How to use QCombobox as one of the columns in model derived from QAbstractItemModel

I have created the model QAbstractItemModel. I have set it to treeview and other columns to other UI components from editor (see image).
I want to use combobox as one of the UI components in editor. I have implemented it by referring to how I did it for QlineEdit. But, its not working. Definitely, I am missing out something. Any inputs in this regard or code sample will help.

Thanks,
IndrajitAttachment 8477

How does your code look like?

Do you use a QDataWidgetMapper or are you manually filling the widgets from model data?

Cheers,
_