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// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef GIN_HANDLE_H_
#define GIN_HANDLE_H_
#include "base/memory/raw_ptr.h"
#include "gin/converter.h"
namespace gin {
// You can use gin::Handle on the stack to retain a gin::Wrappable object.
// Currently we don't have a mechanism for retaining a gin::Wrappable object
// in the C++ heap because strong references from C++ to V8 can cause memory
// leaks.
template<typename T>
class Handle {
public:
Handle() : object_(nullptr) {}
Handle(v8::Local<v8::Value> wrapper, T* object)
: wrapper_(wrapper),
object_(object) {
}
bool IsEmpty() const { return !object_; }
void Clear() {
wrapper_.Clear();
object_ = NULL;
}
T* operator->() const { return object_; }
v8::Local<v8::Value> ToV8() const { return wrapper_; }
T* get() const { return object_; }
private:
v8::Local<v8::Value> wrapper_;
raw_ptr<T> object_;
};
template<typename T>
struct Converter<gin::Handle<T> > {
static v8::Local<v8::Value> ToV8(v8::Isolate* isolate,
const gin::Handle<T>& val) {
return val.ToV8();
}
static bool FromV8(v8::Isolate* isolate, v8::Local<v8::Value> val,
gin::Handle<T>* out) {
T* object = NULL;
if (!Converter<T*>::FromV8(isolate, val, &object)) {
return false;
}
*out = gin::Handle<T>(val, object);
return true;
}
};
// This function is a convenient way to create a handle from a raw pointer
// without having to write out the type of the object explicitly.
template<typename T>
gin::Handle<T> CreateHandle(v8::Isolate* isolate, T* object) {
v8::Local<v8::Object> wrapper;
if (!object->GetWrapper(isolate).ToLocal(&wrapper) || wrapper.IsEmpty())
return gin::Handle<T>();
return gin::Handle<T>(wrapper, object);
}
} // namespace gin
#endif // GIN_HANDLE_H_