/* -*- 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 "nsCOMPtr.h"

#include "nsStringFwd.h"

#include "SVGAttrValueWrapper.h"

#include "nsTArrayForwardDeclare.h"

#include "nsAtom.h"

#include "mozilla/AtomArray.h"

#include "mozilla/MemoryReporting.h"

#include "mozilla/dom/BindingDeclarations.h"

#include "mozilla/EnumTypeTraits.h"

class nsIDocument;

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,

    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(nsAtom* aValue);

  nsAttrValue(already_AddRefed<mozilla::DeclarationBlock> 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<mozilla::DeclarationBlock> aValue,

             const nsAString* aSerialized);

  void SetTo(nsIURI* 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<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 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(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<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 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<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 MiscContainer* AllocMiscContainer();

  static void DeallocMiscContainer(MiscContainer* aCont);

  static nsTArray<const EnumTable*>* 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<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