private void Transform(ChangeAwareList <TransformedItemContainer> transformed, IChangeSet <TSource> changes)
{
if (changes == null)
{
throw new ArgumentNullException(nameof(changes));
}
transformed.EnsureCapacityFor(changes);
foreach (var item in changes)
{
switch (item.Reason)
{
case ListChangeReason.Add:
{
var change = item.Item;
if (change.CurrentIndex < 0 | change.CurrentIndex >= transformed.Count)
{
transformed.Add(_containerFactory(change.Current));
}
else
{
transformed.Insert(change.CurrentIndex, _containerFactory(change.Current));
}
break;
}
case ListChangeReason.AddRange:
{
transformed.AddOrInsertRange(item.Range.Select(_containerFactory), item.Range.Index);
break;
}
case ListChangeReason.Replace:
{
var change = item.Item;
if (change.CurrentIndex == change.PreviousIndex)
{
transformed[change.CurrentIndex] = _containerFactory(change.Current);
}
else
{
transformed.RemoveAt(change.PreviousIndex);
transformed.Insert(change.CurrentIndex, _containerFactory(change.Current));
}
break;
}
case ListChangeReason.Remove:
{
var change = item.Item;
bool hasIndex = change.CurrentIndex >= 0;
if (hasIndex)
{
transformed.RemoveAt(item.Item.CurrentIndex);
}
else
{
var toremove = transformed.FirstOrDefault(t => ReferenceEquals(t.Source, t));
if (toremove != null)
{
transformed.Remove(toremove);
}
}
break;
}
case ListChangeReason.RemoveRange:
{
if (item.Range.Index >= 0)
{
transformed.RemoveRange(item.Range.Index, item.Range.Count);
}
else
{
var toremove = transformed.Where(t => ReferenceEquals(t.Source, t)).ToArray();
transformed.RemoveMany(toremove);
}
break;
}
case ListChangeReason.Clear:
{
//i.e. need to store transformed reference so we can correctly clear
var toClear = new Change <TransformedItemContainer>(ListChangeReason.Clear, transformed);
transformed.ClearOrRemoveMany(toClear);
break;
}
case ListChangeReason.Moved:
{
var change = item.Item;
bool hasIndex = change.CurrentIndex >= 0;
if (!hasIndex)
{
throw new UnspecifiedIndexException("Cannot move as an index was not specified");
}
var collection = transformed as IExtendedList <TransformedItemContainer>;
if (collection != null)
{
collection.Move(change.PreviousIndex, change.CurrentIndex);
}
else
{
var current = transformed[change.PreviousIndex];
transformed.RemoveAt(change.PreviousIndex);
transformed.Insert(change.CurrentIndex, current);
}
break;
}
}
}
}
private void Transform(ChangeAwareList <TransformedItemContainer> transformed, IChangeSet <TSource> changes)
{
if (changes == null)
{
throw new ArgumentNullException(nameof(changes));
}
foreach (var item in changes)
{
switch (item.Reason)
{
case ListChangeReason.Add:
{
var change = item.Item;
if (change.CurrentIndex < 0 | change.CurrentIndex >= transformed.Count)
{
transformed.Add(_containerFactory(change.Current, Optional <TDestination> .None, transformed.Count));
}
else
{
var converted = _containerFactory(change.Current, Optional <TDestination> .None, change.CurrentIndex);
transformed.Insert(change.CurrentIndex, converted);
}
break;
}
case ListChangeReason.AddRange:
{
var startIndex = item.Range.Index < 0 ? transformed.Count : item.Range.Index;
transformed.AddOrInsertRange(item.Range
.Select((t, idx) => _containerFactory(t, Optional <TDestination> .None, idx + startIndex)),
item.Range.Index);
break;
}
case ListChangeReason.Refresh:
{
if (_transformOnRefresh)
{
var change = item.Item;
Optional <TDestination> previous = transformed[change.CurrentIndex].Destination;
var refreshed = _containerFactory(change.Current, previous, change.CurrentIndex);
transformed[change.CurrentIndex] = refreshed;
}
else
{
transformed.RefreshAt(item.Item.CurrentIndex);
}
break;
}
case ListChangeReason.Replace:
{
var change = item.Item;
Optional <TDestination> previous = transformed[change.PreviousIndex].Destination;
if (change.CurrentIndex == change.PreviousIndex)
{
transformed[change.CurrentIndex] = _containerFactory(change.Current, previous, change.CurrentIndex);
