Outdated KMP + Rust template (check mages build.gradle.kts and structure for updated parts)

Kotlin Multiplatform (Compose for Android) app with a Rust core called via JNI.

Layout

• composeApp/ — KMP Android app (Compose)
• rust/ — Rust crate that builds a shared library (libfrair_native.so)

Prerequisites

• Android Studio + Android SDK + NDK installed
• Rust toolchain (rustup), stable channel
• cargo-ndk: cargo install cargo-ndk

Ensure cargo and cargo-ndk are on your PATH, and the Android NDK is installed in your SDK.

Build & Run (Android)

• macOS/Linux:

  ./gradlew :composeApp:assembleDebug

• Windows:

  .\gradlew.bat :composeApp:assembleDebug

Gradle will invoke cargo ndk to build Rust for arm64-v8a, x86_64, and armeabi-v7a, and place the .so files under:

composeApp/src/androidMain/jniLibs/<abi>/libfrair_native.so

Code Usage

Call Rust from shared code via an expect/actual facade:

val msg = RustApi.greet(getPlatform().name)

Rust implements the logic, JNI exposes:

Java_org_mlm_frair_NativeLib_greetFromRust(env, class, name)

Notes

• We catch Rust panics at the JNI boundary and throw a Java RuntimeException, returning "" as a fallback.
• Adjust ndk.abiFilters in composeApp/build.gradle.kts to the ABIs you intend to ship.

Notes:
- Install the Android NDK, cargo-ndk and std libs for targets before building.
- No other files need to change; existing UI (App.kt) will display the Rust greeting.