PROMS/Volian.Controls.Library/vlnTreeView.cs

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+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Text;
+using System.Windows.Forms;
+using System.Runtime.InteropServices; // For DragHelper
+using System.Reflection;
+using VEPROMS.CSLA.Library;
+
+namespace Volian.Controls.Library
+{
+	public delegate void vlnTreeViewEvent(object sender, vlnTreeEventArgs args);
+	public delegate bool vlnTreeViewBoolEvent(object sender, vlnTreeEventArgs args);
+	public delegate TreeNode vlnTreeViewTreeNodeEvent(object sender, vlnTreeEventArgs args);
+	//public delegate void vlnTreeViewDDEvent(object sender, System.Windows.Forms.DragEventArgs args);
+	public partial class vlnTreeEventArgs
+	{
+		#region Business Methods
+		private TreeNode _Node;
+		public TreeNode Node
+		{
+			get { return _Node; }
+			set { _Node = value; }
+		}
+		private TreeNode _Destination=null;
+		public TreeNode Destination
+		{
+			get { return _Destination; }
+			set { _Destination = value; }
+		}
+		private int _Index;
+		public int Index
+		{
+			get { return _Index; }
+			set { _Index = value; }
+		}
+		#endregion
+		#region Factory Methods
+		private vlnTreeEventArgs() { ;}
+		public vlnTreeEventArgs(TreeNode node)
+		{
+			_Node = node;
+		}
+		public vlnTreeEventArgs(TreeNode node, TreeNode destination, int index)
+		{
+			_Node = node;
+			_Destination = destination;
+			_Index = index;
+		}
+		#endregion
+	}
+	public partial class vlnTreeView : TreeView
+	{
+		private static readonly log4net.ILog _MyLog = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
+		#region Events
+		public event vlnTreeViewEvent NodeDragDrop;
+		private void OnNodeDragDrop(object sender, vlnTreeEventArgs args)
+		{
+			if (NodeDragDrop != null) NodeDragDrop(sender, args);
+		}
+		public event vlnTreeViewEvent NodeMove;
+		private void OnNodeMove(object sender, vlnTreeEventArgs args)
+		{
+			if (NodeMove != null) NodeMove(sender, args);
+		}
+		public event vlnTreeViewEvent NodeCopy;
+		private void OnNodeCopy(object sender, vlnTreeEventArgs args)
+		{
+			if (NodeCopy != null) NodeCopy(sender, args);
+		}
+		public event vlnTreeViewBoolEvent NodeDelete;
+		private bool OnNodeDelete(object sender, vlnTreeEventArgs args)
+		{
+			bool result = true;
+			if (NodeDelete != null) result = NodeDelete(sender, args);
+			return result;
+		}
+		public event vlnTreeViewTreeNodeEvent NodeNew;
+		private TreeNode OnNodeNew(object sender, vlnTreeEventArgs args)
+		{
+			if (NodeNew != null) return NodeNew(sender, args);
+			else return new TreeNode("New Item");
+		}
+		public event vlnTreeViewEvent NodeProperties;
+		private void OnNodeProperties(object sender, vlnTreeEventArgs args)
+		{
+			if (NodeProperties != null) NodeProperties(sender, args);
+		}
+		public event vlnTreeViewEvent NodeSelectionChange;
+		private void OnNodeSelectionChange(object sender, vlnTreeEventArgs args)
+		{
+			if (NodeSelectionChange != null) NodeSelectionChange(sender, args);
+		}
+		#endregion
+		#region Business Methods
+		ImageList _dragImageList = new ImageList();
+		#endregion
+		#region Constructors
+		public vlnTreeView()
+		{
+			InitializeComponent();
