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);
}
}
}
