FileSelect - Hassle Free Implementation of the File Menu

// ==================================================================
// 
//  FileSelect - RecentFileList.cs
// 
//  Copyright 2009 Peter Hauptmann
//  This code is published under CodeProject Open License 
//    see http://www.codeproject.com/info/cpol10.aspx
//  Latest version and feedback at
//   http://www.codeproject.com/KB/menus/fileselect.aspx 
// 
// ------------------------------------------------------------------

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.ComponentModel;

namespace PH.UI.FileSelect
{

  /// <summary>Implements an LRU list of file names.</summary>
  public class RecentFileList : Component
  {
    private int m_persistCount = 10;

    /// <summary>Number of files to remember in the <see cref="AllFiles"/> list.</summary>
    /// <remarks>This may be more files than will be displayed, which is controlled by the 
    /// <see cref="ListCount"/> property. This improves user interface behavior when 
    /// the <c>ListCount</c> property changes, but might also be seen as a potential privacy 
    /// leak in critical applications (storing more data than the user sees).</remarks>
    [Category("Behavior")]
    [DefaultValue(10)]
    [Description("number of items that will be remembered in the settings.")]
    public int PersistCount
    {
      get { return Math.Max(m_persistCount, m_listCount); }
      set
      {
        m_persistCount = value;
        RemoveExcessFiles();
      }
    }

    private void RemoveExcessFiles()
    {
      int want = PersistCount;
      if (want < 0)
        want = 0;

      if (want < m_files.Count)
        m_files.RemoveRange(want, m_files.Count - want);
    }

    /// <summary>Number of files to display in the recent file list.</summary>
    /// <remarks>see also <see cref="PersistCount"/></remarks>
    [Category("Behavior")]
    [DefaultValue(4)]
    [Description("number of items that will be shown in the recent file list.")]
    private int m_listCount = 4;
    public int ListCount
    {
      get { return m_listCount; }
      set
      {
        m_listCount = value;
        OnFileListChanged();
      }
    }

    private List<string> m_files = new List<string>();

    /// <summary>number of files in the list, up to <c>ListCount</c>.</summary>
    [Browsable(false)]
    public int Count
    {
      get { return Math.Min(m_files.Count, m_listCount); }
    }

    /// <summary>list of files, up to <see cref="ListCount"/></summary>
    [Browsable(false)]
    public IEnumerable<string> Files
    {
      get
      {
        for (int i = 0; i < Math.Min(m_files.Count, m_listCount); ++i)
          yield return m_files[i];
      }
    }

    /// <summary>clears the recent files list.</summary>
    public void Clear()
    {
      m_files.Clear();
      OnFileListChanged();
    }

    /// <summary>function used to clean up file names.</summary>
    public static string CanonicalName(string file)
    {
      file = Path.GetFullPath(file);
      // file = Path.Canonicalize(path);
      return file;
    }

    /// <summary>adds a file on top of the list.</summary>
    public void Add(string file)
    {
      file = CanonicalName(file);
      int existingIdx = m_files.IndexOf(file);

      if (existingIdx > 0)
        m_files.RemoveAt(existingIdx);

      if (existingIdx != 0)
        m_files.Insert(0, file);

      RemoveExcessFiles();

      OnFileListChanged();
    }

    /// <summary>Index of the file in the list</summary>
    /// <remarks>search includes the files up to <see cref="PersistCount"/>.</remarks>
    /// <param name="file">file to find</param>
    /// <returns>index of the file in the list, or -1 if not found.</returns>
    public int IndexOf(string file)
    {
      file = CanonicalName(file);
      return m_files.IndexOf(file);
    }

    /// <summary>removes the specified file from the list.</summary>
    public void Remove(string file)
    {
      file = CanonicalName(file);
      int idx = m_files.IndexOf(file);
      if (idx >= 0)
      {
        OnFileListChanged();
        m_files.RemoveAt(idx);
      }
    }

    /// <summary>removes the file at the given index.</summary>
    public void RemoveAt(int idx)
    {
      m_files.RemoveAt(idx);
      OnFileListChanged();
    }

    /// <summary>fires when the list of files has changed.</summary>
    public event EventHandler FileListChanged;
    protected virtual void OnFileListChanged()
    {
      if (FileListChanged != null)
        FileListChanged(this, EventArgs.Empty);
    }

    /// <summary>a string property holding all file names, intended for application settings.</summary>
    /// <remarks>You can persist this property in the user settings to remember his list of recent files.</remarks>
    [Browsable(false)]
    public string AllFiles
    {
      get 
      {
        string all = null;
        foreach(string s in m_files)
        {
          if (all == null)
            all = s;
          else
            all = all + "\n" + s;
        }
        return all;
      }
      set
      {
        m_files.Clear();
        string[] files = (value??String.Empty).Split(new char[] { '\r', '\n' }, StringSplitOptions.RemoveEmptyEntries);
        m_files.AddRange(files);
        OnFileListChanged();
      }

    }


  }

  /// <summary>adds additional designer properties to them</summary>
  public class RecentFiles : RecentFileList
  {

    [Browsable(false)]
    public event EventHandler DisplaySettingsChanged;


    private bool m_bAddShortcuts = true;
    [Category("Display")]
    [DefaultValue(true)]
    [Description("Add Numbers as shortcuts to recent file lists")]
    public bool AddShortcuts
    {
      get { return m_bAddShortcuts; }
      set 
      { 
        if (m_bAddShortcuts != value)
        {
          m_bAddShortcuts = value;
          FireDisplaySettingsChanged();
        }
      }
    }

    private int m_displayPathLength = 40;

    [Category("Display")]
    [DefaultValue(40)]
    [Description("Shorten file names in recent file list to N characters. -1 to not shorten names.")]
    public int DisplayPathLength
    {
      get { return m_displayPathLength; }
      set
      {
        if (value >= 0 && value < 10)
          value = 10;
        else if (value < -1)
          value = -1;

        if (value != m_displayPathLength)
        {
          m_displayPathLength = value;
          FireDisplaySettingsChanged();
        }
      }
    }


    private void FireDisplaySettingsChanged()
    {
      if (DisplaySettingsChanged != null)
        DisplaySettingsChanged(this, EventArgs.Empty);
    }
    
  }
}