1 files changed, 355 insertions, 0 deletions
diff --git a/layout/style/CounterStyleManager.h b/layout/style/CounterStyleManager.h
new file mode 100644
index 0000000000..b6d9c2a0a9
--- /dev/null
+++ b/layout/style/CounterStyleManager.h
@@ -0,0 +1,355 @@
+/* -*- 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/. */
+#ifndef mozilla_CounterStyleManager_h_
+#define mozilla_CounterStyleManager_h_
+
+#include "nsGkAtoms.h"
+#include "nsStringFwd.h"
+#include "nsTHashMap.h"
+#include "nsHashKeys.h"
+
+#include "nsStyleConsts.h"
+
+#include "mozilla/Attributes.h"
+
+class nsPresContext;
+
+namespace mozilla {
+
+enum class SpeakAs : uint8_t {
+  Bullets = 0,
+  Numbers = 1,
+  Words = 2,
+  Spellout = 3,
+  Other = 255
+};
+
+class WritingMode;
+
+typedef int32_t CounterValue;
+
+class CounterStyleManager;
+class AnonymousCounterStyle;
+
+struct NegativeType;
+struct PadType;
+
+class CounterStyle {
+ protected:
+  explicit constexpr CounterStyle(ListStyle aStyle) : mStyle(aStyle) {}
+
+ private:
+  CounterStyle(const CounterStyle& aOther) = delete;
+  void operator=(const CounterStyle& other) = delete;
+
+ public:
+  constexpr ListStyle GetStyle() const { return mStyle; }
+  bool IsNone() const { return mStyle == ListStyle::None; }
+  bool IsCustomStyle() const { return mStyle == ListStyle::Custom; }
+  // A style is dependent if it depends on the counter style manager.
+  // Custom styles are certainly dependent. In addition, some builtin
+  // styles are dependent for fallback.
+  bool IsDependentStyle() const;
+
+  virtual void GetPrefix(nsAString& aResult) = 0;
+  virtual void GetSuffix(nsAString& aResult) = 0;
+  void GetCounterText(CounterValue aOrdinal, WritingMode aWritingMode,
+                      nsAString& aResult, bool& aIsRTL);
+  virtual void GetSpokenCounterText(CounterValue aOrdinal,
+                                    WritingMode aWritingMode,
+                                    nsAString& aResult, bool& aIsBullet);
+
+  // XXX This method could be removed once ::-moz-list-bullet and
+  //     ::-moz-list-number are completely merged into ::marker.
+  virtual bool IsBullet() = 0;
+
+  virtual void GetNegative(NegativeType& aResult) = 0;
+  /**
+   * This method returns whether an ordinal is in the range of this
+   * counter style. Note that, it is possible that an ordinal in range
+   * is rejected by the generating algorithm.
+   */
+  virtual bool IsOrdinalInRange(CounterValue aOrdinal) = 0;
+  /**
+   * This method returns whether an ordinal is in the default range of
+   * this counter style. This is the effective range when no 'range'
+   * descriptor is specified.
+   */
+  virtual bool IsOrdinalInAutoRange(CounterValue aOrdinal) = 0;
+  virtual void GetPad(PadType& aResult) = 0;
+  virtual CounterStyle* GetFallback() = 0;
+  virtual SpeakAs GetSpeakAs() = 0;
+  virtual bool UseNegativeSign() = 0;
+
+  virtual void CallFallbackStyle(CounterValue aOrdinal,
+                                 WritingMode aWritingMode, nsAString& aResult,
+                                 bool& aIsRTL);
+  virtual bool GetInitialCounterText(CounterValue aOrdinal,
+                                     WritingMode aWritingMode,
+                                     nsAString& aResult, bool& aIsRTL) = 0;
+
+  virtual AnonymousCounterStyle* AsAnonymous() { return nullptr; }
+
+ protected:
+  const ListStyle mStyle;
+};
+
+class AnonymousCounterStyle final : public CounterStyle {
+ public:
+  explicit AnonymousCounterStyle(const nsAString& aContent);
+  AnonymousCounterStyle(StyleSymbolsType, nsTArray<nsString> aSymbols);
+
+  virtual void GetPrefix(nsAString& aResult) override;
+  virtual void GetSuffix(nsAString& aResult) override;
+  virtual bool IsBullet() override;
+
+  virtual void GetNegative(NegativeType& aResult) override;
+  virtual bool IsOrdinalInRange(CounterValue aOrdinal) override;
+  virtual bool IsOrdinalInAutoRange(CounterValue aOrdinal) override;
+  virtual void GetPad(PadType& aResult) override;
+  virtual CounterStyle* GetFallback() override;
+  virtual SpeakAs GetSpeakAs() override;
+  virtual bool UseNegativeSign() override;
+
+  virtual bool GetInitialCounterText(CounterValue aOrdinal,
+                                     WritingMode aWritingMode,
+                                     nsAString& aResult, bool& aIsRTL) override;
+
+  virtual AnonymousCounterStyle* AsAnonymous() override { return this; }
+
+  bool IsSingleString() const { return mSingleString; }
+  auto GetSymbols() const { return Span<const nsString>{mSymbols}; }
+
+  StyleCounterSystem GetSystem() const;
+
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(AnonymousCounterStyle)
+
+ private:
+  ~AnonymousCounterStyle() = default;
+
+  bool mSingleString;
+  StyleSymbolsType mSymbolsType;
+  nsTArray<nsString> mSymbols;
+};
+
+// A smart pointer to CounterStyle. It either owns a reference to an
+// anonymous counter style, or weakly refers to a named counter style
+// managed by counter style manager.
