50 lines
2.2 KiB
Text
50 lines
2.2 KiB
Text
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Android-specific notes
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Unit tests are the first thing we want to run on Android, to get some
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idea how well, if at all, the basic LO libraraies work. We want to
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build even unit tests as normal Android apps, i.e. packaged as .apk
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files, so that they run in a sandboxed environment like that of
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whatever eventual end-user Android apps there will be that use LO
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code.
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Sure, we could quite easily build unit tests as plain Android
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executables, push them to the device or emulator with adb and run them
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from adb shell, but that would not be a good test as the environment
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would be completely different. They would run as root, and not
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sandboxed. We have no intent to require LibreOffice code to be used
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only on "rooted" devices etc.
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All Android apps are basically Java programs. They run "in" a Dalvik
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virtual machine. Yes, you can also have apps where your code is only
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native code, written in a compiled language like C or C++. But also
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also such apps are actually started by system-provided Java
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bootstrapping code (NativeActivity) running in a Dalvik VM.
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Such a native app (or actually, "activity") is not built as a
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executable program, but as a shared object. The Java NativeActivity
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bootstrapper loads that shared object with dlopen.
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It is somewhat problematic to construct .apk packages except by using
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the high-level tools in the Android SDK. At least I haven't figured
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out how to manually construct an .apk that is properly signed so that
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it will run in the emulator. (I don't have any Android device...) I
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only know how to let the SDK Ant tooling do it...
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A LO Android app would work would something like this:
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We have a top Java bootstrapping class
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org.libreoffice.android.Bootstrap that loads a small helper native
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library liblo-bootstrap.so that implements JNI wrappers for dlopen(),
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dlsym(), and ELF header scanning coresponding to looking for DT_NEEDED
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entries with readelf.
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The Java code then loads the actual native library that corresponds to
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the LibreOffice-related "program" we want to run. For unit tests, a
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library that corresponds to cppunittester program. Then through helper
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functions in liblo-bootstrap it calls a named function in that
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"program".
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This Android-specific code is for now in sal/osl/android.
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--Tor Lillqvist <tml@iki.fi>
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