[jni] Do not require engineId for android app context (#2777)

Author: HosseinYousefi

pkgs/jni/CHANGELOG.md

@@ -1,3 +1,9 @@
+## 0.15.1
+
+- **Breaking Change**: Removed the `engineId` argument from
+  `Jni.androidApplicationContext` as the application context is not dependant on
+  the engine ID.
+
 ## 0.15.0
 
 - **Breaking Change**: Made `Jni.env` internal.

pkgs/jni/android/src/main/java/com/github/dart_lang/jni/JniPlugin.java

@@ -4,6 +4,7 @@
 
 package com.github.dart_lang.jni;
 
+import android.annotation.SuppressLint;
 import android.app.Activity;
 import android.content.Context;
 import androidx.annotation.NonNull;
@@ -18,11 +19,14 @@ public class JniPlugin implements FlutterPlugin, ActivityAware {
   private static final ConcurrentHashMap<Long, JniPlugin> pluginMap = new ConcurrentHashMap<>();
 
   private long engineId;
-  private volatile Context context;
+
+  @SuppressLint("StaticFieldLeak")
+  private static Context context;
+
   private volatile Activity activity;
 
-  public static @NonNull Context getApplicationContext(long engineId) {
-    return Objects.requireNonNull(pluginMap.get(engineId)).context;
+  public static @NonNull Context getApplicationContext() {
+    return context;
   }
 
   public static @Nullable Activity getActivity(long engineId) {
@@ -40,7 +44,6 @@ public void onAttachedToEngine(@NonNull FlutterPluginBinding binding) {
 
   @Override
   public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
-    context = null;
     activity = null;
     pluginMap.remove(engineId);
   }

pkgs/jni/example/lib/main.dart

@@ -49,8 +49,7 @@ void showToast(String text) {
       '(Landroid/app/Activity;Landroid/content/Context;'
           'Ljava/lang/CharSequence;I)'
           'Lcom/github/dart_lang/jni_example/Toaster;');
-  final applicationContext =
-      Jni.androidApplicationContext(PlatformDispatcher.instance.engineId!);
+  final applicationContext = Jni.androidApplicationContext;
   final toaster = makeText(toasterClass, JObject.type, [
     activity,
     applicationContext,

pkgs/jni/lib/src/jni.dart

@@ -216,13 +216,10 @@ abstract final class Jni {
   /// Retrieves the global Android `ApplicationContext` associated with a
   /// Flutter engine.
   ///
-  /// Pass `PlatformDispatcher.instance.engineId` to the [engineId] field.
-  ///
   /// The `ApplicationContext` is a long-lived singleton tied to the
-  /// application's lifecycle. It is safe to store and use from any thread
-  /// for non-UI tasks.
-  static JObject androidApplicationContext(int engineId) {
-    return JniPlugin.getApplicationContext(engineId);
+  /// application's lifecycle. It is safe to store and use from any thread.
+  static JObject get androidApplicationContext {
+    return JniPlugin.getApplicationContext();
   }
 
   /// Retrieves the current Android `Activity` associated with a Flutter engine.

pkgs/jni/lib/src/plugin/generated_plugin.dart

@@ -88,25 +88,26 @@ class JniPlugin extends jni$_.JObject {
 
   static final _id_getApplicationContext = _class.staticMethodId(
     r'getApplicationContext',
-    r'(J)Landroid/content/Context;',
+    r'()Landroid/content/Context;',
   );
 
   static final _getApplicationContext = jni$_.ProtectedJniExtensions.lookup<
-              jni$_.NativeFunction<
-                  jni$_.JniResult Function(jni$_.Pointer<jni$_.Void>,
-                      jni$_.JMethodIDPtr, jni$_.VarArgs<(jni$_.Int64,)>)>>(
-          'globalEnv_CallStaticObjectMethod')
+          jni$_.NativeFunction<
+              jni$_.JniResult Function(
+                jni$_.Pointer<jni$_.Void>,
+                jni$_.JMethodIDPtr,
+              )>>('globalEnv_CallStaticObjectMethod')
       .asFunction<
           jni$_.JniResult Function(
-              jni$_.Pointer<jni$_.Void>, jni$_.JMethodIDPtr, int)>();
+            jni$_.Pointer<jni$_.Void>,
+            jni$_.JMethodIDPtr,
+          )>();
 
-  /// from: `static public android.content.Context getApplicationContext(long j)`
+  /// from: `static public android.content.Context getApplicationContext()`
   /// The returned object must be released after use, by calling the [release] method.
-  static jni$_.JObject getApplicationContext(
-    int j,
-  ) {
+  static jni$_.JObject getApplicationContext() {
     return _getApplicationContext(_class.reference.pointer,
-            _id_getApplicationContext as jni$_.JMethodIDPtr, j)
+            _id_getApplicationContext as jni$_.JMethodIDPtr)
         .object<jni$_.JObject>(const jni$_.$JObject$Type$());
   }
 

pkgs/jni/pubspec.yaml

@@ -4,7 +4,7 @@
 
 name: jni
 description: A library to access JNI from Dart and Flutter that acts as a support library for package:jnigen.
-version: 0.15.0
+version: 0.15.1
 repository: https://github.com/dart-lang/native/tree/main/pkgs/jni
 issue_tracker: https://github.com/dart-lang/native/issues?q=is%3Aissue+is%3Aopen+label%3Apackage%3Ajni
 

pkgs/jnigen/example/in_app_java/lib/main.dart

@@ -10,8 +10,7 @@ import 'package:jni/jni.dart';
 // structure.
 import 'android_utils.g.dart';
 
-JObject context =
-    Jni.androidApplicationContext(PlatformDispatcher.instance.engineId!);
+JObject context = Jni.androidApplicationContext;
 
 final hashmap = HashMap(K: JString.type, V: JString.type);