added App app to app.

racevisionGame/src/main/java/visualiser/app/App.java

@@ -15,6 +15,7 @@ import java.io.IOException;
 
 public class App extends Application {
     private static Stage stage;
+    private static App app;
 
     /**
      * Entry point for running the programme
@@ -31,6 +32,8 @@ public class App extends Application {
      * @throws Exception if something wrong with title screen.
      */
     public void start(Stage stage) throws Exception {
+        App.stage = stage;
+        App.app = this;
         stage.setOnCloseRequest(new EventHandler<WindowEvent>() {
             @Override
             public void handle(WindowEvent event) {
@@ -38,7 +41,7 @@ public class App extends Application {
                 System.exit(0);
             }
         });
-        App.stage = stage;
+
         loadStart(App.stage);
     }