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      1 /*
      2  * (C) 1999-2003 Lars Knoll (knoll (at) kde.org)
      3  * Copyright (C) 2004, 2005, 2006, 2008 Apple Inc. All rights reserved.
      4  * Copyright (C) 2007 Alexey Proskuryakov <ap (at) webkit.org>
      5  *
      6  * This library is free software; you can redistribute it and/or
      7  * modify it under the terms of the GNU Library General Public
      8  * License as published by the Free Software Foundation; either
      9  * version 2 of the License, or (at your option) any later version.
     10  *
     11  * This library is distributed in the hope that it will be useful,
     12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14  * Library General Public License for more details.
     15  *
     16  * You should have received a copy of the GNU Library General Public License
     17  * along with this library; see the file COPYING.LIB.  If not, write to
     18  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     19  * Boston, MA 02110-1301, USA.
     20  */
     21 
     22 #ifndef CSSPrimitiveValue_h
     23 #define CSSPrimitiveValue_h
     24 
     25 #include "core/CSSPropertyNames.h"
     26 #include "core/CSSValueKeywords.h"
     27 #include "core/css/CSSValue.h"
     28 #include "platform/graphics/Color.h"
     29 #include "wtf/Forward.h"
     30 #include "wtf/MathExtras.h"
     31 #include "wtf/PassRefPtr.h"
     32 
     33 namespace WebCore {
     34 
     35 class CSSBasicShape;
     36 class CSSCalcValue;
     37 class CSSToLengthConversionData;
     38 class Counter;
     39 class ExceptionState;
     40 class Length;
     41 class LengthSize;
     42 class Pair;
     43 class Quad;
     44 class RGBColor;
     45 class Rect;
     46 class RenderStyle;
     47 
     48 // Dimension calculations are imprecise, often resulting in values of e.g.
     49 // 44.99998. We need to go ahead and round if we're really close to the next
     50 // integer value.
     51 template<typename T> inline T roundForImpreciseConversion(double value)
     52 {
     53     value += (value < 0) ? -0.01 : +0.01;
     54     return ((value > std::numeric_limits<T>::max()) || (value < std::numeric_limits<T>::min())) ? 0 : static_cast<T>(value);
     55 }
     56 
     57 template<> inline float roundForImpreciseConversion(double value)
     58 {
     59     double ceiledValue = ceil(value);
     60     double proximityToNextInt = ceiledValue - value;
     61     if (proximityToNextInt <= 0.01 && value > 0)
     62         return static_cast<float>(ceiledValue);
     63     if (proximityToNextInt >= 0.99 && value < 0)
     64         return static_cast<float>(floor(value));
     65     return static_cast<float>(value);
     66 }
     67 
     68 // CSSPrimitiveValues are immutable. This class has manual ref-counting
     69 // of unioned types and does not have the code necessary
     70 // to handle any kind of mutations. All DOM-exposed "setters" just throw
     71 // exceptions.
     72 class CSSPrimitiveValue : public CSSValue {
     73 public:
     74     enum UnitType {
     75         CSS_UNKNOWN = 0,
     76         CSS_NUMBER = 1,
     77         CSS_PERCENTAGE = 2,
     78         CSS_EMS = 3,
     79         CSS_EXS = 4,
     80         CSS_PX = 5,
     81         CSS_CM = 6,
     82         CSS_MM = 7,
     83         CSS_IN = 8,
     84         CSS_PT = 9,
     85         CSS_PC = 10,
     86         CSS_DEG = 11,
     87         CSS_RAD = 12,
     88         CSS_GRAD = 13,
     89         CSS_MS = 14,
     90         CSS_S = 15,
     91         CSS_HZ = 16,
     92         CSS_KHZ = 17,
     93         CSS_DIMENSION = 18,
     94         CSS_STRING = 19,
     95         CSS_URI = 20,
     96         CSS_IDENT = 21,
     97         CSS_ATTR = 22,
     98         CSS_COUNTER = 23,
     99         CSS_RECT = 24,
    100         CSS_RGBCOLOR = 25,
    101         // From CSS Values and Units. Viewport-percentage Lengths (vw/vh/vmin/vmax).
    102         CSS_VW = 26,
    103         CSS_VH = 27,
    104         CSS_VMIN = 28,
    105         CSS_VMAX = 29,
    106         CSS_DPPX = 30,
    107         CSS_DPI = 31,
    108         CSS_DPCM = 32,
    109         CSS_FR = 33,
    110         CSS_PAIR = 100, // We envision this being exposed as a means of getting computed style values for pairs (border-spacing/radius, background-position, etc.)
