base/android/jni_weak_ref.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/android/jni_weak_ref.h"
   6
   7 #include "base/android/jni_android.h"
   8 #include "base/logging.h"
   9
  10 using base::android::AttachCurrentThread;
  11
  12 JavaObjectWeakGlobalRef::JavaObjectWeakGlobalRef()
  13   : obj_(NULL) {
  14 }
  15
  16 JavaObjectWeakGlobalRef::JavaObjectWeakGlobalRef(
  17     const JavaObjectWeakGlobalRef& orig)
  18     : obj_(NULL) {
  19   Assign(orig);
  20 }
  21
  22 JavaObjectWeakGlobalRef::JavaObjectWeakGlobalRef(JNIEnv* env, jobject obj)
  23     : obj_(env->NewWeakGlobalRef(obj)) {
  24   DCHECK(obj_);
  25 }
  26
  27 JavaObjectWeakGlobalRef::~JavaObjectWeakGlobalRef() {
  28   reset();
  29 }
  30
  31 void JavaObjectWeakGlobalRef::operator=(const JavaObjectWeakGlobalRef& rhs) {
  32   Assign(rhs);
  33 }
  34
  35 void JavaObjectWeakGlobalRef::reset() {
  36   if (obj_) {
  37     AttachCurrentThread()->DeleteWeakGlobalRef(obj_);
  38     obj_ = NULL;
  39   }
  40 }
  41
  42 base::android::ScopedJavaLocalRef<jobject>
  43     JavaObjectWeakGlobalRef::get(JNIEnv* env) const {
  44   return GetRealObject(env, obj_);
  45 }
  46
  47 base::android::ScopedJavaLocalRef<jobject> GetRealObject(
  48     JNIEnv* env, jweak obj) {
  49   jobject real = NULL;
  50   if (obj) {
  51     real = env->NewLocalRef(obj);
  52     if (!real)
  53       DLOG(ERROR) << "The real object has been deleted!";
  54   }
  55   return base::android::ScopedJavaLocalRef<jobject>(env, real);
  56 }
  57
  58 void JavaObjectWeakGlobalRef::Assign(const JavaObjectWeakGlobalRef& other) {
  59   if (&other == this)
  60     return;
  61
  62   JNIEnv* env = AttachCurrentThread();
  63   if (obj_)
  64     env->DeleteWeakGlobalRef(obj_);
  65
  66   obj_ = other.obj_ ? env->NewWeakGlobalRef(other.obj_) : NULL;
  67 }