Targeting Design-Time Events of User Controls

/* ************************************************************
 * Code Copyright 2006 by the author of 'Targeting Design-Time Events of User Controls' 
 * article that can be found at TheCodeProject.com.  
 * 
 * This code is distributed under the GPL license
 * 
 * This copyright notice is not to be removed at any time
 * 
 * ===========================================================================
 * Target
 * 
 * This control was designed for the purpose of the TheCodeProject
 * article and may not be appropriate for use in commercial applications
 * 
 * This control has a designer specified before the class called the 
 * Target_Designer.  By setting the designer of this control
 * we will allow the control to have full design time support.  The support
 * will increase productivity.
 * 
 * NOTE: Only public methods and properties can be shown on smart tag
 * methods and properties.
 * ************************************************************
 */
using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

[Serializable()]
[Designer(typeof(Target_Designer))]
public class Target:System.Windows.Forms.UserControl
{
    #region Initialization
    public Target()
    {
        //This is just a view styles that would be good idea to put
        //with every custom control.
        this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);
        this.SetStyle(ControlStyles.OptimizedDoubleBuffer, true);
        this.SetStyle(ControlStyles.ResizeRedraw, true);
        this.SetStyle(ControlStyles.SupportsTransparentBackColor, true);
        this.BackColor = Color.Transparent;
    } 
    #endregion

    Collection<Circle> cc = new Collection<Circle>();
    Color c1=Color.Red, c2=Color.White;

    #region Properties
    [TypeConverter()]
    [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
    public Collection<Circle> Circles
    {
        get { return cc; }
        set { cc = value; }
    }
    public Color Color1
    {
        get{return c1;}
        set { c1 = value; this.Invalidate(); }
    }
    public Color Color2
    {
        get{return c2;}
        set { c2 = value; this.Invalidate(); }
    }
    #endregion

    #region Painting
    protected override void OnPaint(PaintEventArgs e)
    {
        Color active = c1;
        Sort(cc);
        foreach (Circle c in cc)
        {
            e.Graphics.FillEllipse(new SolidBrush(active), this.Width / 2 - c.Diameter / 2, this.Height / 2 - c.Diameter / 2, c.Diameter, c.Diameter);
            active = active == c1 ? c2 :c1 ;
        }
    } 
    #endregion

    #region Sort
    internal void Sort(Collection<Circle> c)
    {
        for (int k = 0; k < c.Count - 1; k++)
        {
            Circle tmp;
            if (c[k].Diameter < c[k + 1].Diameter)
            {
                tmp = c[k];
                c[k] = c[k + 1];
                c[k + 1] = tmp;
            }
        }
    } 
    #endregion
}
#region Class Circle
public class Circle
{
    int diameter;
    #region Initialization
    public Circle()
    {
    }
    public Circle(int Diameter)
    {
        diameter = Diameter;
    }
    #endregion
    #region Properties
    public int Diameter
    {
        get { return diameter; }
        set { diameter = value; }
    }
    #endregion
} 
#endregion