/// <summary>
/// Gets the outline item and its ancestors scene.
/// </summary>
/// <param name="item">The outline item.</param>
/// <returns>The <paramref name="item"/> and its ancestors of the scene.</returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="item"/> is <see langword="null"/>.
/// </exception>
public static IEnumerable <OutlineItem> GetSelfAndAncestors(this OutlineItem item)
{
if (item == null)
{
throw new ArgumentNullException(nameof(item));
}
return(TreeHelper.GetSelfAndAncestors(item, GetParentCallback));
}
public static IEnumerable <OutlineItem> GetChildren(this OutlineItem item)
{
if (item?.Children == null)
{
return(LinqHelper.Empty <OutlineItem>());
}
return(item.Children);
}
/// <summary>
/// Gets the leaves of the outline item.
/// </summary>
/// <param name="item">The outline item where to start the search.</param>
/// <returns>The leaves of the outline item.</returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="item"/> is <see langword="null"/>.
/// </exception>
public static IEnumerable <OutlineItem> GetLeaves(this OutlineItem item)
{
if (item == null)
{
throw new ArgumentNullException(nameof(item));
}
return(TreeHelper.GetLeaves(item, GetChildren));
}
/// <summary>
/// Gets the subtree (the given outline item and all of its descendants) using a depth-first or a
/// breadth-first search.
/// </summary>
/// <param name="item">The outline item.</param>
/// <param name="depthFirst">
/// If set to <see langword="true"/> then a depth-first search for descendants will be made;
/// otherwise a breadth-first search will be made.
/// </param>
/// <returns>The subtree (the given outline item and all of its descendants).</returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="item"/> is <see langword="null"/>.
/// </exception>
public static IEnumerable <OutlineItem> GetSubtree(this OutlineItem item, bool depthFirst)
{
if (item == null)
{
throw new ArgumentNullException(nameof(item));
}
return(TreeHelper.GetSubtree(item, GetChildren, depthFirst));
}
/// <overloads>
/// <summary>
/// Gets the subtree (the given outline item and all of its descendants).
/// </summary>
/// </overloads>
///
/// <summary>
/// Gets the subtree (the given outline item and all of its descendants) using a depth-first
/// search.
/// </summary>
/// <param name="item">The outline item.</param>
/// <returns>
/// The subtree (the given outline item and all of its descendants) in depth-first order.
/// </returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="item"/> is <see langword="null"/>.
/// </exception>
public static IEnumerable <OutlineItem> GetSubtree(this OutlineItem item)
{
if (item == null)
{
throw new ArgumentNullException(nameof(item));
}
return(TreeHelper.GetSubtree(item, GetChildrenCallback, true));
}
/// <summary>
/// Gets the root item.
/// </summary>
/// <param name="item">The outline item.</param>
/// <returns>The root item.</returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="item"/> is <see langword="null"/>.
/// </exception>
public static OutlineItem GetRoot(this OutlineItem item)
{
if (item == null)
{
throw new ArgumentNullException(nameof(item));
}
while (item.Parent != null)
{
item = item.Parent;
}
return(item);
}
