QItemDelegate setModelData in QTreeWidget is not called - c++

Question

I am trying to set delegate to my QTreeWidget. The problem is that delegate setModelData is never called. createEditor and setEditorData are called.
Since the editor that I create is simple QLineEdit, commitData() signal doesn't have to be emitted. Also I tried to emit this signal just in case is needed , when editLine editingFinished() was emitted, but that doesn't solve the problem.
As I understand documentaion say that for simple widgets like QLineEdit setModelData should be called without emitting commitData signal, so the following code should work :
MyDlg::MyDlg()
{
mTreeWdg->setItemDelegate(new TestDelegate( this ));
}
MyDlg::OnTreeItemDoubleCliked(QTreeeWidget* item,int column)
{
if(column != 1) return;
item->setFlags(Qt::ItemIsEditable);
mTreeWdg->editItem(item,column);
}
TestDelegate::TestDelegate(QObject *parent )
:QItemDelegate(parent)
{
}
QWidget* TestDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &option,
const QModelIndex &index) const
{
if(index.column() == 1) // value column
{
QLineEdit* edit = new QLineEdit(parent);
return edit;
}
else return 0; // no editor attached
}
void TestDelegate::setEditorData(QWidget *editor, const QModelIndex &index) const
{
if(index.column() == 1)
{
QLineEdit* edit = static_cast<QLineEdit*> (editor);
edit->setText("damn");
}
}
void TestDelegate::setModelData(QWidget *editor, QAbstractItemModel *model,const QModelIndex &index)
{
if(index.column()!= 1)
return;
}
void TestDelegate::updateEditorGeometry(QWidget *editor,const QStyleOptionViewItem &option, const QModelIndex &index) const
{
editor->setGeometry(option.rect);
}

Answer 1

void TestDelegate::setModelData(QWidget *editor, QAbstractItemModel *model,const QModelIndex &index) must be const:
void setModelData(QWidget *editor, QAbstractItemModel *model,const QModelIndex &index) const
Look at the declaration above.