Linux Todolist

using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Windows.Forms;
using System.Drawing.Drawing2D;

namespace uk.org.aspellclark.todolist
{
	/// <summary>
	/// Summary description for TreeList.
	/// </summary>
	public class TreeList : System.Windows.Forms.UserControl
	{
		private System.Windows.Forms.DataGrid _treeGrid;
		private const int __TREE_COLUMN_SIZE__ = 200;
		public TreeListNodeSelected NodeSelectedEvent;

		/// <summary> 
		/// Required designer variable.
		/// </summary>
		private System.ComponentModel.Container components = null;

		public class TreeListNode
		{
			private object[] _columns;
			private ArrayList _childs;
			private TreeListNode _parent;
			
			public TreeListNode(int cols)
			{
				_columns = new object[cols];
			}

			public TreeListNode(object[] cols)
			{
				_columns = cols;
			}

			public void AddChild(TreeListNode child)
			{
				if (_childs == null)
					_childs = new ArrayList();

				_childs.Add(child);
			}

			public object[] Columns
			{
				get { return _columns; }
				set { _columns = value; }
			}

			public ArrayList ChildNodes
			{
				get { return _childs; }
				set { _childs = value; }
			}

			public TreeListNode Parent
			{
				get { return _parent; }
				set { _parent = value; }
			}
		}//class()

		private class TreeListColumnStyle : DataGridTextBoxColumn
		{
			private const int __BOX_SIZE__ = 8;
			private const int __BOX_MARGIN__ = 2;
			private int _col;

			public TreeListColumnStyle(int col)
			{
				_col = col;
			}

			protected override void Paint(System.Drawing.Graphics g, Rectangle bounds, CurrencyManager source, int rowNum, Brush backBrush, Brush foreBrush, bool alignToRight)
			{
				if (_col == 0)
				{
					g.FillRectangle(backBrush, bounds);

					DataRow row = ((DataRowView)source.List[rowNum]).Row;
					bounds.X += GetXOffset(row);

					object expanded = row["__IS_EXPANDED__"];
					if (!Convert.IsDBNull(expanded))
					{
						Pen pen = new Pen(foreBrush);
						int x = bounds.Left + __BOX_MARGIN__;
						int y = bounds.Top + __BOX_MARGIN__ * 2;
						g.DrawRectangle(pen, x, y, __BOX_SIZE__, __BOX_SIZE__);
						g.DrawLine(pen, x + __BOX_MARGIN__, y + __BOX_SIZE__ / 2, x + __BOX_SIZE__ - __BOX_MARGIN__, y + __BOX_SIZE__ / 2);
						if (!Convert.ToBoolean(expanded))
							g.DrawLine(pen, x + __BOX_SIZE__ / 2, y + __BOX_MARGIN__, x + __BOX_SIZE__ / 2, y + __BOX_SIZE__ - __BOX_MARGIN__);

						bounds.X += __BOX_SIZE__;
					}

					bounds.X += (__BOX_MARGIN__ * 3);
				}

				base.Paint(g, bounds, source, rowNum, backBrush, foreBrush, alignToRight);
			}

			private int GetXOffset(DataRow row)
			{
				object parent = row["__PARENT_ROW__"];
				if (Convert.IsDBNull(parent))
					return 0;
				else
					return __BOX_SIZE__ * 2 + GetXOffset((DataRow)parent);
			}
		
			protected override void Edit(System.Windows.Forms.CurrencyManager source, int rowNum, System.Drawing.Rectangle bounds, bool readOnly, string instantText, bool cellIsVisible) 
			{ 
				// don't call the baseclass so no editing done...
				//	base.Edit(source, rowNum, bounds, readOnly, instantText, cellIsVisible); 
			}
		}//class()

		public TreeList()
		{
			// This call is required by the Windows.Forms Form Designer.
			InitializeComponent();
		}

		/// <summary> 
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if(components != null)
				{
					components.Dispose();
				}

