My Personal Commander Variant

// This file is part of the Lobster.MVVM library
// Copyright: Andreas Raczek
// This file is published under the The Code Project Open License (CPOL) 
// See the file "CPOL.html" for the full license governing this code.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel;
using System.Collections.ObjectModel;
using System.Collections;

namespace Lobster.MVVM.VM.TreeVM
{
    public interface ITreeNodeVM : INotifyPropertyChanged, ITemplateNameProvider
    {
        ReadOnlyObservableCollection<ITreeNodeVM> SubItems { get; }
        object Item { get; }
        string DisplayName { get; }
        string DefaultDisplayName { get; set; }

        /// <summary>
        /// Allows binding the selection state of TreeViewItem to
        /// the ViemModel. Doing this is known to be the easiest way
        /// of controlling the item selection in a MVVM treeview.
        /// </summary>
        bool IsSelected { get; set; }

        // ITemplateNameProvider only allows reading, I am extending
        // it here to allow to set it directly
        new string TemplateName { get; set; }
    }

    public interface ITreeLeafVM : ITreeNodeVM
    {
    }

    public delegate ITreeNodeVM TCreateItemBox(ITreeDynamicNode parent, object subItem);

    public interface ITreeNodeFactory
    {
        ITreeLeafVM AddLeaf(object item, string displayNameProperty);
        ITreeStaticNode AddStaticNode(object item, string displayNameProperty);
        ITreeDynamicNode AddDynamicNode(object item, string displayNameProperty, ICollection subItems, TCreateItemBox createItemBox);
    }

    public interface ITreeStaticNode : ITreeNodeVM, ITreeNodeFactory
    {
    }

    public interface ITreeDynamicNode : ITreeNodeVM
    {
        ITreeLeafVM CreateLeaf(object item, string displayNameProperty);
        ITreeDynamicNode CreateDynamicNode(object item, string displayNameProperty, ICollection subItems, TCreateItemBox createItemBox);
    }
}