Specify Kotlin version in modules and refactor (#101315)

dev/devicelab/bin/tasks/build_aar_module_test.dart

@@ -67,7 +67,8 @@ Future<void> main() async {
           '  plugin_with_android:$platformLineSep'
           '    path: ../plugin_with_android$platformLineSep'
           '  plugin_without_android:$platformLineSep'
-          '    path: ../plugin_without_android$platformLineSep',
+          '    path: ../plugin_without_android$platformLineSep'
+          '  webcrypto: 0.5.2$platformLineSep', // Plugin that uses NDK.
       );
       modulePubspec.writeAsStringSync(content, flush: true);
 

packages/flutter_tools/lib/src/android/gradle_errors.dart

@@ -71,13 +71,13 @@ final List<GradleHandledError> gradleErrors = <GradleHandledError>[
   permissionDeniedErrorHandler,
   flavorUndefinedHandler,
   r8FailureHandler,
-  minSdkVersion,
-  transformInputIssue,
-  lockFileDepMissing,
+  minSdkVersionHandler,
+  transformInputIssueHandler,
+  lockFileDepMissingHandler,
   multidexErrorHandler,
   incompatibleKotlinVersionHandler,
   minCompileSdkVersionHandler,
-  jvm11Required,
+  jvm11RequiredHandler,
 ];
 
 const String _boxTitle = 'Flutter Fix';
@@ -381,7 +381,7 @@ final RegExp _minSdkVersionPattern = RegExp(r'uses-sdk:minSdkVersion ([0-9]+) ca
 
 /// Handler when a plugin requires a higher Android API level.
 @visibleForTesting
-final GradleHandledError minSdkVersion = GradleHandledError(
+final GradleHandledError minSdkVersionHandler = GradleHandledError(
   test: (String line) {
     return _minSdkVersionPattern.hasMatch(line);
   },
@@ -423,7 +423,7 @@ final GradleHandledError minSdkVersion = GradleHandledError(
 /// Handler when https://issuetracker.google.com/issues/141126614 or
 /// https://github.com/flutter/flutter/issues/58247 is triggered.
 @visibleForTesting
-final GradleHandledError transformInputIssue = GradleHandledError(
+final GradleHandledError transformInputIssueHandler = GradleHandledError(
   test: (String line) {
     return line.contains('https://issuetracker.google.com/issues/158753935');
   },
@@ -457,7 +457,7 @@ final GradleHandledError transformInputIssue = GradleHandledError(
 
 /// Handler when a dependency is missing in the lockfile.
 @visibleForTesting
-final GradleHandledError lockFileDepMissing = GradleHandledError(
+final GradleHandledError lockFileDepMissingHandler = GradleHandledError(
   test: (String line) {
     return line.contains('which is not part of the dependency lock state');
   },
@@ -541,7 +541,7 @@ final GradleHandledError minCompileSdkVersionHandler = GradleHandledError(
 );
 
 @visibleForTesting
-final GradleHandledError jvm11Required = GradleHandledError(
+final GradleHandledError jvm11RequiredHandler = GradleHandledError(
   test: (String line) {
     return line.contains('Android Gradle plugin requires Java 11 to run');
   },

packages/flutter_tools/lib/src/android/gradle_utils.dart

@@ -30,9 +30,20 @@ import 'android_sdk.dart';
 const String templateDefaultGradleVersion = '7.4';
 const String templateAndroidGradlePluginVersion = '7.1.2';
 // TODO(egarciad): Gradle 7 breaks AARs builds: https://github.com/flutter/flutter/issues/101083
-const String templateAndroidGradlePluginVersionForModule = '4.1.0';
+const String templateDefaultGradleVersionForModule = '4.1.0';
 const String templateKotlinGradlePluginVersion = '1.6.10';
 
+// These versions should match the values in flutter.gradle (FlutterExtension).
+// The Flutter Gradle plugin is only applied to app projects, and modules that are built from source
+// using (include_flutter.groovy).
+// The remaining projects are: plugins, and modules compiled as AARs. In modules, the ephemeral directory
+// `.android` is always regenerated after flutter pub get, so new versions are picked up after a
+// Flutter upgrade.
+const String compileSdkVersion = '31';
+const String minSdkVersion = '16';
+const String targetSdkVersion = '31';
+const String ndkVersion = '21.1.6352462';
+
 final RegExp _androidPluginRegExp = RegExp(r'com\.android\.tools\.build:gradle:(\d+\.\d+\.\d+)');
 
