Hide/show widget on Windows screen lock/unlock

ui/views/win/hwnd_message_handler_delegate.h

 // 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 UI_VIEWS_WIN_HWND_MESSAGE_HANDLER_DELEGATE_H_
 #define UI_VIEWS_WIN_HWND_MESSAGE_HANDLER_DELEGATE_H_
 
 #include "ui/views/views_export.h"
 
 namespace gfx {
@@ skipping 136 matching lines @@
   // Called when the system's work area has changed.
   virtual void HandleWorkAreaChanged() = 0;
 
   // Called when the window's visibility is changing. |visible| holds the new
   // state.
   virtual void HandleVisibilityChanging(bool visible) = 0;
 
   // Called when the window's visibility changed. |visible| holds the new state.
   virtual void HandleVisibilityChanged(bool visible) = 0;
 
+  // Called when the "calculated" window's visibility changed.
+  // OS doesn't mark windows hidden on screen lock or when other opaque windows
+  // cover them.
+  // |visible| holds the new state.
+  virtual void HandleSoftVisibilityChanged(bool visible) = 0;
+
   // Called when the window's client size changed. |new_size| holds the new
   // size.
   virtual void HandleClientSizeChanged(const gfx::Size& new_size) = 0;
 
   // Called when the window's frame has changed.
   virtual void HandleFrameChanged() = 0;
 
   // Called when focus shifted to this HWND from |last_focused_window|.
   virtual void HandleNativeFocus(HWND last_focused_window) = 0;
 
@@ skipping 61 matching lines @@
   // Called when the window size has finished changing.
   virtual void HandleWindowSizeChanged() = 0;
 
  protected:
   virtual ~HWNDMessageHandlerDelegate() {}
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIN_HWND_MESSAGE_HANDLER_DELEGATE_H_