1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4  * License, v. 2.0. If a copy of the MPL was not distributed with this
5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 
7 #ifndef mozilla_gfx_AutoHelpersWin_h
8 #define mozilla_gfx_AutoHelpersWin_h
9 
10 #include <windows.h>
11 
12 namespace mozilla {
13 namespace gfx {
14 
15 // Get the global device context, and auto-release it on destruction.
16 class AutoDC {
17  public:
AutoDC()18   AutoDC() { mDC = ::GetDC(nullptr); }
19 
~AutoDC()20   ~AutoDC() { ::ReleaseDC(nullptr, mDC); }
21 
GetDC()22   HDC GetDC() { return mDC; }
23 
24  private:
25   HDC mDC;
26 };
27 
28 // Select a font into the given DC, and auto-restore.
29 class AutoSelectFont {
30  public:
AutoSelectFont(HDC aDC,LOGFONTW * aLogFont)31   AutoSelectFont(HDC aDC, LOGFONTW* aLogFont) : mOwnsFont(false) {
32     mFont = ::CreateFontIndirectW(aLogFont);
33     if (mFont) {
34       mOwnsFont = true;
35       mDC = aDC;
36       mOldFont = (HFONT)::SelectObject(aDC, mFont);
37     } else {
38       mOldFont = nullptr;
39     }
40   }
41 
AutoSelectFont(HDC aDC,HFONT aFont)42   AutoSelectFont(HDC aDC, HFONT aFont) : mOwnsFont(false) {
43     mDC = aDC;
44     mFont = aFont;
45     mOldFont = (HFONT)::SelectObject(aDC, aFont);
46   }
47 
~AutoSelectFont()48   ~AutoSelectFont() {
49     if (mOldFont) {
50       ::SelectObject(mDC, mOldFont);
51       if (mOwnsFont) {
52         ::DeleteObject(mFont);
53       }
54     }
55   }
56 
IsValid()57   bool IsValid() const { return mFont != nullptr; }
58 
GetFont()59   HFONT GetFont() const { return mFont; }
60 
61  private:
62   HDC mDC;
63   HFONT mFont;
64   HFONT mOldFont;
65   bool mOwnsFont;
66 };
67 
68 }  // namespace gfx
69 }  // namespace mozilla
70 
71 #endif  // mozilla_gfx_AutoHelpersWin_h
72