/* -*- 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 #include "nscore.h" #include "nsString.h" #include "nsStringBuffer.h" #include "nsColor.h" #include "nsCaseTreatment.h" #include "nsMargin.h" #include "nsCOMPtr.h" #include "nsStringFwd.h" #include "nsTArrayForwardDeclare.h" #include "nsAtom.h" #include "mozilla/dom/BindingDeclarations.h" #include "mozilla/AtomArray.h" #include "mozilla/EnumTypeTraits.h" #include "mozilla/MemoryReporting.h" #include "mozilla/SVGAttrValueWrapper.h" class nsIURI; class nsStyledElement; struct MiscContainer; namespace mozilla { class DeclarationBlock; } // 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, eIntMarginValue, 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 aValue, const nsAString* aSerialized); explicit nsAttrValue(const nsIntMargin& aValue); ~nsAttrValue(); inline const nsAttrValue& operator=(const nsAttrValue& aOther); static nsresult 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 aValue, const nsAString* aSerialized); void SetTo(nsIURI* aValue, const nsAString* aSerialized); void SetTo(const nsIntMargin& aValue); void SetTo(const mozilla::SVGOrient& aValue, const nsAString* aSerialized); void SetTo(const mozilla::SVGIntegerPair& aValue, const nsAString* aSerialized); void SetTo(const nsSVGLength2& 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::SVGNumberPair& 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::SVGAnimatedPreserveAspectRatio& aValue, const nsAString* aSerialized); void SetTo(const mozilla::SVGStringList& aValue, const nsAString* aSerialized); void SetTo(const mozilla::SVGTransformList& aValue, const nsAString* aSerialized); void SetTo(const mozilla::SVGViewBox& 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 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 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 float GetPercentValue() const; inline mozilla::AtomArray* GetAtomArrayValue() const; inline mozilla::DeclarationBlock* GetCSSDeclarationValue() const; inline nsIURI* GetURLValue() const; inline double GetDoubleValue() const; bool GetIntMarginValue(nsIntMargin& aMargin) 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; /** * 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 ParseStringOrAtom(const nsAString& aValue); /** * 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 ::value>::type> constexpr EnumTable(const char* aTag, T aValue) : tag(aTag), value(static_cast(aValue)) { static_assert(mozilla::EnumTypeFitsWithin::value, "aValue must be an enum that fits within int16_t"); } /** 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 an integer. Can optionally parse percent (n%). * This method explicitly sets a lower bound of zero on the element, * whether it be percent or raw integer. * * @param aString the string to parse * @return whether the value could be parsed * * @see http://www.whatwg.org/html/#rules-for-parsing-dimension-values */ bool ParseSpecialIntValue(const nsAString& aString); /** * 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 lazy URI. This just sets up the storage for the URI; it * doesn't actually allocate it. */ bool ParseLazyURIValue(const nsAString& aString); /** * Parse a margin string of format 'top, right, bottom, left' into * an nsIntMargin. * * @param aString the string to parse * @return whether the value could be parsed */ bool ParseIntMarginValue(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; 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); 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(); bool EnsureEmptyAtomArray(); already_AddRefed 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); static MiscContainer* AllocMiscContainer(); static void DeallocMiscContainer(MiscContainer* aCont); static nsTArray* sEnumTableArray; static MiscContainer* sMiscContainerCache; uintptr_t mBits; }; inline const nsAttrValue& nsAttrValue::operator=(const nsAttrValue& aOther) { SetTo(aOther); return *this; } inline nsAttrValue::ValueBaseType nsAttrValue::BaseType() const { return static_cast(mBits & NS_ATTRVALUE_BASETYPE_MASK); } inline void* nsAttrValue::GetPtr() const { NS_ASSERTION(BaseType() != eIntegerBase, "getting pointer from non-pointer"); return reinterpret_cast(mBits & NS_ATTRVALUE_POINTERVALUE_MASK); } inline bool nsAttrValue::IsEmptyString() const { return !mBits; } #endif