void item_LayoutStateChangeCompleted(object sender, LayoutStateChangeEventArgs e)
{
if (e.NewState == LayoutState.Unloaded)
{
var item = sender as AnimatedLayoutControl;
item.LayoutStateChangeCompleted -= new EventHandler <LayoutStateChangeEventArgs>(item_LayoutStateChangeCompleted);
BaseItemsSource.Clear();
VisualItems.Clear();
isUnloading = false;
var itemsToAdd = NewRequestedItems.ToArray();
NewRequestedItems.Clear();
foreach (var newItem in itemsToAdd)
{
BaseItemsSource.Add(newItem);
}
}
}
void ObservableItems_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
switch (e.Action)
{
case NotifyCollectionChangedAction.Add:
foreach (var item in e.NewItems)
{
if (isUnloading)
{
NewRequestedItems.Add(item);
}
else
{
BaseItemsSource.Add(item);
}
}
break;
case NotifyCollectionChangedAction.Reset:
if (!IsVisible)
{
BaseItemsSource.Clear();
VisualItems.Clear();
isUnloading = false;
}
else if (VisualItems.Count > 0)
{
isUnloading = true;
AnimatedLayoutControl lastItem = null;
foreach (var item in VisualItems)
{
if ((lastItem == null) || (item.BeginTime > lastItem.BeginTime))
{
lastItem = item;
}
item.LayoutState = LayoutState.Unloaded;
}
lastItem.LayoutStateChangeCompleted += new EventHandler <LayoutStateChangeEventArgs>(item_LayoutStateChangeCompleted);
}
break;
}
}