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Diffstat (limited to 'dom/base/nsAttrValue.h')
| -rw-r--r-- | dom/base/nsAttrValue.h | 577 |
1 files changed, 577 insertions, 0 deletions
diff --git a/dom/base/nsAttrValue.h b/dom/base/nsAttrValue.h new file mode 100644 index 0000000000..4ef63c287f --- /dev/null +++ b/dom/base/nsAttrValue.h @@ -0,0 +1,577 @@ +/* -*- 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/. */ + +/* + * A struct that represents the value (type and actual data) of an + * attribute. + */ + +#ifndef nsAttrValue_h___ +#define nsAttrValue_h___ + +#include <type_traits> + +#include "nscore.h" +#include "nsString.h" +#include "nsStringBuffer.h" +#include "nsColor.h" +#include "nsCaseTreatment.h" +#include "nsMargin.h" +#include "nsStringFwd.h" +#include "nsTArrayForwardDeclare.h" +#include "nsAtom.h" +#include "mozilla/AtomArray.h" +#include "mozilla/EnumTypeTraits.h" +#include "mozilla/MemoryReporting.h" + +class nsIPrincipal; +class nsIURI; +class nsStyledElement; +struct MiscContainer; + +namespace mozilla { +class DeclarationBlock; +class ShadowParts; +class SVGAnimatedIntegerPair; +class SVGAnimatedLength; +class SVGAnimatedNumberPair; +class SVGAnimatedOrient; +class SVGAnimatedPreserveAspectRatio; +class SVGAnimatedViewBox; +class SVGLengthList; +class SVGNumberList; +class SVGPathData; +class SVGPointList; +class SVGStringList; +class SVGTransformList; + +struct AttrAtomArray { + AtomArray mArray; + mutable bool mMayContainDuplicates = false; + UniquePtr<AttrAtomArray> CreateDeduplicatedCopyIfDifferent() const { + if (!mMayContainDuplicates) { + return nullptr; + } + return CreateDeduplicatedCopyIfDifferentImpl(); + } + bool operator==(const AttrAtomArray& aOther) const { + return mArray == aOther.mArray; + } + + private: + UniquePtr<AttrAtomArray> CreateDeduplicatedCopyIfDifferentImpl() const; +}; + +namespace dom { +class DOMString; +} +} // namespace mozilla + +#define NS_ATTRVALUE_MAX_STRINGLENGTH_ATOM 12 + +const uintptr_t NS_ATTRVALUE_BASETYPE_MASK = 3; +#define NS_ATTRVALUE_POINTERVALUE_MASK (~NS_ATTRVALUE_BASETYPE_MASK) + +#define NS_ATTRVALUE_INTEGERTYPE_BITS 4 +#define NS_ATTRVALUE_INTEGERTYPE_MASK \ + (uintptr_t((1 << NS_ATTRVALUE_INTEGERTYPE_BITS) - 1)) +#define NS_ATTRVALUE_INTEGERTYPE_MULTIPLIER (1 << NS_ATTRVALUE_INTEGERTYPE_BITS) +#define NS_ATTRVALUE_INTEGERTYPE_MAXVALUE \ + ((1 << (31 - NS_ATTRVALUE_INTEGERTYPE_BITS)) - 1) +#define NS_ATTRVALUE_INTEGERTYPE_MINVALUE \ + (-NS_ATTRVALUE_INTEGERTYPE_MAXVALUE - 1) + +#define NS_ATTRVALUE_ENUMTABLEINDEX_BITS \ + (32 - 16 - NS_ATTRVALUE_INTEGERTYPE_BITS) +#define NS_ATTRVALUE_ENUMTABLE_VALUE_NEEDS_TO_UPPER \ + (1 << (NS_ATTRVALUE_ENUMTABLEINDEX_BITS - 1)) +#define NS_ATTRVALUE_ENUMTABLEINDEX_MAXVALUE \ + (NS_ATTRVALUE_ENUMTABLE_VALUE_NEEDS_TO_UPPER - 1) +#define NS_ATTRVALUE_ENUMTABLEINDEX_MASK \ + (uintptr_t((((1 << NS_ATTRVALUE_ENUMTABLEINDEX_BITS) - 1) & \ + ~NS_ATTRVALUE_ENUMTABLE_VALUE_NEEDS_TO_UPPER))) + +/** + * A class used to construct a nsString from a nsStringBuffer (we might + * want to move this to nsString at some point). + * + * WARNING: Note that nsCheapString doesn't take an explicit length -- it + * assumes the string is maximally large, given the nsStringBuffer's storage + * size. This means the given string buffer *must* be sized exactly correctly + * for the string it contains (including one byte for a null terminator). If + * it has any unused storage space, then that will result in bogus characters + * at the end of our nsCheapString. + */ +class nsCheapString : public nsString { + public: + explicit nsCheapString(nsStringBuffer* aBuf) { + if (aBuf) aBuf->ToString(aBuf->StorageSize() / sizeof(char16_t) - 1, *this); + } +}; + +class nsAttrValue { + friend struct MiscContainer; + + public: + // This has to be the same as in ValueBaseType + enum ValueType { + eString = 0x00, // 00 + // 01 this value indicates a 'misc' struct + eAtom = 0x02, // 10 + eInteger = 0x03, // 0011 + eColor = 0x07, // 0111 + eEnum = 0x0B, // 1011 This should eventually die + ePercent = 0x0F, // 1111 + // Values