Moving items in ListModel source handled incorrectly

[mirukana]

I'm using a ListModel as sourceModel, and I need to sort my model's data from my backend which calls ListModel.move(), so I want to use SortFilterProxyModel purely for filtering.

The SortFilterProxyModel gets reset whenever a movement happens, which causes all delegates to be constantly deleted-recreated and breaks any ListView.move transition... what causes this behavior?

Here's a sample code that demonstrates the problem.

[oKcerG]

Hello,

Unfortunately the issue is caused by the base class QSortFilterProxyModel emitting a layoutChanged each time the the source model emits a rowMoved : https://code.woboq.org/qt5/qtbase/src/corelib/itemmodels/qsortfilterproxymodel.cpp.html#_ZN28QSortFilterProxyModelPrivate18_q_sourceRowsMovedERK11QModelIndexiiS2_i

I'm afraid this can't be fixed easily.
Refactoring SortFilterProxyModel to not inherit from QSortFilterProxyModel is seriously considered and is the way forward for this lib, but I have yet to begin this task and can not give you a time frame for when it'll be done.

[iberiozko]

Have a nice day :) The problem is, oKcerG did not have a chance to implement the case. All events like *OnChanging. *beforeSOMETING, *afterSOMETHING – are not implemented yet. You shaulh try it yourself... With my pleasure, // Ivan From: miruka [mailto:[email protected]] Sent: Friday, April 10, 2020 2:39 PM To: oKcerG/SortFilterProxyModel Cc: Subscribed Subject: [oKcerG/SortFilterProxyModel] Moving items in ListModel source handled incorrectly (#75) I'm using a ListModel as sourceModel, and I need to sort my model's data from my backend which calls ListModel.move(), so I want to use SortFilterProxyModel purely for filtering. The SortFilterProxyModel gets reset whenever a movement happens, which causes all delegates to be constantly deleted-recreated and breaks any ListView.move transition... what causes this behavior? <https://github.com/mirukana/sortfilterproxy-move-problem/blob/master/src/Window.qml> Here's a sample code that demonstrates the problem. — You are receiving this because you are subscribed to this thread. Reply to this email directly, <#75> view it on GitHub, or <https://github.com/notifications/unsubscribe-auth/ACB5ZUNWXOVHLH4TK7INKRTRL4AMRANCNFSM4MFMW53A> unsubscribe. <https://github.com/notifications/beacon/ACB5ZUJMY4W6NB5LY5G7U6DRL4AMRA5CNFSM4MFMW53KYY3PNVWWK3TUL52HS4DFUVEXG43VMWVGG33NNVSW45C7NFSM4I5CMZHQ.gif>

[mirukana]

Thanks for the answers.
I don't know much C++, so I'll ask: isn't it possible to override that function, or to simply disconnect the signal that calls it?

[iberiozko]

Hello. Beriozko Ivan is on contact… Please, use this mailing-list for conversation, that works really good. For orther cases, shaulth thau contact me via email, me shall be pleased to describe the case. Luks. From: miruka [mailto:[email protected]] Sent: Friday, April 10, 2020 2:39 PMPle To: oKcerG/SortFilterProxyModel Cc: Subscribed Subject: [oKcerG/SortFilterProxyModel] Moving items in ListModel source handled incorrectly (#75) I'm using a ListModel as sourceModel, and I need to sort my model's data from my backend which calls ListModel.move(), so I want to use SortFilterProxyModel purely for filtering. The SortFilterProxyModel gets reset whenever a movement happens, which causes all delegates to be constantly deleted-recreated and breaks any ListView.move transition... what causes this behavior? Here <https://github.com/mirukana/sortfilterproxy-move-problem/blob/master/src/Window.qml> 's a sample code that demonstrates the problem. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#75> , or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACB5ZUNWXOVHLH4TK7INKRTRL4AMRANCNFSM4MFMW53A> . <https://github.com/notifications/beacon/ACB5ZUJMY4W6NB5LY5G7U6DRL4AMRA5CNFSM4MFMW53KYY3PNVWWK3TUL52HS4DFUVEXG43VMWVGG33NNVSW45C7NFSM4I5CMZHQ.gif>