Always show QTreeview branches in the far left column

[Nightfox]

This is my reimplementation! I've tried to change the index but as it's a const function all my changes resolves in error. What would I need to change in this data function to swap say column 0 with column 1?

QVariant MyProxyModel::data ( const QModelIndex & index, int role ) const
{
    if (!index.isValid())
        return QVariant();
 
    return QAbstractProxyModel::data(index, role);
}

QVariant MyProxyModel::data ( const QModelIndex & index, int role ) const
{
    if (!index.isValid())
        return QVariant();

    return QAbstractProxyModel::data(index, role);
}

To copy to clipboard, switch view to plain text mode 

Thank you again for your help!