C++ (Qt)
class RowHoverDelegate : public QStyledItemDelegate
{
    Q_OBJECT
 
public:
    RowHoverDelegate(QTableView *tableView);
    void paint(QPainter *painter, const QStyleOptionViewItem &option,
               const QModelIndex &index) const override;
 
protected:
    bool eventFilter(QObject *obj, QEvent *event) override;
 
private:
    QTableView *m_tableView;
    int m_hoveredRow;
};

C++ (Qt)
RowHoverDelegate::RowHoverDelegate(QTableView *tableWidget)
    : QStyledItemDelegate(tableWidget)
    , m_tableView(tableWidget)
    , m_hoveredRow(-1)
{
    m_tableView->setSelectionBehavior(QAbstractItemView::SelectRows);
    m_tableView->setMouseTracking(true);
    m_tableView->installEventFilter(this);
    m_tableView->viewport()->installEventFilter(this);
}
 
void RowHoverDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
                             const QModelIndex &index) const
{
    QStyleOptionViewItem opt = option;
    if(index.row() == m_hoveredRow) {
      opt.state |= QStyle::State_MouseOver;
    } else {
      opt.state &= ~QStyle::State_MouseOver;
    }
    QStyledItemDelegate::paint(painter, opt, index);
}
 
bool RowHoverDelegate::eventFilter(QObject *obj, QEvent *event)
{
    if (event->type() == QEvent::MouseMove) {
        QMouseEvent *mouseEvent = static_cast<QMouseEvent *>(event);
        m_hoveredRow = m_tableView->rowAt(mouseEvent->pos().y());
    } else if (event->type() == QEvent::Leave) {
        m_hoveredRow = -1;
    }
 
    return QObject::eventFilter(obj, event);
}