How to access a JavaFx Stage from a Controller?

Question

I\'m converting a pure JavaFx app, in which the code below worked fine when put all in one class, to a FXML one, where the Stage declaration and the button handler are in se

Answer 1

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

In your situation, it is probably easiest to get the scene from the ActionEvent parameter of your handler:

@FXML
private void handleSourceBrowse(ActionEvent ae) {
    Node source = (Node) ae.getSource();
    Window theStage = source.getScene().getWindow();

    sourceDirectoryChooser.showDialog(theStage);
}

See JavaFX: How to get stage from controller during initialization? for some more information. I am not in favor of the highest rated answer though, since it adds a compile time dependency to the controller after the .fxml file has been loaded (after all that question was tagged with javafx-2, so not sure if the above approach already worked there, and also the context of the question looks a bit different).

See also How do I open the JavaFX FileChooser from a controller class?