Check Help Links Tool

using System;
using System.Windows.Forms;
using System.Collections;
using System.IO;
using Microsoft.Win32;

namespace Common
{
	/// <summary>
	/// Summary description for RecentFileList.
	/// </summary>
	public class RecentFileList
	{
		public string RegistryKey = "";
		public MenuItem FileMenu = null;
		public int FileMenuPosition = 0;
		public int MaxNumberOfFiles = 16;

		public delegate void MenuClickEventHandler( object sender, MenuClickEventArgs e );
		public event MenuClickEventHandler OnMenuClick;

		private MenuItem Separator = null;
		private ArrayList RecentFiles = null;


		public RecentFileList()
		{
		}

		public void SetMenuItems()
		{
			RemoveMenuItems();

			LoadRecentFiles();

			InsertMenuItems();
		}

		private void RemoveMenuItems()
		{
			if ( Separator != null ) FileMenu.MenuItems.Remove( Separator );

			if ( RecentFiles != null )
			foreach ( RecentFile r in RecentFiles )
				if ( r.MenuItem != null )
					FileMenu.MenuItems.Remove( r.MenuItem );

			Separator = null;
			RecentFiles = null;
		}

		private void InsertMenuItems()
		{
			if ( RecentFiles == null ) return;
			if ( RecentFiles.Count == 0 ) return;

			int i = FileMenuPosition;
			foreach ( RecentFile r in RecentFiles )
			{
				string s = "";
				if ( r.Number < 9 ) s += "&";
				s += ( r.Number + 1 ).ToString();
				s += " ";
				s += Path.GetDirectoryName( r.Filename );
				s += "\\";
				s += Path.GetFileNameWithoutExtension( r.Filename );

				r.MenuItem = new MenuItem( s, new EventHandler( RaiseOnMenuClick ) );

				FileMenu.MenuItems.Add( i++, r.MenuItem );
			}

			Separator = new MenuItem( "-" );
			FileMenu.MenuItems.Add( i, Separator );
		}

		private void LoadRecentFiles()
		{
			RegistryKey k = Registry.CurrentUser.OpenSubKey( RegistryKey );
			if ( k == null ) k = Registry.CurrentUser.CreateSubKey( RegistryKey );

			RecentFiles = new ArrayList( 16 );

			for ( int i = 0 ; i < MaxNumberOfFiles ; i++ )
			{
				string Filename = (string) k.GetValue( i.ToString( "00" ) );

				if ( Filename == null ) break;
				if ( Filename.Length == 0 ) break;

				RecentFiles.Add( new RecentFile( i, Filename ) );
			}
		}

		public void RemoveFile( string Filename )
		{
			RegistryKey k = Registry.CurrentUser.OpenSubKey( RegistryKey );
			if ( k == null ) return;

			for ( int i = 0 ; i < MaxNumberOfFiles ; i++ )
			{
			again:
				string s = (string) k.GetValue( i.ToString( "00" ) );
				if ( s == Filename )
				{
					RemoveFile( i );
					goto again;
				}
			}
		}

		private void RemoveFile( int Number )
		{
			RegistryKey k = Registry.CurrentUser.OpenSubKey( RegistryKey, true );
			if ( k == null ) return;

			k.DeleteValue( Number.ToString( "00" ), false );

			for ( int i = Number ; i < MaxNumberOfFiles - 1 ; i++ )
			{
				int iNext = i + 1;

				if ( k.GetValue( iNext.ToString( "00" ) ) == null ) break;

				k.SetValue( i.ToString( "00" ), k.GetValue( iNext.ToString( "00" ) ) );

				k.DeleteValue( iNext.ToString( "00" ) );
			}
		}

		public void InsertFile( string Filename )
		{
			RegistryKey k = Registry.CurrentUser.OpenSubKey( RegistryKey );
			if ( k == null ) Registry.CurrentUser.CreateSubKey( RegistryKey );
			k = Registry.CurrentUser.OpenSubKey( RegistryKey, true );

			RemoveFile( Filename );

			for ( int i = MaxNumberOfFiles - 2 ; i >= 0 ; i-- )
			{
				if ( k.GetValue( i.ToString( "00" ) ) == null ) continue;

				int iNext = i + 1;

				k.SetValue( iNext.ToString( "00" ), k.GetValue( i.ToString( "00" ) ) );
			}

			k.SetValue( "00", Filename );
		}

		private class RecentFile
		{
			public int Number = 0;
			public string Filename = "";
			public MenuItem MenuItem = null;

			public RecentFile( int Number, string Filename )
			{
				this.Number = Number;
				this.Filename = Filename;
			}
		}

		public class MenuClickEventArgs : EventArgs
		{
			public string Filename = "";

			public MenuClickEventArgs( string Filename )
			{
				this.Filename = Filename;
			}
		}

		private void RaiseOnMenuClick( object sender, EventArgs e )
		{
			MenuItem m = sender as MenuItem;

			string Filename = GetFilename( m );

			if ( OnMenuClick != null ) OnMenuClick( sender, new MenuClickEventArgs( Filename ) );
		}

		private string GetFilename( MenuItem m )
		{
			foreach ( RecentFile r in RecentFiles )
				if ( r.MenuItem == m )
					return r.Filename;
			
			return "";
		}
	}
}