| // Copyright (C) 2013 Google Inc. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| // |
| // An object to store a pointer to a method in an object with the following |
| // signature: |
| // |
| // void Observer::ObserveEvent(bool success, |
| // const Key& key, |
| // const Data& data); |
| |
| #ifndef I18N_ADDRESSINPUT_CALLBACK_H_ |
| #define I18N_ADDRESSINPUT_CALLBACK_H_ |
| |
| #include <cassert> |
| #include <cstddef> |
| |
| namespace i18n { |
| namespace addressinput { |
| |
| // Stores a pointer to a method in an object. Sample usage: |
| // class MyClass { |
| // public: |
| // typedef Callback<MyType, MyDataType> MyCallback; |
| // |
| // void GetDataAsynchronously() { |
| // scoped_ptr<MyCallback> callback(BuildCallback( |
| // this, &MyClass::OnDataReady)); |
| // bool success = ... |
| // MyKeyType key = ... |
| // MyDataType data = ... |
| // (*callback)(success, key, data); |
| // } |
| // |
| // void OnDataReady(bool success, |
| // const MyKeyType& key, |
| // const MyDataType& data) { |
| // ... |
| // } |
| // }; |
| template <typename Key, typename Data> |
| class Callback { |
| public: |
| virtual ~Callback() {} |
| |
| virtual void operator()(bool success, |
| const Key& key, |
| const Data& data) const = 0; |
| }; |
| |
| namespace { |
| |
| template <typename Observer, typename Key, typename Data> |
| class CallbackImpl : public Callback<Key, Data> { |
| public: |
| typedef void (Observer::*ObserveEvent)(bool, const Key&, const Data&); |
| |
| CallbackImpl(Observer* observer, ObserveEvent observe_event) |
| : observer_(observer), |
| observe_event_(observe_event) { |
| assert(observer_ != NULL); |
| assert(observe_event_ != NULL); |
| } |
| |
| virtual ~CallbackImpl() {} |
| |
| virtual void operator()(bool success, |
| const Key& key, |
| const Data& data) const { |
| (observer_->*observe_event_)(success, key, data); |
| } |
| |
| private: |
| Observer* observer_; |
| ObserveEvent observe_event_; |
| }; |
| |
| } // namespace |
| |
| // Returns a callback to |observer->observe_event| method. The caller owns the |
| // result. |
| template <typename Observer, typename Key, typename Data> |
| Callback<Key, Data>* BuildCallback( |
| Observer* observer, |
| void (Observer::*observe_event)(bool, const Key&, const Data&)) { |
| return new CallbackImpl<Observer, Key, Data>(observer, observe_event); |
| } |
| |
| } // namespace addressinput |
| } // namespace i18n |
| |
| #endif // I18N_ADDRESSINPUT_CALLBACK_H_ |