base/android/jni_weak_ref.cc

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/android/jni_weak_ref.h"

#include <utility>

#include "base/android/jni_android.h"

using base::android::AttachCurrentThread;

JavaObjectWeakGlobalRef::JavaObjectWeakGlobalRef() : obj_(nullptr) {}

JavaObjectWeakGlobalRef::JavaObjectWeakGlobalRef(
    const JavaObjectWeakGlobalRef& orig)
    : obj_(nullptr) {
  Assign(orig);
}

JavaObjectWeakGlobalRef::JavaObjectWeakGlobalRef(
    JavaObjectWeakGlobalRef&& orig) noexcept
    : obj_(orig.obj_) {
  orig.obj_ = nullptr;
}

JavaObjectWeakGlobalRef::JavaObjectWeakGlobalRef(JNIEnv* env, jobject obj)
    : obj_(env->NewWeakGlobalRef(obj)) {
}

JavaObjectWeakGlobalRef::JavaObjectWeakGlobalRef(
    JNIEnv* env,
    const base::android::JavaRef<jobject>& obj)
    : obj_(env->NewWeakGlobalRef(obj.obj())) {
}

JavaObjectWeakGlobalRef::~JavaObjectWeakGlobalRef() {
  reset();
}

void JavaObjectWeakGlobalRef::operator=(const JavaObjectWeakGlobalRef& rhs) {
  Assign(rhs);
}

void JavaObjectWeakGlobalRef::operator=(JavaObjectWeakGlobalRef&& rhs) {
  std::swap(obj_, rhs.obj_);
}

void JavaObjectWeakGlobalRef::reset() {
  if (obj_) {
    AttachCurrentThread()->DeleteWeakGlobalRef(obj_);
    obj_ = nullptr;
  }
}

base::android::ScopedJavaLocalRef<jobject>
    JavaObjectWeakGlobalRef::get(JNIEnv* env) const {
  return GetRealObject(env, obj_);
}

base::android::ScopedJavaLocalRef<jobject> GetRealObject(
    JNIEnv* env, jweak obj) {
  jobject real = nullptr;
  if (obj)
    real = env->NewLocalRef(obj);
  return base::android::ScopedJavaLocalRef<jobject>(env, real);
}

void JavaObjectWeakGlobalRef::Assign(const JavaObjectWeakGlobalRef& other) {
  if (&other == this)
    return;

  JNIEnv* env = AttachCurrentThread();
  if (obj_)
    env->DeleteWeakGlobalRef(obj_);

  obj_ = other.obj_ ? env->NewWeakGlobalRef(other.obj_) : nullptr;
}