Added support of calc() for SVGLength

third_party/WebKit/Source/core/svg/SVGLength.cpp

 /*
  * Copyright (C) 2004, 2005, 2006 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Apple Inc. 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 53 matching lines @@
         length->m_value = CSSPrimitiveValue::create(0, CSSPrimitiveValue::UnitType::UserUnits);
 
     return length;
 }
 
 bool SVGLength::operator==(const SVGLength& other) const
 {
     return m_unitMode == other.m_unitMode && m_value == other.m_value;
 }
 
+bool isCalcCSSUnitType(CSSPrimitiveValue::UnitType type)

[fs, 2016/07/16 21:13:02]

Make this static (and isSupportedCSSUnitType too, while at it) and move to down
just before it is used.

[Shanmuga Pandi, 2016/07/18 13:35:33]

Done.

+{
+    return (type >= CSSPrimitiveValue::UnitType::Calc && type <= CSSPrimitiveValue::UnitType::CalcPercentageWithLengthAndNumber);

[fs, 2016/07/16 21:13:02]

Drop parenthesis.

[Shanmuga Pandi, 2016/07/18 13:35:33]

Done.

+}
+
+float SVGLength::resolveCalcValue(const SVGLengthContext& context) const

[fs, 2016/07/16 21:13:02]

We could consider going through CSSPrimitiveValue::convertToLength here instead
to avoid special-case resolving code. (This should hopefully allow us to get rid
of m_unitMode eventually.)

[Shanmuga Pandi, 2016/07/18 13:35:33]

Done.

+{
+    CSSLengthArray lengthArray;
+    m_value->accumulateLengthArray(lengthArray);
+    float value = 0;

[fs, 2016/07/16 21:13:02]

If we end up keeping this I suggest making this 'double', and then converting
(narrowing) to float when returning.

+    for (size_t i = 0; i < CSSPrimitiveValue::LengthUnitTypeCount; i++) {
+        double entry = lengthArray.values[i];
+        if (entry)
+            value += context.convertValueToUserUnits(entry, unitMode(), SVGLength::toUnitType(i));
+    }
+    return value;
+}
+
 float SVGLength::value(const SVGLengthContext& context) const
 {
+    if (isCalculated())
+        return resolveCalcValue(context);
+
     return context.convertValueToUserUnits(
         m_value->getFloatValue(), unitMode(), m_value->typeWithCalcResolved());
 }
 
+void SVGLength::setValueAsNumber(float value)
+{
+    m_value = CSSPrimitiveValue::create(value, CSSPrimitiveValue::UnitType::UserUnits);
+}
+
 void SVGLength::setValue(float value, const SVGLengthContext& context)
 {
     m_value = CSSPrimitiveValue::create(
         context.convertValueFromUserUnits(value, unitMode(), m_value->typeWithCalcResolved()),
         m_value->typeWithCalcResolved());
 }
 
 bool isSupportedCSSUnitType(CSSPrimitiveValue::UnitType type)
 {
-    return (CSSPrimitiveValue::isLength(type) || type == CSSPrimitiveValue::UnitType::Number || type == CSSPrimitiveValue::UnitType::Percentage)
+    return (CSSPrimitiveValue::isLength(type) || type == CSSPrimitiveValue::UnitType::Number
+        || type == CSSPrimitiveValue::UnitType::Percentage || isCalcCSSUnitType(type))
         && type != CSSPrimitiveValue::UnitType::QuirkyEms;
 }
 
 void SVGLength::setUnitType(CSSPrimitiveValue::UnitType type)
 {
     ASSERT(isSupportedCSSUnitType(type));
     m_value = CSSPrimitiveValue::create(m_value->getFloatValue(), type);
 }
 
 float SVGLength::valueAsPercentage() const
@@ skipping 32 matching lines @@
         m_value = CSSPrimitiveValue::create(0, CSSPrimitiveValue::UnitType::UserUnits);
         return SVGParseStatus::NoError;
     }
 
     CSSParserContext svgParserContext(SVGAttributeMode, nullptr);
     CSSValue* parsed = CSSParser::parseSingleValue(CSSPropertyX, string, svgParserContext);
     if (!parsed || !parsed->isPrimitiveValue())
         return SVGParseStatus::ExpectedLength;
 
     CSSPrimitiveValue* newValue = toCSSPrimitiveValue(parsed);
-    // TODO(fs): Enable calc for SVG lengths
-    if (newValue->isCalculated() || !isSupportedCSSUnitType(newValue->typeWithCalcResolved()))
+    if (!isSupportedCSSUnitType(newValue->typeWithCalcResolved()))
         return SVGParseStatus::ExpectedLength;
 
     m_value = newValue;
+

[fs, 2016/07/16 21:13:02]

Drop.

[Shanmuga Pandi, 2016/07/18 13:35:32]

Done.

     return SVGParseStatus::NoError;
 }
 
 String SVGLength::valueAsString() const
 {
     return m_value->customCSSText();
 }
 
 void SVGLength::newValueSpecifiedUnits(CSSPrimitiveValue::UnitType type, float value)
 {
@@ skipping 82 matching lines @@
     SVGLength* toLength = toSVGLength(toValue);
     SVGLength* toAtEndOfDurationLength = toSVGLength(toAtEndOfDurationValue);
 
     SVGLengthContext lengthContext(contextElement);
     float animatedNumber = value(lengthContext);
     animationElement->animateAdditiveNumber(percentage, repeatCount, fromLength->value(lengthContext),
         toLength->value(lengthContext), toAtEndOfDurationLength->value(lengthContext), animatedNumber);
 
     ASSERT(unitMode() == lengthModeForAnimatedLengthAttribute(animationElement->attributeName()));
 
-    CSSPrimitiveValue::UnitType newUnit = percentage < 0.5 ? fromLength->typeWithCalcResolved() : toLength->typeWithCalcResolved();
+    CSSPrimitiveValue::UnitType newUnit = CSSPrimitiveValue::UnitType::UserUnits;
+    if (percentage < 0.5) {
+        if (!fromLength->isCalculated())

[fs, 2016/07/16 21:13:02]

Test for this code? (Preferably i think this would just construct a calc()
expression if the units fall in different categories et.c, but we can fix that
up later I guess...)

[Shanmuga Pandi, 2016/07/18 13:35:32]

Yes. We could just construct a calc_expression later.
Have added some test cases for this on svg_calc_interpolation.html

[fs, 2016/07/18 13:56:48]

Please add a TODO about constructing a calc() expression here.

+            newUnit = fromLength->typeWithCalcResolved();
+    } else {
+        if (!toLength->isCalculated())
+            newUnit = toLength->typeWithCalcResolved();
+    }
     animatedNumber = lengthContext.convertValueFromUserUnits(animatedNumber, unitMode(), newUnit);
     m_value = CSSPrimitiveValue::create(animatedNumber, newUnit);
 }
 
 float SVGLength::calculateDistance(SVGPropertyBase* toValue, SVGElement* contextElement)
 {
     SVGLengthContext lengthContext(contextElement);
     SVGLength* toLength = toSVGLength(toValue);
 
     return fabsf(toLength->value(lengthContext) - value(lengthContext));
 }
 
 } // namespace blink