AcManager.Controls.AcListPage.SelectedAcObject_Outdated C# (CSharp) Method

        private void SelectedAcObject_Outdated(object sender, EventArgs e) {
            SetCurrentValue(SelectedSourceProperty, null);

            var oldItem = _selectedWrapper.Value;
            var id = (sender as AcObjectNew)?.Id;
            if (id == null) return;

            var newItem = ItemsSource.OfType<AcItemWrapper>().GetByIdOrDefault(id);
            if (oldItem != null && newItem == oldItem) {
                CurrentObject = newItem.Loaded();
            } else if (newItem != null) {
                ItemsSource.MoveCurrentTo(newItem);
            } else {
                var replacement = ItemsSource.OfType<AcItemWrapper>().FirstOrDefault(x => (x.Value as AcCommonObject)?.PreviousId == id);
                if (replacement != null) {
                    ItemsSource.MoveCurrentTo(replacement);
                    return;
                }

                if (CurrentObject != null) {
                    SetCurrentValue(SelectedSourceProperty, AcObjectsUriManager.GetUri(CurrentObject));
                } else {
                    ItemsSource.MoveCurrentToFirst();
                }
            }
        }