Here's the current state of my Gtk-based IDE prototype. It's very buggy but there's some basic things work.
https://gfycat.com/YawningLeftCaterpillar It seems doable to make a decent IDE this way, although it's a lot of work and there's a few challenges. Currently I can't set fonts, there's also some problems with getting print commands and errors into the console, and I'm not sure how to implement auto-complete in the editor. GtkSourceView has a system but the documentation is a bit obscure, and I'm not sure it's flexible enough.
