[Qt] QStandardItemModel and checkbox

[tom01ms41]

Hi all:

I have a custom model derived from QStandardItemModel and set setCheckable(true) for each QStandardItem. the view is QTreeView.

I want to do is whenever I click on node's checkbox, the checkState will flip between check/uncheck. other nodes(parent especially) will be Check/Uncheck/PartiallyChecked.

tristate enabled also
@
Qt::ItemFlags FileSystemModel::flags(const QModelIndex & index) const
{
return QStandardItemModel::flags(index) | Qt::ItemIsTristate;
}
@

I've try to modify value in QStandardItemModel::setData
@
bool FileSystemModel::setData(const QModelIndex& index, const QVariant& value, int role)
{
QVariant new_value=value;

if (role==Qt::CheckStateRole) {
    auto check = static_cast<Qt::CheckState> (value.toUInt());
    if (check==Qt::PartiallyChecked)
        new_value = Qt::Unchecked;
}
return QStandardItemModel::setData(index,new_value,role);

}
@

but it not work.
any ideas?