Как написать конструктор от двух классов QObject и QAbstractNativeEventFilter

class MyEventFilter : public QAbstractNativeEventFilter
{
public:
    MyEventFilter();
 
    bool nativeEventFilter(const QByteArray &eventType, void *message, long *result) Q_DECL_OVERRIDE;
};

MyEventFilter::MyEventFilter() : QAbstractNativeEventFilter()
{
    qDebug("init class MyEventFilter");
}
 
bool MyEventFilter::nativeEventFilter(const QByteArray &eventType, void *message, long *result)
{
    if(eventType == "windows_generic_MSG")
    {
        MSG* ev = static_cast<MSG *>(message);
        if (ev->message == WM_DEVICECHANGE)
        {
            if((ev->wParam == DBT_DEVICEARRIVAL) || (ev->wParam == DBT_DEVICEREMOVEPENDING) || (ev->wParam == DBT_DEVICEREMOVECOMPLETE) || (ev->wParam == DBT_CONFIGCHANGED))
            {   
                qDebug()<<"new device";
                return true;
            } //if((ev->wParam
        } // if(ev->message
    }//if(eventType
    return false;
}

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    a.installNativeEventFilter(w.myEventFilter);
    w.show();
 
    return a.exec();
}

class MyEventFilter : public QObject, public QAbstractNativeEventFilter
{
    Q_OBJECT
public:
    MyEventFilter();
 
    bool nativeEventFilter(const QByteArray &eventType, void *message, long *result) Q_DECL_OVERRIDE;
};

MyEventFilter::MyEventFilter() : QAbstractNativeEventFilter()
{
    qDebug("init class MyEventFilter");
}

class MyEventFilter : public QObject, public QAbstractNativeEventFilter
{
    ...
};