1 files changed, 86 insertions, 0 deletions
diff --git a/gfx/2d/AutoHelpersWin.h b/gfx/2d/AutoHelpersWin.h
new file mode 100644
index 000000000..744d0d500
--- /dev/null
+++ b/gfx/2d/AutoHelpersWin.h
@@ -0,0 +1,86 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+* This Source Code Form is subject to the terms of the Mozilla Public
+* License, v. 2.0. If a copy of the MPL was not distributed with this
+* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_gfx_AutoHelpersWin_h
+#define mozilla_gfx_AutoHelpersWin_h
+
+#include <windows.h>
+
+namespace mozilla {
+namespace gfx {
+
+// Get the global device context, and auto-release it on destruction.
+class AutoDC
+{
+public:
+  AutoDC() {
+    mDC = ::GetDC(nullptr);
+  }
+
+  ~AutoDC() {
+    ::ReleaseDC(nullptr, mDC);
+  }
+
+  HDC GetDC() {
+    return mDC;
+  }
+
+private:
+  HDC mDC;
+};
+
+// Select a font into the given DC, and auto-restore.
+class AutoSelectFont
+{
+public:
+  AutoSelectFont(HDC aDC, LOGFONTW *aLogFont)
+    : mOwnsFont(false)
+  {
+    mFont = ::CreateFontIndirectW(aLogFont);
+    if (mFont) {
+      mOwnsFont = true;
+      mDC = aDC;
+      mOldFont = (HFONT)::SelectObject(aDC, mFont);
+    } else {
+      mOldFont = nullptr;
+    }
+  }
+
+  AutoSelectFont(HDC aDC, HFONT aFont)
+    : mOwnsFont(false)
+  {
+    mDC = aDC;
+    mFont = aFont;
+    mOldFont = (HFONT)::SelectObject(aDC, aFont);
+  }
+
+  ~AutoSelectFont() {
+    if (mOldFont) {
+      ::SelectObject(mDC, mOldFont);
+      if (mOwnsFont) {
+        ::DeleteObject(mFont);
+      }
+    }
+  }
+
+  bool IsValid() const {
+    return mFont != nullptr;
+  }
+
+  HFONT GetFont() const {
+    return mFont;
+  }
+
+private:
+  HDC mDC;
+  HFONT mFont;
+  HFONT mOldFont;
+  bool mOwnsFont;
+};
+
+} // gfx
+} // mozilla
+
+#endif // mozilla_gfx_AutoHelpersWin_h