@Gwenn you aren’t going to have a MyUIWidget.generated.h. I don’t even have one of those in my tutorial, include MyUIWidget.generated.h isn’t part of any of my files. Also, what do you mean by “public folder” or “private folder”. The tutorial states the files go in /projectroot/sources/projectname/, wherever that is on your C: D: E: drive (whatever) depends on your own setup, but really you could put them wherever you want and edit the include directive appropraitely, some basic knowledge of filesystems is of course required.
!UPDATE!
I have some new code-samples up for screening. It isn’t on the front wiki page yet. It’s taken me so long to get some work out because I had a hardware failure, I’ve been racing trying to get my environment back to where it was, reinstall Windows, everything installed, download visual studio, stabilize my new hardware/bios settings, install drivers, re-write all the code I lost, re-produce some programmer art, re-download UE4 and all the sample projects, write new code etc etc, etc etc… But here they are, description is within, highly recommended you master Hello Slate first before trying to tackle it, this is quite a bit more complicated.
https://wiki.unrealengine.com/Loading_Slate_Styles_%26_Resources