/// <summary>
/// Resets the collection by reevaluating the groupings.
/// </summary>
void Reset()
{
// find new and old items
var nowItems = groups.Values.SelectMany(i => i);
var newItems = Lambdas.Select(i => Lambdas[i]).Except(nowItems).ToList();
var oldItems = nowItems.Except(newItems).ToList();
// remove old items
foreach (var item in oldItems)
{
RemoveItem(item);
}
// add new items
foreach (var item in newItems)
{
AddItem(item);
}
}
protected override void OnLambdaCollectionReset()
{
// unsubscribe from all items
foreach (var item in items)
{
UnsubscribeItem(item);
}
// reset all items
items.Clear();
items.AddRange(Lambdas.Select(i => i.Value));
// subscribe to all items
foreach (var item in items)
{
SubscribeItem(item);
}
OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
}
public IEnumerator <TResult> GetEnumerator()
{
return(Lambdas.Select(i => i.Value).GetEnumerator());
}