private void Model_CollectionChanged()

in sources/Google.Solutions.Mvvm/Controls/BindableListView.cs [253:335]
68 lines of code
15 McCabe index (conditional complexity)

        private void Model_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            switch (e.Action)
            {
                case NotifyCollectionChangedAction.Add:
                    AddViewItems(e.NewItems.OfType<TModelItem>());
                    break;

                case NotifyCollectionChangedAction.Remove:
                    foreach (var oldModelItem in e.OldItems.OfType<TModelItem>())
                    {
                        var oldViewItem = FindViewItem(oldModelItem);
                        if (oldViewItem != null)
                        {
                            UnobserveItem(oldModelItem);
                            this.Items.Remove(oldViewItem);
                        }
                    }

                    break;

                case NotifyCollectionChangedAction.Replace:
                    if (e.OldItems.Count == e.NewItems.Count)
                    {
                        var count = e.OldItems.Count;
                        for (var i = 0; i < count; i++)
                        {
                            var oldModelItem = (TModelItem)e.OldItems[i];
                            var newModelItem = (TModelItem)e.NewItems[i];

                            var viewItem = FindViewItem(oldModelItem);
                            if (viewItem != null)
                            {
                                UnobserveItem(oldModelItem);
                                ObserveItem(newModelItem);

                                viewItem.Tag = newModelItem;

                                foreach (ColumnHeader column in this.Columns)
                                {
                                    viewItem.SubItems[column.Index].Text =
                                        ExtractColumnValue(column.Index, newModelItem);
                                }
                            }
                        }
                    }

                    break;

                case NotifyCollectionChangedAction.Move:
                    foreach (var oldItem in e.OldItems.OfType<TModelItem>())
                    {
                        var viewItem = FindViewItem(oldItem);
                        if (oldItem != null)
                        {
                            this.Items.Remove(viewItem);
                            this.Items.Insert(e.NewStartingIndex, viewItem);
                        }
                    }

                    break;

                case NotifyCollectionChangedAction.Reset:
                    // Reload everything.
                    UnobserveItems(this.Items.Cast<ListViewItem>()
                        .Select(i => i.Tag)
                        .OfType<TModelItem>());

                    this.Items.Clear();
                    AddViewItems(this.model.EnsureNotNull());

                    break;

                default:
                    break;
            }

            if (this.AutoResizeColumnsOnUpdate)
            {
                AutoResizeColumns(ColumnHeaderAutoResizeStyle.ColumnContent);
                AutoResizeColumns(ColumnHeaderAutoResizeStyle.HeaderSize);
            }
        }