1 files changed, 30 insertions, 0 deletions
diff --git a/gfx/src/RegionBuilder.h b/gfx/src/RegionBuilder.h
new file mode 100644
index 0000000000..c866f8fcf6
--- /dev/null
+++ b/gfx/src/RegionBuilder.h
@@ -0,0 +1,30 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 RegionBuilder_h__
+#define RegionBuilder_h__
+
+#include <nsTArray.h>
+
+template <typename RegionType>
+class RegionBuilder {
+ public:
+  typedef typename RegionType::RectType RectType;
+
+  RegionBuilder() = default;
+
+  void OrWith(const RectType& aRect) {
+    pixman_box32_t box = {aRect.X(), aRect.Y(), aRect.XMost(), aRect.YMost()};
+    mRects.AppendElement(box);
+  }
+
+  RegionType ToRegion() const { return RegionType(mRects); }
+
+ private:
+  nsTArray<pixman_box32_t> mRects;
+};
+
+#endif  // RegionBuilder_h__