What can be simpler than graphical primitives? Part 3

using System;
using System .Collections .Generic;
using System .ComponentModel;
using System .Drawing;
using System .Drawing .Drawing2D;
using System .Windows .Forms;
using Microsoft .Win32;

using MoveGraphLibrary;

namespace GraphicalPrimitives
{
    public partial class Form_Crescent : Form
    {
        int m_version = 620;
        const string strAddRegKey = "Form_Crescent";

        Mover mover;
        Point ptMouse_Down, ptMouse_Up;
        SolitaryControl scCovers;
        Crescent crescent;
        TextM info;
        string infotext = "Resizing can be started at the horns and middle points of both borders.\n" + 
                          "Distance between the horns and width of the crescent are changed independently.\n" +
                          "There are limits on minimal overhanging and minimal width.\n" +
                          "By any inner point a crescent can be moved around or rotated.";
        bool bShowCovers = false;
        Pen penAuxi = new Pen (Color .DarkGray);

        bool bRestore = false;

        // -------------------------------------------------
        public Form_Crescent ()
        {
            InitializeComponent ();
            mover = new Mover (this);
        }
        // -------------------------------------------------        OnLoad
        private void OnLoad (object sender, EventArgs e)
        {
            RestoreFromRegistry ();
            if (!bRestore)
            {
                DefaultView ();
            }
            RenewMover ();
        }
        // -------------------------------------------------        OnFormClosing
        private void OnFormClosing (object sender, FormClosingEventArgs e)
        {
            SaveIntoRegistry ();
        }
        // -------------------------------------------------        DefaultView
        public void DefaultView ()
        {
            ClientSize = new Size (740, 560);
            btnCovers .Location = new Point (20, 20);

            crescent = new Crescent (this, mover, new PointF (400, 300), 80, 40, 140, 0, Color .Blue);

            scCovers = new SolitaryControl (btnCovers);
            info = new TextM (this, new Point (260, 40), infotext);
            info .BackColor = Color .Yellow;
        }
        // -------------------------------------------------        RenewMover
        public void RenewMover ()
        {
            mover .Clear ();
            mover .Add (scCovers);
            mover .Add (info);
            mover .Add (crescent);
        }
        // -------------------------------------------------        OnPaint
        private void OnPaint (object sender, PaintEventArgs e)
        {
            Graphics grfx = e .Graphics;

            crescent .Draw (grfx);
            if (bShowCovers)
            {
                grfx .DrawLine (penAuxi, crescent .InnerCenter, crescent .Point_B);
                grfx .DrawLine (penAuxi, crescent .InnerCenter, crescent .Point_C);
                grfx .DrawLine (penAuxi, crescent .OuterCenter, crescent .Point_B);
                grfx .DrawLine (penAuxi, crescent .OuterCenter, crescent .Point_C);
                grfx .DrawLine (penAuxi, crescent .InnerCenter, crescent .Point_A);
                grfx .DrawLine (penAuxi, crescent .Point_B, crescent .Point_C);

                crescent .DrawCover (grfx, mover);
            }
            info .Draw (grfx);
        }
        // -------------------------------------------------        OnMouseDown
        private void OnMouseDown (object sender, MouseEventArgs e)
        {
            ptMouse_Down = e .Location;
            if (mover .Catch (e .Location, e .Button))
            {
                if (mover .CaughtSource is Crescent)
                {
                    if (e .Button == MouseButtons .Left && mover .CaughtNode < 4)
                    {
                        mover .MouseTraced = false;
                        crescent .StartResizing (e .Location, mover .CaughtNode);
                        mover .MouseTraced = true;
                    }
                    else if (e .Button == MouseButtons .Right)
                    {
                        crescent .StartRotation (e .Location);
                    }
                }
            }
            ContextMenuStrip = null;
        }
        // -------------------------------------------------        OnMouseUp
        private void OnMouseUp (object sender, MouseEventArgs e)
        {
            ptMouse_Up = e .Location;
            double dist = Auxi_Geometry .Distance (ptMouse_Down, ptMouse_Up);

            if (mover .Release ())
            {
                GraphicalObject grobj = mover .WasCaughtSource;
                if (e .Button == MouseButtons .Right && dist <= 3)
                {
                    if (grobj is Crescent)
                    {
                        ColorDialog dlg = new ColorDialog ();

