protected virtual void PrepareItemsOverride(bool force)
        {
            if (_panelTemplateApplied && _itemsHostPanel != null && !force)
            {
                return;
            }
            // Check properties which are necessary in each case
            if (ItemsPanel == null)
            {
                return;
            }

            ItemsPresenter presenter = FindItemsPresenter();

            if (presenter == null)
            {
                return;
            }

            if (!_panelTemplateApplied)
            {
                _panelTemplateApplied = true;
                presenter.ApplyTemplate(ItemsPanel);
                _itemsHostPanel = null;
            }

            if (_itemsHostPanel == null)
            {
                _itemsHostPanel = presenter.ItemsHostPanel;
            }
            if (_itemsHostPanel == null)
            {
                return;
            }

            // Albert: We cannot exit the method if one of the styles is not set because the styles
            // might be found by the SkinEngine's automatic Style assignment (FrameworkElement.CopyDefaultStyle)
            //if (ItemContainerStyle == null || ItemTemplate == null)
            //  return;

            IEnumerable itemsSource = ItemsSource;

            if (itemsSource == null)
            { // In this case, we must set up the items control using the Items property
                ItemCollection items            = _items;
                ItemCollection preparedChildren = new ItemCollection();
                bool           setItems         = false;
                if (items == null)
                {
                    // Restore items from "ItemsSource mode" where they have been set to null
                    items    = new ItemCollection();
                    setItems = true;
                }
                foreach (object item in items)
                {
                    object           itemCopy = MpfCopyManager.DeepCopyWithFixedObject(item, this); // Keep this object as LogicalParent
                    FrameworkElement element  = itemCopy as FrameworkElement ?? PrepareItemContainer(itemCopy);
                    if (element.Style == null && element is ContentControl)
                    {
                        element.Style = ItemContainerStyle;
                    }
                    element.LogicalParent = this;
                    preparedChildren.Add(element);
                }
                presenter.SetDataStrings(BuildDataStrings(items));

                SetPreparedItems(setItems, setItems ? items : null, true, preparedChildren);
            }
            else
            {
                IList <object>  l    = new List <object>();
                ISynchronizable sync = itemsSource as ISynchronizable;
                if (sync != null)
                {
                    lock (sync.SyncRoot)
                        CollectionUtils.AddAll(l, itemsSource);
                }
                else
                {
                    CollectionUtils.AddAll(l, itemsSource);
                }

                presenter.SetDataStrings(BuildDataStrings(l));

                var vsp = _itemsHostPanel as IVirtualizingPanel;
                if (vsp != null)
                {
                    // In this case, the VSP will generate its items by itself
                    ListViewItemGenerator lvig = new ListViewItemGenerator();
                    lvig.Initialize(this, l, ItemContainerStyle, ItemTemplate);
                    SimplePropertyDataDescriptor dd;
                    if (SimplePropertyDataDescriptor.CreateSimplePropertyDataDescriptor(this, "IsEmpty", out dd))
                    {
                        SetValueInRenderThread(dd, l.Count == 0);
                    }
                    vsp.SetItemProvider(lvig);

                    SetPreparedItems(true, null, false, null);
                }
                else
                {
                    ItemCollection preparedItems = new ItemCollection();
                    preparedItems.AddAll(l.Select(PrepareItemContainer));

                    SetPreparedItems(true, null, true, preparedItems);
                }
            }
        }