This project builds an Android library, rgb-lib-android, for the rgb-lib Rust library, which is included as a git submodule. The bindings are created by the rgb-lib-uniffi project, which is located inside the rgb-lib submodule.

To use the Kotlin library add the following to your project gradle dependencies:

repositories {
    mavenCentral()
}

dependencies {
    implementation 'org.rgbtools:rgb-lib-android:<version>'
}

Clone the project, including submodules:

git clone [email protected]:rgb-tools-devs/rgb-lib-kotlin.git --recurse-submodules

When fetching updates, remember to update the submodule as well:

git submodule update --init

Build the docker image (if your user or group IDs are not 1000, adjust the environment variables MYUID and MYGID in the compose.yaml file accordingly):

docker compose run --build --rm builder

Notes:

• image build takes a long time and uses a lot of disk space
• the local directory will be mounted into the container at runtime
• the gradle_cache local directory will be mounted into the container to cache gradle downloads

Setup the following environment variables:

• ANDROID_SDK_ROOT (e.g. export ANDROID_SDK_ROOT=$HOME/Android/Sdk)
• ANDROID_NDK_ROOT (export ANDROID_NDK_ROOT=$ANDROID_SDK_ROOT/ndk/25.<NDK_VERSION>)

Note: NDK version 25.2.x can be installed via android studio (SDK Manager) or command-line tools (sdkmanager).

Add the required Android rust targets:

rustup target add aarch64-linux-android
rustup target add x86_64-linux-android

Build the Android library:

./gradlew :android:buildAndroidLib

Check the build library page alignment:

for LIB in $(find rgb-lib/bindings/uniffi/target/ -wholename '*release/librgblibuniffi.so'); do ls -l "$LIB"; readelf -l "$LIB" |grep -A1 LOAD; done

The last column of each LOAD row is the alignment:

• 0x1000 => pages align to 4KB
• 0x4000 => pages align to 16KB

Download OpenJDK 18 and unpack it to a directory of your choice (e.g. $HOME/jdk).

Setup the following environment variables:

• ANDROID_SDK_ROOT (e.g. export ANDROID_SDK_ROOT="$HOME/Android/Sdk")
• ANDROID_HOME (export ANDROID_HOME="$ANDROID_SDK_ROOT")
• ANDROID_NDK_ROOT (export ANDROID_NDK_ROOT=$ANDROID_SDK_ROOT/ndk/25.2.<NDK_VERSION>)
• JAVA_HOME (e.g. export JAVA_HOME=$HOME/jdk/jdk-18.0.2)
• PATH (export PATH=$JAVA_HOME/bin:$PATH)

Publish the library to your local Maven repository:

./gradlew :android:publishToMavenLocal

Create a ~/.jreleaser/config.yml file with the publishing and signing information:

JRELEASER_GITHUB_OWNER: RGB-Tools
JRELEASER_GITHUB_NAME: rgb-lib-kotlin
JRELEASER_GITHUB_TOKEN: fake-token-not-used

JRELEASER_MAVENCENTRAL_USERNAME: "<your-publisher-portal-username>"
JRELEASER_MAVENCENTRAL_PASSWORD: "<your-publisher-portal-password>"

Test your configuration by running:

./gradlew jreleaserConfig

Build the artifacts by running:

./gradlew :android:publish

Set your GPG password to the apprpriate environment variable by running:

read -rsp "GPG password: " JRELEASER_GPG_PASSPHRASE

Test the publishing by running:

./gradlew jreleaserDeploy --dryrun -Pjreleaser.gpg.keyName="<your_key_id>" -Pjreleaser.gpg.passphrase="$JRELEASER_GPG_PASSPHRASE"

Publish by running:

./gradlew jreleaserDeploy -Pjreleaser.gpg.keyName="<your_key_id>" -Pjreleaser.gpg.passphrase="$JRELEASER_GPG_PASSPHRASE"