Fix CreateHRGNFromSkPath to support arbitrary SkPaths.

ui/gfx/path_win_unittest.cc

Index: ui/gfx/path_win_unittest.cc
diff --git a/ui/gfx/path_win_unittest.cc b/ui/gfx/path_win_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0bd87a426a919b857d1c0bc76ee73d99623b9ef1
--- /dev/null
+++ b/ui/gfx/path_win_unittest.cc
@@ -0,0 +1,82 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/gfx/path_win.h"
+
+#include <algorithm>
+#include <vector>
+
+#include "base/logging.h"
+#include "base/win/scoped_gdi_object.h"
+#include "skia/ext/skia_utils_win.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/skia/include/core/SkPath.h"
+#include "third_party/skia/include/core/SkRegion.h"
+
+namespace gfx {
+namespace {
+
+std::vector<SkIRect> GetRectsFromHRGN(HRGN region) {
+  // Determine the size of output buffer required to receive the region.
+  DWORD bytes_size = GetRegionData(region, 0, NULL);
+  CHECK(bytes_size != 0);
+
+  // Fetch the Windows RECTs that comprise the region.
+  std::vector<char> buffer(bytes_size);;
+  LPRGNDATA region_data = reinterpret_cast<LPRGNDATA>(buffer.data());
+  DWORD result = GetRegionData(region, bytes_size, region_data);
+  CHECK(result == bytes_size);
+
+  // Pull out the rectangles into a SkIRect vector to pass to setRects().
+  const LPRECT rects = reinterpret_cast<LPRECT>(&region_data->Buffer[0]);
+  std::vector<SkIRect> sk_rects(region_data->rdh.nCount);
+  std::transform(rects, rects + region_data->rdh.nCount,
+                 sk_rects.begin(), skia::RECTToSkIRect);
+
+  return sk_rects;
+}
+
+TEST(PathWinTest, BasicSkPathToHRGN) {
+  SkPath path;
+  path.moveTo(0.0f, 0.0f);
+  path.rLineTo(100.0f, 0.0f);
+  path.rLineTo(0.0f, 100.0f);
+  path.rLineTo(-100.0f, 0.0f);
+  path.rLineTo(0.0f, -100.0f);
+  base::win::ScopedRegion region(CreateHRGNFromSkPath(path));
+  std::vector<SkIRect> result = GetRectsFromHRGN(region);
+  EXPECT_EQ(1U, result.size());
+  EXPECT_EQ(0, result[0].left());
+  EXPECT_EQ(0, result[0].top());
+  EXPECT_EQ(100, result[0].right());
+  EXPECT_EQ(100, result[0].bottom());
+}
+
+TEST(PathWinTest, NonContiguousSkPathToHRGN) {
+  SkPath path;
+  path.moveTo(0.0f, 0.0f);
+  path.rLineTo(100.0f, 0.0f);
+  path.rLineTo(0.0f, 100.0f);
+  path.rLineTo(-100.0f, 0.0f);
+  path.rLineTo(0.0f, -100.0f);
+  path.moveTo(150.0f, 0.0f);
+  path.rLineTo(100.0f, 0.0f);
+  path.rLineTo(0.0f, 100.0f);
+  path.rLineTo(-100.0f, 0.0f);
+  path.rLineTo(0.0f, -100.0f);
+  base::win::ScopedRegion region(CreateHRGNFromSkPath(path));
+  std::vector<SkIRect> result = GetRectsFromHRGN(region);
+  EXPECT_EQ(2U, result.size());
+  EXPECT_EQ(0, result[0].left());
+  EXPECT_EQ(0, result[0].top());
+  EXPECT_EQ(100, result[0].right());
+  EXPECT_EQ(100, result[0].bottom());
+  EXPECT_EQ(150, result[1].left());
+  EXPECT_EQ(0, result[1].top());
+  EXPECT_EQ(250, result[1].right());
+  EXPECT_EQ(100, result[1].bottom());
+}
+
+}  // namespace
+}  // namespace gfx