layout/base/ScrollStyles.h

   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_ScrollStyles_h
   8 #define mozilla_ScrollStyles_h
   9
  10 #include <stdint.h>
  11
  12 // Forward declarations
  13 struct nsStyleDisplay;
  14
  15 namespace mozilla {
  16
  17 enum class StyleOverflow : uint8_t;
  18
  19 struct ScrollStyles {
  20   // Always one of Scroll, Hidden, or Auto.
  21   StyleOverflow mHorizontal;
  22   StyleOverflow mVertical;
  23
  24   ScrollStyles(StyleOverflow aH, StyleOverflow aV);
  25
  26   // NOTE: This ctor maps `visible` to `auto` and `clip` to `hidden`.
  27   // It's used for styles that are propagated from the <body> and for
  28   // scroll frames (which we create also for overflow:clip/visible in
  29   // some cases, e.g. form controls).
  30   enum MapOverflowToValidScrollStyleTag { MapOverflowToValidScrollStyle };
  31   ScrollStyles(const nsStyleDisplay&, MapOverflowToValidScrollStyleTag);
  32
  33   bool operator==(const ScrollStyles& aStyles) const {
  34     return aStyles.mHorizontal == mHorizontal && aStyles.mVertical == mVertical;
  35   }
  36   bool operator!=(const ScrollStyles& aStyles) const {
  37     return !(*this == aStyles);
  38   }
  39   bool IsHiddenInBothDirections() const;
  40 };
  41
  42 }  // namespace mozilla
  43
  44 #endif  // mozilla_ScrollStyles_h