public void Sort(UICollectionView collectionView)
{
if (dataType == DataType.CHAPTERS)
{
(list as List <Chapter>).Reverse();
collectionView.PerformBatchUpdates(delegate
{
for (int i = 0; i < (list as List <Chapter>).Count; i++)
{
NSIndexPath fromIndexPath = indexDictionary[(list as List <Chapter>)[i].ID];
NSIndexPath toIndexPath = NSIndexPath.FromRowSection(i, 0);
collectionView.MoveItem(fromIndexPath, toIndexPath);
}
}, delegate
{
collectionView.ReloadData();
});
}
else if (dataType == DataType.BOOKMARKS)
{
(list as List <Bookmark>).Reverse();
collectionView.PerformBatchUpdates(delegate
{
for (int i = 0; i < (list as List <Bookmark>).Count; i++)
{
NSIndexPath fromIndexPath = indexDictionary[(list as List <Bookmark>)[i].PageID];
NSIndexPath toIndexPath = NSIndexPath.FromRowSection(i, 0);
collectionView.MoveItem(fromIndexPath, toIndexPath);
}
}, delegate
{
collectionView.ReloadData();
});
}
else
{
(list as List <Annotation>).Reverse();
collectionView.PerformBatchUpdates(delegate
{
for (int i = 0; i < (list as List <Annotation>).Count; i++)
{
NSIndexPath fromIndexPath = indexDictionary[(list as List <Annotation>)[i].PageID];
NSIndexPath toIndexPath = NSIndexPath.FromRowSection(i, 0);
collectionView.MoveItem(fromIndexPath, toIndexPath);
}
}, delegate
{
collectionView.ReloadData();
});
}
}
void Move(NotifyCollectionChangedEventArgs args)
{
var oldPath = NSIndexPath.Create(0, args.OldStartingIndex);
var newPath = NSIndexPath.Create(0, args.NewStartingIndex);
_collectionView.MoveItem(oldPath, newPath);
}
void Move(NotifyCollectionChangedEventArgs args)
{
var count = args.NewItems.Count;
if (count == 1)
{
// For a single item, we can use MoveItem and get the animation
var oldPath = NSIndexPath.Create(_section, args.OldStartingIndex);
var newPath = NSIndexPath.Create(_section, args.NewStartingIndex);
Update(() => CollectionView.MoveItem(oldPath, newPath), args);
return;
}
var start = Math.Min(args.OldStartingIndex, args.NewStartingIndex);
var end = Math.Max(args.OldStartingIndex, args.NewStartingIndex) + count;
Update(() => CollectionView.ReloadItems(CreateIndexesFrom(start, end)), args);
}
public void Execute()
{
// If we have incremental diffs, animate them in the collection view
_collectionView.PerformBatchUpdates(() =>
{
// For indexes to make sense, updates must be in this order:
// delete, insert, reload, move
if (_changes.RemovedIndexes?.Count > 0)
{
var result = new List <NSIndexPath>();
_changes.RemovedIndexes.EnumerateIndexes((nuint idx, ref bool stop) =>
result.Add(NSIndexPath.FromItemSection((nint)idx, _sectionIndex)));
_collectionView.DeleteItems(result.ToArray());
}
if (_changes.InsertedIndexes?.Count > 0)
{
var result = new List <NSIndexPath>();
_changes.InsertedIndexes.EnumerateIndexes((nuint idx, ref bool stop) =>
result.Add(NSIndexPath.FromItemSection((nint)idx, _sectionIndex)));
_collectionView.InsertItems(result.ToArray());
}
if (_changes.ChangedIndexes?.Count > 0)
{
var result = new List <NSIndexPath>();
_changes.ChangedIndexes.EnumerateIndexes((nuint idx, ref bool stop) =>
result.Add(NSIndexPath.FromItemSection((nint)idx, _sectionIndex)));
_collectionView.ReloadItems(result.ToArray());
}
_changes.EnumerateMoves((fromIndex, toIndex) =>
{
_collectionView.MoveItem(NSIndexPath.FromItemSection((nint)fromIndex, _sectionIndex),
NSIndexPath.FromItemSection((nint)toIndex, _sectionIndex));
});
}, null);
}