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1 $$ This is a pump file for generating file templates. Pump is a python | |
2 $$ script that is part of the Google Test suite of utilities. Description | |
3 $$ can be found here: | |
4 $$ | |
5 $$ http://code.google.com/p/googletest/wiki/PumpManual | |
6 $$ | |
7 | |
8 $$ See comment for MAX_ARITY in base/bind.h.pump. | |
9 $var MAX_ARITY = 7 | |
10 | |
11 // Copyright 2013 The Chromium Authors. All rights reserved. | |
12 // Use of this source code is governed by a BSD-style license that can be | |
13 // found in the LICENSE file. | |
14 | |
15 #ifndef BASE_CALLBACK_REGISTRY_H_ | |
16 #define BASE_CALLBACK_REGISTRY_H_ | |
17 | |
18 #include <list> | |
19 | |
20 #include "base/basictypes.h" | |
21 #include "base/callback.h" | |
22 #include "base/callback_internal.h" | |
23 #include "base/compiler_specific.h" | |
24 #include "base/logging.h" | |
25 #include "base/memory/scoped_ptr.h" | |
26 | |
27 // OVERVIEW: | |
28 // | |
29 // A container for a list of callbacks. Unlike a normal STL vector or list, | |
30 // this container can be modified during iteration without invalidating the | |
31 // iterator. It safely handles the case of a callback removing itself | |
32 // or another callback from the list while callbacks are being run. | |
33 // | |
34 // TYPICAL USAGE: | |
35 // | |
36 // class MyWidget { | |
37 // public: | |
38 // ... | |
39 // | |
40 // typedef base::Callback<void(const Foo&)> OnFooCallback; | |
41 // | |
42 // scoped_ptr<base::CallbackRegistry<void(const Foo&)>::Subscription> | |
43 // RegisterCallback(const OnFooCallback& cb) { | |
44 // return callback_registry_.Add(cb); | |
45 // } | |
46 // | |
47 // private: | |
48 // void NotifyFoo(const Foo& foo) { | |
49 // callback_registry_.Notify(foo); | |
50 // } | |
51 // | |
52 // base::CallbackRegistry<void(const Foo&)> callback_registry_; | |
53 // }; | |
54 // | |
55 // | |
56 // class MyWidgetListener { | |
57 // public: | |
58 // MyWidgetListener::MyWidgetListener() { | |
59 // foo_subscription_ = MyWidget::GetCurrent()->RegisterCallback( | |
60 // base::Bind(&MyWidgetListener::OnFoo, this))); | |
61 // } | |
62 // | |
63 // MyWidgetListener::~MyWidgetListener() { | |
64 // // Subscription gets deleted automatically and will deregister | |
65 // // the callback in the process. | |
66 // } | |
67 // | |
68 // private: | |
69 // void OnFoo(const Foo& foo) { | |
70 // // Do something. | |
71 // } | |
72 // | |
73 // scoped_ptr<base::CallbackRegistry<Foo>::Subscription> foo_subscription_; | |
74 // }; | |
75 | |
76 namespace base { | |
77 | |
78 namespace internal { | |
79 | |
80 template <typename CallbackType> | |
81 class CallbackRegistryBase { | |
82 public: | |
83 class Subscription { | |
84 public: | |
85 Subscription(CallbackRegistryBase<CallbackType>* list, | |
86 typename std::list<CallbackType>::iterator iter) | |
87 : list_(list), | |
88 iter_(iter) {} | |
89 | |
90 ~Subscription() { | |
91 if (list_->active_iterator_count_) | |
92 (*iter_).Reset(); | |
93 else | |
94 list_->callbacks_.erase(iter_); | |
95 } | |
96 | |
97 private: | |
98 CallbackRegistryBase<CallbackType>* list_; | |
99 typename std::list<CallbackType>::iterator iter_; | |
100 | |
101 DISALLOW_COPY_AND_ASSIGN(Subscription); | |
102 }; | |
103 | |
104 // Add a callback to the list. The callback will remain registered until the | |
105 // returned Subscription is destroyed, which must occur before the | |
106 // CallbackRegistry is destroyed. | |
107 scoped_ptr<Subscription> Add(const CallbackType& cb) { | |
108 DCHECK(!cb.is_null()); | |
109 return scoped_ptr<Subscription>( | |
110 new Subscription(this, callbacks_.insert(callbacks_.end(), cb))); | |
111 } | |
112 | |