				Clear();
			}
			base.Dispose( disposing );
		}

		#region Component Designer generated code
		/// <summary> 
		/// Required method for Designer support - do not modify 
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{
			this._treeGrid = new System.Windows.Forms.DataGrid();
			((System.ComponentModel.ISupportInitialize)(this._treeGrid)).BeginInit();
			this.SuspendLayout();
			// 
			// _treeGrid
			// 
			this._treeGrid.CaptionVisible = false;
			this._treeGrid.DataMember = "";
			this._treeGrid.Dock = System.Windows.Forms.DockStyle.Fill;
			this._treeGrid.GridLineStyle = System.Windows.Forms.DataGridLineStyle.None;
			this._treeGrid.HeaderForeColor = System.Drawing.SystemColors.ControlText;
			this._treeGrid.Location = new System.Drawing.Point(0, 0);
			this._treeGrid.Name = "_treeGrid";
			this._treeGrid.ReadOnly = true;
			this._treeGrid.Size = new System.Drawing.Size(320, 256);
			this._treeGrid.TabIndex = 0;
			this._treeGrid.TabStop = false;
			this._treeGrid.MouseDown += new System.Windows.Forms.MouseEventHandler(this.OnMouseDown);
			this._treeGrid.MouseUp += new System.Windows.Forms.MouseEventHandler(this.OnMouseUp);
			// 
			// TreeList
			// 
			this.Controls.Add(this._treeGrid);
			this.Name = "TreeList";
			this.Size = new System.Drawing.Size(320, 256);
			((System.ComponentModel.ISupportInitialize)(this._treeGrid)).EndInit();
			this.ResumeLayout(false);

		}
		#endregion

		private void SetColumnStyles()
		{
			CurrencyManager cm = (CurrencyManager)this.BindingContext[_treeGrid.DataSource];
			((DataView)cm.List).AllowNew = false;
			((DataView)cm.List).AllowEdit = false;
			((DataView)cm.List).AllowDelete = false;
			_treeGrid.ReadOnly = false;
		
			DataTable dt = (DataTable)_treeGrid.DataSource;
			DataGridTableStyle styles = new DataGridTableStyle(cm);
			styles.GridColumnStyles.Clear();
			styles.ReadOnly = true;
			styles.AllowSorting = false;
			styles.RowHeadersVisible = false;
			styles.GridLineStyle = DataGridLineStyle.None;

			for (int i = 0; i < dt.Columns.Count - 3; i++)
			{
				TreeListColumnStyle style = new TreeListColumnStyle(i);
				style.ReadOnly = true;
				style.Width = __TREE_COLUMN_SIZE__;
				style.MappingName = dt.Columns[i].ColumnName;
				style.HeaderText = dt.Columns[i].ColumnName;
				style.TextBox.Visible = false;
				style.NullText = "";
				styles.GridColumnStyles.Add(style);
			}

			DataGridTextBoxColumn hstyle1 = new DataGridTextBoxColumn();
			hstyle1.Width = 0;
			styles.GridColumnStyles.Add(hstyle1);

			DataGridBoolColumn hstyle2 = new DataGridBoolColumn();
			hstyle2.Width = 0;
			styles.GridColumnStyles.Add(hstyle2);

			DataGridBoolColumn hstyle3 = new DataGridBoolColumn();
			hstyle3.Width = 0;
			styles.GridColumnStyles.Add(hstyle3);

			_treeGrid.TableStyles.Add(styles);
		}

		public void SetColumns(string[] names)
		{
			_treeGrid.BeginInit();

			DataTable dt = new DataTable();
			for (int i = 0; i < names.Length; i++)
				dt.Columns.Add(names[i]);

			//add some hidden columns
			DataColumn hcol1 = new DataColumn("__PARENT_ROW__", typeof(object));
			hcol1.ColumnMapping = MappingType.Hidden;
			dt.Columns.Add(hcol1);
			DataColumn hcol2 = new DataColumn("__IS_EXPANDED__", typeof(bool));
			hcol2.ColumnMapping = MappingType.Hidden;
			dt.Columns.Add(hcol2);
			DataColumn hcol3 = new DataColumn("__IS_VISIBLE__", typeof(bool));
			hcol3.ColumnMapping = MappingType.Hidden;
			dt.Columns.Add(hcol3);

			_treeGrid.DataSource = dt;

			SetColumnStyles();