+			this.AllowDrop = true;
+			DragHelper.InitCommonControls();
+			this.ItemDrag += new ItemDragEventHandler(tv_ItemDrag);
+			this.DragDrop += new DragEventHandler(tv_DragDrop);
+			this.DragEnter += new DragEventHandler(tv_DragEnter);
+			this.DragLeave += new EventHandler(tv_DragLeave);
+			this.DragOver += new DragEventHandler(tv_DragOver);
+			this.MouseDown += new MouseEventHandler(tv_MouseDown);
+			base.AfterSelect += new TreeViewEventHandler(tv_AfterSelect);
+		}
+		private void tv_AfterSelect(object sender, TreeViewEventArgs e)
+		{
+			OnNodeSelectionChange(sender, new vlnTreeEventArgs(e.Node));
+		}
+		void tv_MouseDown(object sender, MouseEventArgs e)
+		{
+			if (e.Button == MouseButtons.Right)
+			{
+				TreeNode tn = this.GetNodeAt(new Point(e.X, e.Y));
+				if (tn != null)
+				{
+					this.SelectedNode = tn;
+					Application.DoEvents();
+					// Display Menu
+					ToolStripMenuItem mi = new ToolStripMenuItem();
+					ContextMenu cm = new ContextMenu();
+					cm.MenuItems.Add("New...",new EventHandler(mi_Click));
+					cm.MenuItems.Add("Cut", new EventHandler(mi_Click));
+					cm.MenuItems.Add("Copy", new EventHandler(mi_Click));
+					cm.MenuItems.Add("Paste", new EventHandler(mi_Click));
+					cm.MenuItems.Add("Delete", new EventHandler(mi_Click));
+					cm.MenuItems.Add("Properties...", new EventHandler(mi_Click));
+					cm.Show(this, new Point(e.X, e.Y));
+				}
+			}
+		}
+
+		void mi_Click(object sender, EventArgs e)
+		{
+			MenuItem mi = (MenuItem)sender;
+			switch (mi.Text)
+			{
+				case "New..."://Add a new child node at the current location
+					// Should Give the option to the controling code to Add a New Node
+					SelectedNode.Expand();
+					TreeNode tn = OnNodeNew(this, new vlnTreeEventArgs(SelectedNode));
+					if (tn != null)
+					{
+						SelectedNode.Nodes.Add(tn);
+						if (LabelEdit)
+							tn.BeginEdit();
+						else
+							SelectedNode = tn;
+					}
+					break;
+				case "Cut"://Cut the selected node
+					// Cut to Clipboard
+					break;
+				case "Copy"://Copy the selected node
+					// Add to Clipboard
+					break;
+				case "Paste"://Paste the clipboard node
+					// this is either a copy or a move depending upon where it came from
+					// if it is from a cut then when the paste is done it should be set to a copy
+					break;
+				case "Delete"://Delete the selected node
+					if(OnNodeDelete(this, new vlnTreeEventArgs(SelectedNode)))
+						SelectedNode.Remove();
+					break;
+				case "Properties..."://Show the properties for the selected node
+					OnNodeProperties(this,new vlnTreeEventArgs(SelectedNode));
+					break;
+				default:
+					MessageBox.Show(string.Format("Unrecognized Menu Item '{0}'", mi.Text));
+					break;
+			}
+		}
+		#endregion
+		#region Cursor
+		private bool SetupDragCursor(ImageList il, TreeNode tn)
+		{
+			// Reset image list used for drag image
+			il.Images.Clear();
+			int howBig = tn.Bounds.Size.Width + this.Indent;
+			if (howBig > 256) howBig = 256;
+			il.ImageSize = new Size(howBig, tn.Bounds.Height);
+
+			// Create new bitmap
+			// This bitmap will contain the tree node image to be dragged
+			Bitmap bmp = new Bitmap(tn.Bounds.Width + this.Indent, tn.Bounds.Height);
