private double GetCoordinateForObjectBoundingBox(String attributeName, double defaultValue)
{
String attributeValue = GetAttribute(attributeName);
double absoluteValue = defaultValue;
if (CssUtils.IsPercentageValue(attributeValue))
{
absoluteValue = CssUtils.ParseRelativeValue(attributeValue, 1);
}
else
{
if (CssUtils.IsNumericValue(attributeValue) || CssUtils.IsMetricValue(attributeValue) || CssUtils.IsRelativeValue
(attributeValue))
{
// if there is incorrect value metric, then we do not need to parse the value
int unitsPosition = CssUtils.DeterminePositionBetweenValueAndUnit(attributeValue);
if (unitsPosition > 0)
{
// We want to ignore the unit type. From the svg specification:
// "the normal of the linear gradient is perpendicular to the gradient vector in
// object bounding box space (i.e., the abstract coordinate system where (0,0)
// is at the top/left of the object bounding box and (1,1) is at the bottom/right
// of the object bounding box)".
// Different browsers treats this differently. We chose the "Google Chrome" approach
// which treats the "abstract coordinate system" in the coordinate metric measure,
// i.e. for value '0.5cm' the top/left of the object bounding box would be (1cm, 1cm),
// for value '0.5em' the top/left of the object bounding box would be (1em, 1em) and etc.
// no null pointer should be thrown as determine
absoluteValue = CssUtils.ParseDouble(attributeValue.JSubstring(0, unitsPosition)).Value;
}
}
}
// need to multiply by 0.75 as further the (top, right) coordinates of the object bbox
// would be transformed into (0.75, 0.75) point instead of (1, 1). The reason described
// as a comment inside the method constructing the gradient transformation
return(absoluteValue * 0.75);
}
