TreeView ->"read only" [TreeModelCompleter Tutorial]

[Concept2]

Hi,
first of all thank you very much for your fast response!
My idea was to insert a code like this:

Qt::ItemFlags MyStandardItemModel::flags(const QModelIndex& index) const
{
   return (QStandardItemModel::flags(index) & ~Qt::ItemIsEditable);
}

Qt::ItemFlags MyStandardItemModel::flags(const QModelIndex& index) const
{
   return (QStandardItemModel::flags(index) & ~Qt::ItemIsEditable);
}

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If I do this I get an error as the following: C2352: 'QStandardItemModel::flags' illegal call of non-static member function.
I don't know how to add QAbstractItemModel to my class, because I've already added another subclass of QObject.
Do you have an hint for me?

Is there any other opportunity to make the TreeModelCompleter Example not editable?
best regards