1 /* 2 * Copyright 2004 The WebRTC Project Authors. All rights reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef WEBRTC_BASE_MESSAGEHANDLER_H_ 12 #define WEBRTC_BASE_MESSAGEHANDLER_H_ 13 14 #include "webrtc/base/constructormagic.h" 15 16 namespace rtc { 17 18 struct Message; 19 20 // Messages get dispatched to a MessageHandler 21 22 class MessageHandler { 23 public: 24 virtual ~MessageHandler(); 25 virtual void OnMessage(Message* msg) = 0; 26 27 protected: 28 MessageHandler() {} 29 30 private: 31 DISALLOW_COPY_AND_ASSIGN(MessageHandler); 32 }; 33 34 // Helper class to facilitate executing a functor on a thread. 35 template <class ReturnT, class FunctorT> 36 class FunctorMessageHandler : public MessageHandler { 37 public: 38 explicit FunctorMessageHandler(const FunctorT& functor) 39 : functor_(functor) {} 40 virtual void OnMessage(Message* msg) { 41 result_ = functor_(); 42 } 43 const ReturnT& result() const { return result_; } 44 45 private: 46 FunctorT functor_; 47 ReturnT result_; 48 }; 49 50 // Specialization for ReturnT of void. 51 template <class FunctorT> 52 class FunctorMessageHandler<void, FunctorT> : public MessageHandler { 53 public: 54 explicit FunctorMessageHandler(const FunctorT& functor) 55 : functor_(functor) {} 56 virtual void OnMessage(Message* msg) { 57 functor_(); 58 } 59 void result() const {} 60 61 private: 62 FunctorT functor_; 63 }; 64 65 66 } // namespace rtc 67 68 #endif // WEBRTC_BASE_MESSAGEHANDLER_H_ 69