chore(android): migrate plugins to built-in Kotlin

.github/workflows/code-analysis.yml

@@ -20,11 +20,11 @@ jobs:
       - uses: actions/checkout@v7.0.1
       - uses: actions/setup-java@v5.6.0
         with:
-          java-version: 11
+          java-version: 17
           distribution: temurin
       - uses: subosito/flutter-action@v2.23.0
         with:
-          flutter-version: '3.35.3'
+          flutter-version: '3.44.8'
           cache: true
 
       - name: Install dependencies for google_ml_kit
@@ -140,3 +140,61 @@ jobs:
         run: brew install swiftlint
       - name: Run SwiftLint on Swift code
         run: swiftlint lint
+
+  build-android:
+    name: Build Android example without plugin KGP warnings
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v7.0.1
+      - uses: actions/setup-java@v5.6.0
+        with:
+          java-version: 17
+          distribution: temurin
+      - uses: subosito/flutter-action@v2.23.0
+        with:
+          flutter-version: '3.44.8'
+          cache: true
+      - name: Install dependencies
+        working-directory: ./packages/example
+        run: flutter pub get
+      - name: Build Android example
+        working-directory: ./packages/example
+        shell: bash
+        run: |
+          set -o pipefail
+          flutter build apk --debug 2>&1 | tee android-build.log
+          ! grep -F "plugins that apply Kotlin Gradle Plugin" android-build.log
+
+  # Flutter only supports enabling AGP 9's built-in Kotlin from 3.47 onward.
+  # Keep this beta lane until 3.47 is stable, then pin the stable release.
+  build-android-built-in-kotlin:
+    name: Build Android example with AGP 9 built-in Kotlin
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v7.0.1
+      - uses: actions/setup-java@v5.6.0
+        with:
+          java-version: 21
+          distribution: temurin
+      - uses: subosito/flutter-action@v2.23.0
+        with:
+          flutter-version: '3.47.0-0.2.pre'
+          channel: beta
+          cache: true
+      - name: Enable AGP 9 built-in Kotlin
+        working-directory: ./packages/example
+        shell: bash
+        run: |
+          perl -pi -e 's/version "8\.13\.0"/version "9.3.1"/' android/settings.gradle.kts
+          perl -pi -e 's/gradle-8\.14\.3-all\.zip/gradle-9.6.1-all.zip/' android/gradle/wrapper/gradle-wrapper.properties
+          perl -pi -e 's/android\.builtInKotlin=false/android.builtInKotlin=true/' android/gradle.properties
+      - name: Install dependencies
+        working-directory: ./packages/example
+        run: flutter pub get
+      - name: Build Android example
+        working-directory: ./packages/example
+        shell: bash
+        run: |
+          set -o pipefail
+          flutter build apk --debug 2>&1 | tee android-build.log
+          ! grep -E 'plugins that apply Kotlin Gradle Plugin|applies the Kotlin Gradle Plugin|KGP\) was unsuccessful' android-build.log

packages/example/android/app/build.gradle.kts

@@ -1,7 +1,6 @@
 plugins {
     id("com.android.application")
-    id("kotlin-android")
-    // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
+    // The Flutter Gradle Plugin must be applied after the Android Gradle plugin.
     id("dev.flutter.flutter-gradle-plugin")
 }
 
@@ -14,10 +13,6 @@ android {
         targetCompatibility = JavaVersion.VERSION_11
     }
 
-    kotlinOptions {
-        jvmTarget = JavaVersion.VERSION_11.toString()
-    }
-
     defaultConfig {
         applicationId = "com.google.ml.kit.flutter.example"
         minSdk = 26
@@ -37,6 +32,12 @@ android {
     }
 }
 
+kotlin {
+    compilerOptions {
+        jvmTarget = org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_11
+    }
+}
+
 dependencies {
     // Add language package you need to use
     implementation("com.google.mlkit:text-recognition-chinese:16.0.1")

packages/example/android/gradle.properties

@@ -1,3 +1,4 @@
 org.gradle.jvmargs=-Xmx8G -XX:MaxMetaspaceSize=4G -XX:ReservedCodeCacheSize=512m -XX:+HeapDumpOnOutOfMemoryError
 android.useAndroidX=true
-android.enableJetifier=true
+android.newDsl=false
+android.builtInKotlin=false

