1 /* 2 * libjingle 3 * Copyright 2011 Google Inc. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #ifndef TALK_APP_WEBRTC_NOTIFIER_H_ 29 #define TALK_APP_WEBRTC_NOTIFIER_H_ 30 31 #include <list> 32 33 #include "talk/app/webrtc/mediastreaminterface.h" 34 #include "webrtc/base/common.h" 35 36 namespace webrtc { 37 38 // Implement a template version of a notifier. 39 template <class T> 40 class Notifier : public T { 41 public: 42 Notifier() { 43 } 44 45 virtual void RegisterObserver(ObserverInterface* observer) { 46 ASSERT(observer != NULL); 47 observers_.push_back(observer); 48 } 49 50 virtual void UnregisterObserver(ObserverInterface* observer) { 51 for (std::list<ObserverInterface*>::iterator it = observers_.begin(); 52 it != observers_.end(); it++) { 53 if (*it == observer) { 54 observers_.erase(it); 55 break; 56 } 57 } 58 } 59 60 void FireOnChanged() { 61 // Copy the list of observers to avoid a crash if the observer object 62 // unregisters as a result of the OnChanged() call. If the same list is used 63 // UnregisterObserver will affect the list make the iterator invalid. 64 std::list<ObserverInterface*> observers = observers_; 65 for (std::list<ObserverInterface*>::iterator it = observers.begin(); 66 it != observers.end(); ++it) { 67 (*it)->OnChanged(); 68 } 69 } 70 71 protected: 72 std::list<ObserverInterface*> observers_; 73 }; 74 75 } // namespace webrtc 76 77 #endif // TALK_APP_WEBRTC_NOTIFIER_H_ 78
