public static bool IsFirstChildOfParent(this OutlineItem item)
{
if (item.IndexInParent() == 0)
{
return(true);
}
if (item.IndexInParent() == -1)
{
throw new InvalidOperationException();
}
return(false);
}
public static void ReplaceWith(this OutlineItem itemToReplace, OutlineItem item)
{
var parent = itemToReplace.ParentItem;
var index = itemToReplace.IndexInParent();
parent.Items.RemoveAt(index);
parent.Items.Insert(index, item);
}
public static bool IsLastChildOfParent(this OutlineItem item)
{
var indexInParent = item.IndexInParent();
if (indexInParent != -1)
{
if (item.ParentItem.Items.Count == indexInParent + 1)
{
return(true);
}
}
throw new InvalidOperationException();
}
public static OutlineItem PreviousSibling(this OutlineItem item)
{
var indexInParent = item.IndexInParent();
if (indexInParent == -1)
{
return(null);
}
if (!item.IsFirstChildOfParent())
{
return(item.ParentItem.Items[indexInParent - 1]);
}
return(null);
}
public static OutlineItem NextSibling(this OutlineItem item)
{
var indexInParent = item.IndexInParent();
if (indexInParent == -1)
{
return(null);
}
if (!item.IsLastChildOfParent())
{
return(item.ParentItem.Items[indexInParent + 1]);
}
return(null);
}
