async Task Remove(NotifyCollectionChangedEventArgs args)
{
var startIndex = args.OldStartingIndex;
if (startIndex < 0)
{
// INCC implementation isn't giving us enough information to know where the removed items were in the
// collection. So the best we can do is a ReloadData()
await Reload();
return;
}
if (ReloadRequired())
{
await Reload();
return;
}
// If we have a start index, we can be more clever about removing the item(s) (and get the nifty animations)
var count = args.OldItems.Count;
Count -= count;
// Queue up the updates to the UICollectionView
BatchUpdate(() => _collectionView.DeleteItems(CreateIndexesFrom(startIndex, count)));
}
void Remove(NotifyCollectionChangedEventArgs args)
{
var startIndex = args.OldStartingIndex > -1 ? args.OldStartingIndex : _itemsSource.IndexOf(args.OldItems[0]);
var count = args.OldItems.Count;
_collectionView.DeleteItems(CreateIndexesFrom(startIndex, count));
}
void Remove(NotifyCollectionChangedEventArgs args)
{
if (NotLoadedYet())
{
_collectionView.ReloadData();
return;
}
var startIndex = args.OldStartingIndex;
if (startIndex < 0)
{
// INCC implementation isn't giving us enough information to know where the removed items were in the
// collection. So the best we can do is a ReloadData()
Reload();
return;
}
// If we have a start index, we can be more clever about removing the item(s) (and get the nifty animations)
var count = args.OldItems.Count;
_collectionView.PerformBatchUpdates(() =>
{
_collectionView.DeleteItems(CreateIndexesFrom(startIndex, count));
Count -= count;
}, null);
}
void Remove(NotifyCollectionChangedEventArgs args)
{
var startIndex = args.OldStartingIndex;
if (startIndex < 0)
{
// INCC implementation isn't giving us enough information to know where the removed items were in the
// collection. So the best we can do is a ReloadData()
Reload();
return;
}
// If we have a start index, we can be more clever about removing the item(s) (and get the nifty animations)
var count = args.OldItems.Count;
_collectionView.PerformBatchUpdates(() =>
{
_collectionView.DeleteItems(CreateIndexesFrom(startIndex, count));
if (!_grouped && _collectionView.NumberOfSections() != GroupCount)
{
// We had a non-grouped list with items, and we're removing the last one;
// we also need to remove the group it was in
_collectionView.DeleteSections(new NSIndexSet(0));
}
}, null);
}
/// <summary>
/// Compares the album state before and after the drag to delete items in the collection view that represent photos moved elsewhere.
/// </summary>
void DeleteItems(UICollectionView collectionView)
{
var albumAfterDrag = album;
if (albumBeforeDrag is null || albumAfterDrag is null)
{
return;
}
var indexPathsToDelete = new List <NSIndexPath> ();
for (var i = 0; i < albumBeforeDrag.Photos.Count; i++)
{
var photo = albumBeforeDrag.Photos[i];
if (!albumAfterDrag.Contains(photo))
{
indexPathsToDelete.Add(NSIndexPath.FromItemSection(i, 0));
}
}
if (indexPathsToDelete.Count > 0)
{
collectionView.PerformBatchUpdates(() => {
collectionView.DeleteItems(indexPathsToDelete.ToArray());
}, (finished) => {});
}
}
private void RemoveItem(int index)
{
CollectionResult.PerformBatchUpdates(delegate {
ResultItems.RemoveAt(index);
CollectionResult.DeleteItems(new NSIndexPath[] { NSIndexPath.FromRowSection(index, 0) });
}, null);
HeightOfCollection.Constant = CollectionResult.CollectionViewLayout.CollectionViewContentSize.Height;
}
private async Task DeleteItemsAsync(UICollectionView collectionView, IReadOnlyCollection <int> indexes)
{
await collectionView.PerformBatchUpdatesAsync(() => {
ItemsCount -= indexes.Count;
InvokeHeightWillChange();
collectionView.DeleteItems(indexes.ToNSIndexPaths().ToArray());
});
}
public void RemoveItemView()
{
if (!IsEditing)
{
throw new InvalidOperationException("Set IsEditing before calling insert/update/remove");
}
removeCalendarItem(editingItemIndexPath);
collectionView.DeleteItems(new NSIndexPath[] { editingItemIndexPath });
}
public void PhotoLibraryDidChange(PHChange changeInstance)
{
// Check if there are changes to the assets we are showing.
