private IChangeSet <T> Page(IChangeSet <T> changeset = null) { if (changeset != null) { _all.Clone(changeset); } var previous = _paged; int pages = CalculatePages(); int page = _parameters.Page > pages ? pages : _parameters.Page; int skip = _parameters.Size * (page - 1); var current = _all.Skip(skip) .Take(_parameters.Size) .ToList(); var adds = current.Except(previous); var removes = previous.Except(current); _paged.RemoveMany(removes); adds.ForEach(t => { var index = current.IndexOf(t); _paged.Insert(index, t); }); var startIndex = skip; var moves = changeset.EmptyIfNull() .Where(change => change.Reason == ListChangeReason.Moved && change.MovedWithinRange(startIndex, startIndex + _parameters.Size)); foreach (var change in moves) { //check whether an item has moved within the same page var currentIndex = change.Item.CurrentIndex - startIndex; var previousIndex = change.Item.PreviousIndex - startIndex; _paged.Move(previousIndex, currentIndex); } //find replaces [Is this ever the case that it can be reached] for (int i = 0; i < current.Count; i++) { var currentItem = current[i]; var previousItem = previous[i]; if (ReferenceEquals(currentItem, previousItem)) { continue; } var index = _paged.IndexOf(currentItem); _paged.Move(i, index); } return(_paged.CaptureChanges()); }
private IChangeSet <T> Virtualise(List <T> all, ChangeAwareList <T> virtualised, IChangeSet <T> changeset = null) { if (changeset != null) { all.Clone(changeset); } var previous = virtualised; var current = all.Skip(_parameters.StartIndex) .Take(_parameters.Size) .ToList(); var adds = current.Except(previous); var removes = previous.Except(current); virtualised.RemoveMany(removes); adds.ForEach(t => { var index = current.IndexOf(t); virtualised.Insert(index, t); }); var moves = changeset.EmptyIfNull() .Where(change => change.Reason == ListChangeReason.Moved && change.MovedWithinRange(_parameters.StartIndex, _parameters.StartIndex + _parameters.Size)); foreach (var change in moves) { //check whether an item has moved within the same page var currentIndex = change.Item.CurrentIndex - _parameters.StartIndex; var previousIndex = change.Item.PreviousIndex - _parameters.StartIndex; virtualised.Move(previousIndex, currentIndex); } //find replaces [Is this ever the case that it can be reached] for (var i = 0; i < current.Count; i++) { var currentItem = current[i]; var previousItem = previous[i]; if (ReferenceEquals(currentItem, previousItem)) { continue; } var index = virtualised.IndexOf(currentItem); virtualised.Move(i, index); } return(virtualised.CaptureChanges()); }
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 Insert(ChangeAwareList <T> target, T item) { var index = GetInsertPosition(target, item); target.Insert(index, item); }
private void Insert(T item) { var index = GetInsertPosition(item); _innerList.Insert(index, item); }