diff -r 000000000000 -r 6474c204b198 layout/style/nsStyleCoord.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/style/nsStyleCoord.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,438 @@
+/* -*- 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"
+
+enum nsStyleUnit {
+  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 allocated types.  They are weak pointers to
+  // values allocated by nsStyleContext::Alloc.
+  eStyleUnit_Calc         = 40      // (Calc*) calc() toplevel; always present
+                                    // to distinguish 50% from calc(50%), etc.
+};
+
+typedef union {
+  int32_t     mInt;   // nscoord is a int32_t for now
+  float       mFloat;
+  // An mPointer is a weak pointer to a value that is guaranteed to
+  // outlive the nsStyleCoord.  In the case of nsStyleCoord::Calc*, it
+  // is a pointer owned by the style context, allocated through
+  // nsStyleContext::Alloc (and, therefore, is never stored in the rule
+  // tree).
+  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.
+ */
+class nsStyleCoord {
+public:
+  struct Calc {
+    // 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 Calc& aOther) const {
+      return mLength == aOther.mLength &&
+             mPercent == aOther.mPercent &&
+             mHasPercent == aOther.mHasPercent;
+    }
+    bool operator!=(const Calc& aOther) const { return !(*this == aOther); }
+  };
+
+  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&  operator=(const nsStyleCoord& aOther)
+  {
+    mUnit = aOther.mUnit;
+    mValue = aOther.mValue;
+    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;
+  }
+
+  bool IsCalcUnit() const {
+    return eStyleUnit_Calc == mUnit;
+  }
+
+  bool IsPointerValue() const {
+    return IsCalcUnit();
+  }
+
+  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());
+  }
+
+  bool ConvertsToLength() const {
+    return mUnit == eStyleUnit_Coord ||
+           (IsCalcUnit() && !CalcHasPercent());
+  }
+
+  nscoord     GetCoordValue() const;
+  int32_t     GetIntValue() const;
+  float       GetPercentValue() const;
+  float       GetFactorValue() const;
+  float       GetAngleValue() const;
+  double      GetAngleValueInRadians() const;
+  float       GetFlexFractionValue() const;
+  Calc*       GetCalcValue() const;
+  void        GetUnionValue(nsStyleUnion& aValue) const;
+  uint32_t    HashValue(uint32_t aHash) const;
+
+  void  Reset();  // sets to null
+  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);
+
+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.
+ */
+class nsStyleSides {
+public:
+  nsStyleSides();
+
+//  nsStyleSides&  operator=(const nsStyleSides& aCopy);  // use compiler's version
+  bool           operator==(const nsStyleSides& aOther) const;
+  bool           operator!=(const nsStyleSides& aOther) const;
+
+  inline nsStyleUnit GetUnit(mozilla::css::Side aSide) const;
+  inline nsStyleUnit GetLeftUnit() const;
+  inline nsStyleUnit GetTopUnit() const;
+  inline nsStyleUnit GetRightUnit() const;
+  inline nsStyleUnit GetBottomUnit() const;
+
+  inline nsStyleCoord Get(mozilla::css::Side aSide) const;
+  inline nsStyleCoord GetLeft() const;
+  inline nsStyleCoord GetTop() const;
+  inline nsStyleCoord GetRight() const;
+  inline nsStyleCoord GetBottom() const;
+
+  void  Reset();
+
+  inline void Set(mozilla::css::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);
+
+protected:
+  uint8_t       mUnits[4];
+  nsStyleUnion  mValues[4];
+};
+
+/**
+ * Class that represents a set of top-left/top-right/bottom-left/bottom-right
+ * nsStyleCoord pairs.  This is used to hold the dimensions of the
+ * corners of a box (for, e.g., border-radius and outline-radius).
+ */
+class nsStyleCorners {
+public:
+  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;
+
+  void  Reset();
+
+  inline void Set(uint8_t aHalfCorner, const nsStyleCoord& aCoord);
+
+protected:
+  uint8_t       mUnits[8];
+  nsStyleUnion  mValues[8];
+};
+
+
+// -------------------------
+// nsStyleCoord inlines
+//
+inline nsStyleCoord::nsStyleCoord(nscoord aValue, CoordConstructorType)
+  : mUnit(eStyleUnit_Coord)
+{
+  mValue.mInt = aValue;
+}
+
+// FIXME: In C++0x we can rely on the default copy constructor since
+// default copy construction is defined properly for unions.  But when
+// can we actually use that?  (It seems to work in gcc 4.4.)
