[android] Reuse Java Source objects by holding on to a strong reference in the C++ peer.

21 files changed, 183 insertions, 193 deletions

diff --git a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/NativeMapView.java b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/NativeMapView.java
index e8eb7e8718..f1635c898f 100755
--- a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/NativeMapView.java
+++ b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/NativeMapView.java
@@ -733,7 +733,7 @@ final class NativeMapView {
     if (isDestroyedOn("addSource")) {
       return;
     }
-    nativeAddSource(source.getNativePtr());
+    nativeAddSource(source, source.getNativePtr());
   }
 
   @Nullable
@@ -741,14 +741,15 @@ final class NativeMapView {
     if (isDestroyedOn("removeSource")) {
       return null;
     }
-    return nativeRemoveSourceById(sourceId);
+    Source source = getSource(sourceId);
+    return removeSource(source);
   }
 
   public Source removeSource(@NonNull Source source) {
     if (isDestroyedOn("removeSource")) {
       return null;
     }
-    nativeRemoveSource(source.getNativePtr());
+    nativeRemoveSource(source, source.getNativePtr());
     return source;
   }
 
@@ -1027,11 +1028,9 @@ final class NativeMapView {
 
   private native Source nativeGetSource(String sourceId);
 
-  private native void nativeAddSource(long nativeSourcePtr) throws CannotAddSourceException;
+  private native void nativeAddSource(Source source, long sourcePtr) throws CannotAddSourceException;
 
-  private native Source nativeRemoveSourceById(String sourceId);
-
-  private native void nativeRemoveSource(long sourcePtr);
+  private native void nativeRemoveSource(Source source, long sourcePtr);
 
   private native void nativeAddImage(String name, int width, int height, float pixelRatio,
                                      byte[] array);
diff --git a/platform/android/config.cmake b/platform/android/config.cmake
index 0102d405d7..0175fa7ca6 100644
--- a/platform/android/config.cmake
+++ b/platform/android/config.cmake
@@ -181,8 +181,6 @@ add_library(mbgl-android STATIC
     platform/android/src/style/sources/custom_geometry_source.hpp
     platform/android/src/style/sources/source.cpp
     platform/android/src/style/sources/source.hpp
-    platform/android/src/style/sources/sources.cpp
-    platform/android/src/style/sources/sources.hpp
     platform/android/src/style/sources/raster_source.cpp
     platform/android/src/style/sources/raster_source.hpp
     platform/android/src/style/sources/unknown_source.cpp
diff --git a/platform/android/src/jni.cpp b/platform/android/src/jni.cpp
index f4e5734861..63566e1772 100755
--- a/platform/android/src/jni.cpp
+++ b/platform/android/src/jni.cpp
@@ -47,7 +47,7 @@
 #include "style/functions/interval_stops.hpp"
 #include "style/functions/stop.hpp"
 #include "style/layers/layers.hpp"
-#include "style/sources/sources.hpp"
+#include "style/sources/source.hpp"
 #include "style/light.hpp"
 #include "snapshotter/map_snapshotter.hpp"
 #include "snapshotter/map_snapshot.hpp"
@@ -161,7 +161,7 @@ void registerNatives(JavaVM *vm) {
     // Style
     TransitionOptions::registerNative(env);
     registerNativeLayers(env);
-    registerNativeSources(env);
+    Source::registerNative(env);
     Light::registerNative(env);
     Position::registerNative(env);
     Stop::registerNative(env);
diff --git a/platform/android/src/native_map_view.cpp b/platform/android/src/native_map_view.cpp
index 04cbb21927..36a73fee35 100755
--- a/platform/android/src/native_map_view.cpp
+++ b/platform/android/src/native_map_view.cpp
@@ -856,9 +856,7 @@ jni::Array<jni::Object<Source>> NativeMapView::getSources(JNIEnv& env) {
     jni::Array<jni::Object<Source>> jSources = jni::Array<jni::Object<Source>>::New(env, sources.size(), Source::javaClass);
     int index = 0;
     for (auto source : sources) {
-        auto jSource = jni::Object<Source>(createJavaSourcePeer(env, *rendererFrontend, *source));
-        jSources.Set(env, index, jSource);
-        jni::DeleteLocalRef(env, jSource);
+        jSources.Set(env, index, Source::peerForCoreSource(env, *source, *rendererFrontend));
         index++;
     }
 
@@ -874,38 +872,25 @@ jni::Object<Source> NativeMapView::getSource(JNIEnv& env, jni::String sourceId)
     }
 
     // Create and return the source's native peer
-    return jni::Object<Source>(createJavaSourcePeer(env, *rendererFrontend, *coreSource));
+    return Source::peerForCoreSource(env, *coreSource, *rendererFrontend);
 }
 
