private void HandleModifiedItemsForFooterOfCollection(NotifyKeyGroupsCollectionChangedEventArgs e)
{
if (e.Action != NotifyCollectionChangedAction.Add || !_collectionChangedAction.IsAlive)
{
return;
}
var lastDataSourceItemIndex = ItemCount - 1;
var lastGroupedDataSourceItemIndex = GroupedDataSource.Count - 1;
var lastInsertedSectionIndex = int.MinValue;
if (e.ModifiedSectionsIndexes.Any())
{
lastInsertedSectionIndex = e.ModifiedSectionsIndexes.Max();
}
if (lastInsertedSectionIndex == lastGroupedDataSourceItemIndex)
{
_collectionChangedAction.Execute(lastDataSourceItemIndex);
}
else
{
var(section, modifiedIndexes) = e.ModifiedItemsIndexes.FirstOrDefault(x => x.Section == lastGroupedDataSourceItemIndex);
if (modifiedIndexes != null && modifiedIndexes.Any())
{
var lastInsertedItemIndex = modifiedIndexes.Max();
if (lastInsertedItemIndex == GroupedDataSource[section].Count - 1)
{
_collectionChangedAction.Execute(lastDataSourceItemIndex);
}
}
}
}
private void HandleModifiedItemsForLastItemRequest(NotifyKeyGroupsCollectionChangedEventArgs e)
{
if (e.Action != NotifyCollectionChangedAction.Add)
{
return;
}
var lastModifiedItemsCount = 0;
foreach (var newSectionIndex in e.ModifiedSectionsIndexes)
{
lastModifiedItemsCount += GroupedDataSource[newSectionIndex].Count + 1;
}
foreach (var(section, modifiedIndexes) in e.ModifiedItemsIndexes)
{
lastModifiedItemsCount += modifiedIndexes.Count;
}
if (lastModifiedItemsCount > 0)
{
if (_lastItemsLoadedAction.IsAlive)
{
_lastItemsLoadedAction.Execute(lastModifiedItemsCount);
}
}
}
private void OnMessagesAddedToCollection(object sender, NotifyKeyGroupsCollectionChangedEventArgs e)
{
if (e.Action == NotifyCollectionChangedAction.Add ||
e.Action == NotifyCollectionChangedAction.Reset)
{
MarkMessagesAsRead();
}
}
public void NotifyKeyGroupsCollectionChangedEventArgs_WhenCreated_InitializesProperties(
NotifyCollectionChangedAction action,
List <int> oldSectionsSizes)
{
var args = new NotifyKeyGroupsCollectionChangedEventArgs(action, oldSectionsSizes);
if (oldSectionsSizes == null)
{
oldSectionsSizes = new List <int>();
}
Assert.Equal(action, args.Action);
Assert.Equal(oldSectionsSizes, args.OldSectionsSizes);
Assert.Equal(oldSectionsSizes.Count, args.OldSectionsCount);
Assert.Empty(args.ModifiedSectionsIndexes);
Assert.Empty(args.ModifiedItemsIndexes);
}
protected override void NotifyCollectionChanged(NotifyKeyGroupsCollectionChangedEventArgs e)
{
HandleModifiedItemsForLastItemRequest(e);
HandleModifiedItemsForFooterOfCollection(e);
}
