implementing UnitsCalculator and disable changes in Sketcher

src/Base/Quantity.cpp

@@ -120,6 +120,35 @@ double Quantity::getUserPrefered(QString &unitString)const
 	return Base::UnitsApi::schemaPrefUnit(_Unit,unitString).getValue() * _Value;
 }
 
+std::string Quantity::getUserString(void)const
+{
+    std::stringstream sstream;
+    sstream << _Value << _Unit.getString();
+    //TODO: implementing 
+    return sstream.str();
+}
+
+/// true if it has a number without a unit
+bool Quantity::isDimensionless(void)const
+{
+    return _Value != DOUBLE_MIN && _Unit.isEmpty();
+}
+// true if it has a number and a valid unit
+bool Quantity::isQuantity(void)const
+{
+    return _Value != DOUBLE_MIN && !_Unit.isEmpty();
+}
+// true if it has a number with or without a unit
+bool Quantity::isValid(void)const
+{
+    return _Value != DOUBLE_MIN ;
+}
+
+void Quantity::setInvalid(void)
+{
+    _Value = DOUBLE_MIN ;
+}
+
 // === Parser & Scanner stuff ===============================================
 
 // include the Scanner and the Parser for the Quantitys