Hi, I have found an "issue" (open to debate) where the HeaderBar's nodes are pushed out of view. This issue is easily reproduced by wrapping a scene's root node in a StackPane (something that is common for ControlsFx to do, as an example, & without the developer even being aware -- I suspect other libraries do something similar).
Although the observed behaviour is arguably logically correct, I think this should be preventable (e.g, HeaderBar has/gets special meaning/treatment). Example: run the below code, vertically resize the window, notice the header/title bar stays in place. Click the button and resize the window again and notice the title bar clips off the screen simply by making minor vertical size adjustments. The window icons remain present. public class DisappearingHeaderBug extends Application { @Override public void start(Stage primaryStage) { BorderPane root = new BorderPane(); Button button = new Button("Click for \"bug()\"!"); button.setOnAction(_ -> bug(root)); final VBox vbox = new VBox(120, new Label("Something above..."), button, new Label("Something below...")); root.setCenter(vbox); root.setTop(getHeaderBar()); // root.setTop(new Label("!!! Label !!!")); // This is fine, though primaryStage.initStyle(StageStyle.EXTENDED); primaryStage.setScene(new Scene(root, 300, 500)); primaryStage.show(); } // Wrapping the root node in a stackpane is common private void bug(Pane root) { StackPane stackPane = new StackPane(); root.getScene().setRoot(stackPane); stackPane.getChildren().addFirst(root); } private HeaderBar getHeaderBar() { HeaderBar headerBar = new HeaderBar(); headerBar.setCenter(new Label(" --- HeaderBar ---")); headerBar.setLeading(new Label("L")); return headerBar; } public static void main(String[] args) { launch(args); } } Sample video: https://github.com/user-attachments/assets/93a320a5-0010-4941-a2a4-9e0e65cbd57d I am using this latest HeaderBar/EXTENDED code, from this separate PR: https://github.com/openjdk/jfx/pull/1831 The above issue also occurs simply by using ControlsFx's input field validation, because, unbeknownst to the developer, ControlsFx ultimately wraps the scene's root node in a DecorationPane (which is a StackPane). I feel like HeaderBar + EXTENDED should somehow be given special treatment to remain static and visible and not susceptible to breaking. I do not know if I'd consider this as "bug" or not -- or if there's an easy fix or not -- but it would prevent the usefulness of HeaderBar & EXTENDED if there's no way to overcome it. Kind Regards, Cormac