GoalBook - A Hybrid Smart Client

// <copyright file="FolderComparer.cs" company="GoalBook"> 
//    Copyright © 2009 Mark Brownsword. All rights reserved.
//    This source code and supporting files are licensed under The Code Project  
//    Open License (CPOL) as detailed at http://www.codeproject.com/info/cpol10.aspx. 
// </copyright>
namespace GoalBook.Infrastructure.Comparers
{
    using System;
    using System.Collections;
    using GoalBook.Infrastructure.ObjectModel;

    /// <summary>
    /// Folder Comparer.
    /// </summary>
    public class FolderComparer : IComparer
    {        
        /// <summary>
        /// Declaration for FolderList.
        /// </summary>
        private FolderList folders;

        /// <summary>
        /// Initializes a new instance of the FolderComparer class.
        /// </summary>
        /// <param name="folders">list of folders</param>
        public FolderComparer(FolderList folders)
        {
            this.folders = folders;
        }

        /// <summary>
        /// Compare implementation.
        /// </summary>
        /// <param name="x">x parameter</param>
        /// <param name="y">y parameter</param>
        /// <returns>        
        /// Value               Condition                
        /// Less than zero      x is less than y
        /// Zero                x equals y
        /// Greater than zero   x is greater than y
        /// </returns>
        public int Compare(object x, object y)
        {
            if (x == y)
            {
                return 0;
            }

            if (x == null)
            {
                return -1;
            }

            if (y == null)
            {
                return 1;
            }

            Folder t1 = this.GetFolder(x.ToString());
            Folder t2 = this.GetFolder(y.ToString());

            if (t1 == null)
            {
                return -1;
            }            
            else if (t2 == null)
            {
                return 1;
            }

            if (t1.Order < t2.Order)
            {
                return -1;
            }            
            else if (t1.Order > t2.Order)
            {
                return 1;
            }

            return 0;
        }
        
        /// <summary>
        /// Get Folder.
        /// </summary>
        /// <param name="title">title parameter</param>
        /// <returns>Folder instance</returns>
        private Folder GetFolder(string title)
        {
            foreach (Folder folder in this.folders)
            {
                if (folder.Title == title)
                {
                    return folder;
                }
            }

            return null;
        }            
    }
}