    111         CSS_UNICODE_RANGE = 102,
    112 
    113         // These next types are just used internally to allow us to translate back and forth from CSSPrimitiveValues to CSSParserValues.
    114         CSS_PARSER_OPERATOR = 103,
    115         CSS_PARSER_INTEGER = 104,
    116         CSS_PARSER_HEXCOLOR = 105,
    117 
    118         // This is used internally for unknown identifiers
    119         CSS_PARSER_IDENTIFIER = 106,
    120 
    121         // These are from CSS3 Values and Units, but that isn't a finished standard yet
    122         CSS_TURN = 107,
    123         CSS_REMS = 108,
    124         CSS_CHS = 109,
    125 
    126         // This is used internally for counter names (as opposed to counter values)
    127         CSS_COUNTER_NAME = 110,
    128 
    129         // This is used by the CSS Shapes draft
    130         CSS_SHAPE = 111,
    131 
    132         // Used by border images.
    133         CSS_QUAD = 112,
    134 
    135         CSS_CALC = 113,
    136         CSS_CALC_PERCENTAGE_WITH_NUMBER = 114,
    137         CSS_CALC_PERCENTAGE_WITH_LENGTH = 115,
    138 
    139         CSS_PROPERTY_ID = 117,
    140         CSS_VALUE_ID = 118
    141     };
    142 
    143     enum LengthUnitType {
    144         UnitTypePixels = 0,
    145         UnitTypePercentage,
    146         UnitTypeFontSize,
    147         UnitTypeFontXSize,
    148         UnitTypeRootFontSize,
    149         UnitTypeZeroCharacterWidth,
    150         UnitTypeViewportWidth,
    151         UnitTypeViewportHeight,
    152         UnitTypeViewportMin,
    153         UnitTypeViewportMax,
    154 
    155         // This value must come after the last length unit type to enable iteration over the length unit types.
    156         LengthUnitTypeCount,
    157     };
    158 
    159     typedef Vector<double, CSSPrimitiveValue::LengthUnitTypeCount> CSSLengthArray;
    160     void accumulateLengthArray(CSSLengthArray&, double multiplier = 1) const;
    161 
    162     // This enum follows the BisonCSSParser::Units enum augmented with UNIT_FREQUENCY for frequencies.
    163     enum UnitCategory {
    164         UNumber,
    165         UPercent,
    166         ULength,
    167         UAngle,
    168         UTime,
    169         UFrequency,
    170         UResolution,
    171         UOther
    172     };
    173     static UnitCategory unitCategory(UnitType);
    174 
    175     static UnitType fromName(const String& unit);
    176 
    177     bool isAngle() const
    178     {
    179         return m_primitiveUnitType == CSS_DEG
    180                || m_primitiveUnitType == CSS_RAD
    181                || m_primitiveUnitType == CSS_GRAD
    182                || m_primitiveUnitType == CSS_TURN;
    183     }
    184     bool isAttr() const { return m_primitiveUnitType == CSS_ATTR; }
    185     bool isCounter() const { return m_primitiveUnitType == CSS_COUNTER; }
    186     bool isFontIndependentLength() const { return m_primitiveUnitType >= CSS_PX && m_primitiveUnitType <= CSS_PC; }
    187     bool isFontRelativeLength() const
    188     {
    189         return m_primitiveUnitType == CSS_EMS
    190             || m_primitiveUnitType == CSS_EXS
    191             || m_primitiveUnitType == CSS_REMS
    192             || m_primitiveUnitType == CSS_CHS;
    193     }
    194     bool isViewportPercentageLength() const { return isViewportPercentageLength(static_cast<UnitType>(m_primitiveUnitType)); }
    195     static bool isViewportPercentageLength(UnitType type) { return type >= CSS_VW && type <= CSS_VMAX; }
    196     static bool isLength(UnitType type)
    197     {
    198         return (type >= CSS_EMS && type <= CSS_PC) || type == CSS_REMS || type == CSS_CHS || isViewportPercentageLength(type);
    199     }
    200     bool isLength() const { return isLength(primitiveType()); }
