displaying a tooltip in javafx brings its stage into the foreground

Selim :

I am trying to work around this bug in the jdk: http://bugs.java.com/bugdatabase/view_bug.do?bug_id=8088624

public class Blubb extends Application {
    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage primaryStage) throws Exception {
        Button btn = new Button("Click");
        btn.setTooltip(new Tooltip("Blubb"));

        Scene scene = new Scene(new BorderPane(btn), 320, 240);
        primaryStage.setScene(scene);
        primaryStage.show();

        Stage secondStage = new Stage();
        secondStage.setScene(new Scene(new BorderPane(new Button("Click")), 320, 240));
        //secondStage.initOwner(primaryStage);
        secondStage.show();
    }
}

If the button on the primary stage is hovered, it will come in front of the second stage. I found that calling initOwner() on a Stage will eliminate this behavior.

Now my problem is following: I have multiple "popups" that have a common owner (the primary stage). Hovering over controls on the primary stage doesn't cause any unexpected behavior after the initOwner() workaround. If you however hover over controls in a popup while another popup was in focus, the hovered popup will steal focus.

Is there a way I can work around this bug for not only the primary stage but also the popups?

UPDATE: turns out my workaround has undesired side-effects. Javadocs for Stage state following:

A stage will always be on top of its parent window.

So additionally, what would be a workaround that makes the popup not "always on top" and minimizable?

Matthew Wright :

There is a way to get around it by overlaying StackPanes. Create your Scene with a StackPane so that you can add another StackPane when the stage has lost its focus. The overlayed pane will prevent Tooltips or anything else happening on mouse-over while the pane is not in focus. You may also minimize any of your stages and they won't be always-on-top.

public class Blubb extends Application {

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

    @Override
    public void start(Stage primaryStage) throws Exception {
        Button button_1 = new Button("Button #1");
        button_1.setTooltip(new Tooltip("Blubb #1"));

        StackPane primary = new StackPane(new BorderPane(button_1));
        primaryStage.setScene(new Scene(primary, 320, 240));
        addStageFocusListener(primaryStage, primary);
        primaryStage.show();

        Button button_2 = new Button("Button #2");
        button_2.setTooltip(new Tooltip("Blubb #2"));

        StackPane second = new StackPane(new BorderPane(button_2));
        Stage secondStage = new Stage();
        addStageFocusListener(secondStage, second);
        secondStage.setScene(new Scene(second, 320, 240));
        secondStage.show();
    }

    public void addStageFocusListener(Stage stage, StackPane stackPane) {
        stage.focusedProperty().addListener(new ChangeListener<Boolean>(){
            public final StackPane preventTooltip = new StackPane();
            public void changed(ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean newValue) {
                if(stage.isFocused()) {
                    if(stackPane.getChildren().contains(preventTooltip)) {
                        stackPane.getChildren().remove(preventTooltip);
                    }
                } else {
                    stackPane.getChildren().add(preventTooltip);
                }
            }
        });
    }
}