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