+
+			// Get graphics from bitmap
+			Graphics gfx = Graphics.FromImage(bmp);
+
+			// Draw node icon into the bitmap
+			if (this.ImageList != null) gfx.DrawImage(this.ImageList.Images[0], 0, 0);
+
+			// Draw node label into bitmap
+			gfx.DrawString(tn.Text, this.Font, new SolidBrush(this.ForeColor),
+				//				new SolidBrush(Color.Blue),
+				(float)this.Indent, 1.0f);
+
+			// Add bitmap to imagelist
+			_dragImageList.Images.Add(bmp);
+
+			// Get mouse position in client coordinates
+			Point p = this.PointToClient(Control.MousePosition);
+
+			// Compute delta between mouse position and node bounds
+			int dx = p.X + this.Indent - tn.Bounds.Left;
+			int dy = p.Y - tn.Bounds.Top;
+
+			// Begin dragging image
+			return DragHelper.ImageList_BeginDrag(_dragImageList.Handle, 0, dx, dy);
+		}
+		private void tv_ItemDrag(object sender, System.Windows.Forms.ItemDragEventArgs e)
+		{
+			// Get drag node and select it
+			try
+			{
+				TreeNode dragNode = (TreeNode)e.Item;
+				Type t = dragNode.GetType();
+				if(_MyLog.IsInfoEnabled)_MyLog.InfoFormat("Item Drag {0} - {1}", t.FullName, t.BaseType.FullName);
+				Type t2 = Type.GetType(t.FullName);
+				if(t2 != null)
+					if(_MyLog.IsInfoEnabled)_MyLog.InfoFormat("Item Drag {0} - {1}", t2.FullName, t2.BaseType.FullName);
+				this.SelectedNode = dragNode;
+				if (SetupDragCursor(_dragImageList, dragNode))
+				{
+					this.DoDragDrop(dragNode, DragDropEffects.Move | DragDropEffects.Copy);// Begin dragging
+					DragHelper.ImageList_EndDrag();// End dragging image
+				}
+			}
+			catch (Exception ex)
+			{
+				if(_MyLog.IsErrorEnabled)_MyLog.Error("tv_ItemDrag", ex);
+			}
+		}
+		#endregion
+		public enum DropPosition : int
+		{
+			Child = 0, Before = 1, After = 2
+		}
+		private class DropLocation
+		{
+			#region Business Methods
+			private TreeNode _dropNode;
+			public TreeNode DropNode
+			{
+				get { return _dropNode; }
+				set { _dropNode = value; }
+			}
+			private int _index;
+			public int Index
+			{
+				get { return _index; }
+				set { _index = value; }
+			}
+			private DropPosition _position;
+			public DropPosition Position
+			{
+				get { return _position; }
+				set { _position = value; }
+			}
+			DateTime _lastScroll;
+			public DateTime LastScroll
+			{
+				get { return _lastScroll; }
+			}
+			private string _location = string.Empty; 
+			#endregion
+			#region Constructors
+			public DropLocation(TreeView tv, System.Windows.Forms.DragEventArgs e, DateTime lastScroll)
+			{
+				_lastScroll = lastScroll;
+				_dropNode = tv.GetNodeAt(tv.PointToClient(new Point(e.X, e.Y)));
+				if (_dropNode == null) return;
+				int OffsetY = tv.PointToClient(Cursor.Position).Y - _dropNode.Bounds.Top;
+				if (OffsetY < _dropNode.Bounds.Height / 3) // First Third - Before
+				{
+					_index = _dropNode.Index;
+					_dropNode = _dropNode.Parent;
+					_position = DropPosition.Before;
+					_location = string.Format("Before1 {0}[{1}] y={2}", _dropNode.Text, _index, OffsetY);
+				}
+				else if ((OffsetY / 2) < _dropNode.Bounds.Height / 3) // Second Third - Child
+				{
+					_location = string.Format("Child {0} y={1}", _dropNode.Text, OffsetY);