}
else
{
transformed.RemoveAt(change.PreviousIndex);
transformed.Insert(change.CurrentIndex, _containerFactory(change.Current, Optional <TDestination> .None, change.CurrentIndex));
}
break;
}
case ListChangeReason.Remove:
{
var change = item.Item;
bool hasIndex = change.CurrentIndex >= 0;
if (hasIndex)
{
transformed.RemoveAt(change.CurrentIndex);
}
else
{
var toRemove = transformed.FirstOrDefault(t => ReferenceEquals(t.Source, change.Current));
if (toRemove != null)
{
transformed.Remove(toRemove);
}
}
break;
}
case ListChangeReason.RemoveRange:
{
if (item.Range.Index >= 0)
{
transformed.RemoveRange(item.Range.Index, item.Range.Count);
}
else
{
var toRemove = transformed.Where(t => item.Range.Any(current => ReferenceEquals(t.Source, current)));
transformed.RemoveMany(toRemove);
}
break;
}
case ListChangeReason.Clear:
{
//i.e. need to store transformed reference so we can correctly clear
var toClear = new Change <TransformedItemContainer>(ListChangeReason.Clear, transformed);
transformed.ClearOrRemoveMany(toClear);
break;
}
case ListChangeReason.Moved:
{
var change = item.Item;
bool hasIndex = change.CurrentIndex >= 0;
if (!hasIndex)
{
throw new UnspecifiedIndexException("Cannot move as an index was not specified");
}
transformed.Move(change.PreviousIndex, change.CurrentIndex);
break;
}
}
}
}
private async Task Transform(ChangeAwareList <TransformedItemContainer> transformed, IChangeSet <TSource> changes)
{
if (changes is null)
{
throw new ArgumentNullException(nameof(changes));
}
foreach (var item in changes)
{
switch (item.Reason)
{
case ListChangeReason.Add:
{
var change = item.Item;
if (change.CurrentIndex < 0 | change.CurrentIndex >= transformed.Count)
{
var container = await _containerFactory(item.Item.Current).ConfigureAwait(false);
transformed.Add(container);
}
else
{
var container = await _containerFactory(item.Item.Current).ConfigureAwait(false);
transformed.Insert(change.CurrentIndex, container);
}
break;
}
case ListChangeReason.AddRange:
{
var tasks = item.Range.Select(_containerFactory);
var containers = await Task.WhenAll(tasks).ConfigureAwait(false);
transformed.AddOrInsertRange(containers, item.Range.Index);
break;
}
case ListChangeReason.Replace:
{
var change = item.Item;
var container = await _containerFactory(item.Item.Current).ConfigureAwait(false);
if (change.CurrentIndex == change.PreviousIndex)
{
transformed[change.CurrentIndex] = container;
}
else
{
transformed.RemoveAt(change.PreviousIndex);
transformed.Insert(change.CurrentIndex, container);
}
break;
}
case ListChangeReason.Remove:
{
var change = item.Item;
bool hasIndex = change.CurrentIndex >= 0;
if (hasIndex)
{
transformed.RemoveAt(item.Item.CurrentIndex);
}
else
{
var toRemove = transformed.FirstOrDefault(t => ReferenceEquals(t.Source, t));
if (toRemove is not null)
{
transformed.Remove(toRemove);
}
}
break;
}
case ListChangeReason.RemoveRange:
{
if (item.Range.Index >= 0)
{
transformed.RemoveRange(item.Range.Index, item.Range.Count);
}
else
{
var toRemove = transformed.Where(t => ReferenceEquals(t.Source, t)).ToArray();
transformed.RemoveMany(toRemove);
}
break;
}
case ListChangeReason.Clear:
{
// i.e. need to store transformed reference so we can correctly clear
var toClear = new Change <TransformedItemContainer>(ListChangeReason.Clear, transformed);
transformed.ClearOrRemoveMany(toClear);
break;
}
case ListChangeReason.Moved:
{
var change = item.Item;
bool hasIndex = change.CurrentIndex >= 0;
if (!hasIndex)
{
throw new UnspecifiedIndexException("Cannot move as an index was not specified");
}
if (transformed is IExtendedList <TransformedItemContainer> collection)
{
collection.Move(change.PreviousIndex, change.CurrentIndex);
}
else
{
var current = transformed[change.PreviousIndex];
transformed.RemoveAt(change.PreviousIndex);
transformed.Insert(change.CurrentIndex, current);
}
break;
}
}
}
}