packages/example/lib/activity_indicator/activity_indicator.dart

@@ -3,17 +3,21 @@
 import 'package:flutter/material.dart';
 
 class Toast {
-  void show(String message, Future<String> t, BuildContext context,
-      State<StatefulWidget> state) async {
+  void show(
+    String message,
+    Future<String> t,
+    BuildContext context,
+    State<StatefulWidget> state,
+  ) async {
     ScaffoldMessenger.of(context).hideCurrentSnackBar();
     showLoadingIndicator(context, message);
     final verificationResult = await t;
     Navigator.of(context).pop();
     if (!state.mounted) return;
     ScaffoldMessenger.of(context).hideCurrentSnackBar();
-    ScaffoldMessenger.of(context).showSnackBar(SnackBar(
-      content: Text('Result: ${verificationResult.toString()}'),
-    ));
+    ScaffoldMessenger.of(context).showSnackBar(
+      SnackBar(content: Text('Result: ${verificationResult.toString()}')),
+    );
   }
 
   void showLoadingIndicator(BuildContext context, String text) {
@@ -22,13 +26,15 @@ class Toast {
       barrierDismissible: false,
       builder: (BuildContext context) {
         return PopScope(
-            canPop: false,
-            child: AlertDialog(
-              shape: RoundedRectangleBorder(
-                  borderRadius: BorderRadius.all(Radius.circular(8.0))),
-              backgroundColor: Colors.black87,
-              content: LoadingIndicator(text: text),
-            ));
+          canPop: false,
+          child: AlertDialog(
+            shape: RoundedRectangleBorder(
+              borderRadius: BorderRadius.all(Radius.circular(8.0)),
+            ),
+            backgroundColor: Colors.black87,
+            content: LoadingIndicator(text: text),
+          ),
+        );
       },
     );
   }
@@ -42,31 +48,36 @@ class LoadingIndicator extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return Container(
-        padding: EdgeInsets.all(16),
-        color: Colors.black.withAlpha(204),
-        child: Column(
-            mainAxisAlignment: MainAxisAlignment.center,
-            mainAxisSize: MainAxisSize.min,
-            children: [_getLoadingIndicator(), _getHeading(), _getText(text)]));
+      padding: EdgeInsets.all(16),
+      color: Colors.black.withAlpha(204),
+      child: Column(
+        mainAxisAlignment: MainAxisAlignment.center,
+        mainAxisSize: MainAxisSize.min,
+        children: [_getLoadingIndicator(), _getHeading(), _getText(text)],
+      ),
+    );
   }
 
   Widget _getLoadingIndicator() {
     return Padding(
-        padding: EdgeInsets.only(bottom: 16),
-        child: SizedBox(
-            width: 32,
-            height: 32,
-            child: CircularProgressIndicator(strokeWidth: 3)));
+      padding: EdgeInsets.only(bottom: 16),
+      child: SizedBox(
+        width: 32,
+        height: 32,
+        child: CircularProgressIndicator(strokeWidth: 3),
+      ),
+    );
   }
 
   Widget _getHeading() {
     return Padding(
-        padding: EdgeInsets.only(bottom: 4),
-        child: Text(
-          'Please wait …',
-          style: TextStyle(color: Colors.white, fontSize: 16),
-          textAlign: TextAlign.center,
-        ));
+      padding: EdgeInsets.only(bottom: 4),
+      child: Text(
+        'Please wait …',
+        style: TextStyle(color: Colors.white, fontSize: 16),
+        textAlign: TextAlign.center,
+      ),
+    );
   }
 
   Widget _getText(String displayedText) {

packages/example/lib/main.dart

@@ -27,10 +27,7 @@ Future<void> main() async {
 class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
-    return MaterialApp(
-      debugShowCheckedModeBanner: false,
-      home: Home(),
-    );
+    return MaterialApp(debugShowCheckedModeBanner: false, home: Home());
   }
 }
 
