java - Opening a new FXML attached to the current stage - JavaFX

Question

This is an extension of an SO question in which a file chooser opens and is attached to the primary stage.

How would one go about opening an FXML stage attached to the the primary stage?

The code below loads the FXML and replaces the primaryStage (current stage). How can I load it as an attached window instead?

            Stage stage = (Stage)((Node) event.getTarget()).getScene().getWindow();
            Parent parent = null;
            try {
                parent = FXMLLoader.load(getClass().getResource("/gui/GUpdater-progress.fxml"));
            } catch (IOException e) {
                e.printStackTrace();
            }
            Scene scene = new Scene(parent,600,400);
            stage.setResizable(false);
            stage.setTitle("GUpdater");
            stage.setScene(scene);
            stage.show();

Answer 1

Given your previous question, I imagine that by "attach" you mean something like what the File Chooser does (when there is a parent, the File Chooser will follow it around).

The first thing you need is the "main window", which you can get via

       Window ownerWindow = ((Node) event.getTarget()).getScene().getWindow();

The next thing is to actually load your new stage.

       Stage stage = new Stage();
       stage.initModality(Modality.APPLICATION_MODAL);
       stage.initOwner(ownerWindow);
       Parent root = FXMLLoader.load(getClass().getResource("/gui/GUpdater-progress.fxml"));
       Scene scene = new Scene(root, 600, 400);
       stage.setTitle("GUpdater");
       stage.setScene(scene);
       stage.show();

The key is the stage.initOwner(ownerWindow) part. This new stage you are creating is "owned by" the original window, which is ownerWindow.

In addition, if you want to achieve a feel more like the File Chooser's, you should use

       stage.initStyle(StageStyle.UNDECORATED);

Before setScene() is called. This will remove the border.