var collectionChanges = changeInstance.GetFetchResultChangeDetails(AssetsFetchResults);
if (collectionChanges == null)
{
return;
}
DispatchQueue.MainQueue.DispatchAsync(() => {
// Get the new fetch result.
AssetsFetchResults = collectionChanges.FetchResultAfterChanges;
UICollectionView collectionView = CollectionView;
if (collectionChanges.HasIncrementalChanges || !collectionChanges.HasMoves)
{
collectionView.PerformBatchUpdates(() => {
var removedIndexes = collectionChanges.RemovedIndexes;
if (removedIndexes != null && removedIndexes.Count > 0)
{
collectionView.DeleteItems(removedIndexes.GetIndexPaths(0));
}
var insertedIndexes = collectionChanges.InsertedIndexes;
if (insertedIndexes != null && insertedIndexes.Count > 0)
{
collectionView.InsertItems(insertedIndexes.GetIndexPaths(0));
}
var changedIndexes = collectionChanges.ChangedIndexes;
if (changedIndexes != null && changedIndexes.Count > 0)
{
collectionView.ReloadItems(changedIndexes.GetIndexPaths(0));
}
}, null);
}
else
{
collectionView.ReloadData();
}
ResetCachedAssets();
});
}
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);
}
void HandleChatPromptTypesCollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
collectionView.PerformBatchUpdates(() =>
{
var safetyCheckAdded = e.NewItems != null && e.NewItems.Count > 0;
if (safetyCheckAdded)
{
collectionView.InsertItems(new NSIndexPath[] { NSIndexPath.FromItemSection(e.NewStartingIndex, 0) });
}
else
{
collectionView.DeleteItems(new NSIndexPath[] { NSIndexPath.FromItemSection(2, 0) });
}
((UICollectionViewFlowLayout)collectionView.CollectionViewLayout).ItemSize = new CGSize
{
Height = Shared.Constants.PulloutBottomMargin,
Width = UIScreen.MainScreen.Bounds.Width / (safetyCheckAdded ? 3 : 2),
};
collectionView.CollectionViewLayout.InvalidateLayout();
}, null);
}
private void HandleCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
if (_view == null)
{
return;
}
Action act = () =>
{
switch (e.Action)
{
case NotifyCollectionChangedAction.Add:
{
var count = e.NewItems.Count;
var paths = new NSIndexPath[count];
for (var i = 0; i < count; i++)
{
paths[i] = NSIndexPath.FromRowSection(e.NewStartingIndex + i, 0);
}
_view.InsertItems(paths);
}
break;
case NotifyCollectionChangedAction.Remove:
{
var count = e.OldItems.Count;
var paths = new NSIndexPath[count];
for (var i = 0; i < count; i++)
{
var index = NSIndexPath.FromRowSection(e.OldStartingIndex + i, 0);
paths[i] = index;
var item = e.OldItems[i];
if (Equals(SelectedItem, item))
{
SelectedItem = default(TItem);
}
}
_view.DeleteItems(paths);
}
break;
default:
_view.ReloadData();
break;
}
};
var isMainThread = Thread.CurrentThread == _mainThread;
if (isMainThread)
{
act();
}
else
{
NSOperationQueue.MainQueue.AddOperation(act);
NSOperationQueue.MainQueue.WaitUntilAllOperationsAreFinished();
}
}
public virtual void DeleteItems(IndexPath[] indexPaths)
{
_collectionView.DeleteItems(indexPaths);
}