-void NativeMapView::addSource(JNIEnv& env, jni::jlong sourcePtr) {
+void NativeMapView::addSource(JNIEnv& env, jni::Object<Source> obj, jlong sourcePtr) {
     assert(sourcePtr != 0);
 
     Source *source = reinterpret_cast<Source *>(sourcePtr);
     try {
-        source->addToMap(*map);
-        source->setRendererFrontend(*rendererFrontend);
+        source->addToMap(env, obj, *map, *rendererFrontend);
     } catch (const std::runtime_error& error) {
         jni::ThrowNew(env, jni::FindClass(env, "com/mapbox/mapboxsdk/style/sources/CannotAddSourceException"), error.what());
     }
 }
 
-jni::Object<Source> NativeMapView::removeSourceById(JNIEnv& env, jni::String id) {
-    std::unique_ptr<mbgl::style::Source> coreSource = map->getStyle().removeSource(jni::Make<std::string>(env, id));
-    if (coreSource) {
-        return jni::Object<Source>(createJavaSourcePeer(env, *rendererFrontend, *coreSource));
-    } else {
-        return jni::Object<Source>();
-    }
-}
-
-void NativeMapView::removeSource(JNIEnv&, jlong sourcePtr) {
+void NativeMapView::removeSource(JNIEnv& env, jni::Object<Source> obj, jlong sourcePtr) {
     assert(sourcePtr != 0);
 
     mbgl::android::Source *source = reinterpret_cast<mbgl::android::Source *>(sourcePtr);
-    std::unique_ptr<mbgl::style::Source> coreSource = map->getStyle().removeSource(source->get().getID());
-    if (coreSource) {
-        source->setSource(std::move(coreSource));
-    }
+    source->removeFromMap(env, obj, *map);
 }
 
 void NativeMapView::addImage(JNIEnv& env, jni::String name, jni::jint w, jni::jint h, jni::jfloat scale, jni::Array<jbyte> pixels) {
@@ -1048,7 +1033,6 @@ void NativeMapView::registerNative(jni::JNIEnv& env) {
             METHOD(&NativeMapView::getSources, "nativeGetSources"),
             METHOD(&NativeMapView::getSource, "nativeGetSource"),
             METHOD(&NativeMapView::addSource, "nativeAddSource"),
-            METHOD(&NativeMapView::removeSourceById, "nativeRemoveSourceById"),
             METHOD(&NativeMapView::removeSource, "nativeRemoveSource"),
             METHOD(&NativeMapView::addImage, "nativeAddImage"),
             METHOD(&NativeMapView::addImages, "nativeAddImages"),
diff --git a/platform/android/src/native_map_view.hpp b/platform/android/src/native_map_view.hpp
index d7e3b17b99..507d77ac5f 100755
--- a/platform/android/src/native_map_view.hpp
+++ b/platform/android/src/native_map_view.hpp
@@ -19,7 +19,7 @@
 #include "geometry/lat_lng.hpp"
 #include "geometry/projected_meters.hpp"
 #include "style/layers/layers.hpp"
-#include "style/sources/sources.hpp"
+#include "style/sources/source.hpp"
 #include "geometry/lat_lng_bounds.hpp"
 #include "map/camera_position.hpp"
 #include "map/image.hpp"
@@ -230,11 +230,11 @@ public:
 
     jni::Object<Source> getSource(JNIEnv&, jni::String);
 
-    void addSource(JNIEnv&, jni::jlong);
+    void addSource(JNIEnv&, jni::Object<Source>, jlong nativePtr);
 
     jni::Object<Source> removeSourceById(JNIEnv&, jni::String);
 
-    void removeSource(JNIEnv&, jlong);
+    void removeSource(JNIEnv&, jni::Object<Source>, jlong nativePtr);
 
     void addImage(JNIEnv&, jni::String, jni::jint, jni::jint, jni::jfloat, jni::Array<jbyte>);
 
diff --git a/platform/android/src/style/sources/custom_geometry_source.cpp b/platform/android/src/style/sources/custom_geometry_source.cpp
index e647975e4d..205fe55ed9 100644
--- a/platform/android/src/style/sources/custom_geometry_source.cpp
+++ b/platform/android/src/style/sources/custom_geometry_source.cpp
@@ -46,6 +46,12 @@ namespace android {
         javaPeer(_obj.NewGlobalRef(env))  {
     }
 
