nsAttrValue.h
/* -*- 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 "nsStringGlue.h"
#include "nsStringBuffer.h"
#include "nsColor.h"
#include "nsCaseTreatment.h"
#include "nsMargin.h"
#include "nsCOMPtr.h"
#include "SVGAttrValueWrapper.h"
#include "nsTArrayForwardDeclare.h"
#include "nsIAtom.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/dom/BindingDeclarations.h"
#include "mozilla/EnumTypeTraits.h"
// Undefine LoadImage to prevent naming conflict with Windows.
#undef LoadImage
class nsAString;
class nsIDocument;
class nsStyledElement;
struct MiscContainer;
struct ServoDeclarationBlock;
namespace mozilla {
namespace css {
class Declaration;
struct URLValue;
struct ImageValue;
} // namespace css
} // namespace mozilla
#define NS_ATTRVALUE_MAX_STRINGLENGTH_ATOM 12
#define NS_ATTRVALUE_BASETYPE_MASK (uintptr_t(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:
typedef nsTArray< nsCOMPtr<nsIAtom> > AtomArray;
// 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.
eGeckoCSSDeclaration = 0x10,
eServoCSSDeclaration,
eURL,
eImage,
eAtomArray,
eDoubleValue,
eIntMarginValue,
eSVGAngle,
eSVGTypesBegin = eSVGAngle,
eSVGIntegerPair,
eSVGLength,
eSVGLengthList,
eSVGNumberList,
eSVGNumberPair,
eSVGPathData,
eSVGPointList,
eSVGPreserveAspectRatio,
eSVGStringList,
eSVGTransformList,
eSVGViewBox,
eSVGTypesEnd = eSVGViewBox,
};
nsAttrValue();
nsAttrValue(const nsAttrValue& aOther);
explicit nsAttrValue(const nsAString& aValue);
explicit nsAttrValue(nsIAtom* aValue);
nsAttrValue(mozilla::css::Declaration* aValue, const nsAString* aSerialized);
explicit nsAttrValue(const nsIntMargin& aValue);
~nsAttrValue();
inline const nsAttrValue& operator=(const nsAttrValue& aOther);
static nsresult Init();
static void Shutdown();
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(nsIAtom* aValue);
void SetTo(int16_t aInt);
void SetTo(int32_t aInt, const nsAString* aSerialized);
void SetTo(double aValue, const nsAString* aSerialized);
void SetTo(mozilla::css::Declaration* aValue, const nsAString* aSerialized);
void SetTo(already_AddRefed<ServoDeclarationBlock> aDeclarationBlock,
const nsAString* aSerialized);
void SetTo(mozilla::css::URLValue* aValue, const nsAString* aSerialized);
void SetTo(const nsIntMargin& aValue);
void SetTo(const nsSVGAngle& aValue, const nsAString* aSerialized);
void SetTo(const nsSVGIntegerPair& 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 nsSVGNumberPair& 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 nsSVGViewBox& 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<nsIAtom> 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 nsIAtom* GetAtomValue() const;
inline int32_t GetIntegerValue() const;
bool GetColorValue(nscolor& aColor) const;
inline int16_t GetEnumValue() const;
inline float GetPercentValue() const;
inline AtomArray* GetAtomArrayValue() const;
inline mozilla::css::Declaration* GetGeckoCSSDeclarationValue() const;
inline ServoDeclarationBlock* GetServoCSSDeclarationValue() const;
inline mozilla::css::URLValue* GetURLValue() const;
inline mozilla::css::ImageValue* GetImageValue() 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().
nsIAtom* 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(nsIAtom* 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(nsIAtom* 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<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");
}
/** 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 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);
/**
* Convert a URL nsAttrValue to an Image nsAttrValue.
*
* @param aDocument the document this nsAttrValue belongs to.
*/
void LoadImage(nsIDocument* aDocument);
/**
* 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.
*/
bool ParseStyleAttribute(const nsAString& aString,
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<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);
static nsTArray<const EnumTable*>* sEnumTableArray;
uintptr_t mBits;
};
inline const nsAttrValue&
nsAttrValue::operator=(const nsAttrValue& aOther)
{
SetTo(aOther);
return *this;
}
inline nsIAtom*
nsAttrValue::GetAtomValue() const
{
NS_PRECONDITION(Type() == eAtom, "wrong type");
return reinterpret_cast<nsIAtom*>(GetPtr());
}
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;
}
inline void
nsAttrValue::ToString(mozilla::dom::DOMString& aResult) const
{
switch (Type()) {
case eString:
{
nsStringBuffer* str = static_cast<nsStringBuffer*>(GetPtr());
if (str) {
aResult.SetStringBuffer(str, str->StorageSize()/sizeof(char16_t) - 1);
}
// else aResult is already empty
return;
}
case eAtom:
{
nsIAtom *atom = static_cast<nsIAtom*>(GetPtr());
aResult.SetStringBuffer(atom->GetStringBuffer(), atom->GetLength());
break;
}
default:
{
ToString(aResult.AsAString());
}
}
}
#endif
