Update getCssLength for new types, enable reading negative values.

nel/include/nel/gui/libwww.h

@@ -184,7 +184,7 @@ namespace NLGUI
 	// ***************************************************************************
 	// Read a CSS length value, return true if one of supported units '%, rem, em, px, pt'
 	// On failure: 'value' and 'unit' values are undefined
-	bool getCssLength (float &value, std::string &unit, const std::string &str);
+	bool getCssLength (float &value, std::string &unit, const std::string &str, bool neg = false);
 
 	// Read a width HTML parameter. "100" or "100%". Returns true if percent (0 ~ 1) else false
 	bool getPercentage (sint32 &width, float &percent, const char *str);

nel/src/gui/libwww.cpp

@@ -206,11 +206,15 @@ namespace NLGUI
 	// ***************************************************************************
 
 	// ***************************************************************************
-	bool getCssLength (float &value, std::string &unit, const std::string &str)
+	bool getCssLength (float &value, std::string &unit, const std::string &str, bool neg)
 	{
+		static const std::set<std::string> knownUnits = {
+			"%", "rem", "em", "px", "pt", "vw", "vh", "vi", "vb", "vmin", "vmax"
+		};
+
 		std::string::size_type pos = 0;
 		std::string::size_type len = str.size();
-		if (len == 1 && str[0] == '.')
+		if (len == 0)
 		{
 			return false;
 		}
@@ -222,6 +226,12 @@ namespace NLGUI
 			return true;
 		}
 
+		// +100px; -100px
+		if (str[0] == '+')
+			pos++;
+		else if (neg && str[0] == '-')
+			pos++;
+
 		while(pos < len)
 		{
 			bool isNumeric = (str[pos] >= '0' && str[pos] <= '9')
@@ -236,7 +246,7 @@ namespace NLGUI
 		}
 
 		unit = toLowerAscii(str.substr(pos));
-		if (unit == "%" || unit == "rem" || unit == "em" || unit == "px" || unit == "pt")
+		if (knownUnits.count(unit))
 		{
 			std::string tmpstr = str.substr(0, pos);
 			return fromString(tmpstr, value);