// This function is generic because some lists, like ILexSense.AnthroCodesRC, are lists of interfaces *derived*
// from ICmPossibility (e.g., ICmAnthroItem). This results in type errors at compile time: parameter
// types like IFdoReferenceCollection<ICmPossibility> don't match IFdoReferenceCollection<ICmAnthroCode>.
// Generics solve the problem, and can be automatically inferred by the compiler to boot.
public void SetPossibilitiesCollection <T>(IFdoReferenceCollection <T> dest, IEnumerable <T> newItems)
where T : class, ICmPossibility
{
// If we know of NO valid possibility keys, don't make any changes. That's because knowing of NO valid possibility keys
// is FAR more likely to happen because of a bug than because we really removed an entire possibility list, and if there's
// a bug, we shouldn't drop all the FDO data for this possibility list.
if (PossibilitiesByKey.Count == 0 && _canonicalSource == null)
{
return;
}
// We have to calculate the update (which items to remove and which to add) here; IFdoReferenceCollection won't do it for us.
List <T> itemsToAdd = newItems.ToList();
HashSet <Guid> guidsToAdd = new HashSet <Guid>(itemsToAdd.Select(poss => poss.Guid));
List <T> itemsToRemove = new List <T>();
foreach (T poss in dest)
{
if (!guidsToAdd.Contains(poss.Guid))
{
itemsToRemove.Add(poss);
}
}
dest.Replace(itemsToRemove, itemsToAdd);
}
