layout/style/nsStyleCoord.h
author Ting-Yu Lin <tlin@mozilla.com>
Fri, 18 Nov 2016 18:12:25 +0800
changeset 324063 1710e2f930dbd5b32aa5f126ab031c8353a73523
parent 324062 60506dc6f798fde3715897564930ce5b2dcf5ed8
permissions -rw-r--r--
Bug 1317588 Part 3 - Remove #define NS_SIDE_TOP/RIGHT/BOTTOM/LEFT. r=mats This patch was written with the help of the following script. Also, manually add mozilla qualifier to the enum values in nsStyleCoord.h, gfxRect.h, and Types.h to make it build. function rename() { find .\ -type f\ ! -path "./obj*"\ ! -path "./.git"\ ! -path "./.hg"\ \( -name "*.cpp" -or\ -name "*.h" \)\ -exec sed -i -e "s/$1/$2/g" "{}" \; } rename "NS_SIDE_TOP" "eSideTop" rename "NS_SIDE_RIGHT" "eSideRight" rename "NS_SIDE_BOTTOM" "eSideBottom" rename "NS_SIDE_LEFT" "eSideLeft" MozReview-Commit-ID: 9T0ORsqM6nP

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */

/* representation of length values in computed style data */

#ifndef nsStyleCoord_h___
#define nsStyleCoord_h___

#include "nsCoord.h"
#include "nsStyleConsts.h"

namespace mozilla {

class WritingMode;

// Logical axis, edge and side constants for use in various places.
enum LogicalAxis {
  eLogicalAxisBlock  = 0x0,
  eLogicalAxisInline = 0x1
};
enum LogicalEdge {
  eLogicalEdgeStart  = 0x0,
  eLogicalEdgeEnd    = 0x1
};
enum LogicalSide {
  eLogicalSideBStart = (eLogicalAxisBlock  << 1) | eLogicalEdgeStart,  // 0x0
  eLogicalSideBEnd   = (eLogicalAxisBlock  << 1) | eLogicalEdgeEnd,    // 0x1
  eLogicalSideIStart = (eLogicalAxisInline << 1) | eLogicalEdgeStart,  // 0x2
  eLogicalSideIEnd   = (eLogicalAxisInline << 1) | eLogicalEdgeEnd     // 0x3
};

} // namespace mozilla

enum nsStyleUnit : uint8_t {
  eStyleUnit_Null         = 0,      // (no value) value is not specified
  eStyleUnit_Normal       = 1,      // (no value)
  eStyleUnit_Auto         = 2,      // (no value)
  eStyleUnit_None         = 3,      // (no value)
  eStyleUnit_Percent      = 10,     // (float) 1.0 == 100%
  eStyleUnit_Factor       = 11,     // (float) a multiplier
  eStyleUnit_Degree       = 12,     // (float) angle in degrees
  eStyleUnit_Grad         = 13,     // (float) angle in grads
  eStyleUnit_Radian       = 14,     // (float) angle in radians
  eStyleUnit_Turn         = 15,     // (float) angle in turns
  eStyleUnit_FlexFraction = 16,     // (float) <flex> in fr units
  eStyleUnit_Coord        = 20,     // (nscoord) value is twips
  eStyleUnit_Integer      = 30,     // (int) value is simple integer
  eStyleUnit_Enumerated   = 32,     // (int) value has enumerated meaning

  // The following are reference counted allocated types.
  eStyleUnit_Calc         = 40,     // (Calc*) calc() toplevel; always present
                                    // to distinguish 50% from calc(50%), etc.

  eStyleUnit_MAX          = 40      // highest valid nsStyleUnit value
};

typedef union {
  int32_t     mInt;   // nscoord is a int32_t for now
  float       mFloat;
  // An mPointer is a reference counted pointer.  Currently this can only
  // ever be an nsStyleCoord::Calc*.
  void*       mPointer;
} nsStyleUnion;

