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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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