gin/wrappable.cc

   1 // Copyright 2013 The Chromium 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 #include "gin/wrappable.h"
   6
   7 #include "base/logging.h"
   8 #include "gin/per_isolate_data.h"
   9
  10 namespace gin {
  11
  12 WrappableBase::WrappableBase() {
  13 }
  14
  15 WrappableBase::~WrappableBase() {
  16   wrapper_.Reset();
  17 }
  18
  19 v8::Handle<v8::Object> WrappableBase::GetWrapperImpl(
  20     v8::Isolate* isolate, WrapperInfo* wrapper_info) {
  21     if (wrapper_.IsEmpty())
  22       CreateWrapper(isolate, wrapper_info);
  23     return v8::Local<v8::Object>::New(isolate, wrapper_);
  24 }
  25
  26 void WrappableBase::WeakCallback(
  27     const v8::WeakCallbackData<v8::Object, WrappableBase>& data) {
  28   WrappableBase* wrappable = data.GetParameter();
  29   wrappable->wrapper_.Reset();
  30   delete wrappable;
  31 }
  32
  33 v8::Handle<v8::Object> WrappableBase::CreateWrapper(v8::Isolate* isolate,
  34                                                     WrapperInfo* info) {
  35   PerIsolateData* data = PerIsolateData::From(isolate);
  36   v8::Local<v8::ObjectTemplate> templ = data->GetObjectTemplate(info);
  37   CHECK(!templ.IsEmpty());  // Don't forget to register an object template.
  38   CHECK_EQ(kNumberOfInternalFields, templ->InternalFieldCount());
  39   v8::Handle<v8::Object> wrapper = templ->NewInstance();
  40   wrapper->SetAlignedPointerInInternalField(kWrapperInfoIndex, info);
  41   wrapper->SetAlignedPointerInInternalField(kEncodedValueIndex, this);
  42   wrapper_.Reset(isolate, wrapper);
  43   wrapper_.SetWeak(this, WeakCallback);
  44   return wrapper;
  45 }
  46
  47 namespace internal {
  48
  49 void* FromV8Impl(v8::Isolate* isolate, v8::Handle<v8::Value> val,
  50                  WrapperInfo* wrapper_info) {
  51   if (!val->IsObject())
  52     return NULL;
  53   v8::Handle<v8::Object> obj = v8::Handle<v8::Object>::Cast(val);
  54   WrapperInfo* info = WrapperInfo::From(obj);
  55
  56   // If this fails, the object is not managed by Gin. It is either a normal JS
  57   // object that's not wrapping any external C++ object, or it is wrapping some
  58   // C++ object, but that object isn't managed by Gin (maybe Blink).
  59   if (!info)
  60     return NULL;
  61
  62   // If this fails, the object is managed by Gin, but it's not wrapping an
  63   // instance of the C++ class associated with wrapper_info.
  64   if (info != wrapper_info)
  65     return NULL;
  66
  67   return obj->GetAlignedPointerFromInternalField(kEncodedValueIndex);
  68 }
  69
  70 }  // namespace internal
  71
  72 }  // namespace gin