[android] introduce generic Peer object for JNI wrappingupstream/7743-nativepeer-defaultfilesource

7 files changed, 97 insertions, 94 deletions

diff --git a/platform/android/config.cmake b/platform/android/config.cmake
index 61669d48a7..8a8b5cb768 100644
--- a/platform/android/config.cmake
+++ b/platform/android/config.cmake
@@ -91,7 +91,6 @@ macro(mbgl_platform_core)
 
         # Storage
         PRIVATE platform/android/src/storage/default_file_source_peer.cpp
-        PRIVATE platform/android/src/storage/default_file_source_peer.hpp
 
         # Conversion C++ -> Java
         platform/android/src/conversion/constant.hpp
diff --git a/platform/android/src/jni.cpp b/platform/android/src/jni.cpp
index d136766455..a4631997ad 100755
--- a/platform/android/src/jni.cpp
+++ b/platform/android/src/jni.cpp
@@ -9,12 +9,12 @@
 #include <sys/system_properties.h>
 
 #include "jni.hpp"
+#include "jni/peer.hpp"
 #include "java_types.hpp"
 #include "native_map_view.hpp"
 #include "connectivity_listener.hpp"
 #include "style/layers/layers.hpp"
 #include "style/sources/sources.hpp"
-#include "storage/default_file_source_peer.hpp"
 
 #include "conversion/conversion.hpp"
 #include "conversion/collection.hpp"
@@ -298,7 +298,7 @@ namespace {
 using namespace mbgl::android;
 using DebugOptions = mbgl::MapDebugOptions;
 
-jlong nativeCreate(JNIEnv *env, jni::jobject* obj, jni::Object<DefaultFileSourcePeer> fileSource, jfloat pixelRatio, jint availableProcessors, jlong totalMemory) {
+jlong nativeCreate(JNIEnv *env, jni::jobject* obj, jni::Object<Peer<mbgl::DefaultFileSource>> fileSource, jfloat pixelRatio, jint availableProcessors, jlong totalMemory) {
     mbgl::Log::Debug(mbgl::Event::JNI, "nativeCreate");
     return reinterpret_cast<jlong>(new NativeMapView(env, jni::Unwrap(obj), fileSource, pixelRatio, availableProcessors, totalMemory));
 }
@@ -1705,9 +1705,7 @@ void registerNatives(JavaVM *vm) {
     registerNativeLayers(env);
     registerNativeSources(env);
     ConnectivityListener::registerNative(env);
-
-    mbgl::Log::Error(mbgl::Event::JNI, "registering DefaultFileSource peer");
-    DefaultFileSourcePeer::registerNative(env);
+    Peer<DefaultFileSource>::RegisterNative(env);
 
     latLngClass = &jni::FindClass(env, "com/mapbox/mapboxsdk/geometry/LatLng");
     latLngClass = jni::NewGlobalRef(env, latLngClass).release();
diff --git a/platform/android/src/jni/peer.hpp b/platform/android/src/jni/peer.hpp
new file mode 100644
index 0000000000..2c16cce710
--- /dev/null
+++ b/platform/android/src/jni/peer.hpp
@@ -0,0 +1,40 @@
+#pragma once
+
+#include <jni/jni.hpp>
+
+#include <memory>
+
+namespace mbgl {
+namespace android {
+
+template <typename T>
+class Peer {
+public:
+    static constexpr auto Name();
+    static void RegisterNative(jni::JNIEnv&);
+
+    static T& Get(jni::JNIEnv& env, const jni::Object<Peer<T>>& obj) {
+        jni::Field<Peer, jlong> field{ env, javaClass, peer };
+        return *reinterpret_cast<Peer*>(obj.Get(env, field))->native;
+    }
+
+protected:
+    template <typename... Args>
+    Peer(Args&&... args) : native(std::make_unique<T>(std::forward<Args>(args)...)) {
+    }
+
+    const std::unique_ptr<T> native;
+
+private:
+    static const char* peer;
+    static jni::Class<Peer<T>> javaClass;
+};
+
+template <typename T>
+jni::Class<Peer<T>> Peer<T>::javaClass;
+
+template <typename T>
+const char* Peer<T>::peer = "peer";
+
+} // namespace android
+} // namespace mbgl
diff --git a/platform/android/src/native_map_view.cpp b/platform/android/src/native_map_view.cpp
index 3e2013c0d3..df47c6588b 100755
--- a/platform/android/src/native_map_view.cpp
+++ b/platform/android/src/native_map_view.cpp
@@ -1,5 +1,6 @@
 #include "native_map_view.hpp"
 #include "jni.hpp"
+#include "jni/peer.hpp"
 
 #include <cstdlib>
 #include <ctime>
@@ -40,7 +41,7 @@ void log_egl_string(EGLDisplay display, EGLint name, const char *label) {
 
