/// <summary>
/// Removes items from the tree.
/// </summary>
/// <param name="context">The remove context.</param>
/// <param name="item">The item from which to remove children.</param>
protected virtual void RemoveChildren(IRemoveItemContext context, object item)
{
ExtendedTreeViewItemBase?ItemContainer = ContainerFromItem(item);
if ((ItemContainer != null && ItemContainer.IsExpanded) || (ItemContainer == null && IsItemExpandedAtStart))
{
IList Children = GetItemChildren(item);
#if NETCOREAPP3_1
foreach (object?ChildItem in Children)
{
if (ChildItem != null)
{
RemoveChildren(context, ChildItem);
}
}
#else
foreach (object ChildItem in Children)
{
RemoveChildren(context, ChildItem);
}
#endif
}
if (context != null)
{
InternalRemove(context.ShownIndex, item);
context.NextIndex();
}
if (ExpandedChildren.ContainsKey(item))
{
ExpandedChildren.Remove(item);
}
}
/// <summary>
/// Called when children of an item have been removed.
/// </summary>
/// <param name="item">The item.</param>
/// <param name="startIndex">Index of the first removed child.</param>
/// <param name="itemList">The list of removed children.</param>
protected virtual void OnItemRemoveChildren(object item, int startIndex, IList itemList)
{
NotifyPreviewCollectionModified(TreeViewCollectionOperation.Remove);
if (IsExpanded(item))
{
int ShownPreviousChildrenCount = VisibleChildren.IndexOf(item);
ShownPreviousChildrenCount += CountPreviousChildrenExpanded(item, startIndex, -1);
int ShownIndex = ShownPreviousChildrenCount;
IRemoveItemContext Context = CreateRemoveItemContext(item, ShownIndex);
Context.Start();
#if NETCOREAPP3_1
foreach (object?ChildItem in itemList)
{
if (ChildItem != null)
{
RemoveChildren(Context, ChildItem);
}
}
#else
foreach (object ChildItem in itemList)
{
RemoveChildren(Context, ChildItem);
}
#endif
Context.Complete();
Context.Close();
}
NotifyCollectionModified(TreeViewCollectionOperation.Remove);
}
/// <summary>
/// Called when children of an item are reset.
/// </summary>
/// <param name="item">The item.</param>
protected virtual void OnItemResetChildren(object item)
{
NotifyPreviewCollectionModified(TreeViewCollectionOperation.Remove);
if (IsExpanded(item))
{
object?ParentItem = GetItemParent(item);
int StartIndex;
int RemoveCount;
if (ParentItem != null)
{
StartIndex = VisibleChildren.IndexOf(item) + 1;
IList Siblings = GetItemChildren(ParentItem);
int ItemIndex = Siblings.IndexOf(item);
if (ItemIndex + 1 < Siblings.Count)
{
object NextItem = Siblings[ItemIndex + 1] !;
int EndIndex = VisibleChildren.IndexOf(NextItem);
RemoveCount = EndIndex - StartIndex;
}
else
{
RemoveCount = CountVisibleChildren(item);
}
}
else
{
StartIndex = 1;
RemoveCount = VisibleChildren.Count - 1;
}
IRemoveItemContext Context = CreateRemoveItemContext(item, StartIndex);
Context.Start();
for (int i = 0; i < RemoveCount; i++)
{
object RemovedItem = VisibleChildren[Context.ShownIndex];
InternalRemove(Context.ShownIndex, RemovedItem);
Context.NextIndex();
if (ExpandedChildren.ContainsKey(RemovedItem))
{
ExpandedChildren.Remove(RemovedItem);
}
}
Context.Complete();
Context.Close();
}
NotifyCollectionModified(TreeViewCollectionOperation.Remove);
}
private void OnItemMoveChildrenPreviousAfter(object item, int oldIndex, int newIndex, IList itemList)
{
int ShownPreviousChildrenCount = VisibleChildren.IndexOf(item);
int RemoveIndex = ShownPreviousChildrenCount;
RemoveIndex += CountPreviousChildrenExpanded(item, oldIndex + 1, newIndex);
IRemoveItemContext RemoveContext = CreateRemoveItemContext(item, RemoveIndex);
RemoveContext.Start();
#if NETCOREAPP3_1
foreach (object?ChildItem in itemList)
{
if (ChildItem != null)
{
RemoveChildren(RemoveContext, ChildItem);
}
}
#else
foreach (object ChildItem in itemList)
{
RemoveChildren(RemoveContext, ChildItem);
}
#endif
RemoveContext.Complete();
RemoveContext.Close();
int InsertIndex = ShownPreviousChildrenCount;
InsertIndex += CountPreviousChildrenExpanded(item, newIndex, -1);
IInsertItemContext InsertContext = CreateInsertItemContext(item, InsertIndex);
InsertContext.Start();
#if NETCOREAPP3_1
foreach (object?ChildItem in itemList)
{
if (ChildItem != null)
{
InsertChildren(InsertContext, ChildItem, item);
}
}
#else
foreach (object ChildItem in itemList)
{
InsertChildren(InsertContext, ChildItem, item);
}
#endif
InsertContext.Complete();
InsertContext.Close();
}
