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jni_weak_ref.h
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1 // Copyright 2013 The Flutter 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 #ifndef FLUTTER_FML_PLATFORM_ANDROID_JNI_WEAK_REF_H_
6 #define FLUTTER_FML_PLATFORM_ANDROID_JNI_WEAK_REF_H_
7 
8 #include <jni.h>
9 
10 #include "flutter/fml/platform/android/scoped_java_ref.h"
11 
12 namespace fml {
13 namespace jni {
14 
15 // Manages WeakGlobalRef lifecycle.
16 // This class is not thread-safe w.r.t. get() and reset(). Multiple threads may
17 // safely use get() concurrently, but if the user calls reset() (or of course,
18 // calls the destructor) they'll need to provide their own synchronization.
20  public:
22 
24 
25  JavaObjectWeakGlobalRef(JNIEnv* env, jobject obj);
26 
27  virtual ~JavaObjectWeakGlobalRef();
28 
29  void operator=(const JavaObjectWeakGlobalRef& rhs);
30 
31  ScopedJavaLocalRef<jobject> get(JNIEnv* env) const;
32 
33  bool is_empty() const { return obj_ == NULL; }
34 
35  void reset();
36 
37  private:
38  void Assign(const JavaObjectWeakGlobalRef& rhs);
39 
40  jweak obj_;
41 };
42 
43 // Get the real object stored in the weak reference returned as a
44 // ScopedJavaLocalRef.
45 ScopedJavaLocalRef<jobject> GetRealObject(JNIEnv* env, jweak obj);
46 
47 } // namespace jni
48 } // namespace fml
49 
50 #endif // FLUTTER_FML_PLATFORM_ANDROID_JNI_WEAK_REF_H_
void operator=(const JavaObjectWeakGlobalRef &rhs)
Definition: jni_weak_ref.cc:30
Definition: ascii_trie.cc:9
ScopedJavaLocalRef< jobject > GetRealObject(JNIEnv *env, jweak obj)
Definition: jni_weak_ref.cc:45