+class CounterStylePtr {
+ public:
+  CounterStylePtr() : mRaw(0) {}
+  CounterStylePtr(const CounterStylePtr& aOther) : mRaw(aOther.mRaw) {
+    if (!mRaw) {
+      return;
+    }
+    switch (GetType()) {
+      case eAnonymousCounterStyle:
+        AsAnonymous()->AddRef();
+        break;
+      case eAtom:
+        AsAtom()->AddRef();
+        break;
+      default:
+        MOZ_ASSERT_UNREACHABLE("Unknown type");
+        break;
+    }
+  }
+  CounterStylePtr(CounterStylePtr&& aOther) : mRaw(aOther.mRaw) {
+    aOther.mRaw = 0;
+  }
+  ~CounterStylePtr() { Reset(); }
+
+  CounterStylePtr& operator=(const CounterStylePtr& aOther) {
+    if (this != &aOther) {
+      Reset();
+      new (this) CounterStylePtr(aOther);
+    }
+    return *this;
+  }
+  CounterStylePtr& operator=(CounterStylePtr&& aOther) {
+    if (this != &aOther) {
+      Reset();
+      mRaw = aOther.mRaw;
+      aOther.mRaw = 0;
+    }
+    return *this;
+  }
+  CounterStylePtr& operator=(decltype(nullptr)) {
+    Reset();
+    return *this;
+  }
+  CounterStylePtr& operator=(nsStaticAtom* aStaticAtom) {
+    Reset();
+    mRaw = reinterpret_cast<uintptr_t>(aStaticAtom) | eAtom;
+    return *this;
+  }
+  CounterStylePtr& operator=(already_AddRefed<nsAtom> aAtom) {
+    Reset();
+    mRaw = reinterpret_cast<uintptr_t>(aAtom.take()) | eAtom;
+    return *this;
+  }
+  CounterStylePtr& operator=(AnonymousCounterStyle* aCounterStyle) {
+    Reset();
+    if (aCounterStyle) {
+      CounterStyle* raw = do_AddRef(aCounterStyle).take();
+      mRaw = reinterpret_cast<uintptr_t>(raw) | eAnonymousCounterStyle;
+    }
+    return *this;
+  }
+
+  // TODO(emilio): Make CounterStyle have a single representation, either by
+  // removing CounterStylePtr or by moving this representation to Rust.
+  static CounterStylePtr FromStyle(const StyleCounterStyle& aStyle) {
+    CounterStylePtr ret;
+    if (aStyle.IsName()) {
+      ret = do_AddRef(aStyle.AsName().AsAtom());
+    } else {
+      StyleSymbolsType type = aStyle.AsSymbols()._0;
+      Span<const StyleSymbol> symbols = aStyle.AsSymbols()._1._0.AsSpan();
+      nsTArray<nsString> transcoded(symbols.Length());
+      for (const auto& symbol : symbols) {
+        MOZ_ASSERT(symbol.IsString(), "Should not have <ident> in symbols()");
+        transcoded.AppendElement(
+            NS_ConvertUTF8toUTF16(symbol.AsString().AsString()));
+      }
+      ret = new AnonymousCounterStyle(type, std::move(transcoded));
+    }
+    return ret;
+  }
+
+  explicit operator bool() const { return !!mRaw; }
+  bool operator!() const { return !mRaw; }
+  bool operator==(const CounterStylePtr& aOther) const {
+    // FIXME(emilio): For atoms this is all right, but for symbols doesn't this
+    // cause us to compare as unequal all the time, even if the specified
+    // symbols didn't change?