/**
 * Class that hold a single size specification used by the style
 * system.  The size specification consists of two parts -- a number
 * and a unit.  The number is an integer, a floating point value, an
 * nscoord, or undefined, and the unit is an nsStyleUnit.  Checking
 * the unit is a must before asking for the value in any particular
 * form.
 */
 /** <div rustbindgen private accessor="unsafe"></div> */
class nsStyleCoord {
public:
  // Non-reference counted calc() value.  See nsStyleStruct.h for some uses
  // of this.
  struct CalcValue {
    // Every calc() expression evaluates to a length plus a percentage.
    nscoord mLength;
    float mPercent;
    bool mHasPercent; // whether there was any % syntax, even if 0

    bool operator==(const CalcValue& aOther) const {
      return mLength == aOther.mLength &&
             mPercent == aOther.mPercent &&
             mHasPercent == aOther.mHasPercent;
    }
    bool operator!=(const CalcValue& aOther) const {
      return !(*this == aOther);
    }

    nscoord ToLength() const {
      MOZ_ASSERT(!mHasPercent);
      return mLength;
    }

    // If this returns true the value is definitely zero. It it returns false
    // it might be zero. So it's best used for conservative optimization.
    bool IsDefinitelyZero() const { return mLength == 0 && mPercent == 0; }
  };

  // Reference counted calc() value.  This is the type that is used to store
  // the calc() value in nsStyleCoord.
  struct Calc final : public CalcValue {
    NS_INLINE_DECL_THREADSAFE_REFCOUNTING(Calc)
    Calc() {}

  private:
    Calc(const Calc&) = delete;
    ~Calc() {}
    Calc& operator=(const Calc&) = delete;
  };

  explicit nsStyleCoord(nsStyleUnit aUnit = eStyleUnit_Null);
  enum CoordConstructorType { CoordConstructor };
  inline nsStyleCoord(nscoord aValue, CoordConstructorType);
  nsStyleCoord(int32_t aValue, nsStyleUnit aUnit);
  nsStyleCoord(float aValue, nsStyleUnit aUnit);
  inline nsStyleCoord(const nsStyleCoord& aCopy);
  inline nsStyleCoord(const nsStyleUnion& aValue, nsStyleUnit aUnit);
  ~nsStyleCoord() { Reset(); }

  nsStyleCoord&  operator=(const nsStyleCoord& aOther)
  {
    if (this != &aOther) {
      SetValue(mUnit, mValue, aOther);
    }
    return *this;
  }
  bool           operator==(const nsStyleCoord& aOther) const;
  bool           operator!=(const nsStyleCoord& aOther) const;

  nsStyleUnit GetUnit() const {
    NS_ASSERTION(mUnit != eStyleUnit_Null, "reading uninitialized value");
    return mUnit;
  }

  bool IsAngleValue() const {
    return eStyleUnit_Degree <= mUnit && mUnit <= eStyleUnit_Turn;
  }

  static bool IsCalcUnit(nsStyleUnit aUnit) {
    return aUnit == eStyleUnit_Calc;
  }

  static bool IsPointerUnit(nsStyleUnit aUnit) {
    return IsCalcUnit(aUnit);
  }

  bool IsCalcUnit() const {
    return IsCalcUnit(mUnit);
  }

  bool IsPointerValue() const {
    return IsPointerUnit(mUnit);
  }

  bool IsCoordPercentCalcUnit() const {
    return mUnit == eStyleUnit_Coord ||
           mUnit == eStyleUnit_Percent ||
           IsCalcUnit();
  }

  // Does this calc() expression have any percentages inside it?  Can be
  // called only when IsCalcUnit() is true.
  bool CalcHasPercent() const {
    return GetCalcValue()->mHasPercent;
  }

  bool HasPercent() const {
    return mUnit == eStyleUnit_Percent ||
           (IsCalcUnit() && CalcHasPercent());
  }

  static bool ConvertsToLength(const nsStyleUnit aUnit,
                               const nsStyleUnion aValue) {
    return aUnit == eStyleUnit_Coord ||
           (IsCalcUnit(aUnit) && !AsCalcValue(aValue)->mHasPercent);
  }

