Reorganize 'dir' attribute for some elements
Some of the enumeration values should be disabled for some elements.
They are really confusing. Hopefully, nobody uses them until now!
dir attribute provides the following enumeration values, according to its generic type tDirValidity:
noneupdownbothunknown
There are some elements, which offer all above values within this attribute, e.g.
- mileage direction in
mileageChange - direction of the main track in
track/@mainDir
Type tOrientedElement uses the same attribute as extension base for various elements, e.g.
- direction of
crossSectionfor ocp references - direction of
speedChangefor the speed aspect - direction of
gradientChangefor slope value - direction of
radiusChangefor radius value - direction of
levelCrossingfor what?
Please, review all possible occurences of dir attribute with regard to meaningful enumeration values. Provide intermediate type with less values, if needed.