+inline nsStyleCoord::nsStyleCoord(const nsStyleCoord& aCopy)
+  : mUnit(aCopy.mUnit)
+{
+  if ((eStyleUnit_Percent <= mUnit) && (mUnit < eStyleUnit_Coord)) {
+    mValue.mFloat = aCopy.mValue.mFloat;
+  }
+  else if (IsPointerValue()) {
+    mValue.mPointer = aCopy.mValue.mPointer;
+  }
+  else {
+    mValue.mInt = aCopy.mValue.mInt;
+  }
+}
+
+inline nsStyleCoord::nsStyleCoord(const nsStyleUnion& aValue, nsStyleUnit aUnit)
+  : mUnit(aUnit), mValue(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::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 static_cast<Calc*>(mValue.mPointer);
+  }
+  return nullptr;
+}
+
+
+inline void nsStyleCoord::GetUnionValue(nsStyleUnion& aValue) const
+{
+  aValue = mValue;
+}
+
+// -------------------------
+// nsStyleSides inlines
+//
+inline bool nsStyleSides::operator!=(const nsStyleSides& aOther) const
+{
+  return !((*this) == aOther);
+}
+
+inline nsStyleUnit nsStyleSides::GetUnit(mozilla::css::Side aSide) const
+{
+  return (nsStyleUnit)mUnits[aSide];
+}
+
+inline nsStyleUnit nsStyleSides::GetLeftUnit() const
+{
+  return GetUnit(NS_SIDE_LEFT);
+}
+
+inline nsStyleUnit nsStyleSides::GetTopUnit() const
+{
+  return GetUnit(NS_SIDE_TOP);
+}
+
+inline nsStyleUnit nsStyleSides::GetRightUnit() const
+{
+  return GetUnit(NS_SIDE_RIGHT);
+}
+
+inline nsStyleUnit nsStyleSides::GetBottomUnit() const
+{
+  return GetUnit(NS_SIDE_BOTTOM);
+}
+
+inline nsStyleCoord nsStyleSides::Get(mozilla::css::Side aSide) const
+{
+  return nsStyleCoord(mValues[aSide], nsStyleUnit(mUnits[aSide]));
+}
+
+inline nsStyleCoord nsStyleSides::GetLeft() const
+{
+  return Get(NS_SIDE_LEFT);
+}
+
+inline nsStyleCoord nsStyleSides::GetTop() const
+{
+  return Get(NS_SIDE_TOP);
+}
+
+inline nsStyleCoord nsStyleSides::GetRight() const
+{
+  return Get(NS_SIDE_RIGHT);
+}
+
+inline nsStyleCoord nsStyleSides::GetBottom() const
+{
+  return Get(NS_SIDE_BOTTOM);
+}
+
+inline void nsStyleSides::Set(mozilla::css::Side aSide, const nsStyleCoord& aCoord)
+{
+  mUnits[aSide] = aCoord.GetUnit();
+  aCoord.GetUnionValue(mValues[aSide]);
+}
+
+inline void nsStyleSides::SetLeft(const nsStyleCoord& aCoord)
+{
+  Set(NS_SIDE_LEFT, aCoord);
+}
+
+inline void nsStyleSides::SetTop(const nsStyleCoord& aCoord)
+{
+  Set(NS_SIDE_TOP, aCoord);
+}
+
+inline void nsStyleSides::SetRight(const nsStyleCoord& aCoord)
+{
+  Set(NS_SIDE_RIGHT, aCoord);
+}
+
+inline void nsStyleSides::SetBottom(const nsStyleCoord& aCoord)
+{
+  Set(NS_SIDE_BOTTOM, 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)
+{
+  mUnits[aCorner] = aCoord.GetUnit();
+  aCoord.GetUnionValue(mValues[aCorner]);
+}
+
+#endif /* nsStyleCoord_h___ */