Odin/examples/android/README.md

Android

A NativeActivity app in Odin. It starts at main through core:sys/android/native_app_glue, fills its window with a colour that follows a touch, and reads app/assets/hello.txt through core:os.

Requirements

• The Android NDK, as ODIN_ANDROID_NDK. Odin's bindings come from NDK r30.
• The Android SDK with build-tools and a platform, as ODIN_ANDROID_SDK. On Windows it defaults to %LocalAppData%\Android\Sdk.
• A JDK, through JAVA_HOME or PATH.
• A signing key. By default this is the debug keystore that Android Studio makes, ~/.android/debug.keystore. Otherwise pass -android-keystore, -android-keystore-alias, and -android-keystore-password.
• For an .aab, bundletool's .jar, as ODIN_ANDROID_BUNDLETOOL.

Layout

Path	What
main.odin	The app.
app/AndroidManifest.xml	Names the activity, org.odin_lang.OdinActivity, and the library to load.
app/res/	Resources: here only the app's name.
app/assets/	Files the app reads under /android_asset with core:os.
app/lib/<abi>/	libexample.so for each ABI, built below.

Building

Build the library once per ABI, then bundle the app directory. A phone needs only arm64-v8a, and the emulator x86_64:

mkdir -p examples/android/app/lib/arm64-v8a
odin build examples/android -target:linux_arm64 -subtarget:android -minimum-os-version:29 -build-mode:shared -out:examples/android/app/lib/arm64-v8a/libexample.so
odin bundle android examples/android/app -minimum-os-version:29 -out:examples/android/example.apk

For all four ABIs:

for pair in arm64-v8a:linux_arm64 armeabi-v7a:linux_arm32 x86:linux_i386 x86_64:linux_amd64; do
	abi=${pair%%:*}
	target=${pair#*:}
	mkdir -p examples/android/app/lib/$abi
	odin build examples/android -target:$target -subtarget:android -minimum-os-version:29 -build-mode:shared -out:examples/android/app/lib/$abi/libexample.so
done
odin bundle android examples/android/app -minimum-os-version:29 -out:examples/android/example.apk

• Give every build and the bundle the same -minimum-os-version. It defaults to 34, and 29 is the lowest Odin supports.
• odin build does not create the output directory, hence the mkdir.
• -out:examples/android/example.aab makes an Android App Bundle for Google Play instead.

Running

adb install examples/android/example.apk
adb shell am start -n org.odin_lang.example/org.odin_lang.OdinActivity
adb logcat -s OdinExample org.odin_lang.example

core:log's console logger writes to logcat with its ident as the tag. stdout and stderr go to logcat too, tagged with the package name. Back ends main, and the process with it.