    201     bool isNumber() const { return primitiveType() == CSS_NUMBER; }
    202     bool isPercentage() const { return primitiveType() == CSS_PERCENTAGE; }
    203     bool isPx() const { return primitiveType() == CSS_PX; }
    204     bool isRect() const { return m_primitiveUnitType == CSS_RECT; }
    205     bool isRGBColor() const { return m_primitiveUnitType == CSS_RGBCOLOR; }
    206     bool isShape() const { return m_primitiveUnitType == CSS_SHAPE; }
    207     bool isString() const { return m_primitiveUnitType == CSS_STRING; }
    208     bool isTime() const { return m_primitiveUnitType == CSS_S || m_primitiveUnitType == CSS_MS; }
    209     bool isURI() const { return m_primitiveUnitType == CSS_URI; }
    210     bool isCalculated() const { return m_primitiveUnitType == CSS_CALC; }
    211     bool isCalculatedPercentageWithNumber() const { return primitiveType() == CSS_CALC_PERCENTAGE_WITH_NUMBER; }
    212     bool isCalculatedPercentageWithLength() const { return primitiveType() == CSS_CALC_PERCENTAGE_WITH_LENGTH; }
    213     static bool isDotsPerInch(UnitType type) { return type == CSS_DPI; }
    214     static bool isDotsPerPixel(UnitType type) { return type == CSS_DPPX; }
    215     static bool isDotsPerCentimeter(UnitType type) { return type == CSS_DPCM; }
    216     static bool isResolution(UnitType type) { return type >= CSS_DPPX && type <= CSS_DPCM; }
    217     bool isFlex() const { return primitiveType() == CSS_FR; }
    218     bool isValueID() const { return m_primitiveUnitType == CSS_VALUE_ID; }
    219     bool colorIsDerivedFromElement() const;
    220 
    221     static PassRefPtrWillBeRawPtr<CSSPrimitiveValue> createIdentifier(CSSValueID valueID)
    222     {
    223         return adoptRefWillBeNoop(new CSSPrimitiveValue(valueID));
    224     }
    225     static PassRefPtrWillBeRawPtr<CSSPrimitiveValue> createIdentifier(CSSPropertyID propertyID)
    226     {
    227         return adoptRefWillBeNoop(new CSSPrimitiveValue(propertyID));
    228     }
    229     static PassRefPtrWillBeRawPtr<CSSPrimitiveValue> createParserOperator(int parserOperator)
    230     {
    231         return adoptRefWillBeNoop(new CSSPrimitiveValue(parserOperator, CSS_PARSER_OPERATOR));
    232     }
    233     static PassRefPtrWillBeRawPtr<CSSPrimitiveValue> createColor(unsigned rgbValue)
    234     {
    235         return adoptRefWillBeNoop(new CSSPrimitiveValue(rgbValue, CSS_RGBCOLOR));
    236     }
    237     static PassRefPtrWillBeRawPtr<CSSPrimitiveValue> create(double value, UnitType type)
    238     {
    239         return adoptRefWillBeNoop(new CSSPrimitiveValue(value, type));
    240     }
    241     static PassRefPtrWillBeRawPtr<CSSPrimitiveValue> create(const String& value, UnitType type)
    242     {
    243         return adoptRefWillBeNoop(new CSSPrimitiveValue(value, type));
    244     }
    245     static PassRefPtrWillBeRawPtr<CSSPrimitiveValue> create(const Length& value, float zoom)
    246     {
    247         return adoptRefWillBeNoop(new CSSPrimitiveValue(value, zoom));
    248     }
    249     static PassRefPtrWillBeRawPtr<CSSPrimitiveValue> create(const LengthSize& value, const RenderStyle& style)
    250     {
    251         return adoptRefWillBeNoop(new CSSPrimitiveValue(value, style));
    252     }
    253     template<typename T> static PassRefPtrWillBeRawPtr<CSSPrimitiveValue> create(T value)
    254     {
    255         return adoptRefWillBeNoop(new CSSPrimitiveValue(value));
    256     }
    257 
    258     // This value is used to handle quirky margins in reflow roots (body, td, and th) like WinIE.
    259     // The basic idea is that a stylesheet can use the value __qem (for quirky em) instead of em.
    260     // When the quirky value is used, if you're in quirks mode, the margin will collapse away
    261     // inside a table cell.
