implements oberver pattern

app.h

@@ -7,6 +7,16 @@
 class App : public QObject, public interface::iStompObserver {
 public:
     App();
+    ~App() = default;
+
+    // iStompObserver interface
+private:
+    void connectConfirmation(bool success, int version);
+    void sendConfirmation(bool success);
+    void subscribeConfirmation(bool success);
+    void receiveIndication(int id, QString destination, QString body);
+    void disconnectConfirmation();
+    void disconnectIndication();
 };
 
 #endif // APP_H