/// <summary>
/// Called when a new item container is materialized, to set its selected state.
/// </summary>
/// <param name="sender">The event sender.</param>
/// <param name="e">The event args.</param>
private void ContainerMaterialized(object sender, ItemContainerEventArgs e)
{
var selectedItem = SelectedItem;
if (selectedItem != null)
{
foreach (var container in e.Containers)
{
if (container.Item == selectedItem)
{
((TreeViewItem)container.ContainerControl).IsSelected = true;
if (AutoScrollToSelectedItem)
{
DispatcherTimer.RunOnce(
container.ContainerControl.BringIntoView,
TimeSpan.Zero);
}
break;
}
}
}
}
private void TreeViewItemMaterialized(object sender, ItemContainerEventArgs e)
{
var item = (TreeViewItem)e.Containers[0].ContainerControl;
item.TemplateApplied += TreeViewItemTemplateApplied;
}
/// <summary>
/// Called when containers are dematerialized for the <see cref="ItemsControl"/> by its
/// <see cref="ItemContainerGenerator"/>.
/// </summary>
/// <param name="e">The details of the containers.</param>
protected virtual void OnContainersDematerialized(ItemContainerEventArgs e)
{
var toRemove = new List<ILogical>();
foreach (var container in e.Containers)
{
// If the item is its own container, then it will be removed from the logical tree
// when it is removed from the Items collection.
if (container.ContainerControl != container.Item)
{
toRemove.Add(container.ContainerControl);
}
}
LogicalChildren.RemoveAll(toRemove);
}
/// <inheritdoc/>
protected override void OnContainersMaterialized(ItemContainerEventArgs e)
{
base.OnContainersMaterialized(e);
var selectedIndex = SelectedIndex;
var selectedContainer = e.Containers
.FirstOrDefault(x => (x.ContainerControl as ISelectable)?.IsSelected == true);
if (selectedContainer != null)
{
SelectedIndex = selectedContainer.Index;
}
else if (selectedIndex >= e.StartingIndex &&
selectedIndex < e.StartingIndex + e.Containers.Count)
{
var container = e.Containers[selectedIndex - e.StartingIndex];
if (container.ContainerControl != null)
{
MarkContainerSelected(container.ContainerControl, true);
}
}
}
/// <summary>
/// Called when new containers are materialized for the <see cref="ItemsControl"/> by its
/// <see cref="ItemContainerGenerator"/>.
/// </summary>
/// <param name="e">The details of the containers.</param>
protected virtual void OnContainersMaterialized(ItemContainerEventArgs e)
{
var toAdd = new List<ILogical>();
foreach (var container in e.Containers)
{
// If the item is its own container, then it will be added to the logical tree when
// it was added to the Items collection.
if (container.ContainerControl != container.Item)
{
toAdd.Add(container.ContainerControl);
}
}
LogicalChildren.AddRange(toAdd);
}
