QWidget *myWidget = new QWidget();
myWidget->setLayout(mainLayout);
setWidget(myWidget);

int myHeight, myWidth, myPosX, myPosY,isScroll=5;
if (myWidget->height()>QApplication::desktop()->height()-100)
{
    myHeight = QApplication::desktop()->height()-100;
    isScroll = 20;
}
else myHeight = myWidget->height()+5;
myWidth = myWidget->width()+isScroll; //+20 если будет скроллбар вертикальный
myPosX = QApplication::desktop()->width()/2-myWidth/2;
myPosY = (QApplication::desktop()->height() - myHeight)/2;
          setGeometry(myPosX,myPosY,myWidth,myHeight);

     QScrollArea *scrollView = new QScrollArea();
    ConeEditDialog* dialog = new ConeEditDialog(LabObject,CurrentPrs,myContext);
    scrollView->setWidget(dialog);
    scrollView->show();