below here won't matter, they'll be always stored in the 'misc' + // struct. + eCSSDeclaration = 0x10, + eURL, + eImage, + eAtomArray, + eDoubleValue, + // eShadowParts is refcounted in the misc container, as we do copy attribute + // values quite a bit (for example to process style invalidation), and the + // underlying value could get expensive to copy. + eShadowParts, + eSVGIntegerPair, + eSVGTypesBegin = eSVGIntegerPair, + eSVGOrient, + eSVGLength, + eSVGLengthList, + eSVGNumberList, + eSVGNumberPair, + eSVGPathData, + eSVGPointList, + eSVGPreserveAspectRatio, + eSVGStringList, + eSVGTransformList, + eSVGViewBox, + eSVGTypesEnd = eSVGViewBox, + }; + + nsAttrValue(); + nsAttrValue(const nsAttrValue& aOther); + explicit nsAttrValue(const nsAString& aValue); + explicit nsAttrValue(nsAtom* aValue); + nsAttrValue(already_AddRefed<mozilla::DeclarationBlock> aValue, + const nsAString* aSerialized); + ~nsAttrValue(); + + inline const nsAttrValue& operator=(const nsAttrValue& aOther); + + static void Init(); + static void Shutdown(); + + inline ValueType Type() const; + // Returns true when this value is self-contained and does not depend on + // the state of its associated element. + // Returns false when this value depends on the state of its associated + // element and may be invalid if that state has been changed by changes to + // that element state outside of attribute setting. + inline bool StoresOwnData() const; + + void Reset(); + + void SetTo(const nsAttrValue& aOther); + void SetTo(const nsAString& aValue); + void SetTo(nsAtom* aValue); + void SetTo(int16_t aInt); + void SetTo(int32_t aInt, const nsAString* aSerialized); + void SetTo(double aValue, const nsAString* aSerialized); + void SetTo(already_AddRefed<mozilla::DeclarationBlock> aValue, + const nsAString* aSerialized); + void SetTo(nsIURI* aValue, const nsAString* aSerialized); + void SetTo(const mozilla::SVGAnimatedIntegerPair& aValue, + const nsAString* aSerialized); + void SetTo(const mozilla::SVGAnimatedLength& aValue, + const nsAString* aSerialized); + void SetTo(const mozilla::SVGAnimatedNumberPair& aValue, + const nsAString* aSerialized); + void SetTo(const mozilla::SVGAnimatedOrient& aValue, + const nsAString* aSerialized); + void SetTo(const mozilla::SVGAnimatedPreserveAspectRatio& aValue, + const nsAString* aSerialized); + void SetTo(const mozilla::SVGAnimatedViewBox& aValue, + const nsAString* aSerialized); + void SetTo(const mozilla::SVGLengthList& aValue, + const nsAString* aSerialized); + void SetTo(const mozilla::SVGNumberList& aValue, + const nsAString* aSerialized); + void SetTo(const mozilla::SVGPathData& aValue, const nsAString* aSerialized); + void SetTo(const mozilla::SVGPointList& aValue, const nsAString* aSerialized); + void SetTo(const mozilla::SVGStringList& aValue, + const nsAString* aSerialized); + void SetTo(const mozilla::SVGTransformList& aValue, + const nsAString* aSerialized); + + /** + * Sets this object with the string or atom representation of aValue. + * + * After calling this method, this object will have type eString unless the + * type of aValue is eAtom, in which case this object will also have type + * eAtom. + */ + void SetToSerialized(const nsAttrValue& aValue); + + void SwapValueWith(nsAttrValue& aOther); + + void RemoveDuplicatesFromAtomArray(); + + void ToString(nsAString& aResult) const; + inline void ToString(mozilla::dom::DOMString& aResult) const; + + /** + * Returns the value of this object as an atom. If necessary, the value will + * first be serialised using ToString before converting to an atom. + */ + already_AddRefed<nsAtom> GetAsAtom() const; + + // Methods to get value. These methods do not convert so only use them + // to retrieve the datatype that this nsAttrValue has. + inline bool IsEmptyString() const; + const nsCheapString GetStringValue() const; + inline nsAtom* GetAtomValue() const; + inline int32_t GetIntegerValue() const; + bool GetColorValue(nscolor& aColor) const; + inline int16_t GetEnumValue() const; + inline double GetPercentValue() const; + inline const