void ThemeItemDelegate::paint(QPainter *pPainter, const QStyleOptionViewItem &option, const QModelIndex &index) const
{
    if (option.state == QStyle::State_HasFocus) {
        QRect rect = option.rect;
        QLinearGradient gradient(0, 0, rect.width(), rect.height());
        gradient.setColorAt(0, Qt::white);
        gradient.setColorAt(0.5, Qt::blue);
        gradient.setColorAt(1, Qt::green);
        pPainter->setBrush(gradient);
        pPainter->drawRect(rect);
    }
    QItemDelegate::paint(pPainter, option, index);
}