 NativeMapView::NativeMapView(JNIEnv* env_,
                              jobject obj_,
-                             jni::Object<DefaultFileSourcePeer> fileSource_,
+                             jni::Object<Peer<DefaultFileSource>> fileSource_,
                              float pixelRatio,
                              int availableProcessors_,
                              size_t totalMemory_)
@@ -65,13 +66,9 @@ NativeMapView::NativeMapView(JNIEnv* env_,
         return;
     }
 
-    jni::Field<DefaultFileSourcePeer, jlong> peerField{ *env, DefaultFileSourcePeer::javaClass,
-                                                        "peer" };
-    auto fileSourcePtr = reinterpret_cast<DefaultFileSourcePeer*>(fileSource->Get(*env, peerField));
-
     map = std::make_unique<mbgl::Map>(
         *this, mbgl::Size{ static_cast<uint32_t>(width), static_cast<uint32_t>(height) },
-        pixelRatio, fileSourcePtr->getFileSource(), threadPool, MapMode::Continuous);
+        pixelRatio, Peer<DefaultFileSource>::Get(*env, *fileSource), threadPool, MapMode::Continuous);
 
     float zoomFactor   = map->getMaxZoom() - map->getMinZoom() + 1;
     float cpuFactor    = availableProcessors;
diff --git a/platform/android/src/native_map_view.hpp b/platform/android/src/native_map_view.hpp
index ea75ef7702..bc1306405f 100755
--- a/platform/android/src/native_map_view.hpp
+++ b/platform/android/src/native_map_view.hpp
@@ -6,7 +6,7 @@
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/util/default_thread_pool.hpp>
 
-#include "storage/default_file_source_peer.hpp"
+#include "jni/peer.hpp"
 
 #include <string>
 #include <jni.h>
@@ -14,13 +14,16 @@
 #include <EGL/egl.h>
 
 namespace mbgl {
+
+class DefaultFileSource;
+
 namespace android {
 
 class NativeMapView : public mbgl::View, public mbgl::Backend {
 public:
     NativeMapView(JNIEnv* env,
                   jobject obj,
-                  jni::Object<DefaultFileSourcePeer> fileSourcePeer,
+                  jni::Object<Peer<DefaultFileSource>> fileSourcePeer,
                   float pixelRatio,
                   int availableProcessors,
                   size_t totalMemory);
@@ -101,7 +104,7 @@ private:
     size_t totalMemory = 0;
 
     // Ensure these are initialised last
-    jni::UniqueObject<DefaultFileSourcePeer> fileSource;
+    jni::UniqueObject<Peer<DefaultFileSource>> fileSource;
     mbgl::ThreadPool threadPool;
     std::unique_ptr<mbgl::Map> map;
     mbgl::EdgeInsets insets;
diff --git a/platform/android/src/storage/default_file_source_peer.cpp b/platform/android/src/storage/default_file_source_peer.cpp
index 6f8a36b78a..968ec1c652 100644
--- a/platform/android/src/storage/default_file_source_peer.cpp
+++ b/platform/android/src/storage/default_file_source_peer.cpp
@@ -1,53 +1,59 @@
-#include "default_file_source_peer.hpp"
-
+#include <mbgl/storage/default_file_source.hpp>
 #include <mbgl/storage/default_file_source.hpp>
 
+#include "../jni/peer.hpp"
+
 namespace mbgl {
 namespace android {
 
-jni::Class<DefaultFileSourcePeer> DefaultFileSourcePeer::javaClass;
+template <>
+constexpr auto Peer<DefaultFileSource>::Name() {
+    return "com/mapbox/mapboxsdk/storage/DefaultFileSource";
+}
+
+class Impl : public Peer<DefaultFileSource> {
+public:
+    Impl(jni::JNIEnv& env,
+         jni::String cachePath,
+         jni::String assetRoot,
+         jni::jlong maximumCacheSize)
+        : Peer(jni::Make<std::string>(env, cachePath),
+               jni::Make<std::string>(env, assetRoot),
+               maximumCacheSize) {
+    }
+
+    void setAPIBaseURL(jni::JNIEnv& env, jni::String baseURL) {
+        native->setAPIBaseURL(jni::Make<std::string>(env, baseURL));
+    }
+
+    jni::String getAPIBaseURL(jni::JNIEnv& env) {
+        return jni::Make<jni::String>(env, native->getAPIBaseURL());
+    }
+
+    void setAccessToken(jni::JNIEnv& env, jni::String accessToken) {
+        native->setAccessToken(jni::Make<std::string>(env, accessToken));
+    }
+
+    jni::String getAccessToken(jni::JNIEnv& env) {
+        return jni::Make<jni::String>(env, native->getAccessToken());
+    }
+};
 
