1 files changed, 41 insertions, 0 deletions
diff --git a/widget/windows/ScrollbarUtil.h b/widget/windows/ScrollbarUtil.h
new file mode 100644
index 0000000000..9085653fb2
--- /dev/null
+++ b/widget/windows/ScrollbarUtil.h
@@ -0,0 +1,41 @@
+/* -*- Mode: C++; tab-width: 40; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 ScrollbarUtil_h
+#define ScrollbarUtil_h
+
+#include "nsLayoutUtils.h"
+#include "nsNativeTheme.h"
+
+class ScrollbarUtil {
+ public:
+  static bool IsScrollbarWidthThin(ComputedStyle* aStyle);
+  static bool IsScrollbarWidthThin(nsIFrame* aFrame);
+
+  // Returns the style for custom scrollbar if the scrollbar part frame should
+  // use the custom drawing path, nullptr otherwise.
+  //
+  // Optionally the caller can pass a pointer to aDarkScrollbar for whether
+  // custom scrollbar may be drawn due to dark background.
+  static ComputedStyle* GetCustomScrollbarStyle(nsIFrame* aFrame,
+                                                bool* aDarkScrollbar = nullptr);
+
+  static nscolor GetScrollbarButtonColor(nscolor aTrackColor,
+                                         EventStates aStates);
+  static nscolor GetScrollbarArrowColor(nscolor aButtonColor);
+  static nscolor AdjustScrollbarFaceColor(nscolor aFaceColor,
+                                          EventStates aStates);
+  static nscolor GetScrollbarTrackColor(nsIFrame* aFrame);
+  static nscolor GetScrollbarThumbColor(nsIFrame* aFrame,
+                                        EventStates aEventStates);
+  static Maybe<nsITheme::Transparency> GetScrollbarPartTransparency(
+      nsIFrame* aFrame, StyleAppearance aAppearance);
+
+ protected:
+  ScrollbarUtil() = default;
+  virtual ~ScrollbarUtil() = default;
+};
+
+#endif