1// Copyright 2014 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#ifndef MOJO_BINDINGS_JS_HANDLE_H_ 6#define MOJO_BINDINGS_JS_HANDLE_H_ 7 8#include "base/observer_list.h" 9#include "gin/converter.h" 10#include "gin/handle.h" 11#include "gin/wrappable.h" 12#include "mojo/public/cpp/system/core.h" 13 14namespace gin { 15class HandleCloseObserver; 16 17// Wrapper for mojo Handles exposed to JavaScript. This ensures the Handle 18// is Closed when its JS object is garbage collected. 19class HandleWrapper : public gin::Wrappable<HandleWrapper> { 20 public: 21 static gin::WrapperInfo kWrapperInfo; 22 23 static gin::Handle<HandleWrapper> Create(v8::Isolate* isolate, 24 MojoHandle handle) { 25 return gin::CreateHandle(isolate, new HandleWrapper(handle)); 26 } 27 28 mojo::Handle get() const { return handle_.get(); } 29 mojo::Handle release() { return handle_.release(); } 30 void Close(); 31 32 void AddCloseObserver(HandleCloseObserver* observer); 33 void RemoveCloseObserver(HandleCloseObserver* observer); 34 35 protected: 36 HandleWrapper(MojoHandle handle); 37 virtual ~HandleWrapper(); 38 void NotifyCloseObservers(); 39 40 mojo::ScopedHandle handle_; 41 ObserverList<HandleCloseObserver> close_observers_; 42}; 43 44// Note: It's important to use this converter rather than the one for 45// MojoHandle, since that will do a simple int32 conversion. It's unfortunate 46// there's no way to prevent against accidental use. 47// TODO(mpcomplete): define converters for all Handle subtypes. 48template<> 49struct Converter<mojo::Handle> { 50 static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate, 51 const mojo::Handle& val); 52 static bool FromV8(v8::Isolate* isolate, v8::Handle<v8::Value> val, 53 mojo::Handle* out); 54}; 55 56// We need to specialize the normal gin::Handle converter in order to handle 57// converting |null| to a wrapper for an empty mojo::Handle. 58template<> 59struct Converter<gin::Handle<gin::HandleWrapper> > { 60 static v8::Handle<v8::Value> ToV8( 61 v8::Isolate* isolate, const gin::Handle<gin::HandleWrapper>& val) { 62 return val.ToV8(); 63 } 64 65 static bool FromV8(v8::Isolate* isolate, v8::Handle<v8::Value> val, 66 gin::Handle<gin::HandleWrapper>* out) { 67 if (val->IsNull()) { 68 *out = HandleWrapper::Create(isolate, MOJO_HANDLE_INVALID); 69 return true; 70 } 71 72 gin::HandleWrapper* object = NULL; 73 if (!Converter<gin::HandleWrapper*>::FromV8(isolate, val, &object)) { 74 return false; 75 } 76 *out = gin::Handle<gin::HandleWrapper>(val, object); 77 return true; 78 } 79}; 80 81} // namespace gin 82 83#endif // MOJO_BINDINGS_JS_HANDLE_H_ 84