JavaFX Class controller Stage/Window reference

Question

Is there any way of getting the Stage/Window object of an FXML loaded file from the associated class controller?

Particularly, I have a controller for a modal window and I need the Stage to close it.

Answer 1

@FXML
private Button closeBtn;
Stage currentStage = (Stage)closeBtn.getScene().getWindow();
currentStage.close();

Another way is define a static getter for the Stage and Access it

Main Class

public class Main extends Application {
    private static Stage primaryStage; // **Declare static Stage**

    private void setPrimaryStage(Stage stage) {
        Main.primaryStage = stage;
    }

    static public Stage getPrimaryStage() {
        return Main.primaryStage;
    }

    @Override
    public void start(Stage primaryStage) throws Exception{
        setPrimaryStage(primaryStage); // **Set the Stage**
        Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
        primaryStage.setTitle("Hello World");
        primaryStage.setScene(new Scene(root, 300, 275));
        primaryStage.show();
    }
}

Now you Can access this stage by calling

Main.getPrimaryStage()

In Controller Class

public class Controller {
public void onMouseClickAction(ActionEvent e) {
    Stage s = Main.getPrimaryStage();
    s.close();
}
}

Answer 2

I could not find an elegant solution to the problem. But I found these two alternatives:

• Getting the window reference from a Node in the Scene

  @FXML private Button closeButton ;
  
  public void handleCloseButton() {
    Scene scene = closeButton.getScene();
    if (scene != null) {
      Window window = scene.getWindow();
      if (window != null) {
        window.hide();
      }
    }
  }
  

• Passing the Window as an argument to the controller when the FXML is loaded.

  String resource = "/modalWindow.fxml";
  
  URL location = getClass().getResource(resource);
  FXMLLoader fxmlLoader = new FXMLLoader();
  fxmlLoader.setLocation(location);
  fxmlLoader.setBuilderFactory(new JavaFXBuilderFactory());
  
  Parent root = (Parent) fxmlLoader.load();
  
  controller = (FormController) fxmlLoader.getController();
  
  dialogStage = new Stage();
  
  controller.setStage(dialogStage);
  
  ...
  

  And FormController must implement the setStage method.