base/callback_list.h

   1 // This file was GENERATED by command:
   2 //     pump.py callback_list.h.pump
   3 // DO NOT EDIT BY HAND!!!
   4
   5
   6 // Copyright 2013 The Chromium Authors. All rights reserved.
   7 // Use of this source code is governed by a BSD-style license that can be
   8 // found in the LICENSE file.
   9
  10 #ifndef BASE_CALLBACK_LIST_H_
  11 #define BASE_CALLBACK_LIST_H_
  12
  13 #include <list>
  14
  15 #include "base/basictypes.h"
  16 #include "base/callback.h"
  17 #include "base/callback_internal.h"
  18 #include "base/compiler_specific.h"
  19 #include "base/logging.h"
  20 #include "base/memory/scoped_ptr.h"
  21
  22 // OVERVIEW:
  23 //
  24 // A container for a list of callbacks.  Unlike a normal STL vector or list,
  25 // this container can be modified during iteration without invalidating the
  26 // iterator. It safely handles the case of a callback removing itself
  27 // or another callback from the list while callbacks are being run.
  28 //
  29 // TYPICAL USAGE:
  30 //
  31 // class MyWidget {
  32 //  public:
  33 //   ...
  34 //
  35 //   typedef base::Callback<void(const Foo&)> OnFooCallback;
  36 //
  37 //   scoped_ptr<base::CallbackList<void(const Foo&)>::Subscription>
  38 //   RegisterCallback(const OnFooCallback& cb) {
  39 //     return callback_list_.Add(cb);
  40 //   }
  41 //
  42 //  private:
  43 //   void NotifyFoo(const Foo& foo) {
  44 //      callback_list_.Notify(foo);
  45 //   }
  46 //
  47 //   base::CallbackList<void(const Foo&)> callback_list_;
  48 //
  49 //   DISALLOW_COPY_AND_ASSIGN(MyWidget);
  50 // };
  51 //
  52 //
  53 // class MyWidgetListener {
  54 //  public:
  55 //   MyWidgetListener::MyWidgetListener() {
  56 //     foo_subscription_ = MyWidget::GetCurrent()->RegisterCallback(
  57 //             base::Bind(&MyWidgetListener::OnFoo, this)));
  58 //   }
  59 //
  60 //   MyWidgetListener::~MyWidgetListener() {
  61 //      // Subscription gets deleted automatically and will deregister
  62 //      // the callback in the process.
  63 //   }
  64 //
  65 //  private:
  66 //   void OnFoo(const Foo& foo) {
  67 //     // Do something.
  68 //   }
  69 //
  70 //   scoped_ptr<base::CallbackList<void(const Foo&)>::Subscription>
  71 //       foo_subscription_;
  72 //
  73 //   DISALLOW_COPY_AND_ASSIGN(MyWidgetListener);
  74 // };
  75
  76 namespace base {
  77
  78 namespace internal {
  79
  80 template <typename CallbackType>
  81 class CallbackListBase {
  82  public:
  83   class Subscription {
  84    public:
  85     Subscription(CallbackListBase<CallbackType>* list,
  86                  typename std::list<CallbackType>::iterator iter)
  87         : list_(list),
  88           iter_(iter) {
  89     }
  90
  91     ~Subscription() {
  92       if (list_->active_iterator_count_)
  93         iter_->Reset();
  94       else
  95         list_->callbacks_.erase(iter_);
  96     }
  97
  98    private:
  99     CallbackListBase<CallbackType>* list_;
 100     typename std::list<CallbackType>::iterator iter_;
 101
 102     DISALLOW_COPY_AND_ASSIGN(Subscription);
 103   };
 104
 105   // Add a callback to the list. The callback will remain registered until the
 106   // returned Subscription is destroyed, which must occur before the
 107   // CallbackList is destroyed.
 108   scoped_ptr<Subscription> Add(const CallbackType& cb) WARN_UNUSED_RESULT {
 109     DCHECK(!cb.is_null());
 110     return scoped_ptr<Subscription>(
 111         new Subscription(this, callbacks_.insert(callbacks_.end(), cb)));
 112   }
 113
 114  protected:
 115   // An iterator class that can be used to access the list of callbacks.
