summaryrefslogtreecommitdiffstats
path: root/gin/object_template_builder.h
blob: bf0ece1e723ba1a0644961cfd3a01ce3c14c892a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
// 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.

#ifndef GIN_OBJECT_TEMPLATE_BUILDER_H_
#define GIN_OBJECT_TEMPLATE_BUILDER_H_

#include <type_traits>

#include "base/bind.h"
#include "base/callback.h"
#include "base/strings/string_piece.h"
#include "gin/converter.h"
#include "gin/function_template.h"
#include "gin/gin_export.h"
#include "v8/include/v8.h"

namespace gin {

namespace {

// Base template - used only for non-member function pointers. Other types
// either go to one of the below specializations, or go here and fail to compile
// because of base::Bind().
template<typename T, typename Enable = void>
struct CallbackTraits {
  static v8::Local<v8::FunctionTemplate> CreateTemplate(v8::Isolate* isolate,
                                                         T callback) {
    return CreateFunctionTemplate(isolate, base::Bind(callback));
  }
  static void SetAsFunctionHandler(v8::Isolate* isolate,
                                   v8::Local<v8::ObjectTemplate> tmpl,
                                   T callback) {
    CreateFunctionHandler(isolate, tmpl, base::Bind(callback));
  }
};

// Specialization for base::Callback.
template<typename T>
struct CallbackTraits<base::Callback<T> > {
  static v8::Local<v8::FunctionTemplate> CreateTemplate(
      v8::Isolate* isolate, const base::Callback<T>& callback) {
    return CreateFunctionTemplate(isolate, callback);
  }
  static void SetAsFunctionHandler(v8::Isolate* isolate,
                                   v8::Local<v8::ObjectTemplate> tmpl,
                                   const base::Callback<T>& callback) {
    CreateFunctionHandler(isolate, tmpl, callback);
  }
};

// Specialization for member function pointers. We need to handle this case
// specially because the first parameter for callbacks to MFP should typically
// come from the the JavaScript "this" object the function was called on, not
// from the first normal parameter.
template <typename T>
struct CallbackTraits<
    T,
    typename std::enable_if<std::is_member_function_pointer<T>::value>::type> {
  static v8::Local<v8::FunctionTemplate> CreateTemplate(v8::Isolate* isolate,
                                                         T callback) {
    return CreateFunctionTemplate(isolate, base::Bind(callback),
                                  HolderIsFirstArgument);
  }
  static void SetAsFunctionHandler(v8::Isolate* isolate,
                                   v8::Local<v8::ObjectTemplate> tmpl,
                                   T callback) {
    CreateFunctionHandler(
        isolate, tmpl, base::Bind(callback), HolderIsFirstArgument);
  }
};

// This specialization allows people to construct function templates directly if
// they need to do fancier stuff.
template<>
struct CallbackTraits<v8::Local<v8::FunctionTemplate> > {
  static v8::Local<v8::FunctionTemplate> CreateTemplate(
      v8::Local<v8::FunctionTemplate> templ) {
    return templ;
  }
};

}  // namespace


// ObjectTemplateBuilder provides a handy interface to creating
// v8::ObjectTemplate instances with various sorts of properties.
class GIN_EXPORT ObjectTemplateBuilder {
 public:
  explicit ObjectTemplateBuilder(v8::Isolate* isolate);
  ObjectTemplateBuilder(const ObjectTemplateBuilder& other);
  ~ObjectTemplateBuilder();

  // It's against Google C++ style to return a non-const ref, but we take some
  // poetic license here in order that all calls to Set() can be via the '.'
  // operator and line up nicely.
  template<typename T>
  ObjectTemplateBuilder& SetValue(const base::StringPiece& name, T val) {
    return SetImpl(name, ConvertToV8(isolate_, val));
  }

  // In the following methods, T and U can be function pointer, member function
  // pointer, base::Callback, or v8::FunctionTemplate. Most clients will want to
  // use one of the first two options. Also see gin::CreateFunctionTemplate()
  // for creating raw function templates.
  template<typename T>
  ObjectTemplateBuilder& SetMethod(const base::StringPiece& name,
                                   const T& callback) {
    return SetImpl(name, CallbackTraits<T>::CreateTemplate(isolate_, callback));
  }
  template<typename T>
  ObjectTemplateBuilder& SetProperty(const base::StringPiece& name,
                                     const T& getter) {
    return SetPropertyImpl(name,
                           CallbackTraits<T>::CreateTemplate(isolate_, getter),
                           v8::Local<v8::FunctionTemplate>());
  }
  template<typename T, typename U>
  ObjectTemplateBuilder& SetProperty(const base::StringPiece& name,
                                     const T& getter, const U& setter) {
    return SetPropertyImpl(name,
                           CallbackTraits<T>::CreateTemplate(isolate_, getter),
                           CallbackTraits<U>::CreateTemplate(isolate_, setter));
  }
  template<typename T>
  ObjectTemplateBuilder& SetCallAsFunctionHandler(const T& callback) {
    CallbackTraits<T>::SetAsFunctionHandler(isolate_, template_, callback);
    return *this;
  }
  ObjectTemplateBuilder& AddNamedPropertyInterceptor();
  ObjectTemplateBuilder& AddIndexedPropertyInterceptor();

  v8::Local<v8::ObjectTemplate> Build();

 private:
  ObjectTemplateBuilder& SetImpl(const base::StringPiece& name,
                                 v8::Local<v8::Data> val);
  ObjectTemplateBuilder& SetPropertyImpl(
      const base::StringPiece& name, v8::Local<v8::FunctionTemplate> getter,
      v8::Local<v8::FunctionTemplate> setter);

  v8::Isolate* isolate_;

  // ObjectTemplateBuilder should only be used on the stack.
  v8::Local<v8::ObjectTemplate> template_;
};

}  // namespace gin

#endif  // GIN_OBJECT_TEMPLATE_BUILDER_H_