Javafx Popup can't get focus if other application gains focus - javafx

Question

I use a JavaFX Popup in my application to change the Shipping Address of a customer. That often requires copy pasting the Address from the web browser. If I click on the Popup after the application lost focus it will not regain focus. I first need to click the parent window behind the popup and then click the Popup again to be able to interact with it.
Is there any way to solve that problem, besides using an undecorated stage instead of a Popup?
EDIT:
Here I made a minimal example:
public class HelloApplication extends Application {
#Override
public void start(Stage stage) throws IOException {
Scene scene = new Scene(new VBox(), 600, 600);
stage.setTitle("Hello!");
stage.setScene(scene);
stage.show();
Popup popup = new Popup();
Button btn = new Button("This is a very nice button!");
btn.setOnAction(actionEvent -> System.out.println("button clicked"));
TextField textField = new TextField();
textField.setOnMouseClicked(mouseEvent -> System.out.println("textField clicked"));
VBox popupVBox = new VBox(btn, textField);
popupVBox.setStyle("-fx-background-color: white");
popupVBox.setPadding(new Insets(10));
popup.getContent().add(popupVBox);
popup.show(scene.getWindow());
}
public static void main(String[] args) {
launch();
}
}
If you click outside of the application (for example the web browser, to copy some value) then you can not enter Text into the TextField anymore. The button action listener and even the TextField mouse Listener still work and output "button clicked" and "textField clicked" but the blue halo around them does not apppear and you can not enter (or paste) text into the TextField. After you click somewhere on the main Stage of the application it works again.
I tried adding textField.requestFocus();
to the mouse Listener of the textfield but that does not do anything.
EDIT 2 after the comment from kleopatra:
I tried adding the following code:
popupVBox.setOnMouseEntered(mouseEvent -> {
popup.getOwnerWindow().requestFocus();
parentVBox.toFront(); //This is created above and passed to the new Scene instead of diectly passing new VBox() as in the code snippet posted above
});
With that code added, popup and its children seem to have focus if the mouse is hoverd over it after an other application had focus, i.e. if clicked with the mouse the blue border appears around the button and textField, and if there is any text in the textField I can move the cursor with the mouse and select the text with the mouse, buy any keyboard inputs are ignored. Actually they are executed in the other application which had focus before. If I ctrl+c in Intellij and try to ctrl+v into the textfield it will be pasted to the Intellij editor. Also the arrow keys move the cursor in the intellij window instead of the textField.
The only way to be able to type anything in the TextField is to click the parent window first.
Also
textField.setOnMouseClicked(mouseEvent -> {
textField.requestFocus();
});
does not do anything

Answer 1

not an answer, just to clarify the comment (will delete if seen by OP :)
public class PopupFocus extends Application {
#Override
public void start(Stage stage) throws IOException {
Scene scene = new Scene(new VBox(), 300, 300);
stage.setTitle("Hello!");
stage.setScene(scene);
stage.setX(10);
stage.show();
Popup popup = new Popup();
Button btn = new Button("This is a very nice button!");
btn.setOnAction(actionEvent -> System.out.println("button clicked"));
TextField textField = new TextField();
textField.setOnMouseClicked(mouseEvent -> {
System.out.println("textField clicked");
stage.toFront();
});
VBox popupVBox = new VBox(btn, textField);
popupVBox.setStyle("-fx-background-color: white");
popupVBox.setPadding(new Insets(10));
popup.getContent().add(popupVBox);
// original
popup.show(scene.getWindow());
}
public static void main(String[] args) {
launch();
}
}