/// <summary>
/// Add an item to the desired subgroup(s) of the given group
/// </summary>
/// <param name="item">Item to add</param>
/// <param name="group">Group to add item to</param>
/// <param name="level">The level of grouping</param>
/// <param name="loading">Whether we are currently loading</param>
private void AddToSubgroups(object item, CollectionViewGroupInternal group, int level, bool loading)
{
object name = GetGroupName(item, group.GroupBy, level);
ICollection nameList;
if (name == UseAsItemDirectly)
{
// the item belongs to the group itself (not to any subgroups)
if (loading)
{
group.Add(item);
}
else
{
int localIndex = group.Insert(item, item, ActiveComparer);
int index = group.LeafIndexFromItem(item, localIndex);
OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, item, index));
}
}
else if ((nameList = name as ICollection) == null)
{
// the item belongs to one subgroup
AddToSubgroup(item, group, level, name, loading);
}
else
{
// the item belongs to multiple subgroups
foreach (object o in nameList)
{
AddToSubgroup(item, group, level, o, loading);
}
}
}
//------------------------------------------------------
//
// Private Methods
//
//------------------------------------------------------
/// <summary>
/// Add an item to the subgroup with the given name
/// </summary>
/// <param name="item">Item to add</param>
/// <param name="group">Group to add item to</param>
/// <param name="level">The level of grouping.</param>
/// <param name="name">Name of subgroup to add to</param>
/// <param name="loading">Whether we are currently loading</param>
private void AddToSubgroup(object item, CollectionViewGroupInternal group, int level, object name, bool loading)
{
CollectionViewGroupInternal subgroup;
int index = (_isDataInGroupOrder) ? group.LastIndex : 0;
// find the desired subgroup
for (int n = group.Items.Count; index < n; ++index)
{
subgroup = group.Items[index] as CollectionViewGroupInternal;
if (subgroup == null)
{
continue; // skip children that are not groups
}
if (group.GroupBy.NamesMatch(subgroup.Name, name))
{
group.LastIndex = index;
AddToSubgroups(item, subgroup, level + 1, loading);
return;
}
}
// the item didn't match any subgroups. Create a new subgroup and add the item.
subgroup = new CollectionViewGroupInternal(name, group);
InitializeGroup(subgroup, level + 1, item);
if (loading)
{
group.Add(subgroup);
group.LastIndex = index;
}
else
{
// using insert will find the correct sort index to
// place the subgroup, and will default to the last
// position if no ActiveComparer is specified
group.Insert(subgroup, item, ActiveComparer);
}
AddToSubgroups(item, subgroup, level + 1, loading);
}