gecko-dev/layout/style/CounterStyleManager.h

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/* -*- 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 "nsAtom.h"
#include "nsGkAtoms.h"
#include "nsStringFwd.h"
#include "nsDataHashtable.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(int32_t aStyle) : mStyle(aStyle) {}
private:
CounterStyle(const CounterStyle& aOther) = delete;
void operator=(const CounterStyle& other) = delete;
public:
constexpr int32_t GetStyle() const { return mStyle; }
bool IsNone() const { return mStyle == NS_STYLE_LIST_STYLE_NONE; }
bool IsCustomStyle() const { return mStyle == NS_STYLE_LIST_STYLE_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 int32_t 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(int32_t aStyle);
static CounterStyle* GetNoneStyle() {
return GetBuiltinStyle(NS_STYLE_LIST_STYLE_NONE);
}
static CounterStyle* GetDecimalStyle() {
return GetBuiltinStyle(NS_STYLE_LIST_STYLE_DECIMAL);
}
static CounterStyle* GetDiscStyle() {
return GetBuiltinStyle(NS_STYLE_LIST_STYLE_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;
nsDataHashtable<nsRefPtrHashKey<nsAtom>, CounterStyle*> mStyles;
nsTArray<CounterStyle*> mRetiredStyles;
};
} // namespace mozilla
#endif /* !defined(mozilla_CounterStyleManager_h_) */