layout/style/nsStyleCoord.h

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  37
  38 /* representation of length values in computed style data */
  39
  40 #ifndef nsStyleCoord_h___
  41 #define nsStyleCoord_h___
  42
  43 #include "nscore.h"
  44 #include "nsCoord.h"
  45 #include "nsCRT.h"
  46 #include "nsStyleConsts.h"
  47 class nsString;
  48
  49 enum nsStyleUnit {
  50   eStyleUnit_Null         = 0,      // (no value) value is not specified
  51   eStyleUnit_Normal       = 1,      // (no value)
  52   eStyleUnit_Auto         = 2,      // (no value)
  53   eStyleUnit_None         = 3,      // (no value)
  54   eStyleUnit_Percent      = 10,     // (float) 1.0 == 100%
  55   eStyleUnit_Factor       = 11,     // (float) a multiplier
  56   eStyleUnit_Coord        = 20,     // (nscoord) value is twips
  57   eStyleUnit_Integer      = 30,     // (int) value is simple integer
  58   eStyleUnit_Enumerated   = 32      // (int) value has enumerated meaning
  59 };
  60
  61 typedef union {
  62   PRInt32     mInt;   // nscoord is a PRInt32 for now
  63   float       mFloat;
  64 } nsStyleUnion;
  65
  66 /**
  67  * Class that hold a single size specification used by the style
  68  * system.  The size specification consists of two parts -- a number
  69  * and a unit.  The number is an integer, a floating point value, an
  70  * nscoord, or undefined, and the unit is an nsStyleUnit.  Checking
  71  * the unit is a must before asking for the value in any particular
  72  * form.
  73  */
  74 class nsStyleCoord {
  75 public:
  76   nsStyleCoord(nsStyleUnit aUnit = eStyleUnit_Null);
  77   nsStyleCoord(nscoord aValue);
  78   nsStyleCoord(PRInt32 aValue, nsStyleUnit aUnit);
  79   nsStyleCoord(float aValue, nsStyleUnit aUnit);
  80   inline nsStyleCoord(const nsStyleCoord& aCopy);
  81   inline nsStyleCoord(const nsStyleUnion& aValue, nsStyleUnit aUnit);
  82
  83   nsStyleCoord&  operator=(const nsStyleCoord& aCopy);
  84   PRBool         operator==(const nsStyleCoord& aOther) const;
  85   PRBool         operator!=(const nsStyleCoord& aOther) const;
  86
  87   nsStyleUnit GetUnit(void) const {
  88     NS_ASSERTION(mUnit != eStyleUnit_Null, "reading uninitialized value");
  89     return mUnit;
  90   }
  91   nscoord     GetCoordValue(void) const;
  92   PRInt32     GetIntValue(void) const;
  93   float       GetPercentValue(void) const;
  94   float       GetFactorValue(void) const;
  95   void        GetUnionValue(nsStyleUnion& aValue) const;
  96
  97   void  Reset(void);  // sets to null
  98   void  SetCoordValue(nscoord aValue);
  99   void  SetIntValue(PRInt32 aValue, nsStyleUnit aUnit);
 100   void  SetPercentValue(float aValue);
 101   void  SetFactorValue(float aValue);
 102   void  SetNormalValue(void);
 103   void  SetAutoValue(void);
 104   void  SetNoneValue(void);
 105
 106   void  AppendToString(nsString& aBuffer) const;
 107   void  ToString(nsString& aBuffer) const;
 108
 109 public:
 110   nsStyleUnit   mUnit;
 111   nsStyleUnion  mValue;
 112 };
 113
 114
 115 /**
 116  * Class that represents a set of top/right/bottom/left nsStyleCoords.
 117  * This is commonly used to hold the widths of the borders, margins,
 118  * or paddings of a box.
 119  */
 120 class nsStyleSides {
 121 public:
 122   nsStyleSides(void);
 123
 124 //  nsStyleSides&  operator=(const nsStyleSides& aCopy);  // use compiler's version
 125   PRBool         operator==(const nsStyleSides& aOther) const;
 126   PRBool         operator!=(const nsStyleSides& aOther) const;
 127
 128   // aSide is always one of NS_SIDE_* defined in nsStyleConsts.h
 129
 130   inline nsStyleUnit GetUnit(PRUint8 aSide) const;
 131   inline nsStyleUnit GetLeftUnit(void) const;
 132   inline nsStyleUnit GetTopUnit(void) const;
 133   inline nsStyleUnit GetRightUnit(void) const;
 134   inline nsStyleUnit GetBottomUnit(void) const;
 135
 136   inline nsStyleCoord Get(PRUint8 aSide) const;
 137   inline nsStyleCoord GetLeft() const;
 138   inline nsStyleCoord GetTop() const;
 139   inline nsStyleCoord GetRight() const;
 140   inline nsStyleCoord GetBottom() const;
 141
 142   void  Reset(void);
 143
 144   inline void Set(PRUint8 aSide, const nsStyleCoord& aCoord);
 145   inline void SetLeft(const nsStyleCoord& aCoord);
 146   inline void SetTop(const nsStyleCoord& aCoord);
 147   inline void SetRight(const nsStyleCoord& aCoord);
