Android/r8 optimization

.github/actions/setup-android/action.yml

@@ -3,11 +3,14 @@
 runs:
   using: "composite"
   steps:
+    - name: Set ANDROID_SDK_ROOT
+      run: echo "ANDROID_SDK_ROOT=$HOME/.android/sdk" >> $GITHUB_ENV
+      shell: bash
+
     - uses: android-actions/setup-android@v3
       with:
         log-accepted-android-sdk-licenses: false
-        cmdline-tools-version: 11076708
-        packages: tools platform-tools emulator system-images;android-35;google_apis_playstore;x86_64
+        packages: tools cmdline-tools;latest platform-tools emulator system-images;android-35;google_apis_playstore;x86_64
 
     - name: Enable KVM group perms
       run: |

example/android/javalib/1-hello-world/build.mill

@@ -70,8 +70,11 @@ object app extends AndroidAppModule {
 
 /** Usage
 
-> ./mill show app.androidApk
-".../out/app/androidApk.dest/app.apk"
+> ./mill show app.androidReleaseApk
+".../out/app/androidReleaseApk.dest/app.apk"
+
+> ./mill show app.androidDebugApk
+".../out/app/androidDebugApk.dest/app.apk"
 
 */
 

example/android/javalib/2-app-bundle/build.mill

@@ -28,8 +28,11 @@ object bundle extends AndroidAppBundle {
 
 /** Usage
 
-> ./mill show bundle.androidBundle
-".../out/bundle/androidBundle.dest/signedBundle.aab"
+> ./mill show bundle.androidReleaseBundle
+".../out/bundle/androidReleaseBundle.dest/signedBundle.aab"
+
+> ./mill show bundle.androidDebugBundle
+".../out/bundle/androidDebugBundle.dest/signedBundle.aab"
 
 */
 

example/android/javalib/3-linting/build.mill

@@ -72,7 +72,7 @@ AndroidManifest.xml:3: Error: Avoid hardcoding the debug mode; leaving it out al
 > ./mill app.androidLintRun # Rerun it for new changes to reflect
 
 > cat out/app/androidLintRun.dest/report.txt # Check the content of report again
-../../lint-baseline.xml: Information: 1 errors/warnings were listed in the baseline file (../../lint-baseline.xml) but not found in the project; perhaps they have been fixed? Unmatched issue types: HardcodedDebugMode [LintBaseline]
+../../lint-baseline.xml: Information: 1 errors/warnings were listed in the baseline file (../../lint-baseline.xml) but not found in the project; perhaps they have been fixed? Unmatched issue types: HardcodedDebugMode [LintBaselineFixed]
 
 */
 

example/android/javalib/4-sum-lib-java/build.mill

@@ -127,7 +127,7 @@ Publish ... to /home/.../.m2/repository/...
   },
   "payload": [
     [
-      ".../out/lib/androidAar.dest/library.aar",
+      ".../out/lib/androidReleaseAar.dest/library.aar",
       "lib-0.0.1.aar"
     ],
 ...

example/android/javalib/5-R8/app/proguard-rules.pro

@@ -0,0 +1,24 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+-renamesourcefileattribute SourceFilex
+
+-keep class com.helloworld.** { *; }
+

example/android/javalib/5-R8/app/src/androidTest/java/com/helloworld/app/ExampleInstrumentedTest.java

@@ -0,0 +1,26 @@
+package com.helloworld.app;
+
+import static org.junit.Assert.*;
+
+import android.content.Context;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.platform.app.InstrumentationRegistry;
+import com.helloworld.SampleLogic;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+@RunWith(AndroidJUnit4.class)
+public class ExampleInstrumentedTest {
+  @Test
+  public void useAppContext() {
+    // Context of the app under test.
+    Context appContext = InstrumentationRegistry.getInstrumentation().getTargetContext();
+    assertEquals("com.helloworld.app", appContext.getPackageName());
+    assertEquals(32.0f, SampleLogic.textSize(), 0.0001f);
+  }
+}

example/android/javalib/5-R8/app/src/main/AndroidManifest.xml

@@ -0,0 +1,15 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.helloworld.app" android:versionCode="1" android:versionName="1.0">
+    <uses-sdk android:minSdkVersion="9" android:targetSdkVersion="35"/>
+    <application android:label="@string/app_name" android:theme="@android:style/Theme.Light.NoTitleBar" 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>
+    <instrumentation
+            android:name="androidx.test.runner.AndroidJUnitRunner"
+            android:targetPackage="com.helloworld.app" />
+</manifest>

example/android/javalib/5-R8/app/src/main/java/com/helloworld/SampleLogic.java

@@ -0,0 +1,8 @@
+package com.helloworld;
+
+public class SampleLogic {
+
+  public static float textSize() {
+    return 32f;
+  }
+}

example/android/javalib/5-R8/app/src/main/java/com/helloworld/app/MainActivity.java

