Inserting QStandardItems to the child rows and columns in QStandardItemModel

[ru_core]

Hi all!
There is code which helps to build the tree (picturied lower)

#include <QtGui>
 
int main(int argc, char** argv) 
{
    QApplication       app(argc, argv);
    QStandardItemModel model(5, 3);
 
    for (int nTopRow = 0; nTopRow < 5; ++nTopRow) {
        QModelIndex index = model.index(nTopRow, 0);
        model.setData(index, "item" + QString::number(nTopRow + 1));
 
        model.insertRows(0, 4, index);
        model.insertColumns(0, 3, index);
        for (int nRow = 0; nRow < 4; ++nRow) {
            for (int nCol = 0; nCol < 3; ++nCol) {
                QString strPos = QString("%1,%2").arg(nRow).arg(nCol);
                model.setData(model.index(nRow, nCol, index), strPos);
            }
        }
    }
 
    QTreeView treeView;
    treeView.setModel(&model);
    treeView.show();
 
    return app.exec();
}

#include <QtGui>

int main(int argc, char** argv) 
{
    QApplication       app(argc, argv);
    QStandardItemModel model(5, 3);

    for (int nTopRow = 0; nTopRow < 5; ++nTopRow) {
        QModelIndex index = model.index(nTopRow, 0);
        model.setData(index, "item" + QString::number(nTopRow + 1));

        model.insertRows(0, 4, index);
        model.insertColumns(0, 3, index);
        for (int nRow = 0; nRow < 4; ++nRow) {
            for (int nCol = 0; nCol < 3; ++nCol) {
                QString strPos = QString("%1,%2").arg(nRow).arg(nCol);
                model.setData(model.index(nRow, nCol, index), strPos);
            }
        }
    }

    QTreeView treeView;
    treeView.setModel(&model);
    treeView.show();

    return app.exec();
}

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My task is to insert QStandardItems in the child rows and columns.
tried

void QStandardItemModel::setItem ( int row, int column, QStandardItem * item )

but but the model did not change the count of its rows and columns after new rows and colums have been inserted

do you have any ideas?
Thank you