qt - How to remove rows from QAbstractItemModel or QSortFilterProxyModel w/o invalidating -

i can not wrap head around , i'm not finding sufficient examples. have lot of data, , every , again, rows in middle need removed. may have 10 views (with proxies) connected model... @ time, single 1 (or all) may wish delete 1 row in middle (generally proxy). note i'm using delegate paint.

i can remove row(s) fine, qmodelindex::data() passed qitemdelegate::paint() not have right data. such, believe must run setdata() in model (or proxy) removerows() called. fine , dandy, have run on rows in model shifted due removal? seems painfully slow (and seems go against model/view approach).

i've asked similar questions in number of qt forums, , have gotten absolutely nothing. apparently i've stumped qt community.