+    CustomGeometrySource::CustomGeometrySource(jni::JNIEnv& env,
+                                               mbgl::style::Source& coreSource,
+                                               AndroidRendererFrontend& frontend)
+        : Source(env, coreSource, createJavaPeer(env), frontend) {
+    }
+
     CustomGeometrySource::~CustomGeometrySource() = default;
 
     void CustomGeometrySource::fetchTile (const mbgl::CanonicalTileID& tileID) {
@@ -94,9 +100,9 @@ namespace android {
 
     jni::Class<CustomGeometrySource> CustomGeometrySource::javaClass;
 
-    jni::jobject* CustomGeometrySource::createJavaPeer(jni::JNIEnv& env) {
+    jni::Object<Source> CustomGeometrySource::createJavaPeer(jni::JNIEnv& env) {
         static auto constructor = CustomGeometrySource::javaClass.template GetConstructor<jni::jlong>(env);
-        return CustomGeometrySource::javaClass.New(env, constructor, reinterpret_cast<jni::jlong>(this));
+        return jni::Object<Source>(CustomGeometrySource::javaClass.New(env, constructor, reinterpret_cast<jni::jlong>(this)).Get());
     }
 
     void CustomGeometrySource::registerNative(jni::JNIEnv& env) {
diff --git a/platform/android/src/style/sources/custom_geometry_source.hpp b/platform/android/src/style/sources/custom_geometry_source.hpp
index 50ced9298a..00d8dc918f 100644
--- a/platform/android/src/style/sources/custom_geometry_source.hpp
+++ b/platform/android/src/style/sources/custom_geometry_source.hpp
@@ -27,6 +27,8 @@ public:
                        jni::String,
                        jni::Object<>);
 
+    CustomGeometrySource(jni::JNIEnv&, mbgl::style::Source&, AndroidRendererFrontend&);
+
     ~CustomGeometrySource();
 
     void fetchTile(const mbgl::CanonicalTileID& tileID);
@@ -39,7 +41,8 @@ public:
     jni::Array<jni::Object<geojson::Feature>> querySourceFeatures(jni::JNIEnv&,
                                                                   jni::Array<jni::Object<>> );
 
-    jni::jobject* createJavaPeer(jni::JNIEnv&);
+private:
+    jni::Object<Source> createJavaPeer(jni::JNIEnv&);
 
     jni::UniqueObject<CustomGeometrySource> javaPeer;
 }; // class CustomGeometrySource
diff --git a/platform/android/src/style/sources/geojson_source.cpp b/platform/android/src/style/sources/geojson_source.cpp
index 4468b453f3..6d9ab9e22c 100644
--- a/platform/android/src/style/sources/geojson_source.cpp
+++ b/platform/android/src/style/sources/geojson_source.cpp
@@ -43,8 +43,10 @@ namespace android {
             ) {
     }
 
-    GeoJSONSource::GeoJSONSource(mbgl::style::GeoJSONSource& coreSource)
-        : Source(coreSource) {
+    GeoJSONSource::GeoJSONSource(jni::JNIEnv& env,
+                                 mbgl::style::Source& coreSource,
+                                 AndroidRendererFrontend& frontend)
+            : Source(env, coreSource, createJavaPeer(env), frontend) {
     }
 
     GeoJSONSource::~GeoJSONSource() = default;
@@ -118,9 +120,9 @@ namespace android {
 
     jni::Class<GeoJSONSource> GeoJSONSource::javaClass;
 
-    jni::jobject* GeoJSONSource::createJavaPeer(jni::JNIEnv& env) {
+    jni::Object<Source> GeoJSONSource::createJavaPeer(jni::JNIEnv& env) {
         static auto constructor = GeoJSONSource::javaClass.template GetConstructor<jni::jlong>(env);
-        return GeoJSONSource::javaClass.New(env, constructor, reinterpret_cast<jni::jlong>(this));
+        return jni::Object<Source>(GeoJSONSource::javaClass.New(env, constructor, reinterpret_cast<jni::jlong>(this)).Get());
     }
 
     void GeoJSONSource::registerNative(jni::JNIEnv& env) {
diff --git a/platform/android/src/style/sources/geojson_source.hpp b/platform/android/src/style/sources/geojson_source.hpp
index 52dd632bfa..c46519b04a 100644
--- a/platform/android/src/style/sources/geojson_source.hpp
+++ b/platform/android/src/style/sources/geojson_source.hpp
@@ -21,7 +21,7 @@ public:
 
     GeoJSONSource(jni::JNIEnv&, jni::String, jni::Object<>);
 
-    GeoJSONSource(mbgl::style::GeoJSONSource&);
+    GeoJSONSource(jni::JNIEnv&, mbgl::style::Source&, AndroidRendererFrontend&);
 
     ~GeoJSONSource();
 
@@ -40,7 +40,8 @@ public:
 
     jni::String getURL(jni::JNIEnv&);
 
