Add weak ref promotions

Author: jfirebaugh

include/jni/functions.hpp

@@ -138,6 +138,16 @@ namespace jni
         return UniqueGlobalRef<T>(reinterpret_cast<T*>(obj), GlobalRefDeleter(env));
        }
 
+    // Attempt to promote a weak reference to a strong one. Returns an empty result
+    // if the weak reference has expired.
+    template < class T >
+    UniqueGlobalRef<T> NewGlobalRef(JNIEnv& env, const UniqueWeakGlobalRef<T>& t)
+       {
+        jobject* obj = Wrap<jobject*>(env.NewGlobalRef(Unwrap(t)));
+        CheckJavaException(env);
+        return UniqueGlobalRef<T>(reinterpret_cast<T*>(obj), GlobalRefDeleter(env));
+       }
+
     inline void DeleteGlobalRef(JNIEnv& env, UniqueGlobalRef<jobject>&& ref)
        {
         env.DeleteGlobalRef(Unwrap(ref.release()));
@@ -155,6 +165,16 @@ namespace jni
         return UniqueLocalRef<T>(reinterpret_cast<T*>(obj), LocalRefDeleter(env));
        }
 
+    // Attempt to promote a weak reference to a strong one. Returns an empty result
+    // if the weak reference has expired.
+    template < class T >
+    UniqueLocalRef<T> NewLocalRef(JNIEnv& env, const UniqueWeakGlobalRef<T>& t)
+       {
+        jobject* obj = Wrap<jobject*>(env.NewLocalRef(Unwrap(t)));
+        CheckJavaException(env);
+        return UniqueLocalRef<T>(reinterpret_cast<T*>(obj), LocalRefDeleter(env));
+       }
+
     inline void DeleteLocalRef(JNIEnv& env, UniqueLocalRef<jobject>&& ref)
        {
         env.DeleteLocalRef(Unwrap(ref.release()));

include/jni/unique_pointerlike.hpp

@@ -103,4 +103,24 @@ namespace jni
        {
         return Local<T>(std::move(t), LocalRefDeleter(env));
        }
+
+    // Attempt to promote a weak reference to a strong one. Returns an empty result
+    // if the weak reference has expired.
+    template < class T >
+    Global<T> NewGlobal(JNIEnv& env, const Weak<T>& t)
+       {
+        jobject* obj = Wrap<jobject*>(env.NewGlobalRef(Unwrap(t->Get())));
+        CheckJavaException(env);
+        return SeizeGlobal(env, T(obj));
+       }
+
+    // Attempt to promote a weak reference to a strong one. Returns an empty result
+    // if the weak reference has expired.
+    template < class T >
+    Local<T> NewLocal(JNIEnv& env, const Weak<T>& t)
+       {
+        jobject* obj = Wrap<jobject*>(env.NewLocalRef(Unwrap(t->Get())));
+        CheckJavaException(env);
+        return SeizeLocal(env, T(obj));
+       }
    }