iconverterlocator+generics

[Igor Vaynberg]

i refactored generics in iconverterlocator to how they should be. i
did see something pretty interesting though: we used to have
component.getconverter() which we refactored into
component.getconverter(class) to support multiple converters. but then
checkbox does this:

        public <X> IConverter<X> getConverter(Class<X> type)
        {
                return (IConverter<X>)BooleanConverter.INSTANCE;
        }

which seems wrong to me because if i say getconverter(integer.class) i
expect to get a converter that can converter integers not booleans.

so here is what i propose:

formcomponents are "single type" components where the type is well
known. so we should probably have:

class formcomponent {

        public FINAL <X> IConverter<X> getConverter(Class<X> type) {
           if (type==well_known_formcomponent_type) {
               return getConverter();
           } else { return super.getConverter(type); }
         }

        public IConverter<T> getConverter() {
            return super.getConverter(well_known_formcomponent_type);
       }
}

that way we still have getConverter() without a type param that can
easily be overridden by components

or another solution is to implement checkbox.getconverter(class<T>
type) like this:

if (Boolean.class.isassignablefrom(type)) {
   return BooleanConverter.instance; }
 else { return super.getconverter(type); }


thoughts?