-    jni::jobject* createJavaPeer(jni::JNIEnv&);
+private:
+    jni::Object<Source> createJavaPeer(jni::JNIEnv&);
 
 }; // class GeoJSONSource
 
diff --git a/platform/android/src/style/sources/image_source.cpp b/platform/android/src/style/sources/image_source.cpp
index d46b367c53..0cd6995969 100644
--- a/platform/android/src/style/sources/image_source.cpp
+++ b/platform/android/src/style/sources/image_source.cpp
@@ -23,8 +23,10 @@ namespace android {
             ) {
     }
 
-    ImageSource::ImageSource(mbgl::style::ImageSource& coreSource)
-        : Source(coreSource) {
+    ImageSource::ImageSource(jni::JNIEnv& env,
+                             mbgl::style::Source& coreSource,
+                             AndroidRendererFrontend& frontend)
+            : Source(env, coreSource, createJavaPeer(env), frontend) {
     }
 
     ImageSource::~ImageSource() = default;
@@ -45,9 +47,9 @@ namespace android {
 
     jni::Class<ImageSource> ImageSource::javaClass;
 
-    jni::jobject* ImageSource::createJavaPeer(jni::JNIEnv& env) {
+    jni::Object<Source> ImageSource::createJavaPeer(jni::JNIEnv& env) {
         static auto constructor = ImageSource::javaClass.template GetConstructor<jni::jlong>(env);
-        return ImageSource::javaClass.New(env, constructor, reinterpret_cast<jni::jlong>(this));
+        return jni::Object<Source>(ImageSource::javaClass.New(env, constructor, reinterpret_cast<jni::jlong>(this)).Get());
     }
 
     void ImageSource::registerNative(jni::JNIEnv& env) {
diff --git a/platform/android/src/style/sources/image_source.hpp b/platform/android/src/style/sources/image_source.hpp
index 9787a7294f..f0af28d357 100644
--- a/platform/android/src/style/sources/image_source.hpp
+++ b/platform/android/src/style/sources/image_source.hpp
@@ -21,7 +21,7 @@ public:
 
     ImageSource(jni::JNIEnv&, jni::String, jni::Object<LatLngQuad>);
 
-    ImageSource(mbgl::style::ImageSource&);
+    ImageSource(jni::JNIEnv&, mbgl::style::Source&, AndroidRendererFrontend&);
 
     ~ImageSource();
 
@@ -30,7 +30,8 @@ public:
 
     void setImage(jni::JNIEnv&, jni::Object<Bitmap>);
 
-    jni::jobject* createJavaPeer(jni::JNIEnv&);
+private:
+    jni::Object<Source> createJavaPeer(jni::JNIEnv&);
 
 }; // class ImageSource
 
diff --git a/platform/android/src/style/sources/raster_source.cpp b/platform/android/src/style/sources/raster_source.cpp
index d45342a1ad..33223a5b69 100644
--- a/platform/android/src/style/sources/raster_source.cpp
+++ b/platform/android/src/style/sources/raster_source.cpp
@@ -22,8 +22,10 @@ namespace android {
         ) {
     }
 
-    RasterSource::RasterSource(mbgl::style::RasterSource& coreSource)
-        : Source(coreSource) {
+    RasterSource::RasterSource(jni::JNIEnv& env,
+                               mbgl::style::Source& coreSource,
+                               AndroidRendererFrontend& frontend)
+        : Source(env, coreSource, createJavaPeer(env), frontend) {
     }
 
     RasterSource::~RasterSource() = default;
@@ -35,9 +37,9 @@ namespace android {
 
     jni::Class<RasterSource> RasterSource::javaClass;
 
-    jni::jobject* RasterSource::createJavaPeer(jni::JNIEnv& env) {
+    jni::Object<Source> RasterSource::createJavaPeer(jni::JNIEnv& env) {
         static auto constructor = RasterSource::javaClass.template GetConstructor<jni::jlong>(env);
-        return RasterSource::javaClass.New(env, constructor, reinterpret_cast<jni::jlong>(this));
+        return jni::Object<Source>(RasterSource::javaClass.New(env, constructor, reinterpret_cast<jni::jlong>(this)).Get());
     }
 
     void RasterSource::registerNative(jni::JNIEnv& env) {
diff --git a/platform/android/src/style/sources/raster_source.hpp b/platform/android/src/style/sources/raster_source.hpp
index 84c49d7381..a1da22f40d 100644
--- a/platform/android/src/style/sources/raster_source.hpp
+++ b/platform/android/src/style/sources/raster_source.hpp
@@ -18,13 +18,14 @@ public:
 
