get());
                window.setY(e.getScreenY() - y.get());
            });
            header.setStyle("-fx-border-width:0px 0px 2px 0px;-fx-border-color:black;");
            header.setMinHeight(30);
            header.setAlignment(Pos.CENTER_RIGHT);
            Label lbl = new Label("I am draggable !!");
            lbl.setStyle("-fx-text-fill:white;-fx-font-weight:bold;");
            StackPane.setAlignment(lbl,Pos.CENTER_LEFT);
            header.getChildren().addAll(lbl,close);
            root.getChildren().add(header);
        }

        layout.getChildren().addAll(sizeToScene, btnLayout, tp);
        root.getChildren().add(layout);
        window.show();

    }

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

Edit :: This is different from what I already found in other questions or with the link in the comment. The solution that is specified is what I am aware of and I already mentioned that in the question. I have a heavy screen where it contain many nodes in differnt hirerchy. I am checking for any generic solution to include in one place rather that calling from every node add/remove scenario.

Answer 1

I would say this is not a graceful solution (it's more like a hack), but at least it has worked using your example:

VBox root = new VBox() {
    private boolean needsResize = false;

    @Override
    protected void layoutChildren()
    {
        super.layoutChildren();

        if (!needsResize) {
            needsResize = true;

            Platform.runLater(() -> {
                if (needsResize) {
                    window.sizeToScene();
                    needsResize = false;
                }
            });
        }
    }
};

Of course, you should add in the sizeToScene.isSelected() part, and you could also make this an actual subclass.