layout/generic/AnonymousContentKey.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 /* values to identify particular subtrees of native anonymous content */
   8
   9 #ifndef mozilla_AnonymousContentKey_h
  10 #define mozilla_AnonymousContentKey_h
  11
  12 #include "mozilla/TypedEnumBits.h"
  13 #include <stdint.h>
  14 #include "X11UndefineNone.h"
  15
  16 namespace mozilla {
  17
  18 // clang-format off
  19
  20 // We currently use cached anonymous content styles only for scrollbar parts,
  21 // and we can fit the type of scrollbar part element along with its different
  22 // options (such as orientation, and other attribute values that can affect
  23 // styling) into a uint8_t.
  24 //
  25 // The lower three bits hold a Type_* value identifying the type of
  26 // element, and the remaining bits store Flag_* values.
  27 //
  28 // A value of 0 is used to represent an anonymous content subtree that we don't
  29 // cache styles for.
  30 enum class AnonymousContentKey : uint8_t {
  31   None                           = 0x00,
  32
  33   // all
  34   Type_ScrollCorner              = 0x01,
  35   Type_Scrollbar                 = 0x02,
  36   Type_ScrollbarButton           = 0x03,
  37   Type_Slider                    = 0x04,
  38
  39   // scrollbar, scrollbarbutton, slider
  40   Flag_Vertical                  = 0x08,
  41
  42   // scrollbarbutton
  43   Flag_ScrollbarButton_Down      = 0x10,
  44   Flag_ScrollbarButton_Bottom    = 0x20,
  45   Flag_ScrollbarButton_Decrement = 0x40,
  46 };
  47
  48 // clang-format on
  49
  50 MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(AnonymousContentKey)
  51
  52 }  // namespace mozilla
  53
  54 #endif  // mozilla_AnonymousContentKey_h