layout/style/nsStyleStructFwd.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 /*
   8  * Forward declarations to avoid including all of nsStyleStruct.h.
   9  */
  10
  11 #ifndef nsStyleStructFwd_h_
  12 #define nsStyleStructFwd_h_
  13
  14 namespace mozilla {
  15
  16 enum class StyleStructID : uint32_t {
  17 /*
  18  * Define the constants eStyleStruct_Font, etc.
  19  *
  20  * The C++ standard, section 7.2, guarantees that enums begin with 0 and
  21  * increase by 1.
  22  *
  23  * Note that we rely on the inherited structs being before the rest in
  24  * ComputedStyle.
  25  */
  26 #define STYLE_STRUCT_INHERITED(name) name,
  27 #define STYLE_STRUCT_RESET(name)
  28 #include "nsStyleStructList.h"
  29 #undef STYLE_STRUCT_INHERITED
  30 #undef STYLE_STRUCT_RESET
  31
  32 #define STYLE_STRUCT_RESET(name) name,
  33 #define STYLE_STRUCT_INHERITED(name)
  34 #include "nsStyleStructList.h"
  35 #undef STYLE_STRUCT_INHERITED
  36 #undef STYLE_STRUCT_RESET
  37 };
  38
  39 struct StyleStructConstants {
  40   static const uint32_t kStyleStructCount =
  41 #define STYLE_STRUCT_RESET(name) 1 +
  42 #define STYLE_STRUCT_INHERITED(name) 1 +
  43 #include "nsStyleStructList.h"
  44 #undef STYLE_STRUCT_INHERITED
  45 #undef STYLE_STRUCT_RESET
  46       0;
  47
  48   static const uint32_t kInheritedStyleStructCount =
  49 #define STYLE_STRUCT_RESET(name)
  50 #define STYLE_STRUCT_INHERITED(name) 1 +
  51 #include "nsStyleStructList.h"
  52 #undef STYLE_STRUCT_INHERITED
  53 #undef STYLE_STRUCT_RESET
  54       0;
  55
  56   static const uint32_t kResetStyleStructCount =
  57 #define STYLE_STRUCT_RESET(name) 1 +
  58 #define STYLE_STRUCT_INHERITED(name)
  59 #include "nsStyleStructList.h"
  60 #undef STYLE_STRUCT_INHERITED
  61 #undef STYLE_STRUCT_RESET
  62       0;
  63
  64   static_assert(kStyleStructCount <= 32, "Bitmasks must be bigger!");
  65
  66   static const uint32_t kAllStructsMask = (1 << kStyleStructCount) - 1;
  67   static const uint32_t kInheritedStructsMask =
  68       (1 << kInheritedStyleStructCount) - 1;
  69   static const uint32_t kResetStructsMask =
  70       kAllStructsMask & (~kInheritedStructsMask);
  71
  72   static uint32_t BitFor(StyleStructID aID) {
  73     return 1 << static_cast<uint32_t>(aID);
  74   }
  75 };
  76
  77 }  // namespace mozilla
  78
  79 #endif /* nsStyleStructFwd_h_ */