@@ -57,7 +54,9 @@ class Home extends StatelessWidget {
                       CustomCard('Face Detection', FaceDetectorView()),
                       if (Platform.isAndroid)
                         CustomCard(
-                            'Face Mesh Detection', FaceMeshDetectorView()),
+                          'Face Mesh Detection',
+                          FaceMeshDetectorView(),
+                        ),
                       CustomCard('Image Labeling', ImageLabelView()),
                       CustomCard('Object Detection', ObjectDetectorView()),
                       CustomCard('Text Recognition', TextRecognizerView()),
@@ -69,39 +68,49 @@ class Home extends StatelessWidget {
                         CustomCard('Document Scanner', DocumentScannerView()),
                       if (Platform.isAndroid)
                         CustomCard(
-                            'Subject Segmentation', SubjectSegmenterView())
+                          'Subject Segmentation',
+                          SubjectSegmenterView(),
+                        ),
                     ],
                   ),
-                  SizedBox(
-                    height: 20,
-                  ),
+                  SizedBox(height: 20),
                   ExpansionTile(
                     title: const Text('Natural Language APIs'),
                     children: [
                       CustomCard('Language ID', LanguageIdentifierView()),
                       CustomCard(
-                          'On-device Translation', LanguageTranslatorView()),
+                        'On-device Translation',
+                        LanguageTranslatorView(),
+                      ),
                       CustomCard('Smart Reply', SmartReplyView()),
                       CustomCard('Entity Extraction', EntityExtractionView()),
                     ],
                   ),
-                  SizedBox(
-                    height: 20,
-                  ),
+                  SizedBox(height: 20),
                   if (Platform.isAndroid)
                     ExpansionTile(
                       title: const Text('GenAI APIs'),
                       children: [
-                        CustomCard('Summarization',
-                            _GenAIPlaceholderView('Summarization')),
-                        CustomCard('Proofreading',
-                            _GenAIPlaceholderView('Proofreading')),
                         CustomCard(
-                            'Rewriting', _GenAIPlaceholderView('Rewriting')),
-                        CustomCard('Image Description',
-                            _GenAIPlaceholderView('Image Description')),
-                        CustomCard('Speech Recognition',
-                            _GenAIPlaceholderView('Speech Recognition')),
+                          'Summarization',
+                          _GenAIPlaceholderView('Summarization'),
+                        ),
+                        CustomCard(
+                          'Proofreading',
+                          _GenAIPlaceholderView('Proofreading'),
+                        ),
+                        CustomCard(
+                          'Rewriting',
+                          _GenAIPlaceholderView('Rewriting'),
+                        ),
+                        CustomCard(
+                          'Image Description',
+                          _GenAIPlaceholderView('Image Description'),
+                        ),
+                        CustomCard(
+                          'Speech Recognition',
+                          _GenAIPlaceholderView('Speech Recognition'),
+                        ),
                         CustomCard('Prompt', _GenAIPlaceholderView('Prompt')),
                       ],
                     ),
@@ -123,20 +132,14 @@ class _GenAIPlaceholderView extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return Scaffold(
-      appBar: AppBar(
-        title: Text('$featureName (GenAI)'),
-      ),
+      appBar: AppBar(title: Text('$featureName (GenAI)')),
       body: Center(
         child: Padding(
           padding: const EdgeInsets.all(16.0),
           child: Column(
             mainAxisAlignment: MainAxisAlignment.center,
             children: [
-              Icon(
-                Icons.info_outline,
-                size: 64,
-                color: Colors.blue,
-              ),
+              Icon(Icons.info_outline, size: 64, color: Colors.blue),
               SizedBox(height: 16),
               Text(
                 '$featureName API',
@@ -152,9 +155,9 @@ class _GenAIPlaceholderView extends StatelessWidget {
               Text(
                 'Implementation coming soon.',
                 textAlign: TextAlign.center,
-                style: Theme.of(context).textTheme.bodySmall?.copyWith(
-                      fontStyle: FontStyle.italic,
-                    ),
+                style: Theme.of(
+                  context,
+                ).textTheme.bodySmall?.copyWith(fontStyle: FontStyle.italic),
               ),
             ],
           ),
@@ -184,12 +187,18 @@ class CustomCard extends StatelessWidget {
         ),
         onTap: () {
           if (!featureCompleted) {
-            ScaffoldMessenger.of(context).showSnackBar(SnackBar(
-                content:
-                    const Text('This feature has not been implemented yet')));
+            ScaffoldMessenger.of(context).showSnackBar(
+              SnackBar(
+                content: const Text(
+                  'This feature has not been implemented yet',
+                ),
+              ),
+            );
           } else {
             Navigator.push(
-                context, MaterialPageRoute(builder: (context) => _viewPage));
+              context,
+              MaterialPageRoute(builder: (context) => _viewPage),
+            );
           }
         },
       ),