@@ -0,0 +1,39 @@
+package com.helloworld.app;
+
+import android.app.Activity;
+import android.os.Bundle;
+import android.view.Gravity;
+import android.view.ViewGroup.LayoutParams;
+import android.widget.TextView;
+
+public class MainActivity extends Activity {
+  @Override
+  protected void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+
+    // Create a new TextView
+    TextView textView = new TextView(this);
+
+    // Set the text to the string resource
+    textView.setText(getString(R.string.hello_world));
+
+    // Set text size
+    textView.setTextSize(32);
+
+    // Center the text within the view
+    textView.setGravity(Gravity.CENTER);
+
+    // Set the layout parameters (width and height)
+    textView.setLayoutParams(
+        new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
+
+    // Set the text color using a resource
+    textView.setTextColor(getResources().getColor(R.color.text_green));
+
+    // Set the background color using a resource
+    textView.setBackgroundColor(getResources().getColor(R.color.white));
+
+    // Set the content view to display the TextView
+    setContentView(textView);
+  }
+}

example/android/javalib/5-R8/app/src/main/res/values/colors.xml

@@ -0,0 +1,4 @@
+<resources>
+    <color name="white">#FFFFFF</color>
+    <color name="text_green">#34A853</color>
+</resources>

example/android/javalib/5-R8/app/src/main/res/values/strings.xml

@@ -0,0 +1,4 @@
+<resources>
+    <string name="app_name">HelloWorldApp</string>
+    <string name="hello_world">Hello, World Java!</string>
+</resources>

example/android/javalib/5-R8/app/src/test/java/com/helloworld/ExampleUnitTest.java

@@ -0,0 +1,20 @@
+package com.helloworld;
+
+import static org.junit.Assert.*;
+
+import com.helloworld.app.R;
+import org.junit.Test;
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+public class ExampleUnitTest {
+  @Test
+  public void textSize_isCorrect() {
+
+    assertEquals(32f, SampleLogic.textSize(), 0.000001f);
+    assertEquals(0x7f010000, R.color.text_green);
+  }
+}

example/android/javalib/5-R8/app/test-proguard-rules.pro

@@ -0,0 +1,24 @@
+# Proguard rules for instrumented tests
+
+# Suppress warnings (so that you aren’t spammed with messages for unused rules)
+-ignorewarnings
+
+# Do not run any code optimizations – we want to keep our test code unchanged.
+-dontoptimize
+
+# Keep all annotation metadata (needed for reflection-based test frameworks)
+-keepattributes *Annotation*
+
+# Keep all Espresso framework classes and specifically ensure that the idling resources aren’t stripped
+-keep class androidx.test.espresso.** { *; }
+-keep class androidx.test.espresso.IdlingRegistry { *; }
+-keep class androidx.test.espresso.IdlingResource { *; }
+
+# Suppress notes and warnings for older JUnit and Android test classes
+-dontnote junit.framework.**
+-dontnote junit.runner.**
+
+-dontwarn androidx.test.**
+-dontwarn org.junit.**
+-dontwarn org.hamcrest.**
+-dontwarn com.squareup.javawriter.JavaWriter