  bool ConvertsToLength() const {
    return ConvertsToLength(mUnit, mValue);
  }

  static nscoord ToLength(nsStyleUnit aUnit, nsStyleUnion aValue) {
    MOZ_ASSERT(ConvertsToLength(aUnit, aValue));
    if (IsCalcUnit(aUnit)) {
      return AsCalcValue(aValue)->ToLength(); // Note: This asserts !mHasPercent
    }
    MOZ_ASSERT(aUnit == eStyleUnit_Coord);
    return aValue.mInt;
  }

  nscoord ToLength() const {
    return ToLength(GetUnit(), mValue);
  }

  // Callers must verify IsCalcUnit before calling this function.
  static Calc* AsCalcValue(nsStyleUnion aValue) {
    return static_cast<Calc*>(aValue.mPointer);
  }

  nscoord     GetCoordValue() const;
  int32_t     GetIntValue() const;
  float       GetPercentValue() const;
  float       GetFactorValue() const;
  float       GetFactorOrPercentValue() const;
  float       GetAngleValue() const;
  double      GetAngleValueInDegrees() const;
  double      GetAngleValueInRadians() const;
  float       GetFlexFractionValue() const;
  Calc*       GetCalcValue() const;
  uint32_t    HashValue(uint32_t aHash) const;

  // Sets to null and releases any refcounted objects.  Only use this if the
  // object is initialized (i.e. don't use it in nsStyleCoord constructors).
  void Reset();

  void  SetCoordValue(nscoord aValue);
  void  SetIntValue(int32_t aValue, nsStyleUnit aUnit);
  void  SetPercentValue(float aValue);
  void  SetFactorValue(float aValue);
  void  SetAngleValue(float aValue, nsStyleUnit aUnit);
  void  SetFlexFractionValue(float aValue);
  void  SetNormalValue();
  void  SetAutoValue();
  void  SetNoneValue();
  void  SetCalcValue(Calc* aValue);

  // Resets a coord represented by a unit/value pair.
  static inline void Reset(nsStyleUnit& aUnit, nsStyleUnion& aValue);

  // Sets a coord represented by a unit/value pair from a second
  // unit/value pair.
  static inline void SetValue(nsStyleUnit& aUnit,
                              nsStyleUnion& aValue,
                              nsStyleUnit aOtherUnit,
                              const nsStyleUnion& aOtherValue);

  // Sets a coord represented by a unit/value pair from an nsStyleCoord.
  static inline void SetValue(nsStyleUnit& aUnit, nsStyleUnion& aValue,
                              const nsStyleCoord& aOther);

  // Like the above, but do not reset before setting.
  static inline void InitWithValue(nsStyleUnit& aUnit,
                                   nsStyleUnion& aValue,
                                   nsStyleUnit aOtherUnit,
                                   const nsStyleUnion& aOtherValue);

  static inline void InitWithValue(nsStyleUnit& aUnit, nsStyleUnion& aValue,
                                   const nsStyleCoord& aOther);

private:
  nsStyleUnit   mUnit;
  nsStyleUnion  mValue;
};

/**
 * Class that represents a set of top/right/bottom/left nsStyleCoords.
 * This is commonly used to hold the widths of the borders, margins,
 * or paddings of a box.
 */
 /** <div rustbindgen private accessor="unsafe"></div> */
class nsStyleSides {
public:
  nsStyleSides();
  nsStyleSides(const nsStyleSides&);
  ~nsStyleSides();

  nsStyleSides&  operator=(const nsStyleSides& aCopy);
  bool           operator==(const nsStyleSides& aOther) const;
  bool           operator!=(const nsStyleSides& aOther) const;

  inline nsStyleUnit GetUnit(mozilla::Side aSide) const;
  inline nsStyleUnit GetLeftUnit() const;
  inline nsStyleUnit GetTopUnit() const;
  inline nsStyleUnit GetRightUnit() const;
  inline nsStyleUnit GetBottomUnit() const;

  inline nsStyleCoord Get(mozilla::Side aSide) const;
  inline nsStyleCoord GetLeft() const;
  inline nsStyleCoord GetTop() const;
  inline nsStyleCoord GetRight() const;
  inline nsStyleCoord GetBottom() const;

