internal void HandleItemsChanged(NotifyCollectionChangedEventArgs e)
{
if (this.ItemsHost == null)
{
return;
}
IGeneratorHost host = (IGeneratorHost)this;
if (e.Action == NotifyCollectionChangedAction.Reset)
{
this.Refresh();
}
else if (e.Action == NotifyCollectionChangedAction.Add)
{
object item = e.NewItems[0];
DependencyObject container = host.GetContainerForItem(item, null);
if (container != item)
{
container.SetValue(FrameworkElement.DataContextProperty, item);
}
host.PrepareItemContainer(container, item);
this.ItemContainerGenerator.INTERNAL_RegisterContainer(container, item);
this.ItemsHost.Children.Insert(e.NewStartingIndex, (UIElement)container);
}
else if (e.Action == NotifyCollectionChangedAction.Remove)
{
this.ItemContainerGenerator.INTERNAL_TryUnregisterContainer(
this.ItemsHost.Children[e.OldStartingIndex],
e.OldItems[0]);
this.ItemsHost.Children.RemoveAt(e.OldStartingIndex);
}
else if (e.Action == NotifyCollectionChangedAction.Replace)
{
this.ItemContainerGenerator.INTERNAL_TryUnregisterContainer(
this.ItemsHost.Children[e.OldStartingIndex],
e.OldItems[0]);
object item = e.NewItems[0];
DependencyObject container = host.GetContainerForItem(item, null);
if (container != item)
{
container.SetValue(FrameworkElement.DataContextProperty, item);
}
host.PrepareItemContainer(container, item);
this.ItemContainerGenerator.INTERNAL_RegisterContainer(container, item);
this.ItemsHost.Children[e.OldStartingIndex] = (UIElement)container;
}
else
{
throw new NotSupportedException(string.Format("Unexpected collection change action '{0}'.", e.Action));
}
}
public FrameworkElement Generate(int index)
{
GeneratedItemContainer container = generatedContainers.FirstOrDefault(c => c.Index == index);
if (container == null)
{
container = new GeneratedItemContainer(host.GetContainerForItem(host.View[index]), host.View[index], index);
host.PrepareContainerForItem(container.Item, container.Container);
generatedContainers.Add(container);
}
return(container.Container);
}
internal void Refresh(bool reuseContainers)
{
IGeneratorHost host = this;
DependencyObject[] oldContainers = new DependencyObject[Math.Max(this.ItemsHost.Children.Count, this.Items.CountInternal)];
// First we need to get the containers and their associated item,
// or they will be lost before being able to clear them.
int containersCount = this.ItemsHost.Children.Count;
object[] oldItems = new object[containersCount];
for (int i = 0; i < containersCount; ++i)
{
DependencyObject container = this.ItemsHost.InternalChildren[i];
oldContainers[i] = container;
oldItems[i] = this.ItemContainerGenerator.ItemFromContainer(container);
}
if (!reuseContainers)
{
this.ItemsHost.InternalChildren.Clear();
this.ItemContainerGenerator.INTERNAL_Clear();
for (int i = 0; i < containersCount; ++i)
{
host.ClearContainerForItem(oldContainers[i], oldItems[i]);
}
}
int count = this.Items.CountInternal;
for (int i = 0; i < count; ++i)
{
object item = this.Items[i];
DependencyObject recycledContainer = reuseContainers ? oldContainers[i] : null;
DependencyObject container = host.GetContainerForItem(item, recycledContainer);
if (!reuseContainers)
{
this.ItemContainerGenerator.INTERNAL_RegisterContainer(container, item);
if (container != item)
{
container.SetValue(FrameworkElement.DataContextProperty, item);
}
this.ItemsHost.Children.Add((UIElement)container);
}
host.PrepareItemContainer(container, item);
}
}
private void OnItemAdded(object item, int position)
{
IGeneratorHost host = this;
DependencyObject container = host.GetContainerForItem(item, null);
this.ItemContainerGenerator.INTERNAL_RegisterContainer(container, item);
if (container != item)
{
container.SetValue(DataContextProperty, item);
}
this.ItemsHost.Children.Insert(position, (UIElement)container);
host.PrepareItemContainer(container, item);
}
internal void Refresh()
{
IGeneratorHost host = (IGeneratorHost)this;
this.ItemsHost.Children.Clear();
this.ItemContainerGenerator.INTERNAL_Clear();
foreach (var item in this.Items)
{
DependencyObject container = host.GetContainerForItem(item, null);
if (container != item)
{
container.SetValue(FrameworkElement.DataContextProperty, item);
}
host.PrepareItemContainer(container, item);
this.ItemContainerGenerator.INTERNAL_RegisterContainer(container, item);
this.ItemsHost.Children.Add((UIElement)container);
}
}