/// <summary>
/// Index, group, sort and insert an entity to the collection.
/// If group doesn't exist, it will be created and sorted.
/// </summary>
/// <param name="item">The item to insert into.</param>
/// <param name="ignoreBackendFlatList">Whether ignore backend list or not.</param>
private void AddInternal(CommonViewItemModel item, bool ignoreBackendFlatList = false)
{
if (item != null)
{
var index = Indexer.GetIndexForGroup(item);
// If group exists
if (_itemsIndex.ContainsKey(index))
{
_itemsIndex[index].Add(item);
}
// Or create group
else
{
var newCreatedGroup = new GroupedItems(index, Indexer, ItemComparer);
_itemsIndex.Add(index, newCreatedGroup);
var processed = false;
if (Items.Count != 0)
{
for (int i = 0; i < Items.Count; i++)
{
if (GroupComparer.Compare(Items[i].Title, index) >= 0)
{
Items.Insert(i, newCreatedGroup);
processed = true;
break;
}
}
}
if (!processed)
{
Items.Add(newCreatedGroup);
}
// Add item
newCreatedGroup.Add(item);
}
// Add backend item (optional)
if (!ignoreBackendFlatList)
{
_entityCopies.Add(item);
}
// Notify change if required (precondition: IsEmpty == true)
if (IsEmpty)
{
IsEmpty = false;
}
}
}
private int RenderGroupIfNeeded(object item, object previous, int index)
{
bool isAlternateRow = index % 2 != 0 && (AlternatingGroupFooterTemplate != null || AlternatingGroupHeaderTemplate != null);
if (GroupComparer.Compare(item, previous) == 1)
{
RenderTemplate(isAlternateRow ? AlternatingGroupFooterTemplate : GroupFooterTemplate, previous, index);
}
if (GroupComparer.Compare(previous, item) == -1)
{
RenderTemplate(isAlternateRow ? AlternatingGroupHeaderTemplate : GroupHeaderTemplate, item, index++);
}
return(index);
}