                        dlg .Color = crescent .Color;
                        if (dlg .ShowDialog () == DialogResult .OK)
                        {
                            crescent .Color = dlg .Color;
                            Invalidate ();
                        }
                    }
                    else if (grobj is TextM)
                    {
                        ContextMenuStrip = menuOnInfo;
                    }
                }
            }
        }
        // -------------------------------------------------        OnMouseMove
        private void OnMouseMove (object sender, MouseEventArgs e)
        {
            if (mover .Move (e .Location))
            {
                Invalidate ();
            }
        }
        // -------------------------------------------------        OnContextMenuChanged
        private void OnContextMenuChanged (object sender, EventArgs e)
        {
            if (ContextMenuStrip != null)
            {
                ContextMenuStrip .Show (PointToScreen (ptMouse_Up));
            }
        }

        // *****   menuOnInfo   *****
        // -------------------------------------------------        Click_miInfoFont
        private void Click_miInfoFont (object sender, EventArgs e)
        {
            FontDialogWithTitle dlg = new FontDialogWithTitle ();

            dlg .Font = info .Font;
            dlg .Title = "Information font";
            if (dlg .ShowDialog () == DialogResult .OK)
            {
                info .Font = dlg .Font;
                Invalidate ();
            }
        }
        // -------------------------------------------------        Click_miInfoTextColor
        private void Click_miInfoTextColor (object sender, EventArgs e)
        {
            ColorDialogWithTitle dlg = new ColorDialogWithTitle ();

            dlg .Color = info .Color;
            dlg .Title = "Information color";
            if (dlg .ShowDialog () == DialogResult .OK)
            {
                info .Color = dlg .Color;
                Invalidate ();
            }
        }
        // -------------------------------------------------        Click_miInfoBackColor
        private void Click_miInfoBackColor (object sender, EventArgs e)
        {
            ColorDialogWithTitle dlg = new ColorDialogWithTitle ();

            dlg .Color = info .BackColor;
            dlg .Title = "Information background";
            if (dlg .ShowDialog () == DialogResult .OK)
            {
                info .BackColor = dlg .Color;
                Invalidate ();
            }
        }
        // -------------------------------------------------        Click_btnCovers
        private void Click_btnCovers (object sender, EventArgs e)
        {
            bShowCovers = !bShowCovers;
            Invalidate ();
        }

        const string name = "Main";
        // -------------------------------------------------        SaveIntoRegistry
        private void SaveIntoRegistry ()
        {
            string strRegKey = Form_Main .strRegKey + strAddRegKey;

            RegistryKey regkey = null;
            try
            {
                regkey = Registry .CurrentUser .CreateSubKey (strRegKey);
                if (regkey != null)
                {
                    regkey .SetValue (name, new string [] { m_version .ToString (),             // 0
                                                            ClientSize .Width .ToString (),     // 1
                                                            ClientSize .Height .ToString (),    // 2
                                                            bShowCovers .ToString () },         // 3
                                      RegistryValueKind .MultiString);
                    scCovers .IntoRegistry (regkey, "scCovers");
                    info .IntoRegistry (regkey, "Info");
                    crescent .IntoRegistry (regkey, "one");
                }
            }
            catch
            {
            }
            finally
            {
                if (regkey != null) regkey .Close ();
            }
        }
        // -------------------------------------------------        RestoreFromRegistry
        private void RestoreFromRegistry ()
        {
            string namekey = Auxi_DLL_Internal .PathDefinedByExecutable ();
            namekey += strAddRegKey;

            RegistryKey regkey = null;
            try
            {
                regkey = Registry .CurrentUser .OpenSubKey (namekey);
                if (regkey != null)
                {
                    string [] strs = (string []) regkey .GetValue (name);
                    if (strs != null && strs .Length == 4 && Convert .ToInt32 (strs [0]) >= 620)
                    {
                        ClientSize = Auxi_Convert .ToSize (strs, 1);
                        bShowCovers = Convert .ToBoolean (strs [3]);
                        scCovers = SolitaryControl .FromRegistry (regkey, "scCovers", btnCovers);
                        info = TextM .FromRegistry (this, regkey, "Info");
                        crescent = Crescent .FromRegistry (this, mover, regkey, "one");
                        if (scCovers == null || info == null || crescent == null)
                        {
                            return;
                        }
                        bRestore = true;
                    }
                    regkey .Close ();
                }
            }
            catch
            {
            }
            finally
            {
                if (regkey != null) regkey .Close ();
            }
        }
    }
}