[jezek2]

Thanks, it might be useful for macOS support of non-native widgets in my GUI library. I did some parsing but got stuck at some point.

Seems a better choice to just parse the files than using private APIs as I couldn't see much of the documentation for them (or rather reversed APIs in various projects) + image handling is weirdly complicated in macOS generally so I want to avoid that.

Currently I've experimented by just recreating the graphics from scratch using vector rendering but it's quite cumbersome.

Other libraries, such as Qt, try to draw the native widgets into offscreen image but it's extremely hacky way prone to GUI breaking with any OS update. Java has their own Apple blessed way, but seems quite limited to me and don't want to depend on that either.