text: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #ifndef ASH_SHELL_OBSERVER_H_
  #define ASH_SHELL_OBSERVER_H_
  
  #include "ash/ash_export.h"
  #include "ash/system/user/login_status.h"
  
  namespace aura {
  class Window;
  }
  
  namespace ash {
  
  class ASH_EXPORT ShellObserver {
   public:
    // Invoked after the screen's work area insets changes.
    virtual void OnDisplayWorkAreaInsetsChanged() {}
  
    // Invoked when the user logs in.
    virtual void OnLoginStateChanged(user::LoginStatus status) {}
  
    // Invoked when the application is exiting.
    virtual void OnAppTerminating() {}
  
    // Invoked when the screen is locked (after the lock window is visible) or
    // unlocked.
    virtual void OnLockStateChanged(bool locked) {}
  
    // Invoked when the shelf alignment in |root_window| is changed.
    virtual void OnShelfAlignmentChanged(aura::Window* root_window) {}
  
    // Invoked when the projection touch HUD is toggled.
    virtual void OnTouchHudProjectionToggled(bool enabled) {}
  
    // Invoked when entering or exiting fullscreen mode in |root_window|.
    virtual void OnFullscreenStateChanged(bool is_fullscreen,
                                          aura::Window* root_window) {}
  
    // Called when the overview mode is about to be started (before the windows
    // get re-arranged).
    virtual void OnOverviewModeStarting() {}
  
    // Called before the overview mode is ending (before the windows get arranged
    // to their final position).
    virtual void OnOverviewModeEnding() {}
  
    // Called when the always maximize mode has started. Windows might still
    // animate though.
    virtual void OnMaximizeModeStarted() {}
  
    // Called when the always maximize mode has ended. Windows may still be
    // animating but have been restored.
    virtual void OnMaximizeModeEnded() {}
  
   protected:
    virtual ~ShellObserver() {}
  };
  
  }  // namespace ash
  
  #endif  // ASH_SHELL_OBSERVER_H_
  