 116   class Iterator {
 117    public:
 118     explicit Iterator(CallbackListBase<CallbackType>* list)
 119         : list_(list),
 120           list_iter_(list_->callbacks_.begin()) {
 121       ++list_->active_iterator_count_;
 122     }
 123
 124     Iterator(const Iterator& iter)
 125         : list_(iter.list_),
 126           list_iter_(iter.list_iter_) {
 127       ++list_->active_iterator_count_;
 128     }
 129
 130     ~Iterator() {
 131       if (list_ && --list_->active_iterator_count_ == 0) {
 132         list_->Compact();
 133       }
 134     }
 135
 136     CallbackType* GetNext() {
 137       while ((list_iter_ != list_->callbacks_.end()) && list_iter_->is_null())
 138         ++list_iter_;
 139
 140       CallbackType* cb = NULL;
 141       if (list_iter_ != list_->callbacks_.end()) {
 142         cb = &(*list_iter_);
 143         ++list_iter_;
 144       }
 145       return cb;
 146     }
 147
 148    private:
 149     CallbackListBase<CallbackType>* list_;
 150     typename std::list<CallbackType>::iterator list_iter_;
 151   };
 152
 153   CallbackListBase() : active_iterator_count_(0) {}
 154
 155   ~CallbackListBase() {
 156     DCHECK_EQ(0, active_iterator_count_);
 157     DCHECK_EQ(0U, callbacks_.size());
 158   }
 159
 160   // Returns an instance of a CallbackListBase::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(CallbackListBase);
 183 };
 184
 185 }  // namespace internal
 186
 187 template <typename Sig> class CallbackList;
 188
 189 template <>
 190 class CallbackList<void(void)>
 191     : public internal::CallbackListBase<Callback<void(void)> > {
 192  public:
 193   typedef Callback<void(void)> CallbackType;
 194
 195   CallbackList() {}
 196
 197   void Notify() {
 198     internal::CallbackListBase<CallbackType>::Iterator it =
 199         this->GetIterator();
 200     CallbackType* cb;
 201     while ((cb = it.GetNext()) != NULL) {
 202       cb->Run();
 203     }
 204   }
 205
 206  private:
 207   DISALLOW_COPY_AND_ASSIGN(CallbackList);
 208 };
 209
 210 template <typename A1>
 211 class CallbackList<void(A1)>
 212     : public internal::CallbackListBase<Callback<void(A1)> > {
 213  public:
 214   typedef Callback<void(A1)> CallbackType;
 215
 216   CallbackList() {}
 217
 218   void Notify(typename internal::CallbackParamTraits<A1>::ForwardType a1) {
 219     typename internal::CallbackListBase<CallbackType>::Iterator it =
 220         this->GetIterator();
 221     CallbackType* cb;
 222     while ((cb = it.GetNext()) != NULL) {
 223       cb->Run(a1);
 224     }
 225   }
 226
 227  private:
 228   DISALLOW_COPY_AND_ASSIGN(CallbackList);
 229 };
 230
 231 template <typename A1, typename A2>
 232 class CallbackList<void(A1, A2)>
 233     : public internal::CallbackListBase<Callback<void(A1, A2)> > {
 234  public:
 235   typedef Callback<void(A1, A2)> CallbackType;
 236
 237   CallbackList() {}
 238
 239   void Notify(typename internal::CallbackParamTraits<A1>::ForwardType a1,
 240               typename internal::CallbackParamTraits<A2>::ForwardType a2) {
 241     typename internal::CallbackListBase<CallbackType>::Iterator it =
 242         this->GetIterator();
 243     CallbackType* cb;
 244     while ((cb = it.GetNext()) != NULL) {
 245       cb->Run(a1, a2);
 246     }
 247   }
 248
 249  private:
 250   DISALLOW_COPY_AND_ASSIGN(CallbackList);
 251 };
 252
 253 template <typename A1, typename A2, typename A3>
 254 class CallbackList<void(A1, A2, A3)>
 255     : public internal::CallbackListBase<Callback<void(A1, A2, A3)> > {
 256  public:
 257   typedef Callback<void(A1, A2, A3)> CallbackType;
 258
 259   CallbackList() {}
 260
 261   void Notify(typename internal::CallbackParamTraits<A1>::ForwardType a1,
 262               typename internal::CallbackParamTraits<A2>::ForwardType a2,
 263               typename internal::CallbackParamTraits<A3>::ForwardType a3) {
 264     typename internal::CallbackListBase<CallbackType>::Iterator it =
 265         this->GetIterator();
 266     CallbackType* cb;
 267     while ((cb = it.GetNext()) != NULL) {
 268       cb->Run(a1, a2, a3);
 269     }
 270   }
 271
 272  private:
 273   DISALLOW_COPY_AND_ASSIGN(CallbackList);
 274 };
 275
 276 template <typename A1, typename A2, typename A3, typename A4>
 277 class CallbackList<void(A1, A2, A3, A4)>
 278     : public internal::CallbackListBase<Callback<void(A1, A2, A3, A4)> > {
