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

1 files changed, 40 insertions, 0 deletions

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