     RasterSource(jni::JNIEnv&, jni::String, jni::Object<>, jni::jint);
 
-    RasterSource(mbgl::style::RasterSource&);
+    RasterSource(jni::JNIEnv&, mbgl::style::Source&, AndroidRendererFrontend&);
 
     ~RasterSource();
 
     jni::String getURL(jni::JNIEnv&);
 
-    jni::jobject* createJavaPeer(jni::JNIEnv&);
+private:
+    jni::Object<Source> createJavaPeer(jni::JNIEnv&);
 
 }; // class RasterSource
 
diff --git a/platform/android/src/style/sources/source.cpp b/platform/android/src/style/sources/source.cpp
index 447b13019d..3b89b25d7d 100644
--- a/platform/android/src/style/sources/source.cpp
+++ b/platform/android/src/style/sources/source.cpp
@@ -15,29 +15,70 @@
 
 #include <string>
 
+// Core Sources
+#include <mbgl/style/sources/geojson_source.hpp>
+#include <mbgl/style/sources/image_source.hpp>
+#include <mbgl/style/sources/raster_source.hpp>
+#include <mbgl/style/sources/vector_source.hpp>
+
+// Android Source peers
+#include "geojson_source.hpp"
+#include "image_source.hpp"
+#include "raster_source.hpp"
+#include "unknown_source.hpp"
+#include "vector_source.hpp"
+#include "custom_geometry_source.hpp"
+
 namespace mbgl {
 namespace android {
 
-    /**
-     * Invoked when the construction is initiated from the jvm through a subclass
-     */
-    Source::Source(jni::JNIEnv&, std::unique_ptr<mbgl::style::Source> coreSource)
-        : ownedSource(std::move(coreSource))
-        , source(*ownedSource) {
+    static std::unique_ptr<Source> createSourcePeer(jni::JNIEnv& env, mbgl::style::Source& coreSource, AndroidRendererFrontend& frontend) {
+        if (coreSource.is<mbgl::style::VectorSource>()) {
+            return std::make_unique<VectorSource>(env, *coreSource.as<mbgl::style::VectorSource>(), frontend);
+        } else if (coreSource.is<mbgl::style::RasterSource>()) {
+            return std::make_unique<RasterSource>(env, *coreSource.as<mbgl::style::RasterSource>(), frontend);
+        } else if (coreSource.is<mbgl::style::GeoJSONSource>()) {
+            return std::make_unique<GeoJSONSource>(env, *coreSource.as<mbgl::style::GeoJSONSource>(), frontend);
+        } else if (coreSource.is<mbgl::style::ImageSource>()) {
+            return std::make_unique<ImageSource>(env, *coreSource.as<mbgl::style::ImageSource>(), frontend);
+        } else {
+            return std::make_unique<UnknownSource>(env, coreSource, frontend);
+        }
     }
 
-    Source::Source(mbgl::style::Source& coreSource)
-            : source(coreSource) {
+    jni::Object<Source> Source::peerForCoreSource(jni::JNIEnv& env, mbgl::style::Source& coreSource, AndroidRendererFrontend& frontend) {
+        if (!coreSource.peer.has_value()) {
+            coreSource.peer = createSourcePeer(env, coreSource, frontend);
+        }
+        return *mbgl::util::any_cast<std::unique_ptr<Source>>(&coreSource.peer)->get()->javaPeer;
     }
 
-    Source::~Source() = default;
+    Source::Source(jni::JNIEnv& env, mbgl::style::Source& coreSource, jni::Object<Source> obj, AndroidRendererFrontend& frontend)
+        : source(coreSource)
+        , javaPeer(obj.NewGlobalRef(env))
+        , rendererFrontend(&frontend) {
+    }
 
-    style::Source& Source::get() {
-        return source;
+    Source::Source(jni::JNIEnv&, std::unique_ptr<mbgl::style::Source> coreSource)
+        : ownedSource(std::move(coreSource))
+        , source(*ownedSource) {
     }
 
-    void Source::setSource(std::unique_ptr<style::Source> coreSource) {
-        this->ownedSource = std::move(coreSource);
+    Source::~Source() {
+        // Before being added to a map, the Java peer owns this C++ peer and cleans
+        //  up after itself correctly through the jni native peer bindings.
+        // After being added to the map, the ownership is flipped and the C++ peer has a strong reference
+        //  to it's Java peer, preventing the Java peer from being GC'ed.
+        //  In this case, the core source initiates the destruction, which requires releasing the Java peer,
+        //  while also resetting it's nativePtr to 0 to prevent the subsequent GC of the Java peer from
+        //  re-entering this dtor.
+        if (ownedSource.get() == nullptr && javaPeer.get() != nullptr) {
+            // Manually clear the java peer
+            android::UniqueEnv env = android::AttachEnv();
+            static auto nativePtrField = javaClass.GetField<jlong>(*env, "nativePtr");
+            javaPeer->Set(*env, nativePtrField, (jlong) 0);
+            javaPeer.reset();
+        }
     }
 
     jni::String Source::getId(jni::JNIEnv& env) {
@@ -49,23 +90,48 @@ namespace android {
         return attribution ? jni::Make<jni::String>(env, attribution.value()) : jni::Make<jni::String>(env,"");
     }
 
