disconnect(previous, SIGNAL(scrollOffsetChanged(qreal,qreal)), this, SLOT(updateScrollOffsetScrollBar()));
disconnect(previous, SIGNAL(maximumScrollOffsetChanged(qreal,qreal)), this, SLOT(updateScrollOffsetScrollBar()));
disconnect(previous, SIGNAL(itemOffsetChanged(qreal,qreal)), this, SLOT(updateItemOffsetScrollBar()));
disconnect(previous, SIGNAL(scrollOffsetChanged(qreal,qreal)), this, SLOT(updateScrollOffsetScrollBar()));
disconnect(previous, SIGNAL(maximumScrollOffsetChanged(qreal,qreal)), this, SLOT(updateScrollOffsetScrollBar()));
disconnect(previous, SIGNAL(itemOffsetChanged(qreal,qreal)), this, SLOT(updateItemOffsetScrollBar()));