Add other backend UI framework on non-Darwin platform

[Kyle]

• Add AppKid as UIKit/AppKit alternative on Linux platform
• Take swift-cross-ui's code to use gtk4 as UIKit/AppKit alternative on Windows/Linux platform
• https://github.com/AparokshaUI/adwaita-swift

Will work on this when basic UIView/NSView support is ready.

[Chawye Hsu]

I wonder if it's possible to use the WinUI infra as the backend on Windows platform.

[Kyle]

I wonder if it's possible to use the WinUI infra as the backend on Windows platform.

Theoretically, it is possible. Recently, I have started to add some platform-related code (UIView/NSView) and rendering layer things.

If you are interested you are welcome to contribute platform code on the WinUI layer later.

[Kyle]

https://github.com/microsoft/WinObjC.git

There is a WinObjC project which provide UIKit compatible API on Windows too.

[Chawye Hsu]

IIUC that framework is basically obsolete, it's a pretty good reference though.