mozilla::AttrAtomArray* GetAtomArrayValue() const; + inline mozilla::DeclarationBlock* GetCSSDeclarationValue() const; + inline nsIURI* GetURLValue() const; + inline double GetDoubleValue() const; + inline const mozilla::ShadowParts& GetShadowPartsValue() const; + + /** + * Returns the string corresponding to the stored enum value. + * + * @param aResult the string representing the enum tag + * @param aRealTag wheter we want to have the real tag or the saved one + */ + void GetEnumString(nsAString& aResult, bool aRealTag) const; + + // Methods to get access to atoms we may have + // Returns the number of atoms we have; 0 if we have none. It's OK + // to call this without checking the type first; it handles that. + uint32_t GetAtomCount() const; + // Returns the atom at aIndex (0-based). Do not call this with + // aIndex >= GetAtomCount(). + nsAtom* AtomAt(int32_t aIndex) const; + + uint32_t HashValue() const; + bool Equals(const nsAttrValue& aOther) const; + // aCaseSensitive == eIgnoreCase means ASCII case-insenstive matching + bool Equals(const nsAString& aValue, nsCaseTreatment aCaseSensitive) const; + bool Equals(const nsAtom* aValue, nsCaseTreatment aCaseSensitive) const; + bool HasPrefix(const nsAString& aValue, nsCaseTreatment aCaseSensitive) const; + bool HasSuffix(const nsAString& aValue, nsCaseTreatment aCaseSensitive) const; + bool HasSubstring(const nsAString& aValue, + nsCaseTreatment aCaseSensitive) const; + + /** + * Compares this object with aOther according to their string representation. + * + * For example, when called on an object with type eInteger and value 4, and + * given aOther of type eString and value "4", EqualsAsStrings will return + * true (while Equals will return false). + */ + bool EqualsAsStrings(const nsAttrValue& aOther) const; + + /** + * Returns true if this AttrValue is equal to the given atom, or is an + * array which contains the given atom. + */ + bool Contains(nsAtom* aValue, nsCaseTreatment aCaseSensitive) const; + /** + * Returns true if this AttrValue is an atom equal to the given + * string, or is an array of atoms which contains the given string. + * This always does a case-sensitive comparison. + */ + bool Contains(const nsAString& aValue) const; + + void ParseAtom(const nsAString& aValue); + void ParseAtomArray(const nsAString& aValue); + void ParseAtomArray(nsAtom* aValue); + void ParseStringOrAtom(const nsAString& aValue); + + /** + * Parses an exportparts attribute. + * + * https://drafts.csswg.org/css-shadow-parts/#parsing-mapping-list + */ + void ParsePartMapping(const nsAString&); + + /** + * Structure for a mapping from int (enum) values to strings. When you use + * it you generally create an array of them. + * Instantiate like this: + * EnumTable myTable[] = { + * { "string1", 1 }, + * { "string2", 2 }, + * { nullptr, 0 } + * } + */ + struct EnumTable { + // EnumTable can be initialized either with an int16_t value + // or a value of an enumeration type that can fit within an int16_t. + + constexpr EnumTable(const char* aTag, int16_t aValue) + : tag(aTag), value(aValue) {} + + template <typename T, + typename = typename std::enable_if<std::is_enum<T>::value>::type> + constexpr EnumTable(const char* aTag, T aValue) + : tag(aTag), value(static_cast<int16_t>(aValue)) { + static_assert(mozilla::EnumTypeFitsWithin<T, int16_t>::value, + "aValue must be an enum that fits within int16_t"); + // TODO: statically assert there are no duplicate values, otherwise + // `GetEnumString()` above will return wrong values. + } + + /** The string the value maps to */ + const char* tag; + /** The enum value that maps to this string */ + int16_t value; + }; + + /** + * Parse into an enum value. + * + * @param aValue the string to find the value for + * @param aTable the enumeration to map with + * @param aCaseSensitive specify if the parsing has to be case sensitive + * @param aDefaultValue if non-null, this function will always return true. + * Failure to parse aValue as one of the values in aTable will just + * cause aDefaultValue->value to be stored as the enumeration