113 protected: | |
114 // An iterator class that can be used to access the list of callbacks. | |
115 class Iterator { | |
116 public: | |
117 explicit Iterator(CallbackRegistryBase<CallbackType>* list) | |
118 : list_(list), | |
119 list_iter_(list_->callbacks_.begin()) { | |
120 ++list_->active_iterator_count_; | |
121 } | |
122 | |
123 Iterator(const Iterator& iter) | |
124 : list_(iter.list_), | |
125 list_iter_(iter.list_iter_) { | |
126 ++list_->active_iterator_count_; | |
127 } | |
128 | |
129 ~Iterator() { | |
130 if (list_ && --list_->active_iterator_count_ == 0) { | |
131 list_->Compact(); | |
132 } | |
133 } | |
134 | |
135 CallbackType* GetNext() { | |
136 while ((list_iter_ != list_->callbacks_.end()) && list_iter_->is_null()) | |
137 ++list_iter_; | |
138 | |
139 CallbackType* cb = NULL; | |
140 if (list_iter_ != list_->callbacks_.end()) { | |
141 cb = &(*list_iter_); | |
142 ++list_iter_; | |
143 } | |
144 return cb; | |
145 } | |
146 | |
147 private: | |
148 CallbackRegistryBase<CallbackType>* list_; | |
149 typename std::list<CallbackType>::iterator list_iter_; | |
150 }; | |
151 | |
152 CallbackRegistryBase() | |
153 : active_iterator_count_(0) {} | |
154 | |
155 ~CallbackRegistryBase() { | |
156 DCHECK_EQ(0, active_iterator_count_); | |
157 DCHECK_EQ(0U, callbacks_.size()); | |
158 } | |
159 | |
160 // Returns an instance of a CallbackRegistryBase::Iterator which can be used | |
161 // to run callbacks. | |
162 Iterator GetIterator() { | |
163 return Iterator(this); | |
164 } | |
165 | |
166 // Compact the list: remove any entries which were NULLed out during | |
167 // iteration. | |
168 void Compact() { | |
169 typename std::list<CallbackType>::iterator it = callbacks_.begin(); | |
170 while (it != callbacks_.end()) { | |
171 if ((*it).is_null()) | |
172 it = callbacks_.erase(it); | |
173 else | |
174 ++it; | |
175 } | |
176 } | |
177 | |
178 private: | |
179 std::list<CallbackType> callbacks_; | |
180 int active_iterator_count_; | |
181 | |
182 DISALLOW_COPY_AND_ASSIGN(CallbackRegistryBase); | |
183 }; | |
184 | |
185 } // namespace internal | |
186 | |
187 template <typename Sig> class CallbackRegistry; | |
188 | |
189 | |
190 $range ARITY 0..MAX_ARITY | |
191 $for ARITY [[ | |
192 $range ARG 1..ARITY | |
193 | |
194 $if ARITY == 0 [[ | |
195 template <> | |
196 class CallbackRegistry<void(void)> | |
197 : public internal::CallbackRegistryBase<Callback<void(void)> > { | |
198 ]] $else [[ | |
199 template <$for ARG , [[typename A$(ARG)]]> | |
200 class CallbackRegistry<void($for ARG , [[A$(ARG)]])> | |
201 : public internal::CallbackRegistryBase< | |
202 Callback<void($for ARG , [[A$(ARG)]])> > { | |
203 ]] | |
204 | |
205 public: | |
206 $if ARITY == 0 [[ | |
207 | |
208 typedef Callback<void(void)> CallbackType; | |
209 ]] $else [[ | |
210 | |
211 typedef Callback<void($for ARG , [[A$(ARG)]])> CallbackType; | |
212 ]] | |
213 | |
214 | |
215 CallbackRegistry() {} | |
216 | |
217 void Notify($for ARG , | |
218 [[typename internal::CallbackParamTraits<A$(ARG)>::ForwardType a$(
ARG)]]) { | |
219 $if ARITY == 0 [[ | |
220 | |
221 internal::CallbackRegistryBase<CallbackType>::Iterator it = | |
222 this->GetIterator(); | |
223 ]] $else [[ | |
224 | |
225 typename internal::CallbackRegistryBase<CallbackType>::Iterator it = | |
226 this->GetIterator(); | |
227 ]] | |
228 | |
229 CallbackType* cb; | |
230 while((cb = it.GetNext()) != NULL) { | |
231 cb->Run($for ARG , [[a$(ARG)]]); | |
232 } | |
233 } | |
234 | |
235 private: | |
236 DISALLOW_COPY_AND_ASSIGN(CallbackRegistry); | |
237 }; | |
238 | |
239 | |
240 ]] $$ for ARITY | |
241 } // namespace base | |
242 | |
243 #endif // BASE_CALLBACK_REGISTRY_H | |
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