JavaFxtesting

package com.mycompany.nadiah;

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.control.Label;
import java.io.IOException;
import javafx.scene.control.Button;
import javafx.scene.layout.*;

public class App extends Application {

    private static Scene scene;

    @Override
    public void start(Stage stage) throws IOException {
        stage.setTitle("Testing button");
        Button b = new Button("Button");
        TilePane r = new Tilepane();
        Label l = new Label();
        
        EventHandler<ActionEvent> event = new EventHandler<ActionEvent>(){
            public void handle (ActionEvent e){
                l.setText("Hello!");
            };
        };
        
        b.setOnAction(event);
        
        r.getChildren().add(b);
        r.getChildren().add(l);
        
        scene = new Scene(loadFXML("primary"), 640, 480);
        stage.setScene(scene);
        stage.show();
    }

    static void setRoot(String fxml) throws IOException {
        scene.setRoot(loadFXML(fxml));
    }

    private static Parent loadFXML(String fxml) throws IOException {
        FXMLLoader fxmlLoader = new FXMLLoader(App.class.getResource(fxml + ".fxml"));
        return fxmlLoader.load();
    }

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

    private static class Tilepane extends TilePane {

        public Tilepane() {
        }
    }

}