feat: android maplibre 12.0, remove Helpers, static context and activity in favor of provided solution by jni, use using-pattern to avoid memory leaks (#386)

Author: josxha

android/build.gradle

@@ -12,7 +12,7 @@ buildscript {
     }
 
     dependencies {
-        classpath("com.android.tools.build:gradle:8.13.0")
+        classpath("com.android.tools.build:gradle:8.12.3")
         classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version")
         // noinspection GradleDynamicVersion
         classpath("org.jlleitschuh.gradle:ktlint-gradle:13.1.+")
@@ -67,7 +67,7 @@ android {
 
     dependencies {
         // jnigen picks up api dependencies
-        api 'org.maplibre.gl:android-sdk:11.13.+'
+        api 'org.maplibre.gl:android-sdk:12.0.+'
         testImplementation "org.jetbrains.kotlin:kotlin-test"
         testImplementation "org.mockito:mockito-core:5.20.+"
     }

android/gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,7 @@
+#Fri Oct 31 09:53:25 CET 2025
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.3-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME

android/src/main/kotlin/com/github/josxha/maplibre/Helpers.kt

@@ -1,6 +1,7 @@
 package com.github.josxha.maplibre
 
 import PermissionManagerHostApi
+import android.app.Activity
 import android.content.Context
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.LifecycleOwner
@@ -23,10 +24,10 @@ class MapLibrePlugin :
     PermissionManagerHostApi {
     private var lifecycle: Lifecycle? = null
 
+    private lateinit var activity: Activity
     private lateinit var flutterAssets: FlutterPlugin.FlutterAssets
 
     override fun onAttachedToEngine(binding: FlutterPlugin.FlutterPluginBinding) {
-        MapLibreRegistry.context = binding.applicationContext
         PermissionManagerHostApi.setUp(binding.binaryMessenger, this)
         binding
             .platformViewRegistry
@@ -43,7 +44,7 @@ class MapLibrePlugin :
     }
 
     override fun onAttachedToActivity(binding: ActivityPluginBinding) {
-        MapLibreRegistry.activity = binding.activity
+        activity = binding.activity
         binding.addRequestPermissionsResultListener(this)
         lifecycle = FlutterLifecycleAdapter.getActivityLifecycle(binding)
     }
@@ -91,7 +92,7 @@ class MapLibrePlugin :
                     }
                 },
             )
-        permissionsManager?.requestLocationPermissions(MapLibreRegistry.activity)
+        permissionsManager?.requestLocationPermissions(activity)
     }
 }
 

android/src/main/kotlin/com/github/josxha/maplibre/MapLibrePlugin.kt

@@ -1,8 +1,6 @@
 package com.github.josxha.maplibre
 
 import android.annotation.SuppressLint
-import android.app.Activity
-import android.content.Context
 import androidx.annotation.Keep
 import org.maplibre.android.maps.MapLibreMap
 
@@ -21,10 +19,4 @@ object MapLibreRegistry {
     ) {
         mapRegistry[viewId] = map
     }
-
-    // TODO: Storing the Activity in a static field is a potential memory leak.
-    public var activity: Activity? = null
-
-    // TODO: Storing the Context in a static field is a potential memory leak.
-    public var context: Context? = null
 }

android/src/main/kotlin/com/github/josxha/maplibre/MapLibreRegistry.kt

@@ -8,7 +8,7 @@ plugins {
 android {
     namespace = "com.github.josxha.maplibre_example"
     compileSdk = flutter.compileSdkVersion
-    ndkVersion = "27.0.12077973" // flutter.ndkVersion
+    ndkVersion = "28.2.13676358" // flutter.ndkVersion
 
     compileOptions {
         sourceCompatibility = JavaVersion.VERSION_11

example/android/app/build.gradle.kts

@@ -14,10 +14,11 @@ source_path:
   - 'android/src/main'
 classes:
 # https://github.com/maplibre/maplibre-native/tree/main/platform/android/MapLibreAndroid/src/main/java/org/maplibre/android
+  - 'android.app.Activity'
+  - 'android.content.Context'
   - 'android.graphics.PointF'
   - 'android.graphics.RectF'
   - 'android.location.Location'
-  - 'com.github.josxha.maplibre.Helpers'
   - 'com.github.josxha.maplibre.MapLibreRegistry'
   - 'java.net.URI'
   - 'java.net.URL'
@@ -39,6 +40,7 @@ classes:
   - 'org.maplibre.android.offline.OfflineRegionDefinition'
   - 'org.maplibre.android.offline.OfflineRegionError'
   - 'org.maplibre.android.offline.OfflineRegionStatus'
+  - 'org.maplibre.android.offline.OfflineTilePyramidRegionDefinition'
   - 'org.maplibre.android.storage'
   - 'org.maplibre.android.style.layers'
   - 'org.maplibre.android.style.light'

jnigen.yaml

@@ -51,7 +51,8 @@ extension OffsetExt on Offset {
   pigeon.Offset toOffset() => pigeon.Offset(x: dx, y: dy);
 
