third_party/WebKit/Source/platform/Length.h

   1 /*
   2     Copyright (C) 1999 Lars Knoll (knoll@kde.org)
   3     Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
   4     Copyright (C) 2011 Rik Cabanier (cabanier@adobe.com)
   5     Copyright (C) 2011 Adobe Systems Incorporated. All rights reserved.
   6
   7     This library is free software; you can redistribute it and/or
   8     modify it under the terms of the GNU Library General Public
   9     License as published by the Free Software Foundation; either
  10     version 2 of the License, or (at your option) any later version.
  11
  12     This library is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15     Library General Public License for more details.
  16
  17     You should have received a copy of the GNU Library General Public License
  18     along with this library; see the file COPYING.LIB.  If not, write to
  19     the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20     Boston, MA 02110-1301, USA.
  21 */
  22
  23 #ifndef Length_h
  24 #define Length_h
  25
  26 #include "platform/PlatformExport.h"
  27 #include "platform/animation/AnimationUtilities.h"
  28 #include "wtf/Assertions.h"
  29 #include "wtf/FastAllocBase.h"
  30 #include "wtf/Forward.h"
  31 #include "wtf/HashMap.h"
  32 #include "wtf/MathExtras.h"
  33 #include "wtf/Vector.h"
  34 #include <cstring>
  35
  36 namespace blink {
  37
  38 // FIXME: This enum makes it hard to tell in general what values may be
  39 // appropriate for any given Length.
  40 enum LengthType {
  41     Auto, Percent, Fixed,
  42     Intrinsic, MinIntrinsic,
  43     MinContent, MaxContent, FillAvailable, FitContent,
  44     Calculated,
  45     ExtendToZoom, DeviceWidth, DeviceHeight,
  46     MaxSizeNone
  47 };
  48
  49 enum ValueRange {
  50     ValueRangeAll,
  51     ValueRangeNonNegative
  52 };
  53
  54 struct PixelsAndPercent {
  55     PixelsAndPercent(float pixels, float percent)
  56         : pixels(pixels)
  57         , percent(percent)
  58     {
  59     }
  60     float pixels;
  61     float percent;
  62 };
  63
  64 class CalculationValue;
  65
  66 class PLATFORM_EXPORT Length {
  67     WTF_MAKE_FAST_ALLOCATED(Length);
  68 public:
  69     Length()
  70         :  m_intValue(0), m_quirk(false), m_type(Auto), m_isFloat(false)
  71     {
  72     }
  73
  74     Length(LengthType t)
  75         : m_intValue(0), m_quirk(false), m_type(t), m_isFloat(false)
  76     {
  77         ASSERT(t != Calculated);
  78     }
  79
  80     Length(int v, LengthType t, bool q = false)
  81         : m_intValue(v), m_quirk(q), m_type(t), m_isFloat(false)
  82     {
  83         ASSERT(t != Calculated);
  84     }
  85
  86     Length(LayoutUnit v, LengthType t, bool q = false)
  87         : m_floatValue(v.toFloat()), m_quirk(q), m_type(t), m_isFloat(true)
  88     {
  89         ASSERT(t != Calculated);
  90     }
  91
  92     Length(float v, LengthType t, bool q = false)
  93         : m_floatValue(v), m_quirk(q), m_type(t), m_isFloat(true)
  94     {
  95         ASSERT(t != Calculated);
  96     }
  97
  98     Length(double v, LengthType t, bool q = false)
  99         : m_quirk(q), m_type(t), m_isFloat(true)
 100     {
 101         m_floatValue = static_cast<float>(v);
 102     }
 103
 104     explicit Length(PassRefPtr<CalculationValue>);
 105
 106     Length(const Length& length)
 107     {
 108         memcpy(this, &length, sizeof(Length));
 109         if (isCalculated())
 110             incrementCalculatedRef();
 111     }
 112
 113     Length& operator=(const Length& length)
 114     {
 115         if (length.isCalculated())
 116             length.incrementCalculatedRef();
 117         if (isCalculated())
 118             decrementCalculatedRef();
 119         memcpy(this, &length, sizeof(Length));
 120         return *this;
 121     }
 122
 123     ~Length()
 124     {
 125         if (isCalculated())
 126             decrementCalculatedRef();
 127     }
 128
 129     bool operator==(const Length& o) const { return (m_type == o.m_type) && (m_quirk == o.m_quirk) && (isMaxSizeNone() || (getFloatValue() == o.getFloatValue()) || isCalculatedEqual(o)); }
 130     bool operator!=(const Length& o) const { return !(*this == o); }
 131
 132     const Length& operator*=(float v)
 133     {
 134         if (isCalculated()) {
 135             ASSERT_NOT_REACHED();
 136             return *this;
 137         }
 138
 139         if (m_isFloat)
 140             m_floatValue = static_cast<float>(m_floatValue * v);
 141         else
 142             m_intValue = static_cast<int>(m_intValue * v);
 143
 144         return *this;
 145     }
 146
 147     // FIXME: Make this private (if possible) or at least rename it (http://crbug.com/432707).