value. + * @return whether the enum value was found or not + */ + bool ParseEnumValue(const nsAString& aValue, const EnumTable* aTable, + bool aCaseSensitive, + const EnumTable* aDefaultValue = nullptr); + + /** + * Parse a string into a dimension value. This is similar to + * https://html.spec.whatwg.org/multipage/#rules-for-parsing-dimension-values + * but drops the fractional part of the value for now, until we figure out how + * to store that in our nsAttrValue. + * + * The resulting value (if the parse succeeds) is one of eInteger, + * eDoubleValue, or ePercent, depending on whether we found a fractional part + * and whether we found '%' at the end of the value. + * + * @param aInput the string to parse + * @return whether the value could be parsed + */ + bool ParseHTMLDimension(const nsAString& aInput) { + return DoParseHTMLDimension(aInput, false); + } + + /** + * Parse a string into a nonzero dimension value. This implements + * https://html.spec.whatwg.org/multipage/#rules-for-parsing-non-zero-dimension-values + * subject to the same constraints as ParseHTMLDimension above. + * + * @param aInput the string to parse + * @return whether the value could be parsed + */ + bool ParseNonzeroHTMLDimension(const nsAString& aInput) { + return DoParseHTMLDimension(aInput, true); + } + + /** + * Parse a string value into an integer. + * + * @param aString the string to parse + * @return whether the value could be parsed + */ + bool ParseIntValue(const nsAString& aString) { + return ParseIntWithBounds(aString, INT32_MIN, INT32_MAX); + } + + /** + * Parse a string value into an integer with minimum value and maximum value. + * + * @param aString the string to parse + * @param aMin the minimum value (if value is less it will be bumped up) + * @param aMax the maximum value (if value is greater it will be chopped down) + * @return whether the value could be parsed + */ + bool ParseIntWithBounds(const nsAString& aString, int32_t aMin, + int32_t aMax = INT32_MAX); + + /** + * Parse a string value into an integer with a fallback for invalid values. + * Also allows clamping to a maximum value to support col/colgroup.span (this + * is not per spec right now). + * + * @param aString the string to parse + * @param aDefault the default value + * @param aMax the maximum value (if value is greater it will be clamped) + */ + void ParseIntWithFallback(const nsAString& aString, int32_t aDefault, + int32_t aMax = INT32_MAX); + + /** + * Parse a string value into a non-negative integer. + * This method follows the rules for parsing non-negative integer from: + * http://dev.w3.org/html5/spec/infrastructure.html#rules-for-parsing-non-negative-integers + * + * @param aString the string to parse + * @return whether the value is valid + */ + bool ParseNonNegativeIntValue(const nsAString& aString); + + /** + * Parse a string value into a clamped non-negative integer. + * This method follows the rules for parsing non-negative integer from: + * https://html.spec.whatwg.org/multipage/infrastructure.html#clamped-to-the-range + * + * @param aString the string to parse + * @param aDefault value to return for negative or invalid values + * @param aMin minimum value + * @param aMax maximum value + */ + void ParseClampedNonNegativeInt(const nsAString& aString, int32_t aDefault, + int32_t aMin, int32_t aMax); + + /** + * Parse a string value into a positive integer. + * This method follows the rules for parsing non-negative integer from: + * http://dev.w3.org/html5/spec/infrastructure.html#rules-for-parsing-non-negative-integers + * In addition of these rules, the value has to be greater than zero. + * + * This is generally used for parsing content attributes which reflecting IDL + * attributes are limited to only non-negative numbers greater than zero, see: + * http://dev.w3.org/html5/spec/common-dom-interfaces.html#limited-to-only-non-negative-numbers-greater-than-zero + * + * @param aString the string to parse + * @return whether the value was valid + */ + bool ParsePositiveIntValue(const nsAString& aString); + + /** + * Parse a string into