1 // Copyright (c) 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef ASH_SESSION_STATE_OBSERVER_H_ 6 #define ASH_SESSION_STATE_OBSERVER_H_ 7 8 #include <string> 9 10 #include "ash/ash_export.h" 11 #include "base/basictypes.h" 12 13 namespace ash { 14 15 class ASH_EXPORT SessionStateObserver { 16 public: 17 // Called when active user has changed. ActiveUserChanged(const std::string & user_id)18 virtual void ActiveUserChanged(const std::string& user_id) {} 19 20 // Called when another user gets added to the existing session. UserAddedToSession(const std::string & user_id)21 virtual void UserAddedToSession(const std::string& user_id) {} 22 23 protected: ~SessionStateObserver()24 virtual ~SessionStateObserver() {} 25 }; 26 27 // A class to attach / detach an object as a session state observer with a 28 // scoped pointer. 29 class ASH_EXPORT ScopedSessionStateObserver { 30 public: 31 explicit ScopedSessionStateObserver(ash::SessionStateObserver* observer); 32 virtual ~ScopedSessionStateObserver(); 33 34 private: 35 ash::SessionStateObserver* observer_; 36 37 DISALLOW_COPY_AND_ASSIGN(ScopedSessionStateObserver); 38 }; 39 40 } // namespace ash 41 42 #endif // ASH_SESSION_STATE_OBSERVER_H_ 43