   /// Convert an [Offset] to an [jni.PointF].
-  jni.PointF toPointF() => jni.PointF.new$3(dx, dy);
+  jni.PointF toJPointF({required Arena arena}) =>
+      jni.PointF.new$3(dx, dy)..releasedBy(arena);
 }
 
 /// Extension methods for the [LngLatBounds] class. Not exported publicly.
@@ -65,12 +66,13 @@ extension LngLatBoundsExt on LngLatBounds {
   );
 
   /// Convert an [LngLatBounds] to an internal [jni.LatLngBounds].
-  jni.LatLngBounds toLatLngBounds() => jni.LatLngBounds.from(
-    latitudeNorth,
-    longitudeEast,
-    latitudeSouth,
-    longitudeWest,
-  );
+  jni.LatLngBounds toJLatLngBounds({required Arena arena}) =>
+      jni.LatLngBounds.from(
+        latitudeNorth,
+        longitudeEast,
+        latitudeSouth,
+        longitudeWest,
+      )..releasedBy(arena);
 }
 
 /// Extension methods for the [jni.LatLngBounds] class. Not exported publicly.
@@ -83,7 +85,7 @@ extension LatLngBounds on jni.LatLngBounds {
       latitudeSouth: latitudeSouth,
       latitudeNorth: latitudeNorth,
     );
-    release();
+    if (releaseOriginal) release();
     return bounds;
   }
 }
@@ -102,20 +104,18 @@ extension EdgeInsetsExt on EdgeInsets {
 /// Extension methods for the [EdgeInsets] class. Not exported publicly.
 extension OfflineRegionExt on jni.OfflineRegion {
   /// Convert an [EdgeInsets] to an internal [pigeon.Padding].
-  OfflineRegion toOfflineRegion() {
-    final jDefinition = getDefinition();
+  OfflineRegion toOfflineRegion() => using((arena) {
+    final jDefinition = getDefinition()..releasedBy(arena);
     // TODO add getMetadata();
-    final region = OfflineRegion(
+    return OfflineRegion(
       id: getId(),
       bounds: jDefinition.getBounds()!.toLngLatBounds(releaseOriginal: true),
       minZoom: jDefinition.getMinZoom(),
       maxZoom: jDefinition.getMaxZoom(),
       pixelRatio: jDefinition.getPixelRatio(),
       styleUrl: jDefinition.getStyleURL()!.toDartString(releaseOriginal: true),
     );
-    jDefinition.release();
-    return region;
-  }
+  });
 }
 
 /// Extension methods on [Object].
@@ -125,7 +125,9 @@ extension ObjectExt on Object {
     return switch (this) {
       final List<Object?> value => JArray.of(
         JObject.nullableType,
-        value.map((e) => e?.toJObject(arena)).toList(growable: false),
+        value
+            .map((e) => e?.toJObject(arena)?..releasedBy(arena))
+            .toList(growable: false),
       )..releasedBy(arena),
       final String value => value.toJString()..releasedBy(arena),
       final double value => value.toJDouble()..releasedBy(arena),

lib/src/platform/android/extensions.dart

@@ -0,0 +1,12 @@
+import 'package:jni/jni.dart';
+import 'package:maplibre/src/platform/android/jni.dart';
+
+/// Get the Android [Context]. Requires an [arena] parameter by whom it can
+/// get released.
+Context getJContext(Arena arena) =>
+    Context.fromReference(Jni.getCachedApplicationContext())..releasedBy(arena);
+
+/// Get the Android [Activity]. Requires an [arena] parameter by whom it can
+/// get released.
+Activity getJActivity(Arena arena) =>
+    Activity.fromReference(Jni.getCurrentActivity())..releasedBy(arena);

lib/src/platform/android/functions.dart

@@ -1,8 +1,8 @@
+export 'jni/android/app/_package.dart';
+export 'jni/android/content/_package.dart';
 export 'jni/android/graphics/_package.dart';
 export 'jni/android/location/_package.dart';
 export 'jni/com/github/josxha/maplibre/_package.dart';
-// export 'jni/io/flutter/embedding/engine/plugins/activity/_package.dart';
-// export 'jni/io/flutter/plugin/common/_package.dart';
 export 'jni/java/net/_package.dart';
 export 'jni/org/maplibre/android/_package.dart';
 export 'jni/org/maplibre/android/attribution/_package.dart';