+					_position = DropPosition.Child;
+					_index = 0;
+					if (_dropNode.Parent == null)
+					{
+						if(_MyLog.IsInfoEnabled)_MyLog.Info("Root Node");
+					}
+				}
+				else // Last Third - After Now I need to check the X value
+				{
+					if (_dropNode.NextVisibleNode !=null &&  _dropNode.Nodes.Count > 0)// Has Children - Insert first child
+					{
+						//						_dropNode = _dropNode.Nodes[0];
+						_index = 0;
+						_position = DropPosition.Before;
+						_location = string.Format("Before2 {0}[{1}] y={2}", _dropNode.Text, _index, OffsetY);
+					}
+					else // No Children - Insert Next at various levels
+					{
+						Point pt = tv.PointToClient(new Point(e.X, e.Y));
+						TreeNode nextParent = _dropNode.NextNode;
+						if (nextParent != null) nextParent = nextParent.Parent;
+						do
+						{
+							_index = _dropNode.Index;
+							_dropNode = _dropNode.Parent;
+						} while (pt.X < _dropNode.Bounds.X && _dropNode != nextParent);
+						_location = string.Format("After {0}[{1}] y={2}", _dropNode.Text, _index, OffsetY);
+						_position = DropPosition.After;
+					}
+				}
+				LimitMoves(e);
+			}
+			public void LimitMoves(DragEventArgs e)
+			{
+				if ((e.KeyState & 8) == 0)
+				{
+					//TreeNode dragNode = (TreeNode)e.Data.GetData("System.Windows.Forms.TreeNode");
+					//TreeNode dragNode = (TreeNode)e.Data.GetData("TreeTest.FolderTreeNode");
+					TreeNode dragNode = vlnTreeView.GetTreeNodeFromData(e.Data);
+					switch (_position)
+					{
+						case DropPosition.Before:
+							if (dragNode == _dropNode.Nodes[_index] || dragNode == _dropNode.Nodes[_index].PrevNode)
+							{
+								//					if(_MyLog.IsInfoEnabled)_MyLog.InfoFormat("Before {0} {1} {2} {3} {4}", dragNode.Text ,_position.ToString() , _dropNode.Nodes[_index].Text
+								//						,_dropNode.Nodes[_index].PrevNode,_dropNode.Nodes[_index].NextNode);
+								_dropNode = null;
+							}
+							break;
+						case DropPosition.Child:
+							if (dragNode.Parent == _dropNode)
+							{
+								//					if(_MyLog.IsInfoEnabled)_MyLog.InfoFormat("Child {0} {1} {2} {3} {4} {5}", dragNode.Text ,_position.ToString() , _dropNode.Nodes[_index].Text
+								//						,_dropNode.Nodes[_index].PrevNode,_dropNode.Nodes[_index].NextNode,DateTime.Now);
+								_dropNode = null;
+							}
+							break;
+						case DropPosition.After:
+							if (dragNode == _dropNode.Nodes[_index] || dragNode == _dropNode.Nodes[_index].NextNode)
+							{
+								//					if(_MyLog.IsInfoEnabled)_MyLog.InfoFormat("After {0} {1} {2} {3} {4}", dragNode.Text ,_position.ToString() , _dropNode.Nodes[_index].Text
+								//						,_dropNode.Nodes[_index].PrevNode,_dropNode.Nodes[_index].NextNode);
+								_dropNode = null;
+							}
+							break;
+					}
+				}
+			}
+			#endregion
+			public override string ToString()
+			{
+				return string.Format("{0}[{1}].{2}", _dropNode.Text, _index, _position.ToString());
+			}
+			#region Drawing
+			private void TreeNodeTriangle(Graphics g)
+			{
+				Rectangle r = _dropNode.Bounds;
+				int RightPos = r.Right + 6;
+				Point[] RightTriangle = new Point[]{
+											new Point(RightPos, r.Y ),
