1 files changed, 154 insertions, 0 deletions
diff --git a/layout/style/nsCSSPseudoElements.cpp b/layout/style/nsCSSPseudoElements.cpp
new file mode 100644
index 0000000000..48b4d5c1a7
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+++ b/layout/style/nsCSSPseudoElements.cpp
@@ -0,0 +1,154 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* atom list for CSS pseudo-elements */
+
+#include "nsCSSPseudoElements.h"
+
+#include "mozilla/ArrayUtils.h"
+
+#include "nsCSSAnonBoxes.h"
+#include "nsDOMString.h"
+#include "nsGkAtomConsts.h"
+#include "nsStaticAtomUtils.h"
+#include "nsStringFwd.h"
+
+using namespace mozilla;
+
+// Flags data for each of the pseudo-elements.
+/* static */ const uint32_t nsCSSPseudoElements::kPseudoElementFlags[] = {
+#define CSS_PSEUDO_ELEMENT(name_, value_, flags_) flags_,
+#include "nsCSSPseudoElementList.h"
+#undef CSS_PSEUDO_ELEMENT
+};
+
+/* static */
+nsStaticAtom* nsCSSPseudoElements::GetAtomBase() {
+  return const_cast<nsStaticAtom*>(
+      nsGkAtoms::GetAtomByIndex(kAtomIndex_PseudoElements));
+}
+
+/* static */
+nsAtom* nsCSSPseudoElements::GetPseudoAtom(Type aType) {
+  MOZ_ASSERT(PseudoStyle::IsPseudoElement(aType), "Unexpected type");
+  size_t index = kAtomIndex_PseudoElements + static_cast<size_t>(aType);
+  return nsGkAtoms::GetAtomByIndex(index);
+}
+
+/* static */
+std::tuple<mozilla::Maybe<PseudoStyleType>, RefPtr<nsAtom>>
+nsCSSPseudoElements::ParsePseudoElement(const nsAString& aPseudoElement,
+                                        CSSEnabledState aEnabledState) {
+  if (DOMStringIsNull(aPseudoElement) || aPseudoElement.IsEmpty()) {
+    return {Some(PseudoStyleType::NotPseudo), nullptr};
+  }
+
+  if (aPseudoElement.First() != char16_t(':')) {
+    return {};
+  }
+
+  // deal with two-colon forms of aPseudoElt
+  const char16_t* start = aPseudoElement.BeginReading();
+  const char16_t* end = aPseudoElement.EndReading();
+  NS_ASSERTION(start != end, "aPseudoElement is not empty!");
+  ++start;
+  bool haveTwoColons = true;
+  if (start == end || *start != char16_t(':')) {
+    --start;
+    haveTwoColons = false;
+  }
+
+  // XXX jjaschke: this parsing algorithm should be replaced by the css parser
+  // for correct handling of all edge cases. See Bug 1845712.
+  const int32_t parameterPosition = aPseudoElement.FindChar('(');
+  const bool hasParameter = parameterPosition != kNotFound;
+  if (hasParameter) {
+    end = start + parameterPosition - 1;
+  }
+  RefPtr<nsAtom> pseudo = NS_Atomize(Substring(start, end));
+  MOZ_ASSERT(pseudo);
+
+  Maybe<uint32_t> index = nsStaticAtomUtils::Lookup(pseudo, GetAtomBase(),
+                                                    kAtomCount_PseudoElements);
+  if (index.isNothing()) {
+    return {};
+  }
+  auto type = static_cast<Type>(*index);
+  RefPtr<nsAtom> functionalPseudoParameter;
+  if (hasParameter) {
+    if (type != PseudoStyleType::highlight) {
+      return {};
+    }
+    functionalPseudoParameter =
+        [&aPseudoElement, parameterPosition]() -> already_AddRefed<nsAtom> {
+      const char16_t* start = aPseudoElement.BeginReading();
+      const char16_t* end = aPseudoElement.EndReading();
+      start += parameterPosition + 1;
+      --end;
+      if (*end != ')') {
+        return nullptr;
+      }
+      return NS_Atomize(Substring(start, end));
+    }();
+  }
+
+  if (!haveTwoColons &&
+      !PseudoElementHasFlags(type, CSS_PSEUDO_ELEMENT_IS_CSS2)) {
+    return {};
+  }
+  if (IsEnabled(type, aEnabledState)) {
+    return {Some(type), functionalPseudoParameter};
+  }
+  return {};
+}
+
+/* static */
+mozilla::Maybe<PseudoStyleType> nsCSSPseudoElements::GetPseudoType(
+    const nsAString& aPseudoElement, CSSEnabledState aEnabledState) {
+  auto [pseudoType, _] = ParsePseudoElement(aPseudoElement, aEnabledState);
+  return pseudoType;
+}
+
+/* static */
+bool nsCSSPseudoElements::PseudoElementSupportsUserActionState(
+    const Type aType) {
+  return PseudoElementHasFlags(aType,
+                               CSS_PSEUDO_ELEMENT_SUPPORTS_USER_ACTION_STATE);
+}
+
+/* static */
+nsString nsCSSPseudoElements::PseudoTypeAsString(Type aPseudoType) {
+  switch (aPseudoType) {
+    case PseudoStyleType::before:
+      return u"::before"_ns;
+    case PseudoStyleType::after:
+      return u"::after"_ns;
+    case PseudoStyleType::marker:
+      return u"::marker"_ns;
+    default:
+      MOZ_ASSERT(aPseudoType == PseudoStyleType::NotPseudo,
+                 "Unexpected pseudo type");
+      return u""_ns;
+  }
+}
+
+#ifdef DEBUG
+/* static */
+void nsCSSPseudoElements::AssertAtoms() {
+  nsStaticAtom* base = GetAtomBase();
+#  define CSS_PSEUDO_ELEMENT(name_, value_, flags_)                   \
+    {                                                                 \
+      RefPtr<nsAtom> atom = NS_Atomize(value_);                       \
+      size_t index = static_cast<size_t>(PseudoStyleType::name_);     \
+      MOZ_ASSERT(atom == nsGkAtoms::PseudoElement_##name_,            \
+                 "Static atom for " #name_ " has incorrect value");   \
+      MOZ_ASSERT(atom == &base[index],                                \
+                 "Static atom for " #name_ " not at expected index"); \
+    }
+#  include "nsCSSPseudoElementList.h"
+#  undef CSS_PSEUDO_ELEMENT
+}
+#endif