-    void Source::addToMap(mbgl::Map& _map) {
+    void Source::addToMap(JNIEnv& env, jni::Object<Source> obj, mbgl::Map& map, AndroidRendererFrontend& frontend) {
         // Check to see if we own the source first
         if (!ownedSource) {
             throw std::runtime_error("Cannot add source twice");
         }
 
-        // Add source to map
-        _map.getStyle().addSource(releaseCoreSource());
-    }
+        // Add source to map and release ownership
+        map.getStyle().addSource(std::move(ownedSource));
+
+        // Add peer to core source
+        source.peer = std::unique_ptr<Source>(this);
+
+        // Add strong reference to java source
+        javaPeer = obj.NewGlobalRef(env);
 
-    void Source::setRendererFrontend(AndroidRendererFrontend& frontend_) {
-        rendererFrontend = &frontend_;
+        rendererFrontend = &frontend;
     }
 
-    std::unique_ptr<mbgl::style::Source> Source::releaseCoreSource() {
-        assert(ownedSource != nullptr);
-        return std::move(ownedSource);
+    void Source::removeFromMap(JNIEnv&, jni::Object<Source>, mbgl::Map& map) {
+        // Cannot remove if not attached yet
+        if (ownedSource) {
+            throw std::runtime_error("Cannot remove detached source");
+        }
+
+        // Remove the source from the map and take ownership
+        ownedSource = map.getStyle().removeSource(source.getID());
+
+        // The source may not be removed if any layers still reference it
+        if (!ownedSource) {
+            return;
+        }
+
+        // Release the peer relationships. These will be re-established when the source is added to a map
+        assert(ownedSource->peer.has_value());
+        util::any_cast<std::unique_ptr<Source>>(&(ownedSource->peer))->release();
+        ownedSource->peer.reset();
+
+        // Release the strong reference to the java peer
+        assert(javaPeer);
+        javaPeer.release();
+
+        rendererFrontend = nullptr;
     }
 
     jni::Class<Source> Source::javaClass;
@@ -82,6 +148,13 @@ namespace android {
             METHOD(&Source::getAttribution, "nativeGetAttribution")
         );
 
+        // Register subclasses
+        GeoJSONSource::registerNative(env);
+        ImageSource::registerNative(env);
+        RasterSource::registerNative(env);
+        UnknownSource::registerNative(env);
+        VectorSource::registerNative(env);
+        CustomGeometrySource::registerNative(env);
     }
 
 } // namespace android
diff --git a/platform/android/src/style/sources/source.hpp b/platform/android/src/style/sources/source.hpp
index 383017b66f..718f60b381 100644
--- a/platform/android/src/style/sources/source.hpp
+++ b/platform/android/src/style/sources/source.hpp
@@ -21,48 +21,40 @@ public:
 
     static void registerNative(jni::JNIEnv&);
 
+    static jni::Object<Source> peerForCoreSource(jni::JNIEnv&, mbgl::style::Source&, AndroidRendererFrontend&);
+
     /*
-     * Called when a Java object is created on the c++ side
+     * Called when a Java object is created for a core source that belongs to a map.
      */
-    Source(mbgl::style::Source&);
+    Source(jni::JNIEnv&, mbgl::style::Source&, jni::Object<Source>, AndroidRendererFrontend&);
 
     /*
-     * Called when a Java object was created from the jvm side
+     * Called when a Java object is created for a new core source that does not belong to a map.
      */
     Source(jni::JNIEnv&, std::unique_ptr<mbgl::style::Source>);
 
     virtual ~Source();
 
-    /**
-     * Set core source (ie return ownership after remove)
-     */
-    void setSource(std::unique_ptr<style::Source>);
-
-    style::Source& get();
-
-    void addToMap(mbgl::Map&);
+    void addToMap(JNIEnv&, jni::Object<Source>, mbgl::Map&, AndroidRendererFrontend&);
 
