How to use Autolayout with UIScrollView programmatically?

When I wanted to use Autolayout on a UIScrollView object, I had the following issue: Even though the components would be nicely laid out inside the contentView, I did not know how to end up with the proper height for the contentSize, other than by trying out a value on my own.

Searching the net in order to solve that problem would lead me to solutions, but all meant for people using storyboard, not for folks doing it programmatically. I had to translate the info I could find to my use case, and make it work as I wanted (that is programmatically).

This project shows how to do this. It is certainly not the only way, but it works for me. I hope it will be useful to someone else hitting the same question in the future.