Move base to DEPS

base/android/scoped_java_ref.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef BASE_ANDROID_SCOPED_JAVA_REF_H_
-#define BASE_ANDROID_SCOPED_JAVA_REF_H_
-
-#include <jni.h>
-#include <stddef.h>
-
-#include "base/base_export.h"
-#include "base/basictypes.h"
-
-namespace base {
-namespace android {
-
-// Creates a new local reference frame, in which at least a given number of
-// local references can be created. Note that local references already created
-// in previous local frames are still valid in the current local frame.
-class BASE_EXPORT ScopedJavaLocalFrame {
- public:
-  explicit ScopedJavaLocalFrame(JNIEnv* env);
-  ScopedJavaLocalFrame(JNIEnv* env, int capacity);
-  ~ScopedJavaLocalFrame();
-
- private:
-  // This class is only good for use on the thread it was created on so
-  // it's safe to cache the non-threadsafe JNIEnv* inside this object.
-  JNIEnv* env_;
-
-  DISALLOW_COPY_AND_ASSIGN(ScopedJavaLocalFrame);
-};
-
-// Forward declare the generic java reference template class.
-template<typename T> class JavaRef;
-
-// Template specialization of JavaRef, which acts as the base class for all
-// other JavaRef<> template types. This allows you to e.g. pass
-// ScopedJavaLocalRef<jstring> into a function taking const JavaRef<jobject>&
-template<>
-class BASE_EXPORT JavaRef<jobject> {
- public:
-  jobject obj() const { return obj_; }
-
-  bool is_null() const { return obj_ == NULL; }
-
- protected:
-  // Initializes a NULL reference.
-  JavaRef();
-
-  // Takes ownership of the |obj| reference passed; requires it to be a local
-  // reference type.
-  JavaRef(JNIEnv* env, jobject obj);
-
-  ~JavaRef();
-
-  // The following are implementation detail convenience methods, for
-  // use by the sub-classes.
-  JNIEnv* SetNewLocalRef(JNIEnv* env, jobject obj);
-  void SetNewGlobalRef(JNIEnv* env, jobject obj);
-  void ResetLocalRef(JNIEnv* env);
-  void ResetGlobalRef();
-  jobject ReleaseInternal();
-
- private:
-  jobject obj_;
-
-  DISALLOW_COPY_AND_ASSIGN(JavaRef);
-};
-
-// Generic base class for ScopedJavaLocalRef and ScopedJavaGlobalRef. Useful
-// for allowing functions to accept a reference without having to mandate
-// whether it is a local or global type.
-template<typename T>
-class JavaRef : public JavaRef<jobject> {
- public:
-  T obj() const { return static_cast<T>(JavaRef<jobject>::obj()); }
-
- protected:
-  JavaRef() {}
-  ~JavaRef() {}
-
-  JavaRef(JNIEnv* env, T obj) : JavaRef<jobject>(env, obj) {}
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(JavaRef);
-};
-
-// Holds a local reference to a Java object. The local reference is scoped
-// to the lifetime of this object.
-// Instances of this class may hold onto any JNIEnv passed into it until
-// destroyed. Therefore, since a JNIEnv is only suitable for use on a single
-// thread, objects of this class must be created, used, and destroyed, on a
-// single thread.
-// Therefore, this class should only be used as a stack-based object and from a
-// single thread. If you wish to have the reference outlive the current
-// callstack (e.g. as a class member) or you wish to pass it across threads,
-// use a ScopedJavaGlobalRef instead.
-template<typename T>
-class ScopedJavaLocalRef : public JavaRef<T> {
- public:
-  ScopedJavaLocalRef() : env_(NULL) {}
-
-  // Non-explicit copy constructor, to allow ScopedJavaLocalRef to be returned
-  // by value as this is the normal usage pattern.
-  ScopedJavaLocalRef(const ScopedJavaLocalRef<T>& other)
-      : env_(other.env_) {
-    this->SetNewLocalRef(env_, other.obj());
-  }
-
-  template<typename U>
-  explicit ScopedJavaLocalRef(const U& other)
-      : env_(NULL) {
-    this->Reset(other);
-  }
-
-  // Assumes that |obj| is a local reference to a Java object and takes
-  // ownership  of this local reference.
-  ScopedJavaLocalRef(JNIEnv* env, T obj) : JavaRef<T>(env, obj), env_(env) {}
-
-  ~ScopedJavaLocalRef() {
-    this->Reset();
-  }
-
-  // Overloaded assignment operator defined for consistency with the implicit
-  // copy constructor.
-  void operator=(const ScopedJavaLocalRef<T>& other) {
-    this->Reset(other);
-  }
-
-  void Reset() {
-    this->ResetLocalRef(env_);
-  }
-
-  template<typename U>
-  void Reset(const ScopedJavaLocalRef<U>& other) {
-    // We can copy over env_ here as |other| instance must be from the same
-    // thread as |this| local ref. (See class comment for multi-threading
-    // limitations, and alternatives).
-    this->Reset(other.env_, other.obj());
-  }
-
-  template<typename U>
-  void Reset(const U& other) {
-    // If |env_| was not yet set (is still NULL) it will be attached to the
-    // current thread in SetNewLocalRef().
-    this->Reset(env_, other.obj());
-  }
-
-  template<typename U>
-  void Reset(JNIEnv* env, U obj) {
-    implicit_cast<T>(obj);  // Ensure U is assignable to T
-    env_ = this->SetNewLocalRef(env, obj);
-  }
-
-  // Releases the local reference to the caller. The caller *must* delete the
-  // local reference when it is done with it.
-  T Release() {
-    return static_cast<T>(this->ReleaseInternal());
-  }
-
- private:
-  // This class is only good for use on the thread it was created on so
-  // it's safe to cache the non-threadsafe JNIEnv* inside this object.
-  JNIEnv* env_;
-};
-
-// Holds a global reference to a Java object. The global reference is scoped
-// to the lifetime of this object. This class does not hold onto any JNIEnv*
-// passed to it, hence it is safe to use across threads (within the constraints
-// imposed by the underlying Java object that it references).
-template<typename T>
-class ScopedJavaGlobalRef : public JavaRef<T> {
- public:
-  ScopedJavaGlobalRef() {}
-
-  explicit ScopedJavaGlobalRef(const ScopedJavaGlobalRef<T>& other) {
-    this->Reset(other);
-  }
-
-  ScopedJavaGlobalRef(JNIEnv* env, T obj) { this->Reset(env, obj); }
-
-  template<typename U>
-  explicit ScopedJavaGlobalRef(const U& other) {
-    this->Reset(other);
-  }
-
-  ~ScopedJavaGlobalRef() {
-    this->Reset();
-  }
-
-  void Reset() {
-    this->ResetGlobalRef();
-  }
-
-  template<typename U>
-  void Reset(const U& other) {
-    this->Reset(NULL, other.obj());
-  }
-
-  template<typename U>
-  void Reset(JNIEnv* env, U obj) {
-    implicit_cast<T>(obj);  // Ensure U is assignable to T
-    this->SetNewGlobalRef(env, obj);
-  }
-
-  // Releases the global reference to the caller. The caller *must* delete the
-  // global reference when it is done with it.
-  T Release() {
-    return static_cast<T>(this->ReleaseInternal());
-  }
-};
-
-}  // namespace android
-}  // namespace base
-
-#endif  // BASE_ANDROID_SCOPED_JAVA_REF_H_