[Qt-interest] QAbstractProxyModel methods index, parent, rowCount, columnCount not implemented?

[Ross Bencina]

Hi

I'm trying to implement a QAbstractProxyModel subclass. I get a linker error 
that suggests that index, parent, rowCount and columnCount are pure virtual 
and havn't been implemented by QAbstractProxyModel. This contradicts the 
documentation, which indicates that I only need to implement the map* 
functions. I'm using Qt4.6.7 but the 4.7 documentation is the same:
http://doc.qt.nokia.com/latest/qabstractproxymodel.html

Is this a known bug?

Note that when I provide an implementation of these methods then 
sourceModel() appears to return NULL if it hasn't been expicitly set. This 
appears to violate the following guarantee in the documentation, since 
sourceModel() aooears to be returning NULL, not the empty placeholder model:

> Note: If the source model is deleted or no source model is specified,
> the proxy model operates on a empty placeholder model.


I'm not subclassing QSortFilterProxy because my proxy doesn't change the 
item layout. I just need to decorate some items by changing flags and 
secondary data based on item values.


Thanks

Ross.