How to remove children from a widget?

[kitfox]

I'm having some trouble with crashes when removing child widgets from a parent widget.

I'm creating a control that is used to display the content of a list of data objects in a way that will allow the user to select one of the objects and edit the data in it.

I'm doing this by creating a scrollArea that contains a holder QWidget with a horizontal layout. I then create one of my MixerTrack UI widgets to wrap one mixer track for each track I want the user to edit and add it to my holder. Later, if the track list changes, I remove and delete the holder widget, create a new one, add it to my scrollarea and then create new MixerTrack widgets to wrap my new list data.

This was working well for a while, but recently I've been getting crashes when I perform a delete on my holder widget. I'm not sure why and the stack trace provides no clue. There is nothing happening in the destructor of my widget that should be causing a problem. Commenting out the delete operation prevents the crash, but messes up the display because the old widgets aren't being removed anymore.

Am I going about this right?

void Mixer::updateTracks()
      {
      if (trackHolder) {
            trackAreaLayout->removeWidget(trackHolder);
            delete trackHolder;
            trackHolder = 0;
            }

      if (!_score)
            return;

      trackHolder = new QWidget();
      QHBoxLayout* holderLayout = new QHBoxLayout();
      trackHolder->setLayout(holderLayout);

      trackAreaLayout->addWidget(trackHolder);

      for (Part* part : _score->parts()) {
...
            MixerTrackPart* track = new MixerTrackPart(this, mti, expanded);
            holderLayout->addWidget(track);
...
      }
      update()
}

[J.Hilk]

hi @kitfox
have tried it with deleteLater() istead of delete? It‘s the recommanded way for QWidget/QObject based classes, may already solve the issue.

[kitfox]

@J.Hilk deleteLater() worked! Thanks so much.