/// <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 static void ExpandTo <T>(this VirtualizingTreeView treeView, T item, Func <T, T> getParent)
{
if (item == null)
{
return;
}
ItemContainerData containerData = treeView.GetItemContainerData(item);
if (containerData == null)
{
treeView.ExpandTo(getParent(item), getParent);
treeView.Expand(item);
}
else
{
treeView.Expand(item);
}
}
public static void ExpandTo <T>(
this VirtualizingTreeView treeView,
T item,
Func <T, T> getParent)
{
if ((object)item == null)
{
return;
}
if (treeView.GetItemContainerData((object)item) == null)
{
treeView.ExpandTo <T>(getParent(item), getParent);
treeView.Expand((object)item);
}
else
{
treeView.Expand((object)item);
}
}
/// <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;
}
}
public TreeViewItemContainerData LastDescendant(
VirtualizingTreeView treeView)
{
if (!this.HasChildren(treeView))
{
return((TreeViewItemContainerData)null);
}
int siblingIndex = treeView.IndexOf(this.Item);
TreeViewItemContainerData itemContainerData1 = (TreeViewItemContainerData)null;
while (true)
{
++siblingIndex;
TreeViewItemContainerData itemContainerData2 = (TreeViewItemContainerData)treeView.GetItemContainerData(siblingIndex);
if (itemContainerData2 != null && itemContainerData2.IsDescendantOf(this))
{
itemContainerData1 = itemContainerData2;
}
else
{
break;
}
}
return(itemContainerData1);
}
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);
}
