[WIP] Hello world Kotlin Jetpack Compose Example; Fixes:#3550

example/kotlinlib/android/2-jetpack-compose-hello-world/app/AndroidManifest.xml

@@ -0,0 +1,12 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.helloworld.app">
+ <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="35"/>
+ <application android:label="Hello World" android:debuggable="true">
+ <activity android:name=".MainActivity"
+ android:exported="true">
+ <intent-filter>
+ <action android:name="android.intent.action.MAIN"/>
+ <category android:name="android.intent.category.LAUNCHER"/>
+ </intent-filter>
+ </activity>
+ </application>
+</manifest>

example/kotlinlib/android/2-jetpack-compose-hello-world/app/src/main/kotlin/com/helloworld/app/MainActivity.kt

@@ -0,0 +1,21 @@
+package com.helloworld.app
+
+import android.os.Bundle
+import androidx.activity.ComponentActivity
+import androidx.activity.compose.setContent
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+
+class MainActivity : ComponentActivity() {
+ override fun onCreate(savedInstanceState: Bundle?) {
+ super.onCreate(savedInstanceState)
+ setContent {
+ Greeting("Hello, World!")
+ }
+ }
+}
+
+@Composable
+fun Greeting(name: String) {
+ Text(text = name)
+}

example/kotlinlib/android/2-jetpack-compose-hello-world/build.mill

@@ -0,0 +1,45 @@
+//// SNIPPET:BUILD
+package build
+
+import mill._
+import kotlinlib._
+import coursier.maven.MavenRepository
+import mill.kotlinlib.android.AndroidAppKotlinModule
+import mill.javalib.android.AndroidSdkModule
+
+val maven_google = Seq(
+ MavenRepository("https://maven.google.com/"),
+ MavenRepository("https://repo1.maven.org/maven2")
+)
+
+object androidSdkModule0 extends AndroidSdkModule {
+ def buildToolsVersion = "35.0.0"
+}
+
+object app extends AndroidAppKotlinModule {
+ def kotlinVersion = "2.0.20"
+ def androidSdkModule = mill.define.ModuleRef(androidSdkModule0)
+
+ override def mandatoryIvyDeps: T[Agg[Dep]] = Task {
+ super.mandatoryIvyDeps() ++ Agg(
+ // Jetpack Compose dependencies
+ ivy"androidx.compose.compiler:compiler:1.5.15",
+ ivy"androidx.activity:activity:1.8.2",
+ ivy"androidx.activity:activity-compose:1.8.2",
+ ivy"androidx.compose.runtime:runtime:1.3.1",
+ ivy"androidx.compose.material3:material3:1.0.1"
+ )
+ }
+
+ def repositoriesTask = T.task { super.repositoriesTask() ++ maven_google }
+
+}
+
+////SNIPPET:END
+
+/** Usage
+
+> ./mill show app.androidApk
+".../out/app/androidApk.dest/app.apk"
+
+*/

kotlinlib/src/mill/kotlinlib/android/AndroidAppKotlinModule.scala

@@ -2,6 +2,9 @@ package mill.kotlinlib.android
 
 import mill.kotlinlib.KotlinModule
 import mill.javalib.android.AndroidAppModule
+import mill._
+import coursier.Type
+import upickle.default.ReadWriter
 
 /**
  * Trait for building Android applications using the Mill build tool.
@@ -18,4 +21,55 @@ import mill.javalib.android.AndroidAppModule
  * [[https://developer.android.com/studio Android Studio Documentation]]
  */
 @mill.api.experimental
-trait AndroidAppKotlinModule extends AndroidAppModule with KotlinModule {}
+trait AndroidAppKotlinModule extends AndroidAppModule with KotlinModule {
+ // Implicit ReadWriter for coursier.Type
+ implicit val coursierTypeRW: ReadWriter[Type] = upickle.default.readwriter[String].bimap(
+ t => t.value, // Convert coursier.Type to a String
+ Type(_) // Convert String back to coursier.Type
+ )
+
+ // Implicit ReadWriter for Set[coursier.Type]
+ implicit val coursierTypeSetRW: ReadWriter[Set[Type]] =
+ upickle.default.readwriter[Set[String]].bimap(
+ set => set.map(_.value), // Serialize Set[coursier.Type] to Set[String]
+ set => set.map(Type(_)) // Deserialize Set[String] to Set[coursier.Type]
+ )
+
+ // Artifact types to add "aar" type to the Set of artifact types
+ def artifactTypes: T[Set[Type]] =
+ T { super.artifactTypes() + coursier.Type("aar") }
+
+ // Task to extract JARs from AARs
+ def recompileAARs: T[Seq[PathRef]] = Task {
+ // Get all .aar files from the original compileClasspath
+ val aarFiles = super.compileClasspath().map(_.path).filter(_.ext == "aar").toSeq
+
+ // Extract classes.jar from each .aar file
+ val newJarFiles = aarFiles.map { aarFile =>
+ // Destination for extraction
+ val extractDir = T.dest / aarFile.baseName
+
+ // Unzip the .aar file
+ os.call(Seq("unzip", aarFile.toString, "-d", extractDir.toString))
+
+ // Return the PathRef to classes.jar file
+ PathRef(extractDir / "classes.jar")
+ }
+
+ newJarFiles
+ }
+
+ /**
+ * Updates the compile classpath to include classes `.jar` files.
+ * here we are also removing `.aar` coz they are not worthy after extraction
+ */
+ def updatedCompileClasspath: T[Agg[PathRef]] = Task {
+ super.compileClasspath().filter(_.path.ext == "jar") ++ Agg.from(recompileAARs())
+ }
+
+ /**
+ * Overrides the classpath to include files as `.jar`.
+ */
+ override def compileClasspath: T[Agg[PathRef]] = updatedCompileClasspath()
+
+}