/// <summary>
/// Returns true if TreeViewItem has children. DO NOT USE THIS PROPERTY DURING DRAG&DROP OPERATION
/// </summary>
public bool HasChildren(VirtualizingTreeView treeView)
{
if (treeView == null)
{
return(false);
}
int index = treeView.IndexOf(Item);
TreeViewItemContainerData nextItem = (TreeViewItemContainerData)treeView.GetItemContainerData(index + 1);
return(nextItem != null && nextItem.Parent == this);
}
/// <summary>
/// Get First Child of TreeViewItem
/// </summary>
/// <returns>First Child</returns>
public TreeViewItemContainerData FirstChild(VirtualizingTreeView treeView)
{
if (!HasChildren(treeView))
{
return(null);
}
int siblingIndex = treeView.IndexOf(Item);
siblingIndex++;
TreeViewItemContainerData child = (TreeViewItemContainerData)treeView.GetItemContainerData(siblingIndex);
Debug.Assert(child != null && child.Parent == this);
return(child);
}
public TreeViewItemContainerData NextChild(
VirtualizingTreeView treeView,
TreeViewItemContainerData currentChild)
{
if (currentChild == null)
{
throw new ArgumentNullException(nameof(currentChild));
}
int siblingIndex = treeView.IndexOf(currentChild.Item) + 1;
for (TreeViewItemContainerData itemContainerData = (TreeViewItemContainerData)treeView.GetItemContainerData(siblingIndex); itemContainerData != null && itemContainerData.IsDescendantOf(this); itemContainerData = (TreeViewItemContainerData)treeView.GetItemContainerData(siblingIndex))
{
if (itemContainerData.Parent == this)
{
return(itemContainerData);
}
++siblingIndex;
}
return((TreeViewItemContainerData)null);
}
/// <summary>
/// Get Last Descendant Of TreeViewItem
/// </summary>
/// <returns>Last Descendant</returns>
public TreeViewItemContainerData LastDescendant(VirtualizingTreeView treeView)
{
if (!HasChildren(treeView))
{
return(null);
}
int siblingIndex = treeView.IndexOf(Item);
TreeViewItemContainerData lastDescendant = null;
while (true)
{
siblingIndex++;
TreeViewItemContainerData child = (TreeViewItemContainerData)treeView.GetItemContainerData(siblingIndex);
if (child == null || !child.IsDescendantOf(this))
{
return(lastDescendant);
}
lastDescendant = child;
}
}