+											new Point(RightPos - (r.Height / 2), r.Y + (r.Height / 2)),
+											new Point(RightPos, r.Y + r.Height),
+											new Point(RightPos - (r.Height / 3), r.Y + (r.Height / 2))
+				};
+				g.FillPolygon(System.Drawing.Brushes.Black, RightTriangle);
+			}
+			private void InsertPointer(TreeNode tn, Graphics g)
+			{
+				TreeView tv = _dropNode.TreeView;
+				Rectangle r2 = _dropNode.Nodes[_index].Bounds;
+				Rectangle r3 = tn.Bounds;
+				int y = (_position == DropPosition.Before ? r2.Y : r3.Bottom);
+				int x = r2.Left;
+
+				if (y == 0)
+				{
+					return;
+				}
+				//					if(_MyLog.IsInfoEnabled)_MyLog.InfoFormat("Line at {0} Node {1}[{2}] {3}", _location, _dropNode.Text, _index, _position.ToString());
+				Color lc = (_position == DropPosition.After ? Color.Red : Color.Blue);
+				Brush lb = (_position == DropPosition.After ? Brushes.Red : Brushes.Blue);
+				Point[] RightTriangle;
+				if (_position == DropPosition.After)
+				{
+					RightTriangle = new Point[]{
+												new Point(x, y ),
+												new Point(x+4, y+4),
+												new Point(x+8, y)};
+				}
+				else
+				{
+					RightTriangle = new Point[]{
+												new Point(x, y),
+												new Point(x+4, y-4),
+												new Point(x+8, y)};
+				}
+				g.DrawLine(new System.Drawing.Pen(lc, 2), new Point(r2.Left, y), new Point(tv.Width - 8, y));
+				g.FillPolygon(lb, RightTriangle);
+			}
+			public void ShowLocation(System.Windows.Forms.DragEventArgs e, bool ScrollOnly)
+			{
+				//if (e.Effect == DragDropEffects.None) return;
+				if (_dropNode != null)
+				{
+//					if(_MyLog.IsInfoEnabled)_MyLog.InfoFormat("ShowLocation1 {0} {1}", e.Effect.ToString(), DateTime.Now.Millisecond);
+					DragHelper.ImageList_DragShowNolock(false);
+					TreeView tv = _dropNode.TreeView;
+					TreeNode tmp = tv.GetNodeAt(tv.PointToClient(new Point(e.X, e.Y)));
+//					if (!ScrollOnly)
+//					{
+					if (ScrollTreeView(tmp) || !ScrollOnly)
+					{
+						if(_MyLog.IsInfoEnabled)_MyLog.InfoFormat("ShowLocation2 {0} {1}", e.Effect.ToString(), DateTime.Now.Millisecond);
+						tv.Refresh();
+						if (e.Effect != DragDropEffects.None)
+						{
+							//tv.SelectedNode = dropNode;
+							Graphics g = tv.CreateGraphics();
+							TreeNodeTriangle(g);
+							if (_position != DropPosition.Child)InsertPointer(tmp, g);
+						}
+					}
+//					}
+//					else ScrollTreeView(tmp);
+					DragHelper.ImageList_DragShowNolock(true);
+				}
+			}
+			#endregion
+			public void ShowLocation()
+			{
+				if(_MyLog.IsInfoEnabled)_MyLog.InfoFormat("{0}[{1}] {2}", _dropNode.Text, _index, _position.ToString());
+			}
+			#region AutoScroll
+			private bool ScrollTreeView(TreeNode tn)
+			{
+				bool retval = false;
+				TimeSpan ts = new TimeSpan(DateTime.Now.Ticks - _lastScroll.Ticks);
+				if (ts.Milliseconds > 100)// This controls the scroll speed
+				{
+					int top = tn.Bounds.Top;
+					_lastScroll = DateTime.Now;
+					if (tn.TreeView.ClientSize.Height < tn.Bounds.Bottom) tn.EnsureVisible();// Make sure that the current node is visible
+					if (tn.NextVisibleNode != null && tn.TreeView.ClientSize.Height < tn.NextVisibleNode.Bounds.Bottom)