 /// Provides utilities to run a Gradle task, such as finding the Gradle executable

packages/flutter_tools/lib/src/commands/create_base.dart

@@ -425,6 +425,11 @@ abstract class CreateBase extends FlutterCommand {
       'agpVersion': agpVersion,
       'kotlinVersion': kotlinVersion,
       'gradleVersion': gradleVersion,
+      'gradleVersionForModule': gradle.templateDefaultGradleVersionForModule,
+      'compileSdkVersion': gradle.compileSdkVersion,
+      'minSdkVersion': gradle.minSdkVersion,
+      'ndkVersion': gradle.ndkVersion,
+      'targetSdkVersion': gradle.targetSdkVersion,
     };
   }
 

packages/flutter_tools/lib/src/project.dart

@@ -587,9 +587,13 @@ class AndroidProject extends FlutterProjectPlatform {
         'androidIdentifier': androidIdentifier,
         'androidX': usesAndroidX,
         'agpVersion': gradle.templateAndroidGradlePluginVersion,
-        'agpVersionForModule': gradle.templateAndroidGradlePluginVersionForModule,
         'kotlinVersion': gradle.templateKotlinGradlePluginVersion,
         'gradleVersion': gradle.templateDefaultGradleVersion,
+        'gradleVersionForModule': gradle.templateDefaultGradleVersionForModule,
+        'compileSdkVersion': gradle.compileSdkVersion,
+        'minSdkVersion': gradle.minSdkVersion,
+        'ndkVersion': gradle.ndkVersion,
+        'targetSdkVersion': gradle.targetSdkVersion,
       },
       printStatusWhenWriting: false,
     );

packages/flutter_tools/templates/module/android/gradle/build.gradle.tmpl

 // Generated file. Do not edit.
 
 buildscript {
+    ext.kotlin_version = '{{kotlinVersion}}'
     repositories {
         google()
         mavenCentral()
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:{{agpVersionForModule}}'
+        classpath 'com.android.tools.build:gradle:{{gradleVersionForModule}}'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }
 
@@ -18,6 +20,16 @@ allprojects {
     }
 }
 
-task clean(type: Delete) {
-    delete rootProject.buildDir
+apply plugin: 'com.android.library'
+apply plugin: 'kotlin-android'
+
+android {
+    compileSdkVersion {{compileSdkVersion}}
+    defaultConfig {
+        minSdkVersion {{minSdkVersion}}
+    }
+}
+
+dependencies {
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
 }

packages/flutter_tools/templates/module/android/gradle/settings.gradle.tmpl

+rootProject.name = '{{projectName}}'

packages/flutter_tools/templates/module/android/gradle/src/main/AndroidManifest.xml.tmpl

+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+  package="{{androidIdentifier}}">
+</manifest>

packages/flutter_tools/templates/module/android/host_app_common/app.tmpl/build.gradle.tmpl

@@ -3,7 +3,7 @@ def flutterPluginVersion = 'managed'
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 31
+    compileSdkVersion {{compileSdkVersion}}
 
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
@@ -12,8 +12,8 @@ android {
 
     defaultConfig {
         applicationId "{{androidIdentifier}}.host"
-        minSdkVersion 16
-        targetSdkVersion 31
+        minSdkVersion {{minSdkVersion}}
+        targetSdkVersion {{targetSdkVersion}}
         versionCode 1
         versionName "1.0"
     }

packages/flutter_tools/templates/plugin/android-java.tmpl/build.gradle.tmpl

@@ -22,7 +22,7 @@ rootProject.allprojects {
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 31
+    compileSdkVersion {{compileSdkVersion}}
 
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
@@ -30,6 +30,6 @@ android {
     }
 
     defaultConfig {
-        minSdkVersion 16
+        minSdkVersion {{minSdkVersion}}
     }
 }

packages/flutter_tools/templates/plugin/android-kotlin.tmpl/build.gradle.tmpl

@@ -14,7 +14,7 @@ buildscript {
     }
 }
 
-rootProject.allprojects {
+allprojects {
     repositories {
         google()
         mavenCentral()
@@ -41,7 +41,7 @@ android {
     }
 
     defaultConfig {
-        minSdkVersion 16
+        minSdkVersion {{minSdkVersion}}
     }
 }
 

packages/flutter_tools/templates/plugin_ffi/android.tmpl/build.gradle.tmpl

@@ -27,11 +27,11 @@ apply plugin: 'com.android.library'
 android {
     // Bumping the plugin compileSdkVersion requires all clients of this plugin
     // to bump the version in their app.
-    compileSdkVersion 31
+    compileSdkVersion {{compileSdkVersion}}
 
