ui/gfx/win/scoped_set_map_mode.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_SCOPED_SET_MAP_MODE_H_
   6 #define UI_GFX_WIN_SCOPED_SET_MAP_MODE_H_
   7
   8 #include <windows.h>
   9
  10 #include "base/basictypes.h"
  11 #include "base/logging.h"
  12
  13 namespace gfx {
  14
  15 // Helper class for setting and restore the map mode on a DC.
  16 class ScopedSetMapMode {
  17  public:
  18   ScopedSetMapMode(HDC hdc, int map_mode)
  19       : hdc_(hdc),
  20         old_map_mode_(SetMapMode(hdc, map_mode)) {
  21     DCHECK(hdc_);
  22     DCHECK_NE(map_mode, 0);
  23     DCHECK_NE(old_map_mode_, 0);
  24   }
  25
  26   ~ScopedSetMapMode() {
  27     const int mode = SetMapMode(hdc_, old_map_mode_);
  28     DCHECK_NE(mode, 0);
  29   }
  30
  31  private:
  32   HDC hdc_;
  33   int old_map_mode_;
  34
  35   DISALLOW_COPY_AND_ASSIGN(ScopedSetMapMode);
  36 };
  37
  38 }  // namespace gfx
  39
  40 #endif  // UI_GFX_WIN_SCOPED_SET_MAP_MODE_H_