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nsCSSPseudoElements.h (5949B)


      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 /* atom list for CSS pseudo-elements */
      8 
      9 #ifndef nsCSSPseudoElements_h___
     10 #define nsCSSPseudoElements_h___
     11 
     12 #include "mozilla/CSSEnabledState.h"
     13 #include "mozilla/PseudoStyleType.h"
     14 #include "mozilla/StaticPrefs_dom.h"
     15 #include "mozilla/StaticPrefs_layout.h"
     16 #include "nsGkAtoms.h"
     17 
     18 // Is this pseudo-element a CSS2 pseudo-element that can be specified
     19 // with the single colon syntax (in addition to the double-colon syntax,
     20 // which can be used for all pseudo-elements)?
     21 //
     22 // Note: We also rely on this for IsEagerlyCascadedInServo.
     23 #define CSS_PSEUDO_ELEMENT_IS_CSS2 (1 << 0)
     24 // Flag that indicate the pseudo-element supports a user action pseudo-class
     25 // following it, such as :active or :hover.  This would normally correspond
     26 // to whether the pseudo-element is tree-like, but we don't support these
     27 // pseudo-classes on ::before and ::after generated content yet.  See
     28 // http://dev.w3.org/csswg/selectors4/#pseudo-elements.
     29 #define CSS_PSEUDO_ELEMENT_SUPPORTS_USER_ACTION_STATE (1 << 3)
     30 // Should this pseudo-element be enabled only for UA sheets?
     31 #define CSS_PSEUDO_ELEMENT_ENABLED_IN_UA_SHEETS (1 << 4)
     32 // Should this pseudo-element be enabled only for UA sheets and chrome
     33 // stylesheets?
     34 #define CSS_PSEUDO_ELEMENT_ENABLED_IN_CHROME (1 << 5)
     35 
     36 #define CSS_PSEUDO_ELEMENT_ENABLED_IN_UA_SHEETS_AND_CHROME \
     37  (CSS_PSEUDO_ELEMENT_ENABLED_IN_UA_SHEETS |               \
     38   CSS_PSEUDO_ELEMENT_ENABLED_IN_CHROME)
     39 
     40 // Can we use the ChromeOnly document.createElement(..., { pseudo: "::foo" })
     41 // API for creating pseudo-implementing native anonymous content in JS with this
     42 // pseudo-element?
     43 #define CSS_PSEUDO_ELEMENT_IS_JS_CREATED_NAC (1 << 6)
     44 // Does this pseudo-element act like an item for containers (such as flex and
     45 // grid containers) and thus needs parent display-based style fixup?
     46 #define CSS_PSEUDO_ELEMENT_IS_FLEX_OR_GRID_ITEM (1 << 7)
     47 
     48 class nsCSSPseudoElements {
     49  using EnabledState = mozilla::CSSEnabledState;
     50  using Request = mozilla::PseudoStyleRequest;
     51  using Type = mozilla::PseudoStyleType;
     52 
     53 public:
     54  static bool IsEagerlyCascadedInServo(const Type aType) {
     55    return PseudoElementHasFlags(aType, CSS_PSEUDO_ELEMENT_IS_CSS2);
     56  }
     57 
     58 public:
     59 #ifdef DEBUG
     60  static void AssertAtoms();
     61 #endif
     62 
     63 // Alias nsCSSPseudoElements::foo() to nsGkAtoms::foo.
     64 #define CSS_PSEUDO_ELEMENT(name_, value_, flags_)         \
     65  static nsCSSPseudoElementStaticAtom* name_() {          \
     66    return const_cast<nsCSSPseudoElementStaticAtom*>(     \
     67        static_cast<const nsCSSPseudoElementStaticAtom*>( \
     68            nsGkAtoms::PseudoElement_##name_));           \
     69  }
     70 #include "nsCSSPseudoElementList.h"
     71 #undef CSS_PSEUDO_ELEMENT
     72 
     73  // Returns an empty Request for a syntactically invalid pseudo-element, and
     74  // NotPseudo for the empty / null string.
