[Feature]: auto-discover Java sources bundled in pip installed packages

[T-Dynamos]

If a pip-installable package ships Java source files alongside its Python code, p4a has no way to pick those up automatically. The only supported path is Buildozer's android.add_src, which requires the app developer to add files manually.

Proposed solution

Right after the pip install stage in build.py scan the newly installed top level package directories for a fixed marker folder: android_java/ (for example). If a package contains one, register its path and send to gradle.

Optionally also delete that folder as it's not required/used.

Original idea by @kuzeyron.

CC: @AndreMiras

[kuzeyron]

fixed marker folder, I'd suggest it just uses glob.glob that scans all pip packages for java codes and includes them. Just awkward for the package maintainer to remember to state a fixed path when they have other things to think of while configuring pyproject.toml ('package = ["java/**/*", "java/*"]). glob.glob handles that nicely without complication.

[T-Dynamos]

@kuzeyron pyproject.toml will not exist in install directory.

[kuzeyron]

@kuzeyron pyproject.toml will not exist in install directory.

'package = ["java/**/", "java/"]` is being used when you are uploading to pypi so yeah

[T-Dynamos]

@kuzeyron I see I misread the original message.

Using glob.glob won't be reliable according to me as glob won't be able to determine at which depth folder needs to be included.

Eg: android_java/com/test/Some.java correct include should be android_java in this case but glob might return test.

[kuzeyron]

@kuzeyron I see I misread the original message.

Using glob.glob won't be reliable according to me as glob won't be able to determine at which depth folder needs to be included.

Eg: android_java/com/test/Some.java correct include should be android_java in this case but glob might return test.

Almost all java folders I've seen is like java/org/kivy/android/myjava.java. So that could be standard. Once when that is done I can documentate it.

Could also be without the java folder so the pyproject.toml would just pick up org