README.Android - core - Gitiles

 Android-specific notes

 Unit tests are the first thing we want to run on Android, to get some
 idea how well, if at all, the basic LO libraraies work. We want to
 build even unit tests as normal Android apps, i.e. packaged as .apk
 files, so that they run in a sandboxed environment like that of
 whatever eventual end-user Android apps there will be that use LO
 code.

 Sure, we could quite easily build unit tests as plain Android
 executables, push them to the device or emulator with adb and run them
 from adb shell, but that would not be a good test as the environment
 would be completely different. They would run as root, and not
 sandboxed. We have no intent to require LibreOffice code to be used
 only on "rooted" devices etc.

 All Android apps are basically Java programs. They run "in" a Dalvik
 virtual machine. Yes, you can also have apps where your code is only
 native code, written in a compiled language like C or C++. But also
 also such apps are actually started by system-provided Java
 bootstrapping code (NativeActivity) running in a Dalvik VM.

 Such a native app (or actually, "activity") is not built as a
 executable program, but as a shared object. The Java NativeActivity
 bootstrapper loads that shared object with dlopen.

 It is somewhat problematic to construct .apk packages except by using
 the high-level tools in the Android SDK. At least I haven't figured
 out how to manually construct an .apk that is properly signed so that
 it will run in the emulator. (I don't have any Android device...) I
 only know how to let the SDK Ant tooling do it...

 A LO Android app would work would something like this:

 We have a top Java bootstrapping class
 org.libreoffice.android.Bootstrap that loads a small helper native
 library liblo-bootstrap.so that implements JNI wrappers for dlopen(),
 dlsym(), and ELF header scanning coresponding to looking for DT_NEEDED
 entries with readelf.

 The Java code then loads the actual native library that corresponds to
 the LibreOffice-related "program" we want to run. For unit tests, a
 library that corresponds to cppunittester program. Then through helper
 functions in liblo-bootstrap it calls a named function in that
 "program".

 This Android-specific native code (the lo-bootstrap library) is for
 now in sal/android, and the Java code in the android "module"
 (subdirectory right here).

 --Tor Lillqvist <tml@iki.fi>
	Android-specific notes

	Unit tests are the first thing we want to run on Android, to get some
	idea how well, if at all, the basic LO libraraies work. We want to
	build even unit tests as normal Android apps, i.e. packaged as .apk
	files, so that they run in a sandboxed environment like that of
	whatever eventual end-user Android apps there will be that use LO
	code.

	Sure, we could quite easily build unit tests as plain Android
	executables, push them to the device or emulator with adb and run them
	from adb shell, but that would not be a good test as the environment
	would be completely different. They would run as root, and not
	sandboxed. We have no intent to require LibreOffice code to be used
	only on "rooted" devices etc.

	All Android apps are basically Java programs. They run "in" a Dalvik
	virtual machine. Yes, you can also have apps where your code is only
	native code, written in a compiled language like C or C++. But also
	also such apps are actually started by system-provided Java
	bootstrapping code (NativeActivity) running in a Dalvik VM.

	Such a native app (or actually, "activity") is not built as a
	executable program, but as a shared object. The Java NativeActivity
	bootstrapper loads that shared object with dlopen.

	It is somewhat problematic to construct .apk packages except by using
	the high-level tools in the Android SDK. At least I haven't figured
	out how to manually construct an .apk that is properly signed so that
	it will run in the emulator. (I don't have any Android device...) I
	only know how to let the SDK Ant tooling do it...

	A LO Android app would work would something like this:

	We have a top Java bootstrapping class
	org.libreoffice.android.Bootstrap that loads a small helper native
	library liblo-bootstrap.so that implements JNI wrappers for dlopen(),
	dlsym(), and ELF header scanning coresponding to looking for DT_NEEDED
	entries with readelf.

	The Java code then loads the actual native library that corresponds to
	the LibreOffice-related "program" we want to run. For unit tests, a
	library that corresponds to cppunittester program. Then through helper
	functions in liblo-bootstrap it calls a named function in that
	"program".

	This Android-specific native code (the lo-bootstrap library) is for
	now in sal/android, and the Java code in the android "module"
	(subdirectory right here).

	--Tor Lillqvist <tml@iki.fi>