layout/style/nsCSSPseudoElements.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 /* atom list for CSS pseudo-elements */
   7
   8 #ifndef nsCSSPseudoElements_h___
   9 #define nsCSSPseudoElements_h___
  10
  11 #include "nsIAtom.h"
  12
  13 // Is this pseudo-element a CSS2 pseudo-element that can be specified
  14 // with the single colon syntax (in addition to the double-colon syntax,
  15 // which can be used for all pseudo-elements)?
  16 #define CSS_PSEUDO_ELEMENT_IS_CSS2                     (1<<0)
  17 // Is this pseudo-element a pseudo-element that can contain other
  18 // elements?
  19 // (Currently pseudo-elements are either leaves of the tree (relative to
  20 // real elements) or they contain other elements in a non-tree-like
  21 // manner (i.e., like incorrectly-nested start and end tags).  It's
  22 // possible that in the future there might be container pseudo-elements
  23 // that form a properly nested tree structure.  If that happens, we
  24 // should probably split this flag into two.)
  25 #define CSS_PSEUDO_ELEMENT_CONTAINS_ELEMENTS           (1<<1)
  26 // Flag to add the ability to take into account style attribute set for the
  27 // pseudo element (by default it's ignored).
  28 #define CSS_PSEUDO_ELEMENT_SUPPORTS_STYLE_ATTRIBUTE    (1<<2)
  29 // Flag that indicate the pseudo-element supports a user action pseudo-class
  30 // following it, such as :active or :hover.  This would normally correspond
  31 // to whether the pseudo-element is tree-like, but we don't support these
  32 // pseudo-classes on ::before and ::after generated content yet.  See
  33 // http://dev.w3.org/csswg/selectors4/#pseudo-elements.
  34 #define CSS_PSEUDO_ELEMENT_SUPPORTS_USER_ACTION_STATE  (1<<3)
  35 // Is content prevented from parsing selectors containing this pseudo-element?
  36 #define CSS_PSEUDO_ELEMENT_UA_SHEET_ONLY               (1<<4)
  37
  38 // Empty class derived from nsIAtom so that function signatures can
  39 // require an atom from this atom list.
  40 class nsICSSPseudoElement : public nsIAtom {};
  41
  42 class nsCSSPseudoElements {
  43 public:
  44
  45   static void AddRefAtoms();
  46
  47   static bool IsPseudoElement(nsIAtom *aAtom);
  48
  49   static bool IsCSS2PseudoElement(nsIAtom *aAtom);
  50
  51 #define CSS_PSEUDO_ELEMENT(_name, _value, _flags) \
  52   static nsICSSPseudoElement* _name;
  53 #include "nsCSSPseudoElementList.h"
  54 #undef CSS_PSEUDO_ELEMENT
  55
  56   enum Type {
  57     // If the actual pseudo-elements stop being first here, change
  58     // GetPseudoType.
  59 #define CSS_PSEUDO_ELEMENT(_name, _value_, _flags) \
  60     ePseudo_##_name,
  61 #include "nsCSSPseudoElementList.h"
  62 #undef CSS_PSEUDO_ELEMENT
  63     ePseudo_PseudoElementCount,
  64     ePseudo_AnonBox = ePseudo_PseudoElementCount,
  65 #ifdef MOZ_XUL
  66     ePseudo_XULTree,
  67 #endif
  68     ePseudo_NotPseudoElement,
  69     ePseudo_MAX
  70   };
  71
  72   static Type GetPseudoType(nsIAtom* aAtom);
  73
  74   // Get the atom for a given Type.  aType must be < ePseudo_PseudoElementCount
  75   static nsIAtom* GetPseudoAtom(Type aType);
  76
  77   static bool PseudoElementContainsElements(const Type aType) {
  78     return PseudoElementHasFlags(aType, CSS_PSEUDO_ELEMENT_CONTAINS_ELEMENTS);
  79   }
  80
  81   static bool PseudoElementSupportsStyleAttribute(const Type aType) {
  82     MOZ_ASSERT(aType < ePseudo_PseudoElementCount);
  83     return PseudoElementHasFlags(aType, CSS_PSEUDO_ELEMENT_SUPPORTS_STYLE_ATTRIBUTE);
  84   }
  85
  86   static bool PseudoElementSupportsUserActionState(const Type aType);
  87
  88   static bool PseudoElementIsUASheetOnly(const Type aType) {
  89     MOZ_ASSERT(aType < ePseudo_PseudoElementCount);
  90     return PseudoElementHasFlags(aType, CSS_PSEUDO_ELEMENT_UA_SHEET_ONLY);
  91   }
  92
  93 private:
  94   static uint32_t FlagsForPseudoElement(const Type aType);
  95
  96   // Does the given pseudo-element have all of the flags given?
  97   static bool PseudoElementHasFlags(const Type aType, uint32_t aFlags)
  98   {
  99     return (FlagsForPseudoElement(aType) & aFlags) == aFlags;
 100   }
 101 };
 102
 103 #endif /* nsCSSPseudoElements_h___ */