a color. This implements what HTML5 calls the + * "rules for parsing a legacy color value". + * + * @param aString the string to parse + * @return whether the value could be parsed + */ + bool ParseColor(const nsAString& aString); + + /** + * Parse a string value into a double-precision floating point value. + * + * @param aString the string to parse + * @return whether the value could be parsed + */ + bool ParseDoubleValue(const nsAString& aString); + + /** + * Parse a string into a CSS style rule. + * + * @param aString the style attribute value to be parsed. + * @param aElement the element the attribute is set on. + * @param aMaybeScriptedPrincipal if available, the scripted principal + * responsible for this attribute value, as passed to + * Element::ParseAttribute. + */ + bool ParseStyleAttribute(const nsAString& aString, + nsIPrincipal* aMaybeScriptedPrincipal, + nsStyledElement* aElement); + + size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const; + + nsAtom* GetStoredAtom() const; + nsStringBuffer* GetStoredStringBuffer() const; + + private: + // These have to be the same as in ValueType + enum ValueBaseType { + eStringBase = eString, // 00 + eOtherBase = 0x01, // 01 + eAtomBase = eAtom, // 10 + eIntegerBase = 0x03 // 11 + }; + + inline ValueBaseType BaseType() const; + inline bool IsSVGType(ValueType aType) const; + + /** + * Get the index of an EnumTable in the sEnumTableArray. + * If the EnumTable is not in the sEnumTableArray, it is added. + * + * @param aTable the EnumTable to get the index of. + * @return the index of the EnumTable. + */ + int16_t GetEnumTableIndex(const EnumTable* aTable); + + inline void SetPtrValueAndType(void* aValue, ValueBaseType aType); + void SetIntValueAndType(int32_t aValue, ValueType aType, + const nsAString* aStringValue); + // aType can be ePercent or eDoubleValue. + void SetDoubleValueAndType(double aValue, ValueType aType, + const nsAString* aStringValue); + void SetColorValue(nscolor aColor, const nsAString& aString); + void SetMiscAtomOrString(const nsAString* aValue); + void ResetMiscAtomOrString(); + void SetSVGType(ValueType aType, const void* aValue, + const nsAString* aSerialized); + inline void ResetIfSet(); + + inline void* GetPtr() const; + inline MiscContainer* GetMiscContainer() const; + inline int32_t GetIntInternal() const; + + // Clears the current MiscContainer. This will return null if there is no + // existing container. + MiscContainer* ClearMiscContainer(); + // Like ClearMiscContainer, except allocates a new container if one does not + // exist already. + MiscContainer* EnsureEmptyMiscContainer(); + already_AddRefed<nsStringBuffer> GetStringBuffer( + const nsAString& aValue) const; + // Given an enum table and a particular entry in that table, return + // the actual integer value we should store. + int32_t EnumTableEntryToValue(const EnumTable* aEnumTable, + const EnumTable* aTableEntry); + + template <typename F> + bool SubstringCheck(const nsAString& aValue, + nsCaseTreatment aCaseSensitive) const; + + static MiscContainer* AllocMiscContainer(); + static void DeallocMiscContainer(MiscContainer* aCont); + + static nsTArray<const EnumTable*>* sEnumTableArray; + + /** + * Helper for ParseHTMLDimension and ParseNonzeroHTMLDimension. + * + * @param aInput the string to parse + * @param aEnsureNonzero whether to fail the parse if the value is 0 + * @return whether the value could be parsed + */ + bool DoParseHTMLDimension(const nsAString& aInput, bool aEnsureNonzero); + + uintptr_t mBits; +}; + +inline const nsAttrValue& nsAttrValue::operator=(const nsAttrValue& aOther) { + SetTo(aOther); + return *this; +} + +inline nsAttrValue::ValueBaseType nsAttrValue::BaseType() const { + return static_cast<ValueBaseType>(mBits & NS_ATTRVALUE_BASETYPE_MASK); +} + +inline void* nsAttrValue::GetPtr() const { + NS_ASSERTION(BaseType() != eIntegerBase, "getting pointer from non-pointer"); + return reinterpret_cast<void*>(mBits & NS_ATTRVALUE_POINTERVALUE_MASK); +} + +inline bool nsAttrValue::IsEmptyString() const { return !mBits; } + +#endif |