For creating LV2 UI's I end up more and more writing the same code, so I decided to wrote a Layer for it.
It's supposed to create, manage, draw, and destroy X11 widgets with a cairo surface to draw.
Additional to subscribe to and handle events.

I decided to put it in the Public Domain, so everyone could do what ever he /she want's with it.

The repository contain a example folder showing some of the features supported by the layer.
It's a tiny, but powerful abstraction of the X11 low level API to easier the process to create nice GUI's.
Documentation is included in the source code, it's a single header and a single c file.
All together just 654 lines, were most lines taken by documentation.

So, here you go:
https://github.com/brummer10/Xputty