@Override public void start(Stage primaryStage) { ScreensController mainContainer = new ScreensController(); mainContainer.loadScreen(ScreensFramework.screen1ID, ScreensFramework.screen1File); mainContainer.loadScreen(ScreensFramework.screen2ID, ScreensFramework.screen2File); mainContainer.loadScreen(ScreensFramework.screen3ID, ScreensFramework.screen3File); mainContainer.setScreen(ScreensFramework.screen1ID); Group root = new Group(); root.getChildren().addAll(mainContainer); Scene scene = new Scene(root); primaryStage.setScene(scene); primaryStage.show(); }