Reduce the size of the fullscreen window on activation loss only if the window being activated is …

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 <windows.h>
 
 #include <stddef.h>
+#include <map>
 #include <memory>
 #include <set>
 #include <vector>
 
 #include "base/compiler_specific.h"
+#include "base/lazy_instance.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string16.h"
 #include "base/win/scoped_gdi_object.h"
 #include "base/win/win_util.h"
 #include "ui/accessibility/ax_enums.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/base/win/window_event_target.h"
 #include "ui/events/event.h"
 #include "ui/gfx/geometry/rect.h"
@@ skipping 484 matching lines @@
   // Returns true if the message was handled.
   bool HandleMouseInputForCaption(unsigned int message,
                                   WPARAM w_param,
                                   LPARAM l_param);
 
   // Helper function for setting the bounds of the HWND. For more information
   // please refer to the SetBounds() function.
   void SetBoundsInternal(const gfx::Rect& bounds_in_pixels,
                          bool force_size_changed);
 
+  // Checks if there is a full screen window on the same monitor as the
+  // |window| which is becoming active. If yes then we reduce the size of the
+  // fullscreen window by 1 px to ensure that maximized windows on the same
+  // monitor don't draw over the taskbar.
+  void CheckAndHandleBackgroundFullscreenOnMonitor(HWND window);
+
+  // Provides functionality to reduce the bounds of the fullscreen window by 1
+  // px on activation loss to a window on the same monitor.
+  void OnBackgroundFullscreen();
+
   HWNDMessageHandlerDelegate* delegate_;
 
   std::unique_ptr<FullscreenHandler> fullscreen_handler_;
 
   // Set to true in Close() and false is CloseNow().
   bool waiting_for_close_now_;
 
   bool use_system_default_icon_;
 
   // Whether all ancestors have been enabled. This is only used if is_modal_ is
@@ skipping 114 matching lines @@
   gfx::Point caption_left_button_click_pos_;
 
   // Set to true if the left mouse button has been pressed on the caption.
   // Defaults to false.
   bool left_button_down_on_caption_;
 
   // Set to true if the window is a background fullscreen window, i.e a
   // fullscreen window which lost activation. Defaults to false.
   bool background_fullscreen_hack_;
 
+  // This is a map of the HMONITOR to full screeen window instance. It is safe
+  // to keep a raw pointer to the HWNDMessageHandler instance as we track the
+  // window destruction and ensure that the map is cleaned up.
+  using FullscreenWindowMonitorMap = std::map<HMONITOR, HWNDMessageHandler*>;
+  static base::LazyInstance<FullscreenWindowMonitorMap> fullscreen_monitor_map_;
+
   // The WeakPtrFactories below must occur last in the class definition so they
   // get destroyed last.
 
   // The factory used to lookup appbar autohide edges.
   base::WeakPtrFactory<HWNDMessageHandler> autohide_factory_;
 
   // The factory used with BEGIN_SAFE_MSG_MAP_EX.
   base::WeakPtrFactory<HWNDMessageHandler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HWNDMessageHandler);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIN_HWND_MESSAGE_HANDLER_H_