ui/base/win/atl_module.h

   1 // Copyright (c) 2011 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_BASE_WIN_ATL_MODULE_H_
   6 #define UI_BASE_WIN_ATL_MODULE_H_
   7
   8 #include <atlbase.h>
   9 #include <atlcom.h>
  10
  11 #include "base/basictypes.h"
  12 #include "base/compiler_specific.h"
  13 #include "base/macros.h"
  14
  15 namespace ui {
  16 namespace win {
  17
  18 // Ensure that we have exactly one ATL module registered. It's safe to
  19 // call this more than once. ATL functions will crash if there's no
  20 // ATL module registered, or if you try to register two of them, so
  21 // dynamically registering one if needed makes it much easier for us
  22 // to support different build configurations like multi-dll without
  23 // worrying about which side of a module boundary each ATL module object
  24 // belongs on.
  25 //
  26 // This function must be implemented in this header file rather than a
  27 // source file so that it's inlined into the module where it's included,
  28 // rather than in the "ui" module.
  29 inline void CreateATLModuleIfNeeded() {
  30   if (_pAtlModule == NULL) {
  31     // This creates the module and automatically updates _pAtlModule.
  32     new CComModule;
  33   }
  34 }
  35
  36 }  // namespace win
  37 }  // namespace ui
  38
  39 #endif  // UI_BASE_WIN_ATL_MODULE_H_