QDataWidgetMapper ignores the flags of a QAbstractTableModel

class myModel : public QAbstractTableModel
{
    Q_OBJECT

public:
    myModel();
    int rowCount ( const QModelIndex & parent = QModelIndex() ) const;
    int columnCount ( const QModelIndex & parent = QModelIndex() ) const;
    QVariant data ( const QModelIndex & index, int role = Qt::DisplayRole ) const;
    bool setData ( const QModelIndex & index, const QVariant & value, int role = Qt::EditRole );
    QVariant headerData ( int section, Qt::Orientation orientation, int role = Qt::DisplayRole ) const;
    Qt::ItemFlags flags ( const QModelIndex & index ) const;
protected:
    QList<QString> c1;
    QList<QString> c2;
};

int myModel::rowCount ( const QModelIndex & parent ) const
{
    return c1.count();
}



int myModel::columnCount ( const QModelIndex & parent ) const
{
    return 2;
}



QVariant myModel::data ( const QModelIndex & index, int role ) const
{
    if ( (role != Qt::DisplayRole) && (role != Qt::EditRole) )
        return QVariant();
    return (index.column() == 0) ? QVariant(c1.at(index.row())) : QVariant(c2.at(index.row()));
}



bool myModel::setData ( const QModelIndex & index, const QVariant & value, int role )
{
    if (index.column() == 0)
        c1[index.row()]= value.toString();
    else
        c2[index.row()]= value.toString();
    emit dataChanged( this->index(0,0), this->index(c1.count(),1));
    return true;
}

QVariant myModel::headerData ( int section, Qt::Orientation orientation, int role ) const
{
    return QVariant(QString(""));
}

Qt::ItemFlags myModel::flags( const QModelIndex & index ) const
{
    return Qt::ItemIsSelectable;
}