android_libcpp_shared 0.2.0

Dart / flutter package for Android to add the libc++_shared.so STL C++ shared runtime library to your app

android_libcpp_shared

Dart / flutter package for Android to add the libc++_shared.so STL C++ shared runtime library to your app

Usage

Prerequisites

You obviously need dart/flutter installed, but in addition you must have the Android NDK installed. This package does its best to find the NDK install location during the build hook step.

Adding the dependency

Add the package to your pubspec.yaml dependencies:

dependencies:
  android_libcpp_shared: ^0.2.0

You don't need to import anything into your Dart code, the dependency is sufficient to bundle the native library with your app. The package does include an optional API if you want to directly use functions from libc++_shared.so using dart:ffi, but this is not required to include the library in your app.

Gradle configuration

Consider adding --enable-native-access=ALL-UNNAMED to org.gradle.jvmargs in your gradle.properties file. This will help make sure that future versions of gradle / java won't break with restrictod methods.

Your entire android/gradle.properties file should look something like this (along with any additional properties you have added):

org.gradle.jvmargs=-Xmx8G -XX:MaxMetaspaceSize=4G -XX:ReservedCodeCacheSize=512m -XX:+HeapDumpOnOutOfMemoryError --enable-native-access=ALL-UNNAMED
android.useAndroidX=true
# This builtInKotlin flag was added automatically by Flutter migrator
android.builtInKotlin=false
# This newDsl flag was added automatically by Flutter migrator
android.newDsl=false

Once Flutter has migrated to a newer gradle / android gradle plugin version, these instructions may change.

Optional API

If you want to directly use functions from libc++_shared.so using dart:ffi, you can use API like this:

import 'package:android_libcpp_shared/android_libcpp_shared.dart';

void main() {
  // Example usage of the API to call a function from libc++_shared.so
  final int Function()? nativeRand = libCppShared?.lookup<ffi.NativeFunction<ffi.Int64 Function()>>('rand')
          .asFunction<int Function()>();
  if (nativeRand == null) {
    print('You are not on android');
    return;
  }
  final result = nativeRand();
  print('Random number from libc++_shared.so: $result');
}

License

This project is licensed under the MIT License. See the LICENSE file for details. Parts of the NDK locating code are adapted from the Dart native_toolchain_c package, which is licensed under a BSD-style license. See the NATIVE_LICENSE file for details.