 279  public:
 280   typedef Callback<void(A1, A2, A3, A4)> CallbackType;
 281
 282   CallbackList() {}
 283
 284   void Notify(typename internal::CallbackParamTraits<A1>::ForwardType a1,
 285               typename internal::CallbackParamTraits<A2>::ForwardType a2,
 286               typename internal::CallbackParamTraits<A3>::ForwardType a3,
 287               typename internal::CallbackParamTraits<A4>::ForwardType a4) {
 288     typename internal::CallbackListBase<CallbackType>::Iterator it =
 289         this->GetIterator();
 290     CallbackType* cb;
 291     while ((cb = it.GetNext()) != NULL) {
 292       cb->Run(a1, a2, a3, a4);
 293     }
 294   }
 295
 296  private:
 297   DISALLOW_COPY_AND_ASSIGN(CallbackList);
 298 };
 299
 300 template <typename A1, typename A2, typename A3, typename A4, typename A5>
 301 class CallbackList<void(A1, A2, A3, A4, A5)>
 302     : public internal::CallbackListBase<Callback<void(A1, A2, A3, A4, A5)> > {
 303  public:
 304   typedef Callback<void(A1, A2, A3, A4, A5)> CallbackType;
 305
 306   CallbackList() {}
 307
 308   void Notify(typename internal::CallbackParamTraits<A1>::ForwardType a1,
 309               typename internal::CallbackParamTraits<A2>::ForwardType a2,
 310               typename internal::CallbackParamTraits<A3>::ForwardType a3,
 311               typename internal::CallbackParamTraits<A4>::ForwardType a4,
 312               typename internal::CallbackParamTraits<A5>::ForwardType a5) {
 313     typename internal::CallbackListBase<CallbackType>::Iterator it =
 314         this->GetIterator();
 315     CallbackType* cb;
 316     while ((cb = it.GetNext()) != NULL) {
 317       cb->Run(a1, a2, a3, a4, a5);
 318     }
 319   }
 320
 321  private:
 322   DISALLOW_COPY_AND_ASSIGN(CallbackList);
 323 };
 324
 325 template <typename A1, typename A2, typename A3, typename A4, typename A5,
 326     typename A6>
 327 class CallbackList<void(A1, A2, A3, A4, A5, A6)>
 328     : public internal::CallbackListBase<Callback<void(A1, A2, A3, A4, A5,
 329         A6)> > {
 330  public:
 331   typedef Callback<void(A1, A2, A3, A4, A5, A6)> CallbackType;
 332
 333   CallbackList() {}
 334
 335   void Notify(typename internal::CallbackParamTraits<A1>::ForwardType a1,
 336               typename internal::CallbackParamTraits<A2>::ForwardType a2,
 337               typename internal::CallbackParamTraits<A3>::ForwardType a3,
 338               typename internal::CallbackParamTraits<A4>::ForwardType a4,
 339               typename internal::CallbackParamTraits<A5>::ForwardType a5,
 340               typename internal::CallbackParamTraits<A6>::ForwardType a6) {
 341     typename internal::CallbackListBase<CallbackType>::Iterator it =
 342         this->GetIterator();
 343     CallbackType* cb;
 344     while ((cb = it.GetNext()) != NULL) {
 345       cb->Run(a1, a2, a3, a4, a5, a6);
 346     }
 347   }
 348
 349  private:
 350   DISALLOW_COPY_AND_ASSIGN(CallbackList);
 351 };
 352
 353 template <typename A1, typename A2, typename A3, typename A4, typename A5,
 354     typename A6, typename A7>
 355 class CallbackList<void(A1, A2, A3, A4, A5, A6, A7)>
 356     : public internal::CallbackListBase<Callback<void(A1, A2, A3, A4, A5, A6,
 357         A7)> > {
 358  public:
 359   typedef Callback<void(A1, A2, A3, A4, A5, A6, A7)> CallbackType;
 360
 361   CallbackList() {}
 362
 363   void Notify(typename internal::CallbackParamTraits<A1>::ForwardType a1,
 364               typename internal::CallbackParamTraits<A2>::ForwardType a2,
 365               typename internal::CallbackParamTraits<A3>::ForwardType a3,
 366               typename internal::CallbackParamTraits<A4>::ForwardType a4,
 367               typename internal::CallbackParamTraits<A5>::ForwardType a5,
 368               typename internal::CallbackParamTraits<A6>::ForwardType a6,
 369               typename internal::CallbackParamTraits<A7>::ForwardType a7) {
 370     typename internal::CallbackListBase<CallbackType>::Iterator it =
 371         this->GetIterator();
 372     CallbackType* cb;
 373     while ((cb = it.GetNext()) != NULL) {
 374       cb->Run(a1, a2, a3, a4, a5, a6, a7);
 375     }
 376   }
 377
 378  private:
 379   DISALLOW_COPY_AND_ASSIGN(CallbackList);
 380 };
 381
 382 }  // namespace base
 383
 384 #endif  // BASE_CALLBACK_LIST_H_