Scribble : Drag and Draw : Graphics C# Source Code

    

/*
Professional Windows GUI Programming Using C#
by Jay Glynn, Csaba Torok, Richard Conway, Wahid Choudhury, 
   Zach Greenvoss, Shripad Kulkarni, Neil Whitlow

Publisher: Peer Information
ISBN: 1861007663
*/
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace Scribble
{
    /// <summary>
    /// Summary description for Form1.
    /// </summary>
    public class frmScribble : System.Windows.Forms.Form
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.Container components = null;
        private bool mouseDown = false;
        private Point lastPoint = Point.Empty;
        private string color = "black";
      private Graphics g;
      private Pen p;

        public frmScribble()
        {
            //
            // Required for Windows Form Designer support
            //
            InitializeComponent();
         g = CreateGraphics();
         p = new Pen(Color.FromName(color));

            //
            // TODO: Add any constructor code after InitializeComponent call
            //
        }

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        protected override void Dispose( bool disposing )
        {
         g.Dispose();
         if( disposing )
            {
                if (components != null) 
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }

        protected override void OnMouseDown(MouseEventArgs e)
        {
            mouseDown = true;
            if(e.Button==MouseButtons.Right)
            {
                ContextMenu m = new ContextMenu();
                m.MenuItems.Add(0, new MenuItem("black", new EventHandler(RightMouseButton_Click)));
                m.MenuItems.Add(1, new MenuItem("white", new EventHandler(RightMouseButton_Click)));
                m.MenuItems.Add(2, new MenuItem("red", new EventHandler(RightMouseButton_Click)));
                m.MenuItems.Add(3, new MenuItem("green", new EventHandler(RightMouseButton_Click)));
                m.MenuItems.Add(4, new MenuItem("blue", new EventHandler(RightMouseButton_Click)));
                m.Show(this, new Point(e.X, e.Y));
            }
        }

        protected void RightMouseButton_Click(object sender, EventArgs e)
        {
            color = ((MenuItem)sender).Text;
         p = new Pen(Color.FromName(color));
        }

        protected override void OnMouseUp(MouseEventArgs e)
        {
            mouseDown = false;
        }

        protected override void OnMouseMove(MouseEventArgs e)
        {
            if(lastPoint.Equals(Point.Empty)) lastPoint = new Point(e.X, e.Y);
            if(mouseDown) 
            {
                Point pMousePos = new Point(e.X, e.Y);
            g.DrawLine(p, pMousePos, lastPoint);
            }
            lastPoint = new Point(e.X, e.Y);
        }

        #region Windows Form Designer generated code
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            // 
            // frmScribble
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.ClientSize = new System.Drawing.Size(808, 542);
            this.MaximizeBox = false;
            this.Name = "frmScribble";
            this.Text = "Scribble";

        }
        #endregion

        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main() 
        {
            Application.Run(new frmScribble());
        }
    }
}