 148     inline float value() const
 149     {
 150         return getFloatValue();
 151     }
 152
 153     int intValue() const
 154     {
 155         if (isCalculated()) {
 156             ASSERT_NOT_REACHED();
 157             return 0;
 158         }
 159         return getIntValue();
 160     }
 161
 162     float percent() const
 163     {
 164         ASSERT(type() == Percent);
 165         return getFloatValue();
 166     }
 167     PixelsAndPercent pixelsAndPercent() const;
 168
 169     CalculationValue& calculationValue() const;
 170
 171     LengthType type() const { return static_cast<LengthType>(m_type); }
 172     bool quirk() const { return m_quirk; }
 173
 174     void setQuirk(bool quirk)
 175     {
 176         m_quirk = quirk;
 177     }
 178
 179     void setValue(LengthType t, int value)
 180     {
 181         m_type = t;
 182         m_intValue = value;
 183         m_isFloat = false;
 184     }
 185
 186     void setValue(int value)
 187     {
 188         if (isCalculated()) {
 189             ASSERT_NOT_REACHED();
 190             return;
 191         }
 192         setValue(Fixed, value);
 193     }
 194
 195     void setValue(LengthType t, float value)
 196     {
 197         m_type = t;
 198         m_floatValue = value;
 199         m_isFloat = true;
 200     }
 201
 202     void setValue(LengthType t, LayoutUnit value)
 203     {
 204         m_type = t;
 205         m_floatValue = value.toFloat();
 206         m_isFloat = true;
 207     }
 208
 209     void setValue(float value)
 210     {
 211         *this = Length(value, Fixed);
 212     }
 213
 214     bool isMaxSizeNone() const { return type() == MaxSizeNone; }
 215
 216     // FIXME calc: https://bugs.webkit.org/show_bug.cgi?id=80357. A calculated Length
 217     // always contains a percentage, and without a maxValue passed to these functions
 218     // it's impossible to determine the sign or zero-ness. We assume all calc values
 219     // are positive and non-zero for now.
 220     bool isZero() const
 221     {
 222         ASSERT(!isMaxSizeNone());
 223         if (isCalculated())
 224             return false;
 225
 226         return m_isFloat ? !m_floatValue : !m_intValue;
 227     }
 228     bool isPositive() const
 229     {
 230         if (isMaxSizeNone())
 231             return false;
 232         if (isCalculated())
 233             return true;
 234
 235         return getFloatValue() > 0;
 236     }
 237     bool isNegative() const
 238     {
 239         if (isMaxSizeNone() || isCalculated())
 240             return false;
 241
 242         return getFloatValue() < 0;
 243     }
 244
 245     bool isAuto() const { return type() == Auto; }
 246     bool isFixed() const { return type() == Fixed; }
 247     bool isIntrinsicOrAuto() const { return type() == Auto || isLegacyIntrinsic() || isIntrinsic(); }
 248     bool isLegacyIntrinsic() const { return type() == Intrinsic || type() == MinIntrinsic; }
 249     bool isIntrinsic() const { return type() == MinContent || type() == MaxContent || type() == FillAvailable || type() == FitContent; }
 250     bool isSpecified() const { return type() == Fixed || type() == Percent || type() == Calculated; }
 251     bool isSpecifiedOrIntrinsic() const { return isSpecified() || isIntrinsic(); }
 252     bool isCalculated() const { return type() == Calculated; }
 253     bool isCalculatedEqual(const Length&) const;
 254     bool isMinContent() const { return type() == MinContent; }
 255     bool isMaxContent() const { return type() == MaxContent; }
 256     bool isFillAvailable() const { return type() == FillAvailable; }
 257     bool isFitContent() const { return type() == FitContent; }
 258     bool hasPercent() const { return type() == Percent || type() == Calculated; }
 259
 260     Length blend(const Length& from, double progress, ValueRange range) const
 261     {
 262         ASSERT(isSpecified() && from.isSpecified());
 263
 264         if (progress == 0.0)
 265             return from;
 266
 267         if (progress == 1.0)
 268             return *this;
 269
 270         if (from.type() == Calculated || type() == Calculated)
 271             return blendMixedTypes(from, progress, range);
 272
 273         if (!from.isZero() && !isZero() && from.type() != type())
 274             return blendMixedTypes(from, progress, range);
 275
 276         if (from.isZero() && isZero())
 277             return *this;
 278
 279         LengthType resultType = type();
 280         if (isZero())
 281             resultType = from.type();
 282
 283         float blendedValue = blink::blend(from.value(), value(), progress);
 284         if (range == ValueRangeNonNegative)
 285             blendedValue = clampTo<float>(blendedValue, 0);
 286         return Length(blendedValue, resultType);
 287     }
 288
 289     float getFloatValue() const
 290     {
 291         ASSERT(!isMaxSizeNone());
 292         return m_isFloat ? m_floatValue : m_intValue;
 293     }
 294     float nonNanCalculatedValue(LayoutUnit maxValue) const;
 295
 296     Length subtractFromOneHundredPercent() const;
 297
 298     Length zoom(double factor) const;
 299
 300 private:
 301     int getIntValue() const
 302     {
 303         ASSERT(!isMaxSizeNone());
 304         return m_isFloat ? static_cast<int>(m_floatValue) : m_intValue;
 305     }
 306
 307     Length blendMixedTypes(const Length& from, double progress, ValueRange) const;
 308
 309     int calculationHandle() const
 310     {
 311         ASSERT(isCalculated());
 312         return getIntValue();
 313     }
 314     void incrementCalculatedRef() const;
 315     void decrementCalculatedRef() const;
 316
 317     union {
 318         int m_intValue;
 319         float m_floatValue;
 320     };
 321     bool m_quirk;
 322     unsigned char m_type;
 323     bool m_isFloat;
 324 };
 325
 326 PLATFORM_EXPORT Vector<Length> parseHTMLAreaElementCoords(const String&);
 327
 328 } // namespace blink
 329
 330 #endif // Length_h