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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 AccAttributes_h_
#define AccAttributes_h_
#include "mozilla/ServoStyleConsts.h"
#include "mozilla/Variant.h"
#include "nsTHashMap.h"
#include "nsAtom.h"
#include "nsStringFwd.h"
class nsVariant;
namespace IPC {
template <typename T>
struct ParamTraits;
} // namespace IPC
namespace mozilla {
namespace dom {
class Element;
}
namespace a11y {
struct FontSize {
int32_t mValue;
bool operator==(const FontSize& aOther) const {
return mValue == aOther.mValue;
}
bool operator!=(const FontSize& aOther) const {
return mValue != aOther.mValue;
}
};
struct Color {
nscolor mValue;
bool operator==(const Color& aOther) const { return mValue == aOther.mValue; }
bool operator!=(const Color& aOther) const { return mValue != aOther.mValue; }
};
// A special type. If an entry has a value of this type, it instructs the
// target instance of an Update to remove the entry with the same key value.
struct DeleteEntry {
DeleteEntry() : mValue(true) {}
bool mValue;
bool operator==(const DeleteEntry& aOther) const { return true; }
bool operator!=(const DeleteEntry& aOther) const { return false; }
};
class AccAttributes {
// Warning! An AccAttributes can contain another AccAttributes. This is
// intended for object and text attributes. However, the nested
// AccAttributes should never itself contain another AccAttributes, nor
// should it create a cycle. We don't do cycle collection here for
// performance reasons, so violating this rule will cause leaks!
using AttrValueType =
Variant<bool, float, double, int32_t, RefPtr<nsAtom>, nsTArray<int32_t>,
CSSCoord, FontSize, Color, DeleteEntry, UniquePtr<nsString>,
RefPtr<AccAttributes>, uint64_t>;
static_assert(sizeof(AttrValueType) <= 16);
using AtomVariantMap = nsTHashMap<nsRefPtrHashKey<nsAtom>, AttrValueType>;
protected:
~AccAttributes() = default;
public:
AccAttributes() = default;
AccAttributes(AccAttributes&&) = delete;
AccAttributes& operator=(AccAttributes&&) = delete;
AccAttributes(const AccAttributes&) = delete;
AccAttributes& operator=(const AccAttributes&) = delete;
NS_INLINE_DECL_REFCOUNTING(mozilla::a11y::AccAttributes)
template <typename T,
typename std::enable_if<!std::is_convertible_v<T, nsString> &&
!std::is_convertible_v<T, nsAtom*>,
bool>::type = true>
void SetAttribute(nsAtom* aAttrName, T&& aAttrValue) {
mData.InsertOrUpdate(aAttrName, AsVariant(std::forward<T>(aAttrValue)));
}
void SetAttribute(nsAtom* aAttrName, nsString&& aAttrValue) {
UniquePtr<nsString> value = MakeUnique<nsString>();
*value = std::forward<nsString>(aAttrValue);
mData.InsertOrUpdate(aAttrName, AsVariant(std::move(value)));
}
void SetAttributeStringCopy(nsAtom* aAttrName, nsString aAttrValue) {
SetAttribute(aAttrName, std::move(aAttrValue));
}
void SetAttribute(nsAtom* aAttrName, nsAtom* aAttrValue) {
mData.InsertOrUpdate(aAttrName, AsVariant(RefPtr<nsAtom>(aAttrValue)));
}
template <typename T>
Maybe<const T&> GetAttribute(nsAtom* aAttrName) {
if (auto value = mData.Lookup(aAttrName)) {
if constexpr (std::is_same_v<nsString, T>) {
if (value->is<UniquePtr<nsString>>()) {
const T& val = *(value->as<UniquePtr<nsString>>().get());
return SomeRef(val);
}
} else {
if (value->is<T>()) {
const T& val = value->as<T>();
return SomeRef(val);
}
}
}
return Nothing();
}
template <typename T>
RefPtr<const T> GetAttributeRefPtr(nsAtom* aAttrName) {
if (auto value = mData.Lookup(aAttrName)) {
if (value->is<RefPtr<T>>()) {
RefPtr<const T> ref = value->as<RefPtr<T>>();
return ref;
}
}
return nullptr;
}
// Get stringified value
bool GetAttribute(nsAtom* aAttrName, nsAString& aAttrValue);
bool HasAttribute(nsAtom* aAttrName) { return mData.Contains(aAttrName); }
uint32_t Count() const { return mData.Count(); }
// Update one instance with the entries in another. The supplied AccAttributes
// will be emptied.
void Update(AccAttributes* aOther);
/**
* Return true if all the attributes in this instance are equal to all the
* attributes in another instance.
*/
bool Equal(const AccAttributes* aOther) const;
/**
* Copy attributes from this instance to another instance.
* This should only be used in very specific cases; e.g. merging two sets of
* cached attributes without modifying the cache. It can only copy simple
* value types; e.g. it can't copy array values. Attempting to copy an
* AccAttributes with uncopyable values will cause an assertion.
*/
void CopyTo(AccAttributes* aDest) const;
// An entry class for our iterator.
class Entry {
public:
Entry(nsAtom* aAttrName, const AttrValueType* aAttrValue)
: mName(aAttrName), mValue(aAttrValue) {}
nsAtom* Name() { return mName; }
template <typename T>
Maybe<const T&> Value() {
if constexpr (std::is_same_v<nsString, T>) {
if (mValue->is<UniquePtr<nsString>>()) {
const T& val = *(mValue->as<UniquePtr<nsString>>().get());
return SomeRef(val);
}
} else {
if (mValue->is<T>()) {
const T& val = mValue->as<T>();
return SomeRef(val);
}
}
return Nothing();
}
void NameAsString(nsString& aName) {
mName->ToString(aName);
if (aName.Find("aria-", false, 0, 1) == 0) {
// Found 'aria-'
aName.ReplaceLiteral(0, 5, u"");
}
}
void ValueAsString(nsAString& aValueString) {
StringFromValueAndName(mName, *mValue, aValueString);
}
private:
nsAtom* mName;
const AttrValueType* mValue;
friend class AccAttributes;
};
class Iterator {
public:
explicit Iterator(AtomVariantMap::iterator aIter) : mHashIterator(aIter) {}
Iterator() = delete;
Iterator(const Iterator&) = delete;
Iterator(Iterator&&) = delete;
Iterator& operator=(const Iterator&) = delete;
Iterator& operator=(Iterator&&) = delete;
bool operator!=(const Iterator& aOther) const {
return mHashIterator != aOther.mHashIterator;
}
Iterator& operator++() {
mHashIterator++;
return *this;
}
Entry operator*() {
auto& entry = *mHashIterator;
return Entry(entry.GetKey(), &entry.GetData());
}
private:
AtomVariantMap::iterator mHashIterator;
};
friend class Iterator;
Iterator begin() { return Iterator(mData.begin()); }
Iterator end() { return Iterator(mData.end()); }
private:
static void StringFromValueAndName(nsAtom* aAttrName,
const AttrValueType& aValue,
nsAString& aValueString);
AtomVariantMap mData;
friend struct IPC::ParamTraits<AccAttributes*>;
};
} // namespace a11y
} // namespace mozilla
#endif