Add tree example

src/Spectre.Console/Extensions/BarGraphExtensions.cs

@@ -72,7 +72,7 @@ namespace Spectre.Console
 
             foreach (var item in items)
             {
-                AddItem<T>(chart, item);
+                AddItem(chart, item);
             }
 
             return chart;

src/Spectre.Console/Extensions/HasTreeNodeExtensions.cs

@@ -1,3 +1,6 @@
+using System;
+using Spectre.Console.Rendering;
+
 namespace Spectre.Console
 {
     /// <summary>
@@ -6,21 +9,68 @@ namespace Spectre.Console
     public static class HasTreeNodeExtensions
     {
         /// <summary>
-        /// Adds a child to the end of the node's list of children.
+        /// Adds a child tree node.
         /// </summary>
         /// <typeparam name="T">An object type with tree nodes.</typeparam>
         /// <param name="obj">The object that has tree nodes.</param>
-        /// <param name="child">Child to be added.</param>
+        /// <param name="renderable">The renderable to add.</param>
         /// <returns>The same instance so that multiple calls can be chained.</returns>
-        public static T AddChild<T>(this T obj, TreeNode child)
+        public static T AddNode<T>(this T obj, IRenderable renderable)
             where T : class, IHasTreeNodes
         {
             if (obj is null)
             {
-                throw new System.ArgumentNullException(nameof(obj));
+                throw new ArgumentNullException(nameof(obj));
             }
 
-            obj.Children.Add(child);
+            obj.Children.Add(new TreeNode(renderable));
+            return obj;
+        }
+
+        /// <summary>
+        /// Adds a child tree node.
+        /// </summary>
+        /// <typeparam name="T">An object type with tree nodes.</typeparam>
+        /// <param name="obj">The object that has tree nodes.</param>
+        /// <param name="renderable">The renderable to add.</param>
+        /// <param name="config">An action that can be used to configure the created node further.</param>
+        /// <returns>The same instance so that multiple calls can be chained.</returns>
+        public static T AddNode<T>(this T obj, IRenderable renderable, Action<TreeNode> config)
+            where T : class, IHasTreeNodes
+        {
+            if (obj is null)
+            {
+                throw new ArgumentNullException(nameof(obj));
+            }
+
+            if (config is null)
+            {
+                throw new ArgumentNullException(nameof(config));
+            }
+
+            var node = new TreeNode(renderable);
+            config(node);
+
+            obj.Children.Add(node);
+            return obj;
+        }
+
+        /// <summary>
+        /// Adds a child tree node.
+        /// </summary>
+        /// <typeparam name="T">An object type with tree nodes.</typeparam>
+        /// <param name="obj">The object that has tree nodes.</param>
+        /// <param name="node">The tree node to add.</param>
+        /// <returns>The same instance so that multiple calls can be chained.</returns>
+        public static T AddNode<T>(this T obj, TreeNode node)
+            where T : class, IHasTreeNodes
+        {
+            if (obj is null)
+            {
+                throw new ArgumentNullException(nameof(obj));
+            }
+
+            obj.Children.Add(node);
             return obj;
         }
     }

src/Spectre.Console/Extensions/Obsolete/ObsoleteAlignableExtensions.cs

@@ -22,7 +22,7 @@ namespace Spectre.Console
         {
             if (obj is null)
             {
-                throw new System.ArgumentNullException(nameof(obj));
+                throw new ArgumentNullException(nameof(obj));
             }
 
             obj.Alignment = alignment;