-    void setRendererFrontend(AndroidRendererFrontend&);
-
-    virtual jni::jobject* createJavaPeer(jni::JNIEnv&) = 0;
+    void removeFromMap(JNIEnv&, jni::Object<Source>, mbgl::Map&);
 
     jni::String getId(jni::JNIEnv&);
 
     jni::String getAttribution(jni::JNIEnv&);
 
 protected:
-    // Release the owned view and return it
-    std::unique_ptr<mbgl::style::Source> releaseCoreSource();
-
-    // Set on newly created sources until added to the map
+    // Set on newly created sources until added to the map.
     std::unique_ptr<mbgl::style::Source> ownedSource;
 
-    // Raw pointer that is valid until the source is removed from the map
+    // Raw pointer that is valid at all times.
     mbgl::style::Source& source;
 
-    // RendererFrontend pointer is valid only when
-    // added to the map
-    AndroidRendererFrontend* rendererFrontend;
+    // Set when the source is added to a map.
+    jni::UniqueObject<Source> javaPeer;
+
+    // RendererFrontend pointer is valid only when added to the map.
+    AndroidRendererFrontend* rendererFrontend { nullptr };
 };
 
 } // namespace android
diff --git a/platform/android/src/style/sources/sources.cpp b/platform/android/src/style/sources/sources.cpp
deleted file mode 100644
index 72d7bcda8c..0000000000
--- a/platform/android/src/style/sources/sources.cpp
+++ /dev/null
@@ -1,62 +0,0 @@
-#include "sources.hpp"
-
-#include <mbgl/style/source.hpp>
-#include <mbgl/style/sources/geojson_source.hpp>
-#include <mbgl/style/sources/image_source.hpp>
-#include <mbgl/style/sources/raster_source.hpp>
-#include <mbgl/style/sources/vector_source.hpp>
-
-#include "source.hpp"
-#include "geojson_source.hpp"
-#include "image_source.hpp"
-#include "raster_source.hpp"
-#include "unknown_source.hpp"
-#include "vector_source.hpp"
-#include "custom_geometry_source.hpp"
-
-namespace {
-
-    using namespace mbgl::android;
-
-    Source* initializeSourcePeer(mbgl::style::Source& coreSource) {
-        Source* source;
-        if (coreSource.is<mbgl::style::VectorSource>()) {
-            source = new VectorSource(*coreSource.as<mbgl::style::VectorSource>());
-        } else if (coreSource.is<mbgl::style::RasterSource>()) {
-            source = new RasterSource(*coreSource.as<mbgl::style::RasterSource>());
-        } else if (coreSource.is<mbgl::style::GeoJSONSource>()) {
-            source = new GeoJSONSource(*coreSource.as<mbgl::style::GeoJSONSource>());
-        } else if (coreSource.is<mbgl::style::ImageSource>()) {
-            source = new ImageSource(*coreSource.as<mbgl::style::ImageSource>());
-        } else {
-            source = new UnknownSource(coreSource);
-        }
-
-        return source;
-    }
-} // namespace
-
-namespace mbgl {
-namespace android {
-
-
-jni::jobject* createJavaSourcePeer(jni::JNIEnv& env, AndroidRendererFrontend& frontend, mbgl::style::Source& coreSource) {
-    std::unique_ptr<Source> peerSource = std::unique_ptr<Source>(initializeSourcePeer(coreSource));
-    peerSource->setRendererFrontend(frontend);
-    jni::jobject* result = peerSource->createJavaPeer(env);
-    peerSource.release();
-    return result;
-}
-
-void registerNativeSources(jni::JNIEnv& env) {
-    Source::registerNative(env);
-    GeoJSONSource::registerNative(env);
-    ImageSource::registerNative(env);
-    RasterSource::registerNative(env);
-    UnknownSource::registerNative(env);
-    VectorSource::registerNative(env);
-    CustomGeometrySource::registerNative(env);
-}
-
-}
-}
diff --git a/platform/android/src/style/sources/sources.hpp b/platform/android/src/style/sources/sources.hpp
deleted file mode 100644
index c7b36818b2..0000000000
--- a/platform/android/src/style/sources/sources.hpp
+++ /dev/null
@@ -1,18 +0,0 @@
-#pragma once
-
-#include <mbgl/style/source.hpp>
-
-#include "source.hpp"
-#include "../../android_renderer_frontend.hpp"
-
-#include <jni/jni.hpp>
-
-namespace mbgl {
-namespace android {
-
-    jni::jobject* createJavaSourcePeer(jni::JNIEnv&, AndroidRendererFrontend&, mbgl::style::Source&);
-
-    void registerNativeSources(jni::JNIEnv&);
-
-} // namespace android
-} // namespace mbgl
diff --git a/platform/android/src/style/sources/unknown_source.cpp b/platform/android/src/style/sources/unknown_source.cpp
index 79f27bdfbf..4b5510c1db 100644
--- a/platform/android/src/style/sources/unknown_source.cpp
+++ b/platform/android/src/style/sources/unknown_source.cpp
@@ -12,15 +12,17 @@ namespace {
 namespace mbgl {
 namespace android {
 
