[Gin] Add a mechanism for wrapping C++ object

gin/wrappable_unittest.cc

+// 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 file.
+
+#include "base/logging.h"
+#include "gin/arguments.h"
+#include "gin/gin.h"
+#include "gin/per_isolate_data.h"
+#include "gin/test/v8_test.h"
+#include "gin/wrappable.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace gin {
+namespace {
+
+class MyObject : public Wrappable {
+ public:
+  static scoped_refptr<MyObject> Create();
+
+  int value() const { return value_; }
+  void set_value(int value) { value_ = value; }
+
+  static WrapperInfo kWrapperInfo;
+  virtual WrapperInfo* GetWrapperInfo() OVERRIDE;
+
+ private:
+  MyObject() : value_(0) {}
+  virtual ~MyObject() {}
+
+  int value_;
+};
+
+WrapperInfo MyObject::kWrapperInfo = { kEmbedderNativeGin };
+
+scoped_refptr<MyObject> MyObject::Create() {
+  return make_scoped_refptr(new MyObject());
+}
+
+WrapperInfo* MyObject::GetWrapperInfo() {
+  return &kWrapperInfo;
+}
+
+}  // namespace
+
+template<>
+struct Converter<MyObject*> : public WrappableConverter<MyObject> {};
+
+namespace {
+
+// TODO(abarth): This is too much typing.
+
+void MyObjectGetValue(const v8::FunctionCallbackInfo<v8::Value>& info) {
+  Arguments args(info);
+
+  MyObject* obj = 0;
+  CHECK(args.Holder(&obj));
+
+  args.Return(obj->value());
+}
+
+void MyObjectSetValue(const v8::FunctionCallbackInfo<v8::Value>& info) {
+  Arguments args(info);
+
+  MyObject* obj = 0;
+  CHECK(args.Holder(&obj));
+
+  int val = 0;
+  if (!args.GetNext(&val))
+    return args.ThrowError();
+
+  obj->set_value(val);
+}
+
+void RegisterTemplate(v8::Isolate* isolate) {
+  PerIsolateData* data = PerIsolateData::From(isolate);
+  DCHECK(data->GetObjectTemplate(&MyObject::kWrapperInfo).IsEmpty());
+
+  v8::Handle<v8::ObjectTemplate> templ = v8::ObjectTemplate::New();
+  templ->SetInternalFieldCount(kNumberOfInternalFields);
+  templ->SetAccessorProperty(
+      StringToSymbol(isolate, "value"),
+      v8::FunctionTemplate::New(MyObjectGetValue),
+      v8::FunctionTemplate::New(MyObjectSetValue));
+
+  data->SetObjectTemplate(&MyObject::kWrapperInfo, templ);
+}
+
+typedef V8Test WrappableTest;
+
+TEST_F(WrappableTest, WrapAndUnwrap) {
+  v8::Isolate* isolate = instance_->isolate();
+  v8::HandleScope handle_scope(isolate);
+
+  RegisterTemplate(isolate);
+  scoped_refptr<MyObject> obj = MyObject::Create();
+
+  v8::Handle<v8::Value> wrapper = ConvertToV8(isolate, obj.get());
+  EXPECT_FALSE(wrapper.IsEmpty());
+
+  MyObject* unwrapped = 0;
+  EXPECT_TRUE(ConvertFromV8(wrapper, &unwrapped));
+  EXPECT_EQ(obj, unwrapped);
+}
+
+TEST_F(WrappableTest, GetAndSetProperty) {
+  v8::Isolate* isolate = instance_->isolate();
+  v8::HandleScope handle_scope(isolate);
+
+  RegisterTemplate(isolate);
+  scoped_refptr<MyObject> obj = MyObject::Create();
+
+  obj->set_value(42);
+  EXPECT_EQ(42, obj->value());
+
+  v8::Handle<v8::String> source = StringToV8(isolate,
+      "(function (obj) {"
+      "   if (obj.value !== 42) throw 'FAIL';"
+      "   else obj.value = 191; })");
+  EXPECT_FALSE(source.IsEmpty());
+
+  v8::TryCatch try_catch;
+  v8::Handle<v8::Script> script = v8::Script::New(source);
+  EXPECT_FALSE(script.IsEmpty());
+  v8::Handle<v8::Value> val = script->Run();
+  EXPECT_FALSE(val.IsEmpty());
+  v8::Handle<v8::Function> func;
+  EXPECT_TRUE(ConvertFromV8(val, &func));
+  v8::Handle<v8::Value> argv[] = {
+    ConvertToV8(isolate, obj.get()),
+  };
+  func->Call(v8::Undefined(isolate), 1, argv);
+
+  EXPECT_EQ(191, obj->value());
+}
+
+}  // namespace
+}  // namespace gin