refactor: Migrate google_mlkit_commons from Java to Kotlin (#842)

Author: bensonarafat

.editorconfig

@@ -0,0 +1,3 @@
+# ktlint: allow underscore in package names (Flutter plugin convention, e.g. com.google_mlkit_commons)
+[*.{kt,kts}]
+ktlint_standard_package-name = disabled

.github/workflows/code-analysis.yml

@@ -128,3 +128,9 @@ jobs:
 
       # Statically analyze the Dart code for any errors.
       - run: flutter analyze .
+
+      # Statically analyze Kotlin code (e.g. google_mlkit_commons Android) with ktlint.
+      - name: Install ktlint
+        run: brew install ktlint
+      - name: Run ktlint on Kotlin code
+        run: ktlint

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "java.configuration.updateBuildConfiguration": "automatic"
+}

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

@@ -33,7 +33,7 @@ android {
     }
 
     aaptOptions {
-        noCompress("tflite")  // Your model's file extension: "tflite", "lite", etc.
+        noCompress("tflite") // Your model's file extension: "tflite", "lite", etc.
     }
 }
 

packages/example/android/build.gradle.kts

@@ -5,7 +5,10 @@ allprojects {
     }
 }
 
-val newBuildDir: Directory = rootProject.layout.buildDirectory.dir("../../build").get()
+val newBuildDir: Directory =
+    rootProject.layout.buildDirectory
+        .dir("../../build")
+        .get()
 rootProject.layout.buildDirectory.value(newBuildDir)
 
 subprojects {

packages/example/android/settings.gradle.kts

@@ -1,11 +1,12 @@
 pluginManagement {
-    val flutterSdkPath = run {
-        val properties = java.util.Properties()
-        file("local.properties").inputStream().use { properties.load(it) }
-        val flutterSdkPath = properties.getProperty("flutter.sdk")
-        require(flutterSdkPath != null) { "flutter.sdk not set in local.properties" }
-        flutterSdkPath
-    }
+    val flutterSdkPath =
+        run {
+            val properties = java.util.Properties()
+            file("local.properties").inputStream().use { properties.load(it) }
+            val flutterSdkPath = properties.getProperty("flutter.sdk")
+            require(flutterSdkPath != null) { "flutter.sdk not set in local.properties" }
+            flutterSdkPath
+        }
 
     includeBuild("$flutterSdkPath/packages/flutter_tools/gradle")
 
@@ -19,7 +20,7 @@ pluginManagement {
 plugins {
     id("dev.flutter.flutter-plugin-loader") version "1.0.0"
     id("com.android.application") version "8.13.0" apply false
-    id("org.jetbrains.kotlin.android") version "2.2.0" apply false
+    id("org.jetbrains.kotlin.android") version "2.2.20" apply false
 }
 
 include(":app")

packages/google_mlkit_commons/android/build.gradle

@@ -2,13 +2,15 @@ group = "com.google_mlkit_commons"
 version = "1.0"
 
 buildscript {
+    ext.kotlin_version = "2.2.20"
     repositories {
         google()
         mavenCentral()
     }
 
     dependencies {
         classpath("com.android.tools.build:gradle:8.13.0")
+        classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:2.2.20")
     }
 }
 
@@ -20,6 +22,7 @@ rootProject.allprojects {
 }
 
 apply plugin: "com.android.library"
+apply plugin: "kotlin-android"
 
 android {
     namespace = "com.google_mlkit_commons"
@@ -30,6 +33,14 @@ android {
         sourceCompatibility = JavaVersion.VERSION_11
         targetCompatibility = JavaVersion.VERSION_11
     }
+    
+    kotlinOptions {
+        jvmTarget = '11'
+    }
+
+    sourceSets {
+        main.java.srcDirs += "src/main/kotlin"
+    }
 
     defaultConfig {
         minSdk = 21

packages/google_mlkit_commons/android/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.0-milestone-1-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists