using System;

 using System.Collections.Generic;

 using System.Text;

 using System.Collections.ObjectModel;

 using System.ComponentModel;

 using System.Windows.Forms;

 namespace Aga.Controls.Tree

 {

 	internal class TreeColumnCollection : Collection<TreeColumn>

 	{

 		private TreeViewAdv _treeView;

 		public TreeColumnCollection(TreeViewAdv treeView)

 		{

 			_treeView = treeView;

 		}

 		protected override void InsertItem(int index, TreeColumn item)

 		{

 			base.InsertItem(index, item);

 			BindEvents(item);

 			_treeView.UpdateColumns();

 		}

 		protected override void RemoveItem(int index)

 		{

 			UnbindEvents(this[index]);

 			base.RemoveItem(index);

 			_treeView.UpdateColumns();

 		}

 		protected override void SetItem(int index, TreeColumn item)

 		{

 			UnbindEvents(this[index]);

 			base.SetItem(index, item);

 			item.Owner = this;

 			BindEvents(item);

 			_treeView.UpdateColumns();

 		}

 		protected override void ClearItems()

 		{

 			foreach (TreeColumn c in Items)

 				UnbindEvents(c);

 			Items.Clear();

 			_treeView.UpdateColumns();

 		}

 		private void BindEvents(TreeColumn item)

 		{

 			item.Owner = this;

 			item.HeaderChanged += HeaderChanged;

 			item.IsVisibleChanged += IsVisibleChanged;

 			item.WidthChanged += WidthChanged;

 			item.SortOrderChanged += SortOrderChanged;

 		}

 		private void UnbindEvents(TreeColumn item)

 		{

 			item.Owner = null;

 			item.HeaderChanged -= HeaderChanged;

 			item.IsVisibleChanged -= IsVisibleChanged;

 			item.WidthChanged -= WidthChanged;

 			item.SortOrderChanged -= SortOrderChanged;

 		}

 		void SortOrderChanged(object sender, EventArgs e)

 		{

 			TreeColumn changed = sender as TreeColumn;

 			//Only one column at a time can have a sort property set

 			if (changed.SortOrder != SortOrder.None)

 			{

 				foreach (TreeColumn col in this)

 				{

 					if (col != changed)

 						col.SortOrder = SortOrder.None;

 				}

 			}

 			_treeView.UpdateHeaders();

 		}

 		void WidthChanged(object sender, EventArgs e)

 		{

 			_treeView.ChangeColumnWidth(sender as TreeColumn);

 		}

 		void IsVisibleChanged(object sender, EventArgs e)

 		{

 			_treeView.FullUpdate();

 		}

 		void HeaderChanged(object sender, EventArgs e)

 		{

 			_treeView.UpdateView();

 		}

 	}

 }