  // Methods to access the units and values in terms of logical sides
  // for a given writing mode.
  // NOTE: The definitions are in WritingModes.h (after we have the full
  // declaration of WritingMode available).
  inline nsStyleUnit GetUnit(mozilla::WritingMode aWritingMode,
                             mozilla::LogicalSide aSide) const;
  inline nsStyleUnit GetIStartUnit(mozilla::WritingMode aWritingMode) const;
  inline nsStyleUnit GetBStartUnit(mozilla::WritingMode aWritingMode) const;
  inline nsStyleUnit GetIEndUnit(mozilla::WritingMode aWritingMode) const;
  inline nsStyleUnit GetBEndUnit(mozilla::WritingMode aWritingMode) const;

  // Return true if either the start or end side in the axis is 'auto'.
  inline bool HasBlockAxisAuto(mozilla::WritingMode aWritingMode) const;
  inline bool HasInlineAxisAuto(mozilla::WritingMode aWritingMode) const;

  inline nsStyleCoord Get(mozilla::WritingMode aWritingMode,
                          mozilla::LogicalSide aSide) const;
  inline nsStyleCoord GetIStart(mozilla::WritingMode aWritingMode) const;
  inline nsStyleCoord GetBStart(mozilla::WritingMode aWritingMode) const;
  inline nsStyleCoord GetIEnd(mozilla::WritingMode aWritingMode) const;
  inline nsStyleCoord GetBEnd(mozilla::WritingMode aWritingMode) const;

  // Sets each side to null and releases any refcounted objects.  Only use this
  // if the object is initialized (i.e. don't use it in nsStyleSides
  // constructors).
  void Reset();

  inline void Set(mozilla::Side aSide, const nsStyleCoord& aCoord);
  inline void SetLeft(const nsStyleCoord& aCoord);
  inline void SetTop(const nsStyleCoord& aCoord);
  inline void SetRight(const nsStyleCoord& aCoord);
  inline void SetBottom(const nsStyleCoord& aCoord);

  nscoord ToLength(mozilla::Side aSide) const {
    return nsStyleCoord::ToLength(mUnits[aSide], mValues[aSide]);
  }

  bool ConvertsToLength() const {
    NS_FOR_CSS_SIDES(side) {
      if (!nsStyleCoord::ConvertsToLength(mUnits[side], mValues[side])) {
        return false;
      }
    }
    return true;
  }

protected:
  nsStyleUnit   mUnits[4];
  nsStyleUnion  mValues[4];
};

/**
 * Class that represents a set of top-left/top-right/bottom-right/bottom-left
 * nsStyleCoord pairs.  This is used to hold the dimensions of the
 * corners of a box (for, e.g., border-radius and outline-radius).
 */
 /** <div rustbindgen private accessor="unsafe"></div> */
class nsStyleCorners {
public:
  nsStyleCorners();
  nsStyleCorners(const nsStyleCorners&);
  ~nsStyleCorners();

  // use compiler's version
  nsStyleCorners& operator=(const nsStyleCorners& aCopy);
  bool           operator==(const nsStyleCorners& aOther) const;
  bool           operator!=(const nsStyleCorners& aOther) const;

  // aCorner is always one of NS_CORNER_* defined in nsStyleConsts.h
  inline nsStyleUnit GetUnit(uint8_t aHalfCorner) const;

  inline nsStyleCoord Get(uint8_t aHalfCorner) const;

  // Sets each corner to null and releases any refcounted objects.  Only use
  // this if the object is initialized (i.e. don't use it in nsStyleCorners
  // constructors).
  void Reset();

  inline void Set(uint8_t aHalfCorner, const nsStyleCoord& aCoord);

protected:
  // Stored as:
  // top-left.x, top-left.y,
  // top-right.x, top-right.y,
  // bottom-right.x, bottom-right.y,
  // bottom-left.x, bottom-left.y
  nsStyleUnit   mUnits[8];
  nsStyleUnion  mValues[8];
};


