desktop_drop: restore Android compatibility with AGP < 9 hosts

packages/desktop_drop/CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## 0.8.2
+
+* [desktop_drop] [Android] restore compatibility with hosts on Android Gradle Plugin < 9 by applying the Kotlin Gradle Plugin conditionally, per the Flutter built-in Kotlin migration guide
+* [desktop_drop] [Android] bump bundled Kotlin Gradle Plugin to 2.2.0 to support the `kotlin.compilerOptions` DSL on AGP < 9 hosts
+
 ## 0.8.1
 
 * [desktop_drop] [Linux] register the `application/vnd.portal.filetransfer` drag target and deliver its key via a new `performOperation_portal` channel message

packages/desktop_drop/android/build.gradle

@@ -2,7 +2,7 @@ group 'com.example.desktop_drop'
 version '1.0-SNAPSHOT'
 
 buildscript {
-    ext.kotlin_version = '1.9.25'
+    ext.kotlin_version = '2.2.0'
     repositories {
         google()
         mavenCentral()
@@ -16,6 +16,16 @@ buildscript {
 
 apply plugin: 'com.android.library'
 
+// Apply KGP only when the host does not provide built-in Kotlin.
+// AGP 9+ ships Kotlin built-in and hard-fails if kotlin-android is applied,
+// while hosts on AGP < 9 do not apply any Kotlin plugin to this subproject.
+// See https://docs.flutter.dev/release/breaking-changes/migrate-to-built-in-kotlin/for-plugin-authors
+// ("Support Flutter versions earlier than 3.44").
+def agpMajor = com.android.Version.ANDROID_GRADLE_PLUGIN_VERSION.tokenize('.')[0] as int
+if (agpMajor < 9) {
+    apply plugin: 'kotlin-android'
+}
+
 rootProject.allprojects {
     repositories {
         google()

packages/desktop_drop/pubspec.yaml

@@ -1,7 +1,7 @@
 name: desktop_drop
 resolution: workspace
 description: A plugin which allows user dragging files to your flutter desktop applications.
-version: 0.8.1
+version: 0.8.2
 homepage: https://github.com/MixinNetwork/flutter-plugins/tree/main/packages/desktop_drop
 
 environment: