minimumSizeHint() is not computed until some events are processed in the event loop

Change the behavior of minimumSizeHint() or point out in the doc that

minimumSizeHint() is not computed until some events are processed in the event loop, so a better solution is to get minimumSizeHint() is in the slot QTimer.singleShot

Two posts mentioned the feature 

https://stackoverflow.com/a/28760211/1485853

https://forum.qt.io/topic/4500/resize-top-level-window-to-fit-contents/4