In Windows desktop Chrome AURA the HandleVisibilityChanged function on the HWNDMessageHandlerDelega…

ui/views/win/hwnd_message_handler.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_H_
 #define UI_VIEWS_WIN_HWND_MESSAGE_HANDLER_H_
 
 #include <atlbase.h>
 #include <atlapp.h>
 #include <atlmisc.h>
@@ skipping 276 matching lines @@
     MSG_WM_NCACTIVATE(OnNCActivate)
     MSG_WM_NCCALCSIZE(OnNCCalcSize)
     MSG_WM_NCHITTEST(OnNCHitTest)
     MSG_WM_NCPAINT(OnNCPaint)
     MSG_WM_NOTIFY(OnNotify)
     MSG_WM_PAINT(OnPaint)
     MSG_WM_SETFOCUS(OnSetFocus)
     MSG_WM_SETICON(OnSetIcon)
     MSG_WM_SETTEXT(OnSetText)
     MSG_WM_SETTINGCHANGE(OnSettingChange)
+    MSG_WM_SHOWWINDOW(OnShowWindow)

[Ben Goodger (Google), 2013/04/17 18:22:12]

is this message sent under every situation that a window is made visible? e.g.
if I call SetWindowPos(hwnd, NULL, x, y, w, h, SWP_SHOWWINDOW); does it get
called?

[ananta, 2013/04/18 19:15:30]

Sadly no. It gets called for SetWindowPost with SWP_SHOWWINDOW in conjunction
with other flags. As per msdn even ShowWindow will cause this message to not be
sent if the window has the WS_MAXIMIZE style.

I reverted the change to this file and am proposing a different fix to this for
AURA. Please refer to the CL description for more information.

Thanks
Ananta

     MSG_WM_SIZE(OnSize)
     MSG_WM_SYSCOMMAND(OnSysCommand)
     MSG_WM_THEMECHANGED(OnThemeChanged)
     MSG_WM_WINDOWPOSCHANGING(OnWindowPosChanging)
     MSG_WM_WINDOWPOSCHANGED(OnWindowPosChanged)
   END_MSG_MAP()
 
   // Message Handlers.
   // This list is in _ALPHABETICAL_ order!
   // TODO(beng): Once this object becomes the WindowImpl, these methods can
@@ skipping 37 matching lines @@
   void OnSetFocus(HWND last_focused_window);
   LRESULT OnSetIcon(UINT size_type, HICON new_icon);
   LRESULT OnSetText(const wchar_t* text);
   void OnSettingChange(UINT flags, const wchar_t* section);
   void OnSize(UINT param, const CSize& size);
   void OnSysCommand(UINT notification_code, const CPoint& point);
   void OnThemeChanged();
   LRESULT OnTouchEvent(UINT message, WPARAM w_param, LPARAM l_param);
   void OnWindowPosChanging(WINDOWPOS* window_pos);
   void OnWindowPosChanged(WINDOWPOS* window_pos);
+  void OnShowWindow(BOOL visible, int lparam);
 
   HWNDMessageHandlerDelegate* delegate_;
 
   scoped_ptr<FullscreenHandler> fullscreen_handler_;
 
   base::WeakPtrFactory<HWNDMessageHandler> close_widget_factory_;
 
   bool remove_standard_frame_;
 
   bool use_system_default_icon_;
@@ skipping 90 matching lines @@
 
   // True the first time nccalc is called on a sizable widget
   bool is_first_nccalc_;
 
   DISALLOW_COPY_AND_ASSIGN(HWNDMessageHandler);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIN_HWND_MESSAGE_HANDLER_H_