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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/. */
+
+/*
+ * 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