RmlUi VS sciter

How about https://github.com/mikke89/RmlUi ?

Check out these: https://github.com/ocornut/imgui https://github.com/mikke89/RmlUi

See the release notes here: https://github.com/mikke89/RmlUi/releases/tag/5.0

You're right, it's a fork of libRocket. The original library hasn't seen any development in years, so in a sense RmlUi is a continuation of it too. There's been a lot of changes since then, you can see all of it in the full changelog here.

I haven't actually used either one, but there's HikoGUI (previously known as TTauri) under the Boost license and RmlUI under MIT. Not sure if they're very OS-integrated in the way you want or not.

RmlUI

> wondering if css and svg could be used as abstraction over graphics and UI libraries

There's another project called Sciter that uses CSS to target native graphics libraries: https://sciter.com

> I wonder how hard it was to implement css. I've heard it can be pretty complex.

It was hard, but the biggest barrier is the obscurity of the knowledge.

Text layout is the hardest, because working with glyphs and iterating them in reverse for RTL is brain-breaking. And line wrapping gets really complicated. It's also the most obscure because nobody has written down everything you need to know in one place. After I finished block layout early on, I had to stop for a couple of years (only working a few hours a week though) and learn all of the ins, outs, dos, and don'ts around shaping and itemizing text. A lot of that I learned by reading Pango's [1] source code, and a lot I pieced together from Google searches.

But other than that, the W3C specifications cover almost everything. The CSS2 standard [2] is one of the most beautiful things I've ever read. It's internally consistent, concise, and obviously the result of years of deliberation, trial and error. (CSS3 is great, but CSS2 is the bedrock for everything).

[1] https://gitlab.gnome.org/GNOME/pango/

otherwise, if we have only retained mode as in browsers, we will need to modify the DOM heavily and create temporary elements for handles.

[1] https://sciter.com

I've still never used it but I've long been curious about Sciter:

https://sciter.com

These bullet points are exactly what I did in Sciter (https://sciter.com)

- Windowing

-- Tabs

-- Menus

-- Painting

-- Animation

-- Text

-The compositor

-Handling input

-- Pointer input

-- Keyboard input

- Accessibility

- Internationalization and localization

- Cross-platform APIs

- The web view

- Native look and feel

On top of that DOM and CSS implementations to achieve declarative UI. And JS as a languuage behind UI - declarative in some sense way of defining UI behavior.

I'm not sure if it can support all the libraries but yes it can be used to make desktop apps. Theres also Sciter.

https://sciter.com/