widget not visible after layout->setAlignment

[jacek]

Just tried that (added uicb.O->show() to the center macro above) and it has no effect. I don't see how this would be the issue since one widget is shown correctly.

Then maybe there is some problem with that custom widget?

Try something like this:

int main( int argc, char **argv )
{
  QApplication app( argc, argv );
 
  TimeSlider w;
  w.show();
 
  return app.exec();
}

int main( int argc, char **argv )
{
  QApplication app( argc, argv );

  TimeSlider w;
  w.show();

  return app.exec();
}

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to check whether this TimeSlider behaves correctly.

Its inserted into a splitter which is parented to the main window. So no, not really.

But splitters behave like layouts, so it should be OK.