			_treeGrid.EndInit();
		}

		static private void AddNode(DataTable dt, TreeListNode node, DataRow parentRow)
		{
			if (node.Columns.Length != dt.Columns.Count - 3)
				throw new Exception("Node values don't match expected columns.");

			DataRow row = dt.NewRow();
			for (int i = 0; i < node.Columns.Length; i++)
				row[i] = node.Columns[i];
				
			if (parentRow != null)
			{
				row["__PARENT_ROW__"] = parentRow;
				node.Parent = (TreeList.TreeListNode)dt.ExtendedProperties[parentRow];
			}

			if (node.ChildNodes != null)
				row["__IS_EXPANDED__"] = true;

			row["__IS_VISIBLE__"] = true;

			dt.Rows.Add(row);

			dt.ExtendedProperties.Add(row, node);

			if (node.ChildNodes != null)
			{
				foreach (TreeListNode child in node.ChildNodes)
					AddNode(dt, child, row);
			}
		}

		private void UpdateChildrenVisibility(DataTable dt, int startIdx, DataRow parentRow, bool visible)
		{
			for (int i = startIdx; i < dt.Rows.Count; i++)
			{
				DataRow row = dt.Rows[i];
				object parent = row["__PARENT_ROW__"];
				if (Convert.IsDBNull(parent))
					continue;

				if (!parentRow.Equals(parent))
					continue;
					
				row["__IS_VISIBLE__"] = visible;
				if (!Convert.IsDBNull(row["__IS_EXPANDED__"]) && Convert.ToBoolean(row["__IS_EXPANDED__"]))
					UpdateChildrenVisibility(dt, i + 1, row, visible);
			}
		}

		private void OnMouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
		{
			if (e.Button != MouseButtons.Left)
				return;

			DataGrid.HitTestInfo hi = _treeGrid.HitTest(e.X, e.Y);
			if (hi.Type != DataGrid.HitTestType.Cell)
				return;

			CurrencyManager source = (CurrencyManager)_treeGrid.BindingContext[_treeGrid.DataSource];
			if (hi.Row >= 0 && hi.Row < source.List.Count)
			{
				_treeGrid.CurrentRowIndex = hi.Row;
				DataRow parentRow = ((DataRowView)source.List[hi.Row]).Row;

				object expanded = parentRow["__IS_EXPANDED__"];
				if (Convert.IsDBNull(expanded))
					return;

				//this.dataGrid1.TableStyles[0].GridColumnStyles[0];
				bool visibility = Convert.ToBoolean(expanded);
				parentRow["__IS_EXPANDED__"] = !visibility;
				
				UpdateChildrenVisibility((DataTable)_treeGrid.DataSource, hi.Row + 1, parentRow, !visibility);
			}
		}

		private void OnMouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
		{
			_treeGrid.Select(_treeGrid.CurrentRowIndex);
			if (NodeSelectedEvent != null)
				NodeSelectedEvent(this.SelectedNode);
		}

		public void AddNode(TreeListNode node)
		{
			_treeGrid.SuspendLayout();
			_treeGrid.BeginInit();

			DataTable dt = (DataTable)_treeGrid.DataSource;
			AddNode(dt, node, null);

			_treeGrid.EndInit();

			dt.DefaultView.RowFilter = "__IS_VISIBLE__=true";
			_treeGrid.Select(0);
			_treeGrid.ResumeLayout(false);
		}

		public void Clear()
		{
			if (_treeGrid.DataSource != null)
			{
				((DataTable)_treeGrid.DataSource).Dispose();
				_treeGrid.DataSource = null;
				_treeGrid.TableStyles.Clear();
			}
		}

		public TreeList.TreeListNode SelectedNode
		{
			get
			{
				CurrencyManager cm = (CurrencyManager)_treeGrid.BindingContext[_treeGrid.DataSource];
				DataRowView rv = (DataRowView)cm.List[_treeGrid.CurrentRowIndex];
				return (TreeList.TreeListNode)((DataTable)_treeGrid.DataSource).ExtendedProperties[rv.Row];
			}
		}
	}

	public delegate void TreeListNodeSelected(TreeList.TreeListNode node);

}