ui/gfx/win/singleton_hwnd.h

   1 // Copyright (c) 2012 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 UI_GFX_WIN_SINGLETON_HWND_H_
   6 #define UI_GFX_WIN_SINGLETON_HWND_H_
   7
   8 #include <windows.h>
   9 #include <vector>
  10
  11 #include "base/observer_list.h"
  12 #include "ui/gfx/gfx_export.h"
  13 #include "ui/gfx/win/window_impl.h"
  14
  15 template<typename T> struct DefaultSingletonTraits;
  16
  17 namespace gfx {
  18
  19 class SingletonHwndObserver;
  20
  21 // Singleton message-only HWND that allows interested clients to receive WM_*
  22 // notifications.
  23 class GFX_EXPORT SingletonHwnd : public WindowImpl {
  24  public:
  25   static SingletonHwnd* GetInstance();
  26
  27   // Windows callback for WM_* notifications.
  28   BOOL ProcessWindowMessage(HWND window,
  29                             UINT message,
  30                             WPARAM wparam,
  31                             LPARAM lparam,
  32                             LRESULT& result,
  33                             DWORD msg_map_id) override;
  34
  35  private:
  36   friend class SingletonHwndObserver;
  37   friend struct DefaultSingletonTraits<SingletonHwnd>;
  38
  39   SingletonHwnd();
  40   ~SingletonHwnd() override;
  41
  42   // Add/remove SingletonHwndObserver to forward WM_* notifications.
  43   void AddObserver(SingletonHwndObserver* observer);
  44   void RemoveObserver(SingletonHwndObserver* observer);
  45
  46   // List of registered observers.
  47   base::ObserverList<SingletonHwndObserver, true> observer_list_;
  48
  49   DISALLOW_COPY_AND_ASSIGN(SingletonHwnd);
  50 };
  51
  52 }  // namespace gfx
  53
  54 #endif  // UI_GFX_WIN_SINGLETON_HWND_H_