    262     static PassRefPtrWillBeRawPtr<CSSPrimitiveValue> createAllowingMarginQuirk(double value, UnitType type)
    263     {
    264         CSSPrimitiveValue* quirkValue = new CSSPrimitiveValue(value, type);
    265         quirkValue->m_isQuirkValue = true;
    266         return adoptRefWillBeNoop(quirkValue);
    267     }
    268 
    269     ~CSSPrimitiveValue();
    270 
    271     void cleanup();
    272 
    273     UnitType primitiveType() const;
    274 
    275     double computeDegrees();
    276 
    277     enum TimeUnit { Seconds, Milliseconds };
    278     template <typename T, TimeUnit timeUnit> T computeTime()
    279     {
    280         if (timeUnit == Seconds && m_primitiveUnitType == CSS_S)
    281             return getValue<T>();
    282         if (timeUnit == Seconds && m_primitiveUnitType == CSS_MS)
    283             return getValue<T>() / 1000;
    284         if (timeUnit == Milliseconds && m_primitiveUnitType == CSS_MS)
    285             return getValue<T>();
    286         if (timeUnit == Milliseconds && m_primitiveUnitType == CSS_S)
    287             return getValue<T>() * 1000;
    288         ASSERT_NOT_REACHED();
    289         return 0;
    290     }
    291 
    292     /*
    293      * Computes a length in pixels out of the given CSSValue
    294      *
    295      * The metrics have to be a bit different for screen and printer output.
    296      * For screen output we assume 1 inch == 72 px, for printer we assume 300 dpi
    297      *
    298      * this is screen/printer dependent, so we probably need a config option for this,
    299      * and some tool to calibrate.
    300      */
    301     template<typename T> T computeLength(const CSSToLengthConversionData&);
    302 
    303     // Converts to a Length, mapping various unit types appropriately.
    304     template<int> Length convertToLength(const CSSToLengthConversionData&);
    305 
    306     double getDoubleValue(UnitType, ExceptionState&) const;
    307     double getDoubleValue(UnitType) const;
    308     double getDoubleValue() const;
    309 
    310     // setFloatValue(..., ExceptionState&) and setStringValue() must use unsigned short instead of UnitType to match IDL bindings.
    311     void setFloatValue(unsigned short unitType, double floatValue, ExceptionState&);
    312     float getFloatValue(unsigned short unitType, ExceptionState& exceptionState) const { return getValue<float>(static_cast<UnitType>(unitType), exceptionState); }
    313     float getFloatValue(UnitType type) const { return getValue<float>(type); }
    314     float getFloatValue() const { return getValue<float>(); }
    315 
    316     int getIntValue(UnitType type, ExceptionState& exceptionState) const { return getValue<int>(type, exceptionState); }
    317     int getIntValue(UnitType type) const { return getValue<int>(type); }
    318     int getIntValue() const { return getValue<int>(); }
    319 
    320     template<typename T> inline T getValue(UnitType type, ExceptionState& exceptionState) const { return clampTo<T>(getDoubleValue(type, exceptionState)); }
    321     template<typename T> inline T getValue(UnitType type) const { return clampTo<T>(getDoubleValue(type)); }
    322     template<typename T> inline T getValue() const { return clampTo<T>(getDoubleValue()); }
    323 
    324     void setStringValue(unsigned short stringType, const String& stringValue, ExceptionState&);
    325     String getStringValue(ExceptionState&) const;
    326     String getStringValue() const;
    327 
    328     Counter* getCounterValue(ExceptionState&) const;
    329     Counter* getCounterValue() const { return m_primitiveUnitType != CSS_COUNTER ? 0 : m_value.counter; }
    330 
    331     Rect* getRectValue(ExceptionState&) const;
    332     Rect* getRectValue() const { return m_primitiveUnitType != CSS_RECT ? 0 : m_value.rect; }
    333 
    334     Quad* getQuadValue(ExceptionState&) const;
    335     Quad* getQuadValue() const { return m_primitiveUnitType != CSS_QUAD ? 0 : m_value.quad; }
    336 
    337     PassRefPtrWillBeRawPtr<RGBColor> getRGBColorValue(ExceptionState&) const;
    338     RGBA32 getRGBA32Value() const { return m_primitiveUnitType != CSS_RGBCOLOR ? 0 : m_value.rgbcolor; }
    339 
    340     Pair* getPairValue(ExceptionState&) const;
    341     Pair* getPairValue() const { return m_primitiveUnitType != CSS_PAIR ? 0 : m_value.pair; }
    342 
    343     CSSBasicShape* getShapeValue() const { return m_primitiveUnitType != CSS_SHAPE ? 0 : m_value.shape; }
    344 
    345     CSSCalcValue* cssCalcValue() const { return m_primitiveUnitType != CSS_CALC ? 0 : m_value.calc; }
    346 
    347     CSSPropertyID getPropertyID() const { return m_primitiveUnitType == CSS_PROPERTY_ID ? m_value.propertyID : CSSPropertyInvalid; }
    348     CSSValueID getValueID() const { return m_primitiveUnitType == CSS_VALUE_ID ? m_value.valueID : CSSValueInvalid; }
    349 
    350     template<typename T> inline operator T() const; // Defined in CSSPrimitiveValueMappings.h
    351 
    352     static const char* unitTypeToString(UnitType);
    353     String customCSSText(CSSTextFormattingFlags = QuoteCSSStringIfNeeded) const;
    354 
    355     bool isQuirkValue() { return m_isQuirkValue; }
    356 
    357     PassRefPtrWillBeRawPtr<CSSPrimitiveValue> cloneForCSSOM() const;
    358     void setCSSOMSafe() { m_isCSSOMSafe = true; }
    359 
    360     bool equals(const CSSPrimitiveValue&) const;
    361 
    362     void traceAfterDispatch(Visitor*);
    363 
    364     static UnitType canonicalUnitTypeForCategory(UnitCategory);
    365     static double conversionToCanonicalUnitsScaleFactor(UnitType);
    366 
    367     // Returns true and populates lengthUnitType, if unitType is a length unit. Otherwise, returns false.
