using System;

 using System.Collections.Generic;

 using System.Text;

 namespace Aga.Controls.Tree

 {

 	public abstract class TreeModelBase: ITreeModel

 	{

 		public abstract System.Collections.IEnumerable GetChildren(TreePath treePath);

 		public abstract bool IsLeaf(TreePath treePath);

 		public event EventHandler<TreeModelEventArgs> NodesChanged;

 		protected void OnNodesChanged(TreeModelEventArgs args)

 		{

 			if (NodesChanged != null)

 				NodesChanged(this, args);

 		}

 		public event EventHandler<TreePathEventArgs> StructureChanged;

 		protected void OnStructureChanged(TreePathEventArgs args)

 		{

 			if (StructureChanged != null)

 				StructureChanged(this, args);

 		}

 		public event EventHandler<TreeModelEventArgs> NodesInserted;

 		protected void OnNodesInserted(TreeModelEventArgs args)

 		{

 			if (NodesInserted != null)

 				NodesInserted(this, args);

 		}

 		public event EventHandler<TreeModelEventArgs> NodesRemoved;

 		protected void OnNodesRemoved(TreeModelEventArgs args)

 		{

 			if (NodesRemoved != null)

 				NodesRemoved(this, args);

 		}

 		public virtual void Refresh()

 		{

 			OnStructureChanged(new TreePathEventArgs(TreePath.Empty));

 		}

 	}

 }