-    UnknownSource::UnknownSource(mbgl::style::Source& coreSource)
-            : Source(coreSource) {
+    UnknownSource::UnknownSource(jni::JNIEnv& env,
+                                 mbgl::style::Source& coreSource,
+                                 AndroidRendererFrontend& frontend)
+        : Source(env, coreSource, createJavaPeer(env), frontend) {
     }
 
     jni::Class<UnknownSource> UnknownSource::javaClass;
 
-    jni::jobject* UnknownSource::createJavaPeer(jni::JNIEnv& env) {
+    jni::Object<Source> UnknownSource::createJavaPeer(jni::JNIEnv& env) {
         static auto constructor = UnknownSource::javaClass.template GetConstructor<jni::jlong>(env);
-        return UnknownSource::javaClass.New(env, constructor, reinterpret_cast<jni::jlong>(this));
+        return jni::Object<Source>(UnknownSource::javaClass.New(env, constructor, reinterpret_cast<jni::jlong>(this)).Get());
     }
 
     void UnknownSource::registerNative(jni::JNIEnv& env) {
diff --git a/platform/android/src/style/sources/unknown_source.hpp b/platform/android/src/style/sources/unknown_source.hpp
index 4a003c9a7f..414d420c61 100644
--- a/platform/android/src/style/sources/unknown_source.hpp
+++ b/platform/android/src/style/sources/unknown_source.hpp
@@ -16,11 +16,12 @@ public:
 
     static void registerNative(jni::JNIEnv&);
 
-    UnknownSource(mbgl::style::Source&);
+    UnknownSource(jni::JNIEnv&, mbgl::style::Source&, AndroidRendererFrontend&);
 
     ~UnknownSource() = default;
 
-    jni::jobject* createJavaPeer(jni::JNIEnv&);
+private:
+    jni::Object<Source> createJavaPeer(jni::JNIEnv&);
 
 }; // class UnknownSource
 
diff --git a/platform/android/src/style/sources/vector_source.cpp b/platform/android/src/style/sources/vector_source.cpp
index 7fe45441bd..9a9548d283 100644
--- a/platform/android/src/style/sources/vector_source.cpp
+++ b/platform/android/src/style/sources/vector_source.cpp
@@ -30,8 +30,10 @@ namespace android {
         ) {
     }
 
-    VectorSource::VectorSource(mbgl::style::VectorSource& coreSource)
-        : Source(coreSource) {
+    VectorSource::VectorSource(jni::JNIEnv& env,
+                               mbgl::style::Source& coreSource,
+                               AndroidRendererFrontend& frontend)
+        : Source(env, coreSource, createJavaPeer(env), frontend) {
     }
 
     VectorSource::~VectorSource() = default;
@@ -56,9 +58,9 @@ namespace android {
 
     jni::Class<VectorSource> VectorSource::javaClass;
 
-    jni::jobject* VectorSource::createJavaPeer(jni::JNIEnv& env) {
+    jni::Object<Source> VectorSource::createJavaPeer(jni::JNIEnv& env) {
         static auto constructor = VectorSource::javaClass.template GetConstructor<jni::jlong>(env);
-        return VectorSource::javaClass.New(env, constructor, reinterpret_cast<jni::jlong>(this));
+        return jni::Object<Source>(VectorSource::javaClass.New(env, constructor, reinterpret_cast<jni::jlong>(this)).Get());
     }
 
     void VectorSource::registerNative(jni::JNIEnv& env) {
diff --git a/platform/android/src/style/sources/vector_source.hpp b/platform/android/src/style/sources/vector_source.hpp
index 509fe068d1..16049f5c77 100644
--- a/platform/android/src/style/sources/vector_source.hpp
+++ b/platform/android/src/style/sources/vector_source.hpp
@@ -19,7 +19,7 @@ public:
 
     VectorSource(jni::JNIEnv&, jni::String, jni::Object<>);
 
-    VectorSource(mbgl::style::VectorSource&);
+    VectorSource(jni::JNIEnv&, mbgl::style::Source&, AndroidRendererFrontend&);
 
     ~VectorSource();
 
@@ -28,7 +28,8 @@ public:
 
     jni::String getURL(jni::JNIEnv&);
 
-    jni::jobject* createJavaPeer(jni::JNIEnv&);
+private:
+    jni::Object<Source> createJavaPeer(jni::JNIEnv&);
 
 }; // class VectorSource