Android: Fix resource linking on multimodule projects

example/androidlib/java/1-hello-world/build.mill

@@ -99,7 +99,7 @@ object app extends AndroidAppModule {
 /** Usage
 
 > ./mill show app.test
-...compiling 1 Java source...
+...compiling 2 Java sources to out/app/test/compile.dest/classes...
 
 > cat out/app/test/testForked.dest/out.json
 ["",[{"fullyQualifiedName":"com.helloworld.ExampleUnitTest.textSize_isCorrect","selector":"com.helloworld.ExampleUnitTest.textSize_isCorrect","duration":...,"status":"Success"}]]

libs/androidlib/src/mill/androidlib/AndroidAppModule.scala

@@ -235,6 +235,10 @@ trait AndroidAppModule extends AndroidModule { outer =>
     )
   }
 
+  override def androidAaptNonFinalIds: T[Boolean] = Task {
+    false
+  }
+
   /**
    * Regex patterns of files to be excluded from packaging into the APK.
    */

libs/androidlib/src/mill/androidlib/AndroidModule.scala

@@ -128,20 +128,44 @@ trait AndroidModule extends JavaModule { outer =>
   def androidVersionCode: T[Int] = 1
 
   /**
-   * Specifies AAPT options for Android resource compilation.
+   * Specifies AAPT options for Android resource linking.
    */
   def androidAaptOptions: T[Seq[String]] = Task {
-    if (androidIsDebug()) {
-      Seq(
-        "--proguard-minimal-keep-rules",
-        "--debug-mode",
-        "--auto-add-overlay"
-      )
-    } else {
-      Seq("--auto-add-overlay")
+    val debugOptions = Seq(
+      "--proguard-minimal-keep-rules",
+      "--debug-mode"
+    )
+
+    val extraPackages = androidAaptLinkExtraPackages().flatMap(ns => Seq("--extra-packages", ns))
+
+    Seq(
+      "--auto-add-overlay",
+      "--no-version-vectors",
+      "--no-proguard-location-reference"
+    ) ++ extraPackages
+      ++ Option.when(androidAaptNonFinalIds())(Seq("--non-final-ids")).toSeq.flatten
+      ++ Option.when(androidIsDebug())(debugOptions).toSeq.flatten
+  }
+
+  /**
+   * Collect the namespaces from the Android module dependencies to be
+   * passed to AAPT during resource linking.
+   */
+  def androidAaptLinkExtraPackages: T[Seq[String]] = Task {
+    // TODO: cleanup once we properly pass resources from dependencies
+    recursiveModuleDeps.collect {
+      case p: AndroidModule => p.androidNamespace
     }
   }
 
+  /**
+   * Sets whether resource IDs generated by AAPT should be non-final.
+   * Default is true for non-app modules.
+   */
+  def androidAaptNonFinalIds: T[Boolean] = Task {
+    true
+  }
+
   def androidProviderProguardConfigRules: T[Seq[String]] = Task {
     val androidNs = "http://schemas.android.com/apk/res/android"
     val manifest = androidMergedManifest().path
@@ -487,7 +511,8 @@ trait AndroidModule extends JavaModule { outer =>
     // * it will generate R.java for the library even library has no resources declared
     // * R.java will have not only resource ID from this library, but from other libraries as well. They should be stripped.
     val rClassDir = androidLinkedResources().path / "generatedSources/java"
-    val mainRClassPath = os.walk(rClassDir)
+    val rSources = os.walk(rClassDir).filter(p => os.isFile(p) && p.ext == "java")
+    val mainRClassPath = rSources
       .find(_.last == "R.java")
       .get
 
@@ -508,7 +533,7 @@ trait AndroidModule extends JavaModule { outer =>
       )
     } yield PathRef(libRClassPath)
 
-    libClasses :+ PathRef(mainRClassPath)
+    libClasses ++ rSources.map(PathRef(_))
   }
 
   /**

libs/androidlib/src/mill/androidlib/hilt/AndroidHiltSupport.scala

@@ -24,6 +24,11 @@ import mill.{T, Task}
 @mill.api.experimental
 trait AndroidHiltSupport extends KspModule, AndroidKotlinModule {
 
+  // Dagger does not work with the bt api
+  override def kotlincUseBtApi: T[Boolean] = Task {
+    false
+  }
+
   override def kspProcessorOptions: T[Map[String, String]] = Task {
     super.kspProcessorOptions() ++ Map(
       "dagger.fastInit" -> "enabled",