+						tn.NextVisibleNode.EnsureVisible();// Make sure that the next node is visible
+					else
+						if (tn.PrevVisibleNode != null && tn.PrevVisibleNode.PrevVisibleNode != null && tn.PrevVisibleNode.PrevVisibleNode.IsVisible == false)
+							tn.PrevVisibleNode.PrevVisibleNode.EnsureVisible();// Make sure that the previous node is visible					}
+						else
+							if (tn.PrevVisibleNode != null && tn.PrevVisibleNode.IsVisible == false)
+								tn.PrevVisibleNode.EnsureVisible();// Make sure that the previous node is visible
+					retval = (top != tn.Bounds.Top);
+					//					if (retval) if(_MyLog.IsInfoEnabled)_MyLog.Info("Scroll");
+				}
+				return retval;
+			}
+			#endregion
+			public bool Equals(DropLocation dl)
+			{
+				return (dl != null && _lastScroll.Equals(dl.LastScroll) && _dropNode.Equals(dl.DropNode) &&
+					_position.Equals(dl.Position));
+			}
+		}
+		private DropLocation _LastDropLocation = null;
+		private void tv_DragOver(object sender, System.Windows.Forms.DragEventArgs e)
+		{
+			try
+			{
+				TreeNode dragNode = GetTreeNodeFromData(e.Data);
+				// Compute drag position and move image
+				Point formP = this.FindForm().PointToClient(new Point(e.X, e.Y));
+				DragHelper.ImageList_DragMove(formP.X - this.Left, formP.Y - this.Top);
+				DropLocation dl = new DropLocation(this, e, _LastDropLocation == null ? DateTime.Now : _LastDropLocation.LastScroll);
+				string s = string.Empty;
+				if (dl.DropNode == null)
+				{
+					e.Effect = DragDropEffects.None;
+				}
+				else
+				{
+					DragDropEffects ee = e.Effect;
+					if ((e.KeyState & 8) == 8)
+						ee = DragDropEffects.Copy; // Copy it
+					else
+						ee = DragDropEffects.Move; // Move it
+					if (IsChild(dragNode, dl.DropNode))
+						ee = DragDropEffects.None; // Don't copy or move to a child node
+					if (e.Effect != ee) e.Effect = ee;
+					dl.ShowLocation(e, dl.Equals(_LastDropLocation));
+					_LastDropLocation = dl;
+				}
+			}
+			catch (Exception ex)
+			{
+				if(_MyLog.IsErrorEnabled)_MyLog.Error("tv_DragOver", ex);
+			}
+		}
+		private static TreeNode GetTreeNodeFromData(IDataObject datobj)
+		{
+			foreach (string s in datobj.GetFormats())
+			{
+				try
+				{
+					return (TreeNode)datobj.GetData(s);
+				}
+				catch (Exception ex)
+				{
+					if(_MyLog.IsErrorEnabled)_MyLog.Error("GetTreeNodeFromData", ex);
+				}
+			}
+			return null;
+		}
+		private void tv_DragDrop(object sender, System.Windows.Forms.DragEventArgs e)
+		{
+			try
+			{
+				TreeNode dragNode = GetTreeNodeFromData(e.Data);
+				DragHelper.ImageList_DragLeave(this.Handle);
+				int index = _LastDropLocation.Index + (_LastDropLocation.Position == DropPosition.After ? 1 : 0);
+				if (dragNode.Parent == _LastDropLocation.DropNode && dragNode.Index <= _LastDropLocation.Index) index--;
+				if (e.Effect == DragDropEffects.Move)// If Move Remove drag node from parent
+					dragNode.Remove();
+				else
+					dragNode = Clone(dragNode);
+				_LastDropLocation.DropNode.Nodes.Insert(index, dragNode);
+				this.SelectedNode = dragNode;
+				OnNodeDragDrop(sender, new vlnTreeEventArgs(dragNode, _LastDropLocation.DropNode,index));
+			}
+			catch (Exception ex)
+			{
