/// <summary>
/// Finds the index of the specified item
/// </summary>
/// <param name="item">Item we are looking for</param>
/// <param name="seed">Seed of the item we are looking for</param>
/// <param name="comparer">Comparer used to find the item</param>
/// <param name="low">Low range of item index</param>
/// <param name="high">High range of item index</param>
/// <returns>Index of the specified item</returns>
protected virtual int FindIndex(object item, object seed, IComparer comparer, int low, int high)
{
int index;
if (comparer != null)
{
ListComparer listComparer = comparer as ListComparer;
if (listComparer != null)
{
// reset the IListComparer before each search. This cannot be done
// any less frequently (e.g. in Root.AddToSubgroups), due to the
// possibility that the item may appear in more than one subgroup.
listComparer.Reset();
}
CollectionViewGroupComparer groupComparer = comparer as CollectionViewGroupComparer;
if (groupComparer != null)
{
// reset the CollectionViewGroupComparer before each search. This cannot be done
// any less frequently (e.g. in Root.AddToSubgroups), due to the
// possibility that the item may appear in more than one subgroup.
groupComparer.Reset();
}
for (index = low; index < high; ++index)
{
CollectionViewGroupInternal subgroup = this.ProtectedItems[index] as CollectionViewGroupInternal;
object seed1 = (subgroup != null) ? subgroup.SeedItem : this.ProtectedItems[index];
if (seed1 == DependencyProperty.UnsetValue)
{
continue;
}
if (comparer.Compare(seed, seed1) < 0)
{
break;
}
}
}
else
{
index = high;
}
return(index);
}
