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_SESSION_STATE_OBSERVER_H_ 6 #define ASH_SESSION_SESSION_STATE_OBSERVER_H_ 7 8 #include <string> 9 10 #include "ash/ash_export.h" 11 #include "ash/session/session_state_delegate.h" 12 #include "base/basictypes.h" 13 14 namespace ash { 15 16 class ASH_EXPORT SessionStateObserver { 17 public: 18 // Called when active user has changed. 19 virtual void ActiveUserChanged(const std::string& user_id) {} 20 21 // Called when another user gets added to the existing session. 22 virtual void UserAddedToSession(const std::string& user_id) {} 23 24 // Called when session state is changed. 25 virtual void SessionStateChanged(SessionStateDelegate::SessionState state) {} 26 27 protected: 28 virtual ~SessionStateObserver() {} 29 }; 30 31 // A class to attach / detach an object as a session state observer with a 32 // scoped pointer. 33 class ASH_EXPORT ScopedSessionStateObserver { 34 public: 35 explicit ScopedSessionStateObserver(ash::SessionStateObserver* observer); 36 virtual ~ScopedSessionStateObserver(); 37 38 private: 39 ash::SessionStateObserver* observer_; 40 41 DISALLOW_COPY_AND_ASSIGN(ScopedSessionStateObserver); 42 }; 43 44 } // namespace ash 45 46 #endif // ASH_SESSION_SESSION_STATE_OBSERVER_H_ 47