+				if(_MyLog.IsErrorEnabled)_MyLog.Error("tv_DragDrop", ex);
+			}
+		}
+		private void DumpMembers(object o)
+		{
+			Type t = o.GetType();
+			if(_MyLog.IsInfoEnabled)_MyLog.InfoFormat("\r\n\r\nMembers for type {0}", t.ToString());
+			MemberInfo[] mis = t.GetMembers();
+			int i = 0;
+			foreach (MemberInfo mi in mis)
+			{
+				i++;
+				try
+				{
+					if(mi.MemberType != MemberTypes.Method)
+						if(_MyLog.IsInfoEnabled)_MyLog.InfoFormat("{0} {1} {2}", i, mi.Name, mi.MemberType);
+//						if (fi.Name == "TreeView")
+//							fi.SetValue(o, null);
+				}
+				catch (Exception ex)
+				{
+						if(_MyLog.IsErrorEnabled)_MyLog.Error("DumpMembers", ex);
+				}
+			}
+		}
+		private TreeNode Clone(TreeNode tn)
+		{
+
+			TreeNode tmp = (TreeNode)tn.Clone();
+			ExpandMatch(tmp,tn);
+			return tmp;
+		}
+		private void tv_DragDropOld(object sender, System.Windows.Forms.DragEventArgs e)
+		{
+			TreeNode dragNode = (TreeNode)e.Data.GetData("System.Windows.Forms.TreeNode");// Get the drag node
+			DragHelper.ImageList_DragLeave(this.Handle);
+			TreeNode cloneNode = (TreeNode)dragNode.Clone();// copy the source node
+			ExpandMatch(cloneNode, dragNode);
+			_LastDropLocation.DropNode.Nodes.Insert(_LastDropLocation.Index + (_LastDropLocation.Position == DropPosition.After ? 1 : 0), cloneNode);
+			if (e.Effect == DragDropEffects.Move)// If Move Remove drag node from parent
+				dragNode.Remove();
+			this.SelectedNode = cloneNode;
+		}
+		private void tv_DragEnter(object sender, System.Windows.Forms.DragEventArgs e)
+		{
+			DragHelper.ImageList_DragEnter(this.Handle, e.X - this.Left, e.Y - this.Top);
+		}
+		private void tv_DragLeave(object sender, System.EventArgs e)
+		{
+			DragHelper.ImageList_DragLeave(this.Handle);
+			this.Refresh();
+		}
+		private void ExpandMatch(TreeNode tn1, TreeNode tn2)
+		{
+			if (tn2.IsExpanded) tn1.Expand();
+			foreach (TreeNode tc in tn2.Nodes) ExpandMatch(tn1.Nodes[tc.Index], tc);
+		}
+		private bool IsChild(TreeNode parent, TreeNode child)
+		{
+			if (parent.Equals(child)) return true;// Check against self
+			foreach (TreeNode tc in parent.Nodes) if (IsChild(tc, child)) return true;//Check all children
+			return false;// Must not be a child at this level
+		}
+	}
+	public class DragHelper
+	{
+		[DllImport("comctl32.dll")]
+		public static extern bool InitCommonControls();
+
+		[DllImport("comctl32.dll", CharSet = CharSet.Auto)]
+		public static extern bool ImageList_BeginDrag(IntPtr himlTrack, int
+			iTrack, int dxHotspot, int dyHotspot);
+
+		[DllImport("comctl32.dll", CharSet = CharSet.Auto)]
+		public static extern bool ImageList_DragMove(int x, int y);
+
+		[DllImport("comctl32.dll", CharSet = CharSet.Auto)]
+		public static extern void ImageList_EndDrag();
+
+		[DllImport("comctl32.dll", CharSet = CharSet.Auto)]
+		public static extern bool ImageList_DragEnter(IntPtr hwndLock, int x, int y);
+
+		[DllImport("comctl32.dll", CharSet = CharSet.Auto)]
+		public static extern bool ImageList_DragLeave(IntPtr hwndLock);
+
+		[DllImport("comctl32.dll", CharSet = CharSet.Auto)]
+		public static extern bool ImageList_DragShowNolock(bool fShow);
+		static DragHelper()
+		{
+			InitCommonControls();
+		}
+	}
+}