C++ & Qt

25 March 2026 00:25

Also the below calls are very expensive and should be aboided if used.

resizeColumnsToContents() / resizeRowsToContents()

C++ & Qt

24 March 2026 21:20

I have done similar things with tables in qml. Apparently qml uses single point precision for row offsets, so if the number of rows are big enough the layout gets weird (even if the performance is good)

C++ & Qt

24 March 2026 21:13

You can also do that in the parent widget by using only x rows in the listview.

C++ & Qt

24 March 2026 15:47

Uniform row heights is also good, but I suppose you want it to look as in the image above

C++ & Qt

24 March 2026 14:18

Are you using, by any chance, any call to view->setIndexWidget()? This implies a huge performance penalty. Also, if you can move to QML, it reuses delegates and has no calls to paint(), which is quite likely to be executed in CPU instead of GPU.

C++ & Qt

24 March 2026 14:05

no I did not. i guess the table resize entire table at once. if i will manage to run profiler i will get back to you

C++ & Qt

24 March 2026 14:03

l have change resizeToContents and Stretch to FIxed and yes it is fast alright

C++ & Qt

24 March 2026 13:57

so, what can I do regarding the performance????

C++ & Qt

24 March 2026 13:55

i have this log_view inherited from table view that uses custom table model to show logs. i want the logs to have 4 columns: timestamp, level, service, message. first 3 columns should be sized to fit, fotrh should stretch to the widget end and use word wrap. i have accomplished there requirements with

log_view::log_view(log_model* lm) {
 setModel(lm);
 setAlternatingRowColors(true);
 setSelectionMode(QAbstractItemView::SelectionMode::SingleSelection);
 setSelectionBehavior(QAbstractItemView::SelectionBehavior::SelectRows);
 verticalHeader()->setSectionResizeMode(QHeaderView::ResizeMode::ResizeToContents);

 auto header = horizontalHeader();

 header->setSectionResizeMode(0, QHeaderView::ResizeMode::ResizeToContents);
 header->setSectionResizeMode(1, QHeaderView::ResizeMode::ResizeToContents);
 header->setSectionResizeMode(2, QHeaderView::ResizeMode::ResizeToContents);

 header->setSectionResizeMode(3, QHeaderView::ResizeMode::Stretch);
 setWordWrap(true);
 connect(header, &QHeaderView::sectionResized, this, 
  [this](int logicalIndex, int /*oldSize*/, int /*newSize*/) {
    if (logicalIndex == 3)
   resizeRowsToContents();
  }
 );
 
};

C++ & Qt

24 March 2026 06:32

Report sent⁣⁣⁣⁣

C++ & Qt

23 March 2026 19:07

The qmlls improvements sounds nice

C++ & Qt

16 March 2026 06:32

@Rasmussen_Maja [8318401428] banned.

C++ & Qt

16 March 2026 04:58

@admin

C++ & Qt

10 March 2026 22:15

Welcome to the group, @hishamzidanx! :-)

Wanna share your story of how you started with Qt, QML or C++? Maybe some nice feature that made you stick with it.
Rules are set on the description of the group. :)

C++ & Qt

02 March 2026 10:45

https://treelinev1.devpost.com/ anyone wants to team up for this,dm....

C++ & Qt

25 March 2026 00:18

It's been quite a long since I used widgets. I can suggest the below solution.

Try disable updates while resizing.

Qt repaints continuously during a resize event. You can suppress this.

Override resizeEvent.

void MyWidget::resizeEvent(QResizeEvent *event)
{
tableWidget->setUpdatesEnabled(false);
QWidget::resizeEvent(event);
tableWidget->setUpdatesEnabled(true);
}

C++ & Qt

24 March 2026 21:15

In one of my projects, I have a thumbnail view that with about 100k pictures. Performance was really bad - in the end, I just implemented the paintEvent() myself. It's really nice now.

C++ & Qt

24 March 2026 21:13

I'd probably subclass the list widget and only render the visible portion of the list.

C++ & Qt

24 March 2026 15:08

200 rows should work even without models I think

C++ & Qt

24 March 2026 14:05

I think there may be ways to make the size estimation faster

C++ & Qt

24 March 2026 14:04

Did you try running callgrind (or any other profiler) to reveal where the bootleneck is in?

C++ & Qt

24 March 2026 13:59

Is it faster if all columns have fixed with?

C++ & Qt

24 March 2026 13:57

the before and after. as you can see i get desired behaivour, the first long message row gets resized to fit the message well

C++ & Qt

24 March 2026 06:57

@GerdSimonsen [8367815543] banned.

C++ & Qt

24 March 2026 06:32

@admin

C++ & Qt

16 March 2026 07:45

Welcome to the group, @rickliu2000! :-)

Wanna share your story of how you started with Qt, QML or C++? Maybe some nice feature that made you stick with it.
Rules are set on the description of the group. :)

C++ & Qt

16 March 2026 04:58

Report sent⁣⁣⁣⁣

C++ & Qt

13 March 2026 21:02

Welcome to the group, -! :-)

Wanna share your story of how you started with Qt, QML or C++? Maybe some nice feature that made you stick with it.
Rules are set on the description of the group. :)

C++ & Qt

04 March 2026 11:11

Welcome to the group, @imrandogan46! :-)

Wanna share your story of how you started with Qt, QML or C++? Maybe some nice feature that made you stick with it.
Rules are set on the description of the group. :)

C++ & Qt

02 March 2026 09:20

Welcome to the group, @Le_Burrito! :-)

Wanna share your story of how you started with Qt, QML or C++? Maybe some nice feature that made you stick with it.
Rules are set on the description of the group. :)