Always show QTreeview branches in the far left column

[Nightfox]

I'm working with a Qtreeview and I'm facing some problems having the treview shown when either the first column is hidden or when I rearrange the tree.

I'm using a custom model where I've tried to put in a 'branch column' (m_branchcolumn see below) to map the parent to the first visible column in the treeview but it doesn't work. I always see the treeview nodes (the plus and minus signs) in column zero. I'm using an internal record representation like the nodeitem from the simple treeview example shipped with Qt.

QModelIndex ViewModel::parent(const QModelIndex &child) const
{
    if (!child.isValid())
        return QModelIndex();
 
    Record *rec = recordFromIndex(child);
    if (!rec)
        return QModelIndex();
 
    Record *parentRecord = rec->parent;
    if (!parentRecord)
        return QModelIndex();
 
    if(parentRecord == rootRecord)
        return QModelIndex();
 
    Record *grandparentRecord = parentRecord->parent;
 
    if (!grandparentRecord)
        return QModelIndex();
 
    int row = grandparentRecord->children.indexOf(parentRecord);
    return createIndex(row, m_branchcolumn, parentRecord);
}

QModelIndex ViewModel::parent(const QModelIndex &child) const
{
    if (!child.isValid())
        return QModelIndex();

    Record *rec = recordFromIndex(child);
    if (!rec)
        return QModelIndex();

    Record *parentRecord = rec->parent;
    if (!parentRecord)
        return QModelIndex();

    if(parentRecord == rootRecord)
        return QModelIndex();

    Record *grandparentRecord = parentRecord->parent;

    if (!grandparentRecord)
        return QModelIndex();
    
    int row = grandparentRecord->children.indexOf(parentRecord);
    return createIndex(row, m_branchcolumn, parentRecord);
}

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How can I make sure always to show the tree branches in the far left visible column even after column change and with hidden columns?