using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Windows.Forms;

using System.Text;

using Autodesk.Navisworks.Api.Controls;

      static public string WriteSelectionSetContent(SavedItem item, string label, string lineText)
      {
         //set the output
         string output = lineText + "+ " + label + "\n";

         //See if this SavedItem is a GroupItem
         if (item.IsGroup)
         {
            //Indent the lines below this item
            lineText += "   ";

            //iterate the children and output
            foreach (SavedItem childItem in ((GroupItem)item).Children)
            {
               output += WriteSelectionSetContent(childItem, childItem.DisplayName, lineText);
            }
         }

         //return the node information
         return output;
      }

      /// <summary>
      /// Outputs to a message box the structure of the selection sets
      /// </summary>
      static public void ListSelectionSets()
      {
         //build output string for display
         string output =
            WriteSelectionSetContent(
            Autodesk.Navisworks.Api.Application.ActiveDocument.SelectionSets.RootItem,
            Autodesk.Navisworks.Api.Application.ActiveDocument.Title,
            "");

         //output in a message box
         MessageBox.Show(output);
      }