 #define NATIVE_METHOD(MethodPtr, name)                                                             \
     jni::MakeNativePeerMethod<decltype(MethodPtr), (MethodPtr)>(name)
 
-void DefaultFileSourcePeer::registerNative(jni::JNIEnv& env) {
-    javaClass = *jni::Class<DefaultFileSourcePeer>::Find(env).NewGlobalRef(env).release();
+template <>
+void Peer<DefaultFileSource>::RegisterNative(jni::JNIEnv& env) {
+    javaClass = *jni::Class<Peer<DefaultFileSource>>::Find(env).NewGlobalRef(env).release();
 
-    jni::RegisterNativePeer<DefaultFileSourcePeer>(
-        env, javaClass, "peer",
-        std::make_unique<DefaultFileSourcePeer, JNIEnv&, jni::String, jni::String, jni::jlong>,
+    jni::RegisterNativePeer<Impl>(
+        env, javaClass, peer,
+        std::make_unique<Impl, JNIEnv&, jni::String, jni::String, jni::jlong>,
         "initialize", "finalize",
-        NATIVE_METHOD(&DefaultFileSourcePeer::setAPIBaseURL, "setAPIBaseURL"),
-        NATIVE_METHOD(&DefaultFileSourcePeer::getAPIBaseURL, "getAPIBaseURL"),
-        NATIVE_METHOD(&DefaultFileSourcePeer::setAccessToken, "setAccessToken"),
-        NATIVE_METHOD(&DefaultFileSourcePeer::getAccessToken, "getAccessToken"));
-}
-
-DefaultFileSourcePeer::DefaultFileSourcePeer(jni::JNIEnv& env,
-                                             jni::String cachePath,
-                                             jni::String assetRoot,
-                                             jni::jlong maximumCacheSize)
-    : native(std::make_unique<DefaultFileSource>(jni::Make<std::string>(env, cachePath),
-                                                 jni::Make<std::string>(env, assetRoot),
-                                                 maximumCacheSize)) {
-}
-
-DefaultFileSourcePeer::~DefaultFileSourcePeer() = default;
-
-void DefaultFileSourcePeer::setAPIBaseURL(jni::JNIEnv& env, jni::String baseURL) {
-    native->setAPIBaseURL(jni::Make<std::string>(env, baseURL));
-}
-
-jni::String DefaultFileSourcePeer::getAPIBaseURL(jni::JNIEnv& env) {
-    return jni::Make<jni::String>(env, native->getAPIBaseURL());
-}
-
-void DefaultFileSourcePeer::setAccessToken(jni::JNIEnv& env, jni::String accessToken) {
-    native->setAccessToken(jni::Make<std::string>(env, accessToken));
-}
-
-jni::String DefaultFileSourcePeer::getAccessToken(jni::JNIEnv& env) {
-    return jni::Make<jni::String>(env, native->getAccessToken());
+        NATIVE_METHOD(&Impl::setAPIBaseURL, "setAPIBaseURL"),
+        NATIVE_METHOD(&Impl::getAPIBaseURL, "getAPIBaseURL"),
+        NATIVE_METHOD(&Impl::setAccessToken, "setAccessToken"),
+        NATIVE_METHOD(&Impl::getAccessToken, "getAccessToken"));
 }
 
 } // namespace android
diff --git a/platform/android/src/storage/default_file_source_peer.hpp b/platform/android/src/storage/default_file_source_peer.hpp
deleted file mode 100644
index c0f60447b3..0000000000
--- a/platform/android/src/storage/default_file_source_peer.hpp
+++ /dev/null
@@ -1,40 +0,0 @@
-#pragma once
-
-#include <jni/jni.hpp>
-
-#include <memory>
-
-namespace mbgl {
-
-class DefaultFileSource;
-
-namespace android {
-
-class DefaultFileSourcePeer {
-public:
-    static constexpr auto Name() { return "com/mapbox/mapboxsdk/storage/DefaultFileSource"; }
-    static jni::Class<DefaultFileSourcePeer> javaClass;
-    static void registerNative(jni::JNIEnv&);
-
-    DefaultFileSourcePeer(jni::JNIEnv&,
-                          jni::String cachePath,
-                          jni::String assetRoot,
-                          jni::jlong maximumCacheSize);
-    ~DefaultFileSourcePeer();
-
-    void setAPIBaseURL(jni::JNIEnv&, jni::String);
-    jni::String getAPIBaseURL(jni::JNIEnv&);
-
-    void setAccessToken(jni::JNIEnv&, jni::String);
-    jni::String getAccessToken(jni::JNIEnv&);
-
-    DefaultFileSource& getFileSource() {
-      return *native;
-    }
-
-private:
-    const std::unique_ptr<DefaultFileSource> native;
-};
-
-} // namespace android
-} // namespace mbgl