electron/shell/common/gin_helper/wrappable.h
2020-04-02 16:07:56 -07:00

103 lines
3 KiB
C++

// Copyright 2013 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.chromium file.
#ifndef SHELL_COMMON_GIN_HELPER_WRAPPABLE_H_
#define SHELL_COMMON_GIN_HELPER_WRAPPABLE_H_
#include "base/bind.h"
#include "gin/per_isolate_data.h"
#include "shell/common/gin_helper/constructor.h"
namespace gin_helper {
namespace internal {
void* FromV8Impl(v8::Isolate* isolate, v8::Local<v8::Value> val);
} // namespace internal
template <typename T>
class Wrappable : public WrappableBase {
public:
Wrappable() = default;
template <typename Sig>
static void SetConstructor(v8::Isolate* isolate,
const base::Callback<Sig>& constructor) {
v8::Local<v8::FunctionTemplate> templ = gin_helper::CreateFunctionTemplate(
isolate, base::Bind(&internal::InvokeNew<Sig>, constructor));
templ->InstanceTemplate()->SetInternalFieldCount(1);
T::BuildPrototype(isolate, templ);
gin::PerIsolateData::From(isolate)->SetFunctionTemplate(&kWrapperInfo,
templ);
}
static v8::Local<v8::FunctionTemplate> GetConstructor(v8::Isolate* isolate) {
// Fill the object template.
auto* data = gin::PerIsolateData::From(isolate);
auto templ = data->GetFunctionTemplate(&kWrapperInfo);
if (templ.IsEmpty()) {
templ = v8::FunctionTemplate::New(isolate);
templ->InstanceTemplate()->SetInternalFieldCount(1);
T::BuildPrototype(isolate, templ);
data->SetFunctionTemplate(&kWrapperInfo, templ);
}
return templ;
}
protected:
// Init the class with T::BuildPrototype.
void Init(v8::Isolate* isolate) {
v8::Local<v8::FunctionTemplate> templ = GetConstructor(isolate);
// |wrapper| may be empty in some extreme cases, e.g., when
// Object.prototype.constructor is overwritten.
v8::Local<v8::Object> wrapper;
if (!templ->InstanceTemplate()
->NewInstance(isolate->GetCurrentContext())
.ToLocal(&wrapper)) {
// The current wrappable object will be no longer managed by V8. Delete
// this now.
delete this;
return;
}
InitWith(isolate, wrapper);
}
private:
static gin::WrapperInfo kWrapperInfo;
DISALLOW_COPY_AND_ASSIGN(Wrappable);
};
// static
template <typename T>
gin::WrapperInfo Wrappable<T>::kWrapperInfo = {gin::kEmbedderNativeGin};
} // namespace gin_helper
namespace gin {
template <typename T>
struct Converter<
T*,
typename std::enable_if<
std::is_convertible<T*, gin_helper::WrappableBase*>::value>::type> {
static v8::Local<v8::Value> ToV8(v8::Isolate* isolate, T* val) {
if (val)
return val->GetWrapper();
else
return v8::Null(isolate);
}
static bool FromV8(v8::Isolate* isolate, v8::Local<v8::Value> val, T** out) {
*out = static_cast<T*>(static_cast<gin_helper::WrappableBase*>(
gin_helper::internal::FromV8Impl(isolate, val)));
return *out != nullptr;
}
};
} // namespace gin
#endif // SHELL_COMMON_GIN_HELPER_WRAPPABLE_H_