using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Text;
using System.Windows.Forms;



namespace WindowsApplication3
{
    public partial class Form1 : Form
    {

        private void Form1_Load(object sender, EventArgs e)
        {

        }



        private Graphics DrawingSurface;

        private System.Drawing.Pen ErasePen;

        private System.Drawing.Pen DrawPen;

        private System.Drawing.Point ptsStart;

        private System.Drawing.Point ptsPrevious;

        
    
        public Form1()

        {

            InitializeComponent();


            SetStyle(ControlStyles.AllPaintingInWmPaint, true);

            SetStyle(ControlStyles.OptimizedDoubleBuffer, true);

            SetStyle(ControlStyles.UserPaint, true);

            SetStyle(ControlStyles.ResizeRedraw, true);
            DrawingSurface = CreateGraphics();

            // Pen to erase a previous line

           ErasePen = new System.Drawing.Pen(BackColor);

            // Pen to draw a new line

            DrawPen = new System.Drawing.Pen(Color.Blue);

          

            //ControlStyles.OptimizedDoubleBuffer | ControlStyles.AllPaintingInWmPaint |ControlStyles.UserPaint, true);

        }



        protected override void OnMouseDown(MouseEventArgs e)

        {

            //Check if the left mouse button has

            //generated the associated event.

            if (e.Button == MouseButtons.Left)

            {

                //Store the starting point for your rubber-band line.

                ptsStart.X = e.X;

                ptsStart.Y = e.Y;

                //Store the previous endpoint for your rubber-band line.

                ptsPrevious = ptsStart;

            }

        }





        protected override void OnMouseMove(MouseEventArgs e)

        {

            //Check if the left mouse button is pressed.

            if (e.Button == MouseButtons.Left)

            {

                //Declare a local variable for the current endpoint '

                //of your rubber-band line.

                Point ptsCurrent = new Point();

                //Store the current endpoint of your rubber-band line.

                ptsCurrent.X = e.X;

                ptsCurrent.Y = e.Y;

                //Draw your actual rubber-band lines.

                DrawingSurface.DrawLine(ErasePen, ptsStart.X, ptsStart.Y,

                    ptsPrevious.X, ptsPrevious.Y);

                DrawingSurface.DrawLine(DrawPen, ptsStart.X, ptsStart.Y,

                    ptsCurrent.X, ptsCurrent.Y);
                

                //Store the current endpoint for the next call to OnMouseMove.

                ptsPrevious = ptsCurrent;

            }          

        }

    
    }

}
    

public class Line
{
        private Point m_start;
        private Point m_end;

        public Line(Point start, Point end)
        {
                m_start = start;
                m_end = end;
        }

        public void Draw(Graphic g)
        {
                // Your drawing code to draw
                // a line
        }
};


// The in your mousemove() or mouseup()
protected override void OnMouseMove(MouseEventArgs e)
{
        Point currentPoint = new Point();
        currentPoint.X = e.X;
        currentPoint.Y = e.Y;

        Line l = new Line(previousPoint, currentPoint);

        // TODO: Add the line object to the collection
}

protected override void OnPaint(...)
{
        // TODO: iterate over the list of line objects
        // and pass it in the graphics object to draw on the form
}