> Reason is a combination of Google making Play publishing something between hard and impossible
Can someone expand on what's going on here?
[1]: https://forum.syncthing.net/t/discontinuing-syncthing-androi...
They're Java-only APIs and since Syncthings core isn't written in Java, the author would have to write JNI glue to call Android when writing/reading files (and honestly this would be quite tedious, because the way SAF works is to assign Uris to each file and you need to keep querying it to get folder structure since you can't just concat paths like with files).
The author didn't want to do that and tried to persuade Google to continue letting them access all files, all photos and all documents directly and Google said no. That was the "difficulty" - turns out it's really hard to publish on Play if you refuse to follow the guidelines. Just like on AppStore.
Likewise they will be rather surprised to insist in targeting iOS/iPadOS/watchOS as if they are UNIX clones.
Fun fact: the official Dropbox Android app used to use inotify to watch for changes to the publicly writeable synced files in order to sync back to the cloud! Had to be replaced by java Storage Access Framework APIs later.
Another fun fact is that the Android sdk came with a JNI wrapper around inotify but it buggily stored inotify handles in a static (global, within an app vm) dictionary, meaning you'd silently lose tracking if you created more than one Java file watcher object that happened to be for the same path, so I had to rewrite that JNI wrapper back in the day to avoid that global state bug.