I do think that all screenshots posted here are from said wiki article, I don't think all the code changes have been added there though - as far as I recall, we began using git at some point, while the original patches were just added to the wiki "verbatim", i.e. the wiki may not contain the latest changes reflected in the screenshots posted here, but that should be obvious given that those are showing Canvas GUI dialogs and a number of independent/separate views:
viewtopic.php?f=71&t=23929&start=30#p317930The underlying boilerplate code is still spot-on though, i.e. all that is needed is F-JJTH's code integrating the view-mgr lookup.
I could obviously post the missing bits here, but if I remember correctly, Icecode GL wanted to get Stuart involved before sharing his code, because it was work-in-progress at the time (i.e. late August 2017).
If in doubt, I'd suggest to get in touch with Icecode GL - especially if you should know how to use git, and how to patch/rebuild fgfs from source, ideally with some C++/OSG expertise. Feel free to ping me if Icecode GL is currently n/a, and I will be updating the wiki with the original patches that we used to create those screenshots.
But again, if you'd like to see this "fly", I really suggest to spread the word and get people involved who can help with C++/OSG side of things, or this may linger on our hard drives for another couple of months (or even years). After all, this wouldn't be the first Canvas related addition that doesn't make it back upstream ...
Anyway, but tinkering with this at this point, makes really only sense if you already know how to use Nasal/Canvas - and ideally, how to patch SG/FG and rebuild the whole shebang. Otherwise, it's just going to be a frustrating experience - which is one of the reasons why we didn't update the wiki to contain the WIP patches.