private void Regroup(TSource modifiedItem)
{
var currentGroup = this.ItemToGroupIndex[modifiedItem];
TKey newKey = this.KeySelector(modifiedItem);
if (EqualityComparer <TKey> .Default.Equals(currentGroup.Key, newKey))
{
return;
}
GroupedReadOnlyContinuousCollection <TKey, TSource> newGroupForModifiedItem = GetCollectionForKey(newKey);
while (currentGroup.InternalCollection.Remove(modifiedItem))
{
newGroupForModifiedItem.InternalCollection.Add(modifiedItem);
}
if (currentGroup.Count == 0)
{
this.Output.Remove(currentGroup);
}
this.ItemToGroupIndex[modifiedItem] = newGroupForModifiedItem;
}
private GroupedReadOnlyContinuousCollection <TKey, TSource> GetCollectionForKey(TKey key)
{
GroupedReadOnlyContinuousCollection <TKey, TSource> group =
this.Output.FirstOrDefault(item => EqualityComparer <TKey> .Default.Equals(item.Key, key));
if (group == null)
{
group = new GroupedReadOnlyContinuousCollection <TKey, TSource>(key);
this.Output.Add(group);
}
return(group);
}