example/android/javalib/5-R8/build.mill

@@ -0,0 +1,146 @@
+// This section sets up a basic Android project using Mill.
+// We utilize `AndroidAppModule` and `AndroidSdkModule` to streamline the process of
+// building an Android application with minimal configuration.
+//
+// By extending `AndroidAppModule`, we inherit all Android-related tasks such as
+// resource generation, APK building, DEX conversion, and APK signing.
+// Additionally, `AndroidSdkModule` is embedded, making SDK management seamless.
+
+//// SNIPPET:BUILD
+package build
+
+import mill._, javalib._
+
+import mill.javalib.android.{AndroidAppModule, AndroidSdkModule}
+import mill.javalib.android.AndroidTestModule
+
+// Create and configure an Android SDK module to manage Android SDK paths and tools.
+object androidSdkModule0 extends AndroidSdkModule {
+  def buildToolsVersion = "35.0.0"
+}
+
+// Actual android application
+object app extends AndroidAppModule {
+  def androidSdkModule = mill.define.ModuleRef(androidSdkModule0)
+  def androidMinSdk = 19
+  def androidCompileSdk = 35
+
+  // Configuration for ReleaseKey
+  def androidReleaseKeyName: T[Option[String]] = Task { Some("releaseKey.jks") }
+  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 = "java-test"
+
+  object test extends AndroidAppTests with TestModule.Junit4 {
+    def testFramework = "com.novocode.junit.JUnitFramework"
+    def ivyDeps = super.ivyDeps() ++ Seq(
+      ivy"junit:junit:4.13.2"
+    )
+  }
+
+  object it extends AndroidAppInstrumentedTests with AndroidTestModule.AndroidJUnit {
+
+    def androidSdkModule = mill.define.ModuleRef(androidSdkModule0)
+
+    override def instrumentationPackage = "com.helloworld.app"
+
+    /* TODO currently the dependency resolution ignores the platform type and kotlinx-coroutines-core has
+     * conflicting classes with kotlinx-coroutines-core-jvm . Remove the exclusions once the dependency
+     * resolution resolves conflicts between androidJvm and jvm platform types
+     */
+    def ivyDeps = super.ivyDeps() ++ Seq(
+      ivy"androidx.test.ext:junit:1.2.1".exclude((
+        "org.jetbrains.kotlinx",
+        "kotlinx-coroutines-core-jvm"
+      )),
+      ivy"androidx.test:runner:1.6.2",
+      ivy"androidx.test.espresso:espresso-core:3.5.1".exclude((
+        "org.jetbrains.kotlinx",
+        "kotlinx-coroutines-core-jvm"
+      )),
+      ivy"junit:junit:4.13.2"
+    )
+  }
+
+}
+
+////SNIPPET:END
+
+/** Usage
+
+> ./mill show app.androidReleaseApk
+".../out/app/androidReleaseApk.dest/app.apk"
+
+> ./mill show app.androidDebugApk
+".../out/app/androidDebugApk.dest/app.apk"
+
+*/
+
+// This command triggers the build process, which installs the Android Setup, compiles the Java
+// code, generates Android resources, converts Java bytecode to DEX format, packages everything
+// into an APK, optimizes the APK using `zipalign`, and finally signs it.
+//
+// This Mill build configuration is designed to build a simple "Hello World" Android application.
+// By extending `AndroidAppModule`, we leverage its predefined Android build tasks, ensuring that
+// all necessary steps (resource generation, APK creation, and signing) are executed automatically.
+//
+// #### Project Structure:
+// The project follows the standard Android app layout. Below is a typical project folder structure:
+//
+// ----
+// .
+//├── app
+//│     └── src
+//│         ├── androidTest/java/com/helloworld/app/ExampleInstrumentedTest.java
+//│         ├── main
+//│         │     ├── AndroidManifest.xml
+//│         │     ├── java/com/helloworld/app/MainActivity.java
+//│         │     └── res
+//│         │         └── values
+//│         │             ├── colors.xml
+//│         │             └── strings.xml
+//│         └── test/java/com/helloworld/app/ExampleUnitTest.java
+//└── build.mill
+// ----
+//
+
+/** Usage
+
+> ./mill show app.test
+...compiling 2 Java source...
+
+> cat out/app/test/testForked.dest/worker-0/out.json
+["",[{"fullyQualifiedName":"com.helloworld.ExampleUnitTest.textSize_isCorrect","selector":"com.helloworld.ExampleUnitTest.textSize_isCorrect","duration":...,"status":"Success"}]]
+
+*/
+
+// This command runs unit tests on your local environment.
+
+/** Usage
+
+> ./mill show app.createAndroidVirtualDevice
+...Name: java-test, DeviceId: medium_phone...
+
+> ./mill show app.startAndroidEmulator
+
+> ./mill show app.androidReleaseInstall
+...All files should be loaded. Notifying the device...
+
+> ./mill show app.androidDebugInstall
+...All files should be loaded. Notifying the device...
+
+> ./mill show app.stopAndroidEmulator
+
+> ./mill show app.deleteAndroidVirtualDevice
+
+*/
+
+// The android tests (existing typically in androidTest directory, aka instrumented tests)
+// typically run on an android device.
+// The createAndroidVirtualDevice command creates an AVD (Android Virtual Device)
+// and the startAndroidEmulator command starts the AVD. The it task runs the android tests
+// against the available AVD. The stopAndroidEmulator command stops the AVD and the
+// destroyAndroidVirtualDevice command destroys the AVD.
+// The provided commands can be used in a CI/CD pipeline assuming the right setup is in place.