/// <summary>
/// Handles child collection changes.
/// </summary>
/// <param name="parent">
/// The parent.
/// </param>
/// <param name="e">
/// The <see cref="System.Collections.Specialized.NotifyCollectionChangedEventArgs"/> instance containing the event data.
/// </param>
internal void ChildCollectionChanged(TreeListBoxItem parent, NotifyCollectionChangedEventArgs e)
{
switch (e.Action)
{
case NotifyCollectionChangedAction.Remove:
case NotifyCollectionChangedAction.Move:
foreach (var item in e.OldItems)
{
var container = this.ContainerFromItem(item);
if (container != null && container.IsExpanded)
{
container.IsExpanded = false;
}
this.Items.Remove(item);
}
break;
case NotifyCollectionChangedAction.Reset:
var itemsToRemove = new List<TreeListBoxItem>();
foreach (var item in this.Items)
{
var container = this.ContainerFromItem(item);
if (container == null || !ReferenceEquals(container.ParentItem, parent))
{
continue;
}
itemsToRemove.Add(container);
}
foreach (var container in itemsToRemove)
{
if (container.IsExpanded)
{
container.IsExpanded = false;
}
this.Items.Remove(container.Content);
}
parent.IsExpanded = false;
parent.HasItems = false;
break;
case NotifyCollectionChangedAction.Replace:
// todo: remove old items and child items
throw new NotImplementedException();
}
switch (e.Action)
{
case NotifyCollectionChangedAction.Move:
case NotifyCollectionChangedAction.Add:
if (parent.IsExpanded)
{
int i;
if (e.NewStartingIndex + e.NewItems.Count < parent.Children.Count)
{
// inserted items
var followingChild = parent.Children[e.NewStartingIndex + e.NewItems.Count];
i = this.Items.IndexOf(followingChild);
}
else
{
// added items
var parentSibling = parent.GetNextSibling();
if (parentSibling == null)
{
// No sibling found, so add at the end of the list.
i = this.Items.Count;
}
else
{
// Found the sibling, so add the items before this item.
i = this.Items.IndexOf(parentSibling.Content);
//// int i0 = this.ItemContainerGenerator.IndexFromContainer(parentSibling);
}
}
if (i < 0)
{
Debug.WriteLine("TreeListBox bug.");
}
else
{
foreach (var item in e.NewItems)
{
this.parentContainerMap[item] = parent;
if (this.Items.Contains(item))
{
Debug.WriteLine("TreeListBox bug.");
}
this.Items.Insert(i++, item);
}
}
}
break;
case NotifyCollectionChangedAction.Replace:
for (int i = 0; i < e.NewItems.Count; i++)
{
this.Items[e.NewStartingIndex + i] = e.NewItems[i];
}
// todo: add new items and child items
throw new NotImplementedException();
}
parent.HasItems = parent.Children.Cast<object>().Any();
}
/// <summary>
/// Inserts the specified items in the tree.
/// </summary>
/// <param name="parentContainer">The parent container.</param>
/// <param name="newItems">The new items.</param>
/// <param name="newStartingIndex">New index of the starting.</param>
private void InsertItems(TreeListBoxItem parentContainer, IList newItems, int newStartingIndex)
{
// Find the index where the new items should be added
int i;
if (newStartingIndex + newItems.Count < parentContainer.Children.Count)
{
// inserted items
var followingChild = parentContainer.Children[newStartingIndex + newItems.Count];
i = this.Items.IndexOf(followingChild);
}
else
{
// added items
var parentSibling = parentContainer.GetNextSibling();
if (parentSibling == null)
{
// No sibling found, so add at the end of the list.
i = this.Items.Count;
}
else
{
// Found the sibling, so add the items before this item.
i = this.Items.IndexOf(parentSibling.Content);
}
}
if (i < 0)
{
#if !DEBUG
throw new InvalidOperationException("Could not get parent index in TreeListBox.");
#else
System.Diagnostics.Trace.WriteLine("Could not get parent index in TreeListBox.");
#endif
}
foreach (var item in newItems)
{
this.InsertItem(i, item, parentContainer.Content);
}
}
