RSS Reader in Windows System Tray

/////////////////////////
//infoBot.net
//author: Xiaozheng Chen
//modified:  Dec 15, 2006
//chenxiaozheng@gmail.com
////////////////////////

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Windows.Forms;
using System.Xml;

namespace infoBot
{
    public interface IConfigurable
    {
        void CreateFromXML(XmlNode node);
        void SaveToXML(XmlDocument doc, XmlNode node);
        ToolStripMenuItem GenerateMenuItem();
    }
    class RssGroup : IConfigurable
    {
        public string name;
        public string head;
        public string link;
        RssManager mgr;
        ToolStripMenuItem menu;
        public List<RssPiece> rsses = new List<RssPiece>();
        public RssGroup(RssManager mgr)
        {
            this.mgr = mgr;
        }
        public RssGroup(RssManager mgr, string siteName, string rssHead, string siteLink)
        {
            this.mgr = mgr;
            name = siteName;
            head = rssHead;
            link = siteLink;
        }
        public void CreateFromXML(XmlNode node)
        {
            foreach (XmlNode chd in node.ChildNodes)
            {
                string chdname = chd.Name;
                if (chdname == "item")
                {
                    RssPiece rss = new RssPiece(this);
                    rss.CreateFromXML(chd);
                    rsses.Add(rss);
                }
                else if (chdname == "title")
                {
                    name = chd.InnerText;
                }
                else if (chdname == "rsshead")
                {
                    head = chd.InnerText;
                }
                else if (chdname == "link")
                {
                    link = chd.InnerText;
                }
            }
        }
        public void SaveToXML(XmlDocument doc, XmlNode node)
        {
            XmlNode nd = doc.CreateElement("title");
            nd.InnerText = name;
            node.AppendChild(nd);
            nd = doc.CreateElement("link");
            nd.InnerText = link;
            node.AppendChild(nd);
            nd = doc.CreateElement("rsshead");
            nd.InnerText = head;
            node.AppendChild(nd);

            foreach (RssPiece rss in rsses)
            {
                nd = doc.CreateElement("item");
                rss.SaveToXML(doc, nd);
                node.AppendChild(nd);
            }
        }
        
        public ToolStripMenuItem GenerateMenuItem()
        {
            menu = new ToolStripMenuItem(name);
            foreach (RssPiece rss in rsses)
            {
                menu.DropDownItems.Add(rss.GenerateMenuItem());
            }
           // menu.Click += new EventHandler(HandleClick);
            ToolStripTextBox box = new ToolStripTextBox();
            box.Text = "New...";
            box.Click += new EventHandler(OnClickNew);
            box.KeyDown += new KeyEventHandler(OnFinishEntering);
            box.LostFocus += new EventHandler(OnLeaveEnter);
            menu.DropDownItems.Add(box);             
            return menu;
        }


        public void OnLeaveEnter(object o, EventArgs e)
        {
            ((ToolStripTextBox)o).Text = " New...";
        }

        public void OnClickNew(object o, EventArgs e)
        {
            ((ToolStripTextBox)o).Text = "";
        }

        private string ProcessURL(string name)
        {
            int starpos = head.IndexOf("*");
            if (starpos < 0)
            {
                return (head + name);
            }
            string preRss = head.Substring(0, starpos);
            string postRss = head.Substring(starpos + 1, head.Length - starpos - 1);
            return (preRss + name + postRss);
        }


        public void OnFinishEntering(object o, EventArgs e)
        {
            if (((KeyEventArgs)e).KeyCode == Keys.Enter)
            {
                ToolStripTextBox box = (ToolStripTextBox)o;
                string rssname = box.Text.Trim();
                RssPiece rss = new RssPiece(rssname, ProcessURL(rssname), this);
                rss.SetHandlers(new RssPiece.DelEventHandler(mgr.HandleRssDeleted),
                       new RssPiece.AddEventHandler(mgr.HandleRssAdded));
                rsses.Add(rss);               
                menu.DropDownItems.Insert(menu.DropDownItems.Count - 1, 
                    rss.GenerateMenuItem());
                box.Text = "";                
            }
        }
    }
    class RssPiece : IConfigurable
    {
        public string name;
        public string link;
        public bool chkflg;
        public RssGroup group;
        public delegate void DelEventHandler(RssPiece rss);
        public delegate void AddEventHandler(RssGroup group, RssPiece rss);
        public DelEventHandler delHandler;
        public AddEventHandler addHandler;
        private ToolStripMenuItem menu = null;

        public RssPiece(RssGroup group)
        {
            this.group = group;
        }
        public void SetHandlers(DelEventHandler del, AddEventHandler add)
        {
            delHandler = del;
            addHandler = add;
        }
        public RssPiece(string rssName, string rssLink, RssGroup group)
        {
            name = rssName;
            link = rssLink;
            chkflg = false;
            this.group = group;
        }
        public void CreateFromXML(XmlNode node)
        {
            RssPiece retval = new RssPiece(null);

            foreach (XmlNode chd in node.ChildNodes)
            {
                if (chd.Name == "name")
                    name = chd.InnerText.Trim();
                else if (chd.Name == "checked")
                {
                    chkflg = chd.InnerText.Trim().Equals("1");
                }
                else if (chd.Name == "link")
                {
                    link = chd.InnerText.Trim();
                }
            }
        }
        public void SaveToXML(XmlDocument doc, XmlNode node)
        {
            XmlNode nd = doc.CreateElement("name");
            nd.InnerText = name;
            node.AppendChild(nd);
            nd = doc.CreateElement("checked");
            nd.InnerText = chkflg ? "1" : "0";
            node.AppendChild(nd);
            nd = doc.CreateElement("link");
            nd.InnerText = link;
            node.AppendChild(nd);
        }
        private void HandleClick(object o, EventArgs a)
        {
            chkflg = !chkflg;
            menu.Checked = chkflg;
            if (chkflg)
            {
                System.Diagnostics.Debug.Assert(group != null);
                addHandler(group, this);
            }
            else
            {
                delHandler(this);
            }
        }
        public ToolStripMenuItem GenerateMenuItem()
        {
            menu = new ToolStripMenuItem(name);
            menu.Click += new EventHandler(HandleClick);
            menu.Checked = chkflg;
            menu.DisplayStyle = ToolStripItemDisplayStyle.Text;
            menu.MouseDown += new MouseEventHandler(menu_MouseDown);
            //menu.DragLeave += new EventHandler(UserErase);
            menu.MouseDown += new MouseEventHandler(UserMouseDown);
            menu.MouseUp += new MouseEventHandler(UserMouseUp);
            menu.MouseLeave += new EventHandler(UserMouseLeave);
//            menu.DO
            return menu;
        }

        private bool _dragFlg = false;

        private void UserMouseLeave(object o, EventArgs a)
        {
            if (_dragFlg)
            {
                //System.Diagnostics.Debug.WriteLine(this.name + "  deleted ");
                delHandler(this);
                group.rsses.Remove(this);
                menu.Owner.Items.Remove(menu);
                _dragFlg = false;
            }
        }

        private void UserMouseDown(object o, MouseEventArgs e)
        {
            _dragFlg = true;
        }

        private void UserMouseUp(object o, MouseEventArgs e)
        {
            _dragFlg = false;
        }

      
        void menu_MouseDown(object sender, MouseEventArgs e)
        {
            //throw new Exception("The method or operation is not implemented.");
        }
    }
}