// -------------------------
// nsStyleCoord inlines
//
inline nsStyleCoord::nsStyleCoord(nscoord aValue, CoordConstructorType)
  : mUnit(eStyleUnit_Coord)
{
  mValue.mInt = aValue;
}

inline nsStyleCoord::nsStyleCoord(const nsStyleCoord& aCopy)
  : mUnit(eStyleUnit_Null)
{
  InitWithValue(mUnit, mValue, aCopy);
}

inline nsStyleCoord::nsStyleCoord(const nsStyleUnion& aValue, nsStyleUnit aUnit)
  : mUnit(eStyleUnit_Null)
{
  InitWithValue(mUnit, mValue, aUnit, aValue);
}

inline bool nsStyleCoord::operator!=(const nsStyleCoord& aOther) const
{
  return !((*this) == aOther);
}

inline nscoord nsStyleCoord::GetCoordValue() const
{
  NS_ASSERTION((mUnit == eStyleUnit_Coord), "not a coord value");
  if (mUnit == eStyleUnit_Coord) {
    return mValue.mInt;
  }
  return 0;
}

inline int32_t nsStyleCoord::GetIntValue() const
{
  NS_ASSERTION((mUnit == eStyleUnit_Enumerated) ||
               (mUnit == eStyleUnit_Integer), "not an int value");
  if ((mUnit == eStyleUnit_Enumerated) ||
      (mUnit == eStyleUnit_Integer)) {
    return mValue.mInt;
  }
  return 0;
}

inline float nsStyleCoord::GetPercentValue() const
{
  NS_ASSERTION(mUnit == eStyleUnit_Percent, "not a percent value");
  if (mUnit == eStyleUnit_Percent) {
    return mValue.mFloat;
  }
  return 0.0f;
}

inline float nsStyleCoord::GetFactorValue() const
{
  NS_ASSERTION(mUnit == eStyleUnit_Factor, "not a factor value");
  if (mUnit == eStyleUnit_Factor) {
    return mValue.mFloat;
  }
  return 0.0f;
}

inline float nsStyleCoord::GetFactorOrPercentValue() const
{
  NS_ASSERTION(mUnit == eStyleUnit_Factor || mUnit == eStyleUnit_Percent,
               "not a percent or factor value");
  if (mUnit == eStyleUnit_Factor || mUnit == eStyleUnit_Percent) {
    return mValue.mFloat;
  }
  return 0.0f;
}

inline float nsStyleCoord::GetAngleValue() const
{
  NS_ASSERTION(mUnit >= eStyleUnit_Degree &&
               mUnit <= eStyleUnit_Turn, "not an angle value");
  if (mUnit >= eStyleUnit_Degree && mUnit <= eStyleUnit_Turn) {
    return mValue.mFloat;
  }
  return 0.0f;
}

inline float nsStyleCoord::GetFlexFractionValue() const
{
  NS_ASSERTION(mUnit == eStyleUnit_FlexFraction, "not a fr value");
  if (mUnit == eStyleUnit_FlexFraction) {
    return mValue.mFloat;
  }
  return 0.0f;
}

inline nsStyleCoord::Calc* nsStyleCoord::GetCalcValue() const
{
  NS_ASSERTION(IsCalcUnit(), "not a pointer value");
  if (IsCalcUnit()) {
    return AsCalcValue(mValue);
  }
  return nullptr;
}

/* static */ inline void
nsStyleCoord::Reset(nsStyleUnit& aUnit, nsStyleUnion& aValue)
{
  MOZ_ASSERT(aUnit <= eStyleUnit_MAX,
             "calling Reset on uninitialized nsStyleCoord?");

  switch (aUnit) {
    case eStyleUnit_Calc:
      static_cast<Calc*>(aValue.mPointer)->Release();
      break;
    default:
      MOZ_ASSERT(!IsPointerUnit(aUnit), "check pointer refcounting logic");
  }

  aUnit = eStyleUnit_Null;
  aValue.mInt = 0;
}

/* static */ inline void
nsStyleCoord::SetValue(nsStyleUnit& aUnit,
                       nsStyleUnion& aValue,
                       nsStyleUnit aOtherUnit,
                       const nsStyleUnion& aOtherValue)
{
  Reset(aUnit, aValue);
  InitWithValue(aUnit, aValue, aOtherUnit, aOtherValue);
}