 148   inline void SetBottom(const nsStyleCoord& aCoord);
 149
 150   void  AppendToString(nsString& aBuffer) const;
 151   void  ToString(nsString& aBuffer) const;
 152
 153 protected:
 154   PRUint8       mUnits[4];
 155   nsStyleUnion  mValues[4];
 156 };
 157
 158 // -------------------------
 159 // nsStyleCoord inlines
 160 //
 161 inline nsStyleCoord::nsStyleCoord(const nsStyleCoord& aCopy)
 162   : mUnit(aCopy.mUnit)
 163 {
 164   if ((eStyleUnit_Percent <= mUnit) && (mUnit < eStyleUnit_Coord)) {
 165     mValue.mFloat = aCopy.mValue.mFloat;
 166   }
 167   else {
 168     mValue.mInt = aCopy.mValue.mInt;
 169   }
 170 }
 171
 172 inline nsStyleCoord::nsStyleCoord(const nsStyleUnion& aValue, nsStyleUnit aUnit)
 173   : mUnit(aUnit)
 174 {
 175 #if PR_BYTES_PER_INT == PR_BYTES_PER_FLOAT
 176   mValue.mInt = aValue.mInt;
 177 #else
 178   memcpy(&mValue, &aValue, sizeof(nsStyleUnion));
 179 #endif
 180 }
 181
 182 inline PRBool nsStyleCoord::operator!=(const nsStyleCoord& aOther) const
 183 {
 184   return PRBool(! ((*this) == aOther));
 185 }
 186
 187 inline PRInt32 nsStyleCoord::GetCoordValue(void) const
 188 {
 189   NS_ASSERTION((mUnit == eStyleUnit_Coord), "not a coord value");
 190   if (mUnit == eStyleUnit_Coord) {
 191     return mValue.mInt;
 192   }
 193   return 0;
 194 }
 195
 196 inline PRInt32 nsStyleCoord::GetIntValue(void) const
 197 {
 198   NS_ASSERTION((mUnit == eStyleUnit_Enumerated) ||
 199                (mUnit == eStyleUnit_Integer), "not an int value");
 200   if ((mUnit == eStyleUnit_Enumerated) ||
 201       (mUnit == eStyleUnit_Integer)) {
 202     return mValue.mInt;
 203   }
 204   return 0;
 205 }
 206
 207 inline float nsStyleCoord::GetPercentValue(void) const
 208 {
 209   NS_ASSERTION(mUnit == eStyleUnit_Percent, "not a percent value");
 210   if (mUnit == eStyleUnit_Percent) {
 211     return mValue.mFloat;
 212   }
 213   return 0.0f;
 214 }
 215
 216 inline float nsStyleCoord::GetFactorValue(void) const
 217 {
 218   NS_ASSERTION(mUnit == eStyleUnit_Factor, "not a factor value");
 219   if (mUnit == eStyleUnit_Factor) {
 220     return mValue.mFloat;
 221   }
 222   return 0.0f;
 223 }
 224
 225 inline void nsStyleCoord::GetUnionValue(nsStyleUnion& aValue) const
 226 {
 227   memcpy(&aValue, &mValue, sizeof(nsStyleUnion));
 228 }
 229
 230 // -------------------------
 231 // nsStyleSides inlines
 232 //
 233 inline PRBool nsStyleSides::operator!=(const nsStyleSides& aOther) const
 234 {
 235   return PRBool(! ((*this) == aOther));
 236 }
 237
 238 inline nsStyleUnit nsStyleSides::GetUnit(PRUint8 aSide) const
 239 {
 240   return (nsStyleUnit)mUnits[aSide];
 241 }
 242
 243 inline nsStyleUnit nsStyleSides::GetLeftUnit(void) const
 244 {
 245   return GetUnit(NS_SIDE_LEFT);
 246 }
 247
 248 inline nsStyleUnit nsStyleSides::GetTopUnit(void) const
 249 {
 250   return GetUnit(NS_SIDE_TOP);
 251 }
 252
 253 inline nsStyleUnit nsStyleSides::GetRightUnit(void) const
 254 {
 255   return GetUnit(NS_SIDE_RIGHT);
 256 }
 257
 258 inline nsStyleUnit nsStyleSides::GetBottomUnit(void) const
 259 {
 260   return GetUnit(NS_SIDE_BOTTOM);
 261 }
 262
 263 inline nsStyleCoord nsStyleSides::Get(PRUint8 aSide) const
 264 {
 265   return nsStyleCoord(mValues[aSide], nsStyleUnit(mUnits[aSide]));
 266 }
 267
 268 inline nsStyleCoord nsStyleSides::GetLeft() const
 269 {
 270   return Get(NS_SIDE_LEFT);
 271 }
 272
 273 inline nsStyleCoord nsStyleSides::GetTop() const
 274 {
 275   return Get(NS_SIDE_TOP);
 276 }
 277
 278 inline nsStyleCoord nsStyleSides::GetRight() const
 279 {
 280   return Get(NS_SIDE_RIGHT);
 281 }
 282
 283 inline nsStyleCoord nsStyleSides::GetBottom() const
 284 {
 285   return Get(NS_SIDE_BOTTOM);
 286 }
 287
 288 inline void nsStyleSides::Set(PRUint8 aSide, const nsStyleCoord& aCoord)
 289 {
 290   mUnits[aSide] = aCoord.GetUnit();
 291   aCoord.GetUnionValue(mValues[aSide]);
 292 }
 293
 294 inline void nsStyleSides::SetLeft(const nsStyleCoord& aCoord)
 295 {
 296   Set(NS_SIDE_LEFT, aCoord);
 297 }
 298
 299 inline void nsStyleSides::SetTop(const nsStyleCoord& aCoord)
 300 {
 301   Set(NS_SIDE_TOP, aCoord);
 302 }
 303
 304 inline void nsStyleSides::SetRight(const nsStyleCoord& aCoord)
 305 {
 306   Set(NS_SIDE_RIGHT, aCoord);
 307 }
 308
 309 inline void nsStyleSides::SetBottom(const nsStyleCoord& aCoord)
 310 {
 311   Set(NS_SIDE_BOTTOM, aCoord);
 312 }
 313
 314 #endif /* nsStyleCoord_h___ */