double CSSPrimitiveValue::computeLengthDouble(const CSSToLengthConversionData& conversionData)
{
// The logic in this function is duplicated in MediaValues::computeLength
// because MediaValues::computeLength needs nearly identical logic, but we haven't found a way to make
// CSSPrimitiveValue::computeLengthDouble more generic (to solve both cases) without hurting performance.
if (type() == UnitType::Calc)
return m_value.calc->computeLengthPx(conversionData);
double factor;
switch (type()) {
case UnitType::Ems:
factor = conversionData.emFontSize();
break;
case UnitType::Exs:
factor = conversionData.exFontSize();
break;
case UnitType::Rems:
factor = conversionData.remFontSize();
break;
case UnitType::Chs:
factor = conversionData.chFontSize();
break;
case UnitType::Pixels:
factor = 1.0;
break;
case UnitType::Centimeters:
factor = cssPixelsPerCentimeter;
break;
case UnitType::Millimeters:
factor = cssPixelsPerMillimeter;
break;
case UnitType::Inches:
factor = cssPixelsPerInch;
break;
case UnitType::Points:
factor = cssPixelsPerPoint;
break;
case UnitType::Picas:
factor = cssPixelsPerPica;
break;
case UnitType::ViewportWidth:
factor = conversionData.viewportWidthPercent();
break;
case UnitType::ViewportHeight:
factor = conversionData.viewportHeightPercent();
break;
case UnitType::ViewportMin:
factor = conversionData.viewportMinPercent();
break;
case UnitType::ViewportMax:
factor = conversionData.viewportMaxPercent();
break;
case UnitType::CalcPercentageWithLength:
case UnitType::CalcPercentageWithNumber:
ASSERT_NOT_REACHED();
return -1.0;
default:
ASSERT_NOT_REACHED();
return -1.0;
}
// We do not apply the zoom factor when we are computing the value of the font-size property. The zooming
// for font sizes is much more complicated, since we have to worry about enforcing the minimum font size preference
// as well as enforcing the implicit "smart minimum."
double result = getDoubleValue() * factor;
if (isFontRelativeLength())
return result;
return result * conversionData.zoom();
}