/* static */ inline void
nsStyleCoord::InitWithValue(nsStyleUnit& aUnit,
                            nsStyleUnion& aValue,
                            nsStyleUnit aOtherUnit,
                            const nsStyleUnion& aOtherValue)
{
  aUnit = aOtherUnit;
  aValue = aOtherValue;

  switch (aUnit) {
    case eStyleUnit_Calc:
      static_cast<Calc*>(aValue.mPointer)->AddRef();
      break;
    default:
      MOZ_ASSERT(!IsPointerUnit(aUnit), "check pointer refcounting logic");
  }
}

/* static */ inline void
nsStyleCoord::SetValue(nsStyleUnit& aUnit, nsStyleUnion& aValue,
                       const nsStyleCoord& aOther)
{
  SetValue(aUnit, aValue, aOther.mUnit, aOther.mValue);
}

/* static */ inline void
nsStyleCoord::InitWithValue(nsStyleUnit& aUnit, nsStyleUnion& aValue,
                            const nsStyleCoord& aOther)
{
  InitWithValue(aUnit, aValue, aOther.mUnit, aOther.mValue);
}


// -------------------------
// nsStyleSides inlines
//
inline bool nsStyleSides::operator!=(const nsStyleSides& aOther) const
{
  return !((*this) == aOther);
}

inline nsStyleUnit nsStyleSides::GetUnit(mozilla::Side aSide) const
{
  return (nsStyleUnit)mUnits[aSide];
}

inline nsStyleUnit nsStyleSides::GetLeftUnit() const
{
  return GetUnit(mozilla::eSideLeft);
}

inline nsStyleUnit nsStyleSides::GetTopUnit() const
{
  return GetUnit(mozilla::eSideTop);
}

inline nsStyleUnit nsStyleSides::GetRightUnit() const
{
  return GetUnit(mozilla::eSideRight);
}

inline nsStyleUnit nsStyleSides::GetBottomUnit() const
{
  return GetUnit(mozilla::eSideBottom);
}

inline nsStyleCoord nsStyleSides::Get(mozilla::Side aSide) const
{
  return nsStyleCoord(mValues[aSide], nsStyleUnit(mUnits[aSide]));
}

inline nsStyleCoord nsStyleSides::GetLeft() const
{
  return Get(mozilla::eSideLeft);
}

inline nsStyleCoord nsStyleSides::GetTop() const
{
  return Get(mozilla::eSideTop);
}

inline nsStyleCoord nsStyleSides::GetRight() const
{
  return Get(mozilla::eSideRight);
}

inline nsStyleCoord nsStyleSides::GetBottom() const
{
  return Get(mozilla::eSideBottom);
}

inline void nsStyleSides::Set(mozilla::Side aSide, const nsStyleCoord& aCoord)
{
  nsStyleCoord::SetValue(mUnits[aSide], mValues[aSide], aCoord);
}

inline void nsStyleSides::SetLeft(const nsStyleCoord& aCoord)
{
  Set(mozilla::eSideLeft, aCoord);
}

inline void nsStyleSides::SetTop(const nsStyleCoord& aCoord)
{
  Set(mozilla::eSideTop, aCoord);
}

inline void nsStyleSides::SetRight(const nsStyleCoord& aCoord)
{
  Set(mozilla::eSideRight, aCoord);
}

inline void nsStyleSides::SetBottom(const nsStyleCoord& aCoord)
{
  Set(mozilla::eSideBottom, aCoord);
}

// -------------------------
// nsStyleCorners inlines
//
inline bool nsStyleCorners::operator!=(const nsStyleCorners& aOther) const
{
  return !((*this) == aOther);
}

inline nsStyleUnit nsStyleCorners::GetUnit(uint8_t aCorner) const
{
  return (nsStyleUnit)mUnits[aCorner];
}

inline nsStyleCoord nsStyleCorners::Get(uint8_t aCorner) const
{
  return nsStyleCoord(mValues[aCorner], nsStyleUnit(mUnits[aCorner]));
}

inline void nsStyleCorners::Set(uint8_t aCorner, const nsStyleCoord& aCoord)
{
  nsStyleCoord::SetValue(mUnits[aCorner], mValues[aCorner], aCoord);
}

#endif /* nsStyleCoord_h___ */