+    return mRaw == aOther.mRaw;
+  }
+  bool operator!=(const CounterStylePtr& aOther) const {
+    return mRaw != aOther.mRaw;
+  }
+
+  nsAtom* AsAtom() const {
+    MOZ_ASSERT(IsAtom());
+    return reinterpret_cast<nsAtom*>(mRaw & ~eMask);
+  }
+  AnonymousCounterStyle* AsAnonymous() const {
+    MOZ_ASSERT(IsAnonymous());
+    return static_cast<AnonymousCounterStyle*>(
+        reinterpret_cast<CounterStyle*>(mRaw & ~eMask));
+  }
+
+  bool IsAtom() const { return GetType() == eAtom; }
+  bool IsAnonymous() const { return GetType() == eAnonymousCounterStyle; }
+
+  bool IsNone() const { return IsAtom() && AsAtom() == nsGkAtoms::none; }
+
+ private:
+  enum Type : uintptr_t {
+    eAnonymousCounterStyle = 0,
+    eAtom = 1,
+    eMask = 1,
+  };
+
+  static_assert(alignof(CounterStyle) >= 1 << eMask,
+                "We're gonna tag the pointer, so it better fit");
+  static_assert(alignof(nsAtom) >= 1 << eMask,
+                "We're gonna tag the pointer, so it better fit");
+
+  Type GetType() const { return static_cast<Type>(mRaw & eMask); }
+
+  void Reset() {
+    if (!mRaw) {
+      return;
+    }
+    switch (GetType()) {
+      case eAnonymousCounterStyle:
+        AsAnonymous()->Release();
+        break;
+      case eAtom:
+        AsAtom()->Release();
+        break;
+      default:
+        MOZ_ASSERT_UNREACHABLE("Unknown type");
+        break;
+    }
+    mRaw = 0;
+  }
+
+  // mRaw contains the pointer, and its last bit is used to store the type of
+  // the pointer.
+  // If the type is eAtom, the pointer owns a reference to an nsAtom
+  // (potentially null).
+  // If the type is eAnonymousCounterStyle, it owns a reference to an
+  // anonymous counter style (never null).
+  uintptr_t mRaw;
+};
+
+class CounterStyleManager final {
+ private:
+  ~CounterStyleManager();
+
+ public:
+  explicit CounterStyleManager(nsPresContext* aPresContext);
+
+  void Disconnect();
+
+  bool IsInitial() const {
+    // only 'none', 'decimal', and 'disc'
+    return mStyles.Count() == 3;
+  }
+
+  // Returns the counter style object for the given name from the style
+  // table if it is already built, and nullptr otherwise.
+  CounterStyle* GetCounterStyle(nsAtom* aName) const {
+    return mStyles.Get(aName);
+  }
+  // Same as GetCounterStyle but try to build the counter style object
+  // rather than returning nullptr if that hasn't been built.
+  CounterStyle* ResolveCounterStyle(nsAtom* aName);
+  CounterStyle* ResolveCounterStyle(const CounterStylePtr& aPtr) {
+    if (aPtr.IsAtom()) {
+      return ResolveCounterStyle(aPtr.AsAtom());
+    }
+    return aPtr.AsAnonymous();
+  }
+
+  static CounterStyle* GetBuiltinStyle(ListStyle aStyle);
+  static CounterStyle* GetNoneStyle() {
+    return GetBuiltinStyle(ListStyle::None);
+  }
+  static CounterStyle* GetDecimalStyle() {
+    return GetBuiltinStyle(ListStyle::Decimal);
+  }
+  static CounterStyle* GetDiscStyle() {
+    return GetBuiltinStyle(ListStyle::Disc);
+  }
+
+  // This method will scan all existing counter styles generated by this
+  // manager, and remove or mark data dirty accordingly. It returns true
+  // if any counter style is changed, false elsewise. This method should
+  // be called when any counter style may be affected.
+  bool NotifyRuleChanged();
+  // NotifyRuleChanged will evict no longer needed counter styles into
+  // mRetiredStyles, and this function destroys all objects listed there.
+  // It should be called only after no one may ever use those objects.
+  void CleanRetiredStyles();
+
+  nsPresContext* PresContext() const { return mPresContext; }
+
+  NS_INLINE_DECL_REFCOUNTING(CounterStyleManager)
+
+ private:
+  void DestroyCounterStyle(CounterStyle* aCounterStyle);
+
+  nsPresContext* mPresContext;
+  nsTHashMap<RefPtr<nsAtom>, CounterStyle*> mStyles;
+  nsTArray<CounterStyle*> mRetiredStyles;
+};
+
+}  // namespace mozilla
+
+#endif /* !defined(mozilla_CounterStyleManager_h_) */