    368     static bool unitTypeToLengthUnitType(UnitType, LengthUnitType&);
    369     static UnitType lengthUnitTypeToUnitType(LengthUnitType);
    370 
    371 private:
    372     CSSPrimitiveValue(CSSValueID);
    373     CSSPrimitiveValue(CSSPropertyID);
    374     // int vs. unsigned is too subtle to distinguish types, so require a UnitType.
    375     CSSPrimitiveValue(int parserOperator, UnitType);
    376     CSSPrimitiveValue(unsigned color, UnitType); // RGB value
    377     CSSPrimitiveValue(const Length&, float zoom);
    378     CSSPrimitiveValue(const LengthSize&, const RenderStyle&);
    379     CSSPrimitiveValue(const String&, UnitType);
    380     CSSPrimitiveValue(double, UnitType);
    381 
    382     template<typename T> CSSPrimitiveValue(T); // Defined in CSSPrimitiveValueMappings.h
    383     template<typename T> CSSPrimitiveValue(T* val)
    384         : CSSValue(PrimitiveClass)
    385     {
    386         init(PassRefPtrWillBeRawPtr<T>(val));
    387     }
    388 
    389     template<typename T> CSSPrimitiveValue(PassRefPtrWillBeRawPtr<T> val)
    390         : CSSValue(PrimitiveClass)
    391     {
    392         init(val);
    393     }
    394 
    395     static void create(int); // compile-time guard
    396     static void create(unsigned); // compile-time guard
    397     template<typename T> operator T*(); // compile-time guard
    398 
    399     void init(const Length&);
    400     void init(const LengthSize&, const RenderStyle&);
    401     void init(PassRefPtrWillBeRawPtr<Counter>);
    402     void init(PassRefPtrWillBeRawPtr<Rect>);
    403     void init(PassRefPtrWillBeRawPtr<Pair>);
    404     void init(PassRefPtrWillBeRawPtr<Quad>);
    405     void init(PassRefPtrWillBeRawPtr<CSSBasicShape>);
    406     void init(PassRefPtrWillBeRawPtr<CSSCalcValue>);
    407     bool getDoubleValueInternal(UnitType targetUnitType, double* result) const;
    408 
    409     double computeLengthDouble(const CSSToLengthConversionData&);
    410 
    411     union {
    412         CSSPropertyID propertyID;
    413         CSSValueID valueID;
    414         int parserOperator;
    415         double num;
    416         StringImpl* string;
    417         unsigned rgbcolor;
    418         // FIXME: oilpan: Should be members, but no support for members in unions. Just trace the raw ptr for now.
    419         CSSBasicShape* shape;
    420         CSSCalcValue* calc;
    421         Counter* counter;
    422         Pair* pair;
    423         Rect* rect;
    424         Quad* quad;
    425     } m_value;
    426 };
    427 
    428 typedef CSSPrimitiveValue::CSSLengthArray CSSLengthArray;
    429 
    430 DEFINE_CSS_VALUE_TYPE_CASTS(CSSPrimitiveValue, isPrimitiveValue());
    431 
    432 } // namespace WebCore
    433 
    434 #endif // CSSPrimitiveValue_h
    435