     // Bumping the plugin ndkVersion requires all clients of this plugin to bump
     // the version in their app and to download a newer version of the NDK.
-    ndkVersion "21.1.6352462"
+    ndkVersion "{{ndkVersion}}"
 
     // Invoke the shared CMake build with the Android Gradle Plugin.
     externalNativeBuild {
@@ -54,6 +54,6 @@ android {
     }
 
     defaultConfig {
-        minSdkVersion 16
+        minSdkVersion {{minSdkVersion}}
     }
 }

packages/flutter_tools/templates/template_manifest.json

@@ -210,6 +210,8 @@
         "templates/module/android/deferred_component/src/main/AndroidManifest.xml.tmpl",
         "templates/module/android/gradle/build.gradle.tmpl",
         "templates/module/android/gradle/gradle.properties.tmpl",
+        "templates/module/android/gradle/settings.gradle.tmpl",
+        "templates/module/android/gradle/src/main/AndroidManifest.xml.tmpl",
         "templates/module/android/host_app_common/app.tmpl/build.gradle.tmpl",
         "templates/module/android/host_app_common/app.tmpl/src/main/AndroidManifest.xml.tmpl",
         "templates/module/android/host_app_common/app.tmpl/src/main/java/androidIdentifier/host/MainActivity.java.tmpl",

packages/flutter_tools/test/general.shard/android/gradle_errors_test.dart

@@ -29,13 +29,13 @@ void main() {
           permissionDeniedErrorHandler,
           flavorUndefinedHandler,
           r8FailureHandler,
-          minSdkVersion,
-          transformInputIssue,
-          lockFileDepMissing,
+          minSdkVersionHandler,
+          transformInputIssueHandler,
+          lockFileDepMissingHandler,
           multidexErrorHandler,
           incompatibleKotlinVersionHandler,
           minCompileSdkVersionHandler,
-          jvm11Required,
+          jvm11RequiredHandler,
         ])
       );
     });
@@ -754,13 +754,13 @@ assembleProfile
 
     testWithoutContext('pattern', () {
       expect(
-        minSdkVersion.test(stdoutLine),
+        minSdkVersionHandler.test(stdoutLine),
         isTrue,
       );
     });
 
     testUsingContext('suggestion', () async {
-      await minSdkVersion.handler(
+      await minSdkVersionHandler.handler(
         line: stdoutLine,
         project: FlutterProject.fromDirectoryTest(globals.fs.currentDirectory),
       );
@@ -798,7 +798,7 @@ assembleProfile
   group('transform input issue', () {
     testWithoutContext('pattern', () {
       expect(
-        transformInputIssue.test(
+        transformInputIssueHandler.test(
           'https://issuetracker.google.com/issues/158753935'
         ),
         isTrue,
@@ -806,7 +806,7 @@ assembleProfile
     });
 
     testUsingContext('suggestion', () async {
-      await transformInputIssue.handler(
+      await transformInputIssueHandler.handler(
         project: FlutterProject.fromDirectoryTest(globals.fs.currentDirectory),
       );
 
@@ -836,7 +836,7 @@ assembleProfile
   group('Dependency mismatch', () {
     testWithoutContext('pattern', () {
       expect(
-        lockFileDepMissing.test('''
+        lockFileDepMissingHandler.test('''
 * What went wrong:
 Execution failed for task ':app:generateDebugFeatureTransitiveDeps'.
 > Could not resolve all artifacts for configuration ':app:debugRuntimeClasspath'.
@@ -848,7 +848,7 @@ Execution failed for task ':app:generateDebugFeatureTransitiveDeps'.
     });
 
     testUsingContext('suggestion', () async {
-      await lockFileDepMissing.handler(
+      await lockFileDepMissingHandler.handler(
         project: FlutterProject.fromDirectoryTest(globals.fs.currentDirectory),
       );
 
@@ -960,7 +960,7 @@ Execution failed for task ':app:checkDebugAarMetadata'.
   group('Java 11 requirement', () {
     testWithoutContext('pattern', () {
       expect(
-        jvm11Required.test('''
+        jvm11RequiredHandler.test('''
 * What went wrong:
 A problem occurred evaluating project ':flutter'.
 > Failed to apply plugin 'com.android.internal.library'.
@@ -975,7 +975,7 @@ A problem occurred evaluating project ':flutter'.
     });
 
     testUsingContext('suggestion', () async {
-      await jvm11Required.handler();
+      await jvm11RequiredHandler.handler();
 
       expect(
         testLogger.statusText,