[Interest] QSortFilterProxyModel::removeRows()

[Paul England]

On 06/01/2012 03:01 PM, Jordi Pujol wrote:
> El dv 01 de 06 de 2012 a les 14:15 +0900, en/na Paul England va
> escriure:
>> Hi
>>
>> I wrote this really long email, and learned a lot about the problem in
>> doing so.  So, I guess it was time well spent.  Still frustrated.
>> Here's the summed up problem:
>>
>> I have a QAbstrctTabelModel, QSortFilterProxyModel, QItemDelegate, and
>> a QTableView (all subclassed).  As you'd expect, the
>> QSortFilterProxyModel filters out what I don't want, the delegate
>> paints what I do, and the view displays everything.  Some rows are
>> updated, and based on user-defined criteria, need to be removed
>> *AFTER* the proxy  has let them in.  Before, I was calling
>> invalidate() in the proxy, but that was calling filterAcceptsRow() on
>> all rows (visible or not).  Yikes.  So, I'm now doing removeRows() for
>> the row(s) that must be removed.
>>
>> Caveat: my subclassed delegate's paint() is being passed a
>> QModelIndex() with the *old* data.
>>
>> Example, my rows are.
>> Harry
>> Larry
>> Bob
>>
>> bool my_proxy::removeRows( int row, int count, const QModelIndex& )
>> {
>>
>>     beginRemoveRows( QModelIndex(), row, count + row - 1 );
>>     // remove data from model here
>>     endRemoveRows();
>>
>> }
>> men
>> if I do:
>> removeRows( 2, 1 );
>>
>> My model will then show it only has two items. 
>> Harry and Bob
>>
>> HOWEVER, for the subsequent call to my_delegeate::paint( QPainter*,
>> const QStyledOptionViewItem& opt, const QModelIndex& index ) will have
>> the old index.  paint will be called twice, and
>> index.data().toString() will have Harry for the 1st one, and Larry for
>> the 2nd.  
>>
>> Am I missing something?
>> Thanks
> Perhaps the fact that indexes are 0-based ?
>
> 0 - Harry
> 1 - Larry
> 2 - Bob
>
> So if you call removeRows( 2, 1 ); you're removing Bob, as expected...

Sorry for not being clear.   I am taking the 0-based index into
account.  removeRows should actually pass 1,1 in that case.

I know that it's not working b/c when paint is called, I grab the
underlying data structure that supposedly changed (indexed by row).  I'm
checking it against QModelIndex::data() within paint() and they do not
match.