Unusual TableView

Hellow. I make the grid based on QTableView. The first column is not edited. The second column can edited by user. Cells of the third column is comboboxes. I want show comboboxes in cells of the third column always. When user select any item in the commobox any value must insert in the second column. But if I use tableView->openPersistentEditor(); it's not work if I not edit some cell before select item. There is code:

Code:

---

void Dialog::setupDelegateAndGrid()
{
    if (m_fields.count() == 0)
        return;
 
    QStringList itemsList;
    itemsList << "Default comboBox Text";
    for (int i = 0; i < m_fields.count(); i++)
    {
        itemsList << m_fields.value(i).fieldName;
    }
    m_delegate = new ComboBoxDelegate();
    connect(m_delegate, SIGNAL(textChanged(QString)), this, SLOT(comboTextChanged(QString)));
    m_delegate->setItems(itemsList);
 
    m_model = new QStandardItemModel(m_fields.count(), 3);
    m_model->setHeaderData(0, Qt::Horizontal, tr("Column1"));
    m_model->setHeaderData(1, Qt::Horizontal, tr("Column2"));
    m_model->setHeaderData(2, Qt::Horizontal, tr("Column3"));
 
    tableView->setModel(m_model);
    tableView->setItemDelegateForColumn(2, m_delegate);
    tableView->setEditTriggers(QAbstractItemView::AllEditTriggers);
    for (int i = 0; i < m_model->rowCount(); i++)
    {
        tableView->openPersistentEditor(m_model->index(i, 1));
        tableView->openPersistentEditor(m_model->index(i, 2));
        m_model->setData(m_model->index(i, 2, "Default comboBox Text" Qt::DisplayRole);
        QStandardItem *item = new QStandardItem();
        item->setEditable(false);
        m_model->setItem(i, 0, item);
    }
}
 
void Dialog::comboTextChanged(QString text)
{
    for (int i = 0; i < m_fields.count(); i++)
    {
        if (m_fields.value(i).fieldName == text)
        {
            m_model->setData(m_model->index(tableView->currentIndex().row(), 2), m_fields.value(i).defaultValue.toString(), Qt::DisplayRole);
            break;
        }
    }
}

---

Help me to solve this problem. Thanks.