public virtual void RetainAll <U>(SCG.IEnumerable <U> items) where U : T
{
updatecheck();
HashBag <T> res = new HashBag <T>(itemequalityComparer);
foreach (U item in items)
{
KeyValuePair <T, int> p = new KeyValuePair <T, int>(item);
if (dict.Find(ref p))
{
KeyValuePair <T, int> q = p;
if (res.dict.Find(ref q))
{
if (q.Value < p.Value)
{
q.Value++;
res.dict.Update(q);
res.size++;
}
}
else
{
q.Value = 1;
res.dict.Add(q);
res.size++;
}
}
}
if (size == res.size)
{
return;
}
CircularQueue <T> wasRemoved = null;
if ((ActiveEvents & EventTypeEnum.Removed) != 0)
{
wasRemoved = new CircularQueue <T>();
foreach (KeyValuePair <T, int> p in dict)
{
int removed = p.Value - res.ContainsCount(p.Key);
if (removed > 0)
#warning We could send bag events here easily using a CircularQueue of (should?)
{
for (int i = 0; i < removed; i++)
{
wasRemoved.Enqueue(p.Key);
}
}
}
}
dict = res.dict;
size = res.size;
if ((ActiveEvents & EventTypeEnum.Removed) != 0)
{
raiseForRemoveAll(wasRemoved);
}
else if ((ActiveEvents & EventTypeEnum.Changed) != 0)
{
raiseCollectionChanged();
}
}