     75  static mozilla::Maybe<Request> ParsePseudoElement(
     76      const nsAString& aPseudoElement,
     77      EnabledState = EnabledState::ForAllContent);
     78 
     79  // Get the atom for a given Type. aType must be <
     80  // PseudoType::CSSPseudoElementsEnd.
     81  // This only ever returns static atoms, so it's fine to return a raw pointer.
     82  static nsAtom* GetPseudoAtom(Type aType);
     83 
     84  static bool PseudoElementSupportsUserActionState(const Type aType);
     85 
     86  static bool PseudoElementIsJSCreatedNAC(Type aType) {
     87    return PseudoElementHasFlags(aType, CSS_PSEUDO_ELEMENT_IS_JS_CREATED_NAC);
     88  }
     89 
     90  static bool PseudoElementIsFlexOrGridItem(const Type aType) {
     91    return PseudoElementHasFlags(aType,
     92                                 CSS_PSEUDO_ELEMENT_IS_FLEX_OR_GRID_ITEM);
     93  }
     94 
     95  static bool EnabledInContent(Type aType) {
     96    switch (aType) {
     97      case Type::highlight:
     98        return mozilla::StaticPrefs::dom_customHighlightAPI_enabled();
     99      case Type::targetText:
    100        return mozilla::StaticPrefs::dom_text_fragments_enabled();
    101      case Type::sliderTrack:
    102      case Type::sliderThumb:
    103      case Type::sliderFill:
    104        return mozilla::StaticPrefs::layout_css_modern_range_pseudos_enabled();
    105      case Type::detailsContent:
    106        return mozilla::StaticPrefs::layout_css_details_content_enabled();
    107      case Type::viewTransition:
    108      case Type::viewTransitionGroup:
    109      case Type::viewTransitionImagePair:
    110      case Type::viewTransitionOld:
    111      case Type::viewTransitionNew:
    112        return mozilla::StaticPrefs::dom_viewTransitions_enabled();
    113      default:
    114        return !PseudoElementHasAnyFlag(
    115            aType, CSS_PSEUDO_ELEMENT_ENABLED_IN_UA_SHEETS_AND_CHROME);
    116    }
    117  }
    118 
    119  static bool IsEnabled(Type aType, EnabledState aEnabledState) {
    120    if (EnabledInContent(aType)) {
    121      return true;
    122    }
    123 
    124    if ((aEnabledState & EnabledState::InUASheets) &&
    125        PseudoElementHasFlags(aType, CSS_PSEUDO_ELEMENT_ENABLED_IN_UA_SHEETS)) {
    126      return true;
    127    }
    128 
    129    if ((aEnabledState & EnabledState::InChrome) &&
    130        PseudoElementHasFlags(aType, CSS_PSEUDO_ELEMENT_ENABLED_IN_CHROME)) {
    131      return true;
    132    }
    133 
    134    return false;
    135  }
    136 
    137  static nsString PseudoRequestAsString(const Request& aPseudoRequest);
    138 
    139 private:
    140  // Does the given pseudo-element have all of the flags given?
    141  static bool PseudoElementHasFlags(const Type aType, uint32_t aFlags) {
    142    MOZ_ASSERT(aType < Type::CSSPseudoElementsEnd);
    143    return (kPseudoElementFlags[size_t(aType)] & aFlags) == aFlags;
    144  }
    145 
    146  static bool PseudoElementHasAnyFlag(const Type aType, uint32_t aFlags) {
    147    MOZ_ASSERT(aType < Type::CSSPseudoElementsEnd);
    148    return (kPseudoElementFlags[size_t(aType)] & aFlags) != 0;
    149  }
    150 
    151  static nsStaticAtom* GetAtomBase();
    152 
    153  static const uint32_t kPseudoElementFlags[size_t(Type::CSSPseudoElementsEnd)];
    154 };
    155 
    156 #endif /* nsCSSPseudoElements_h___ */