Move viewport unit resolution to style recalc time

Source/platform/Length.h

 /*
     Copyright (C) 1999 Lars Knoll (knoll@kde.org)
     Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
     Copyright (C) 2011 Rik Cabanier (cabanier@adobe.com)
     Copyright (C) 2011 Adobe Systems Incorporated. All rights reserved.
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
     version 2 of the License, or (at your option) any later version.
@@ skipping 17 matching lines @@
 #include "wtf/Assertions.h"
 #include "wtf/FastAllocBase.h"
 #include "wtf/Forward.h"
 #include "wtf/HashMap.h"
 #include "wtf/MathExtras.h"
 #include "wtf/Vector.h"
 #include <cstring>
 
 namespace WebCore {
 
+// FIXME: This enum makes it hard to tell in general what values may be
+// appropriate for any given Length.
 enum LengthType {
     Auto, Percent, Fixed,
     Intrinsic, MinIntrinsic,
     MinContent, MaxContent, FillAvailable, FitContent,
     Calculated,
-    ViewportPercentageWidth, ViewportPercentageHeight, ViewportPercentageMin, ViewportPercentageMax,
-    ExtendToZoom,
+    ExtendToZoom, DeviceWidth, DeviceHeight,

[johnme, 2013/12/18 12:04:15]

I'm probably missing something, but why did you add DeviceWidth and DeviceHeight
here? Shouldn't they always behave identically to 100vw and 100vh (bearing in
mind that vw/vh behave differently in @viewport, being relative to the initial
viewport there[1], rather than the layout viewport (ICB) like they usually
are[2])?

[1]: http://dev.w3.org/csswg/css-device-adapt/#viewport-descriptors
[2]: http://www.w3.org/TR/css3-values/#viewport-relative-lengths

[Timothy Loh, 2013/12/23 06:28:16]

See other comments about vw/vh meaning.

This seems like the simplest way to handle this to me. Resolving these here just
complicates the logic around resizing since we'd have to update these also. Also
calling document::setHasViewportUnits would be a bit odd here, since we don't
actually have viewport units!

     Undefined
 };
 
 enum ValueRange {
     ValueRangeAll,
     ValueRangeNonNegative
 };
 
 class CalculationValue;
 
@@ skipping 167 matching lines @@
 
         return getFloatValue() < 0;
     }
 
     bool isAuto() const { return type() == Auto; }
     bool isPercent() const { return type() == Percent || type() == Calculated; }
     bool isFixed() const { return type() == Fixed; }
     bool isIntrinsicOrAuto() const { return type() == Auto || isLegacyIntrinsic() || isIntrinsic(); }
     bool isLegacyIntrinsic() const { return type() == Intrinsic || type() == MinIntrinsic; }
     bool isIntrinsic() const { return type() == MinContent || type() == MaxContent || type() == FillAvailable || type() == FitContent; }
-    bool isSpecified() const { return type() == Fixed || type() == Percent || type() == Calculated || isViewportPercentage(); }
+    bool isSpecified() const { return type() == Fixed || type() == Percent || type() == Calculated; }
     bool isSpecifiedOrIntrinsic() const { return isSpecified() || isIntrinsic(); }
     bool isCalculated() const { return type() == Calculated; }
     bool isCalculatedEqual(const Length&) const;
     bool isMinContent() const { return type() == MinContent; }
     bool isMaxContent() const { return type() == MaxContent; }
     bool isFillAvailable() const { return type() == FillAvailable; }
     bool isFitContent() const { return type() == FitContent; }
 
     Length blend(const Length& from, double progress, ValueRange range) const
     {
@@ skipping 27 matching lines @@
         return Length(blendedValue, resultType);
     }
 
     float getFloatValue() const
     {
         ASSERT(!isUndefined());
         return m_isFloat ? m_floatValue : m_intValue;
     }
     float nonNanCalculatedValue(int maxValue) const;
 
-    bool isViewportPercentage() const
-    {
-        LengthType lengthType = type();
-        return lengthType >= ViewportPercentageWidth && lengthType <= ViewportPercentageMax;
-    }
-    float viewportPercentageLength() const
-    {
-        ASSERT(isViewportPercentage());
-        return getFloatValue();
-    }
 private:
     int getIntValue() const
     {
         ASSERT(!isUndefined());
         return m_isFloat ? static_cast<int>(m_floatValue) : m_intValue;
     }
     void initFromLength(const Length& length)
     {
         memcpy(this, &length, sizeof(Length));
 
@@ skipping 18 matching lines @@
     bool m_quirk;
     unsigned char m_type;
     bool m_isFloat;
 };
 
 PLATFORM_EXPORT Vector<Length> parseHTMLAreaElementCoords(const String&);
 
 } // namespace WebCore
 
 #endif // Length_h