WiP: added volume update and control

TODO: collect volume change events and send only one

mainwindow.h

@@ -23,16 +23,18 @@ protected:
 
 private slots:
     void on_btn_onoff_clicked();
-    void replyFinished();
+    void replyFinished(QNetworkReply *reply);
     void on_txt_address_textEdited(const QString &arg1);
 
+    void on_dial_valueChanged(int value);
+
 private:
     Ui::MainWindow *ui;
 
     QString mAddress;
-    QNetworkReply *mReply;
 
     bool mPowered = false;
+    int mVolume = 0;
 
     void sendCommand(QString cmd);
     void updateUi();