Android Native Example

This page provides an example of using Mill to build an Android application that utilizes Android Native for based on the official example of Endless Tunnel.

Android Mill Setup for building Endless Tunnel with Android Native

This is how endless-tunnel from android ndk-sample can be built with mill. The original code is in https://github.com/android/ndk-samples/tree/main/endless-tunnel

build.mill (download, browse)

package build

import mill.*, androidlib.*, scalalib.*

object androidSdkModule0 extends AndroidSdkModule {
  def buildToolsVersion = "35.0.0"
}

object `endless-tunnel` extends mill.api.Module {
  object app extends AndroidNativeAppModule {

    def androidSdkModule = mill.api.ModuleRef(androidSdkModule0)

    def androidMinSdk = 19

    def androidCompileSdk = 35

    def androidApplicationId = "com.google.sample.tunnel"

    def androidApplicationNamespace = "com.google.sample.tunnel"

    override def androidNativeLibName: T[String] = "libgame"

    /**
     * Configuration for ReleaseKey
     * WARNING: Replace these default values with secure and private credentials before using in production.
     * Never use these defaults in a production environment as they are not secure.
     * This is just for testing purposes.
     */
    def androidReleaseKeyAlias: T[Option[String]] = Task {
      Some("releaseKey")
    }

    def androidReleaseKeyPass: T[Option[String]] = Task {
      Some("MillBuildTool")
    }

    def androidReleaseKeyStorePass: T[Option[String]] = Task {
      Some("MillBuildTool")
    }

    override def androidVirtualDeviceIdentifier: String = "cpp-test"

    override def androidCMakeExtraArgs: T[Seq[String]] =
      super.androidCMakeExtraArgs() ++ Seq("-DANDROID_STL=c++_static")

  }
}

> ./mill show endless-tunnel.app.androidApk
".../out/endless-tunnel/app/androidApk.dest/app.apk"

> ./mill show endless-tunnel.app.createAndroidVirtualDevice
...Name: cpp-test, DeviceId: medium_phone...

> ./mill show endless-tunnel.app.startAndroidEmulator

> ./mill show endless-tunnel.app.androidInstall
...All files should be loaded. Notifying the device...

> ./mill show endless-tunnel.app.androidRun --activity android.app.NativeActivity
[
  "Starting: Intent { cmp=com.google.sample.tunnel/android.app.NativeActivity }",
  "Status: ok",
  "LaunchState: COLD",
  "Activity: com.google.sample.tunnel/android.app.NativeActivity",
  "TotalTime: ...",
  "WaitTime: ...",
  "Complete"
]

> ./mill show endless-tunnel.app.stopAndroidEmulator

> ./mill show endless-tunnel.app.deleteAndroidVirtualDevice

This example demonstrates how to build an Android app that uses Hilt for dependency injection, translating the original Gradle configuration to Mill.