The dimension information specified in layout and profile.

Format: #n | content | flex | flex #n | #n %

class AmountInfo {
 AmountType type;
 num value;

 /** Constructor.
  */
 AmountInfo(String profile) {
   //no need to trim since it was trimmed
   if (profile == null || profile.isEmpty || profile == "none") {
     type = AmountType.NONE;
   } else if (profile == "content") {
     type = AmountType.CONTENT;
   } else if (profile == "ignore") {
     type = AmountType.IGNORE;
   } else if (profile.startsWith("flex")) {
     type = AmountType.FLEX;
     value = profile.length > 4 ? int.parse(profile.substring(4).trim()): 1;
     if (value < 1) value = 1;
   } else if (profile.endsWith("%")) {
     type = AmountType.RATIO;
     value= double.parse(profile.substring(0, profile.length - 1).trim()) / 100;
   } else {
     type = AmountType.FIXED;
     value = CssUtil.intOf(profile, reportError: true); //report error if no number at all
       //since it is common to end the number with px (because of CSS),
       //we retrieve only the number (and ignore the text following it).
   }
 }
 String toString() {
   return "$type:$value";
 }
}