Как добавить окно(QWidget) в модуль?

При разборе очередного модуля нужно добавить UI-интерфейс для добавления нужных элементов. Можете что посоветовать? Спасибо.

main.cpp

#include "VeyonCore.h"
#include <QCoreApplication>
#include <QAbstractNativeEventFilter>
#include <QWidget>
#include <QMainWindow>
#include "WindowsService.h"
#include "ComputerControlServer.h"
#include "VeyonConfiguration.h"

#ifdef VEYON_BUILD_WIN32
static HANDLE hShutdownEvent = NULL;
// event filter which makes ICA recognize logoff events etc.
class LogoffEventFilter : public QAbstractNativeEventFilter
{
public:
    virtual bool nativeEventFilter( const QByteArray& eventType, void *message, long *result)
    {
        Q_UNUSED(eventType);
        Q_UNUSED(result);
        DWORD winMsg = ( ( MSG *) message )->message;
        if( winMsg == WM_QUERYENDSESSION )
        {
            qInfo( "Got WM_QUERYENDSESSION - initiating server shutdown" );
            // tell UltraVNC server to quit
            SetEvent( hShutdownEvent );
        }
        return false;
    }
};
#endif

int main( int argc, char **argv )
{
    // decide in what mode to run
    if( argc >= 2 )
    {
#ifdef VEYON_BUILD_WIN32
        for( int i = 1; i < argc; ++i )
        {
            if( QString( argv[i] ).toLower().contains( "service" ) )
            {
                WindowsService winService( "VeyonService", "-service", "Veyon Service",
                                            QString(), argc, argv );
                if( winService.evalArgs( argc, argv ) )
                {
                    return 0;
                }
                break;
            }
        }
#endif
    }
    QCoreApplication app( argc, argv );
    VeyonCore core( &app, QStringLiteral("Service") );
    // parse arguments
    QStringListIterator argIt( app.arguments() );
    argIt.next();
    while( argc > 1 && argIt.hasNext() )
    {
        const QString a = argIt.next().toLower();
        if( a == QStringLiteral("-session") && argIt.hasNext() )
        {
            int sessionId = argIt.next().toUInt();
            if( sessionId > 0 )
            {
                core.config().setPrimaryServicePort( core.config().primaryServicePort() + sessionId );
                core.config().setVncServerPort( core.config().vncServerPort() + sessionId );
                core.config().setFeatureWorkerManagerPort( core.config().featureWorkerManagerPort() + sessionId );
            }
        }
    }
#ifdef VEYON_BUILD_WIN32
    hShutdownEvent = OpenEvent( EVENT_ALL_ACCESS, false, L"Global\\SessionEventUltra" );
    if( !hShutdownEvent )
    {
        // no global event available already as we're not running under the
        // control of the veyon service supervisor?
        if( GetLastError() == ERROR_FILE_NOT_FOUND )
        {
            qWarning( "Creating session event" );
            // then create our own event as otherwise the VNC server main loop
            // will eat 100% CPU due to failing WaitForSingleObject() calls
            hShutdownEvent = CreateEvent( NULL, false, false, L"Global\\SessionEventUltra" );
        }
        else
        {
            qWarning( "Could not open or create session event" );
        }
    }
    LogoffEventFilter eventFilter;
    app.installNativeEventFilter( &eventFilter );
#endif
    auto server = new ComputerControlServer;
    server->start();
    qInfo( "Exec" );
    int ret = app.exec();
    delete server;
    qInfo( "Exec Done" );
#ifdef VEYON_BUILD_WIN32
    CloseHandle( hShutdownEvent );
#endif
    return ret;
}

ComputerControlServer.cpp

#include <QCoreApplication>
#include <QHostInfo>
#include <QWidget>
#include "AccessControlProvider.h"
#include "ComputerControlServer.h"
#include "ComputerControlClient.h"
#include "FeatureMessage.h"
#include "VeyonConfiguration.h"
#include "LocalSystem.h"
#include "SystemTrayIcon.h"

ComputerControlServer::ComputerControlServer( QObject* parent ) :
    QObject( parent ),
    m_allowedIPs(),
    m_failedAuthHosts(),
    m_builtinFeatures(),
    m_featureManager(),
    m_featureWorkerManager( m_featureManager ),
    m_serverAuthenticationManager( this ),
    m_serverAccessControlManager( m_featureWorkerManager, m_builtinFeatures.desktopAccessDialog(), this ),
    m_vncServer(),
    m_vncProxyServer( VeyonCore::config().localConnectOnly() || AccessControlProvider().isAccessToLocalComputerDenied() ?
                          QHostAddress::LocalHost : QHostAddress::Any,
                      VeyonCore::config().primaryServicePort(),
                      this,
                      this )
{
    m_builtinFeatures.systemTrayIcon().setToolTip(
                tr( "%1 Service %2 at %3:%4" ).arg( VeyonCore::applicationName(), QStringLiteral(VEYON_VERSION),
                    QHostInfo::localHostName(),
                    QString::number( VeyonCore::config().primaryServicePort() ) ),
                m_featureWorkerManager );
    // make app terminate once the VNC server thread has finished
    connect( &m_vncServer, &VncServer::finished, QCoreApplication::instance(), &QCoreApplication::quit );
    connect( &m_serverAuthenticationManager, &ServerAuthenticationManager::authenticationError,
             this, &ComputerControlServer::showAuthenticationErrorMessage );
}

ComputerControlServer::~ComputerControlServer()
{
    qDebug(Q_FUNC_INFO);
    m_vncProxyServer.stop();
}

void ComputerControlServer::start()
{
    m_vncServer.start();
    m_vncProxyServer.start( m_vncServer.serverPort(), m_vncServer.password() );
    QWidget *mw = new QWidget;
    mw->setWindowTitle("Main Window");
    mw->show();
}

VncProxyConnection* ComputerControlServer::createVncProxyConnection( QTcpSocket* clientSocket,
                                                                     int vncServerPort,
                                                                     const QString& vncServerPassword,
                                                                     QObject* parent )
{
    return new ComputerControlClient( this, clientSocket, vncServerPort, vncServerPassword, parent );
}

bool ComputerControlServer::handleFeatureMessage( QTcpSocket* socket )
{
    char messageType;
    if( socket->getChar( &messageType ) == false )
    {
        qWarning( "ComputerControlServer::handleFeatureMessage(): could not read feature message!" );
        return false;
    }
    // receive message
    FeatureMessage featureMessage( socket );
    if( featureMessage.isReadyForReceive() == false )
    {
        socket->ungetChar( messageType );
        return false;
    }
    featureMessage.receive();
    return m_featureManager.handleServiceFeatureMessage( featureMessage, m_featureWorkerManager );
}

void ComputerControlServer::showAuthenticationErrorMessage( const QString& host, const QString& user )
{
    qWarning() << "ComputerControlServer: failed authenticating client" << host << user;
    QMutexLocker l( &m_dataMutex );
    if( m_failedAuthHosts.contains( host ) == false )
    {
        m_failedAuthHosts += host;
        m_builtinFeatures.systemTrayIcon().showMessage(
                    tr( "Authentication error" ),
                    tr( "User %1 (IP: %2) tried to access this computer "
                        "but could not authenticate successfully!" ).arg( user, host ),
                    m_featureWorkerManager );
    }
}

P.S.: исходный проект называется Veyon rev.4.0.4, модуль service. Собирался проект в Qt через CMakeLists.txt. Добавлять файл в проект(к примеру, UI) отказывается(ПКМ->"Добавить новый...").