Moveable Resizable Objects

using System;
using System .Collections .Generic;
using System .Drawing;
using System .Windows .Forms;

using MoveGraphLibrary;

namespace Test_MoveGraphLibrary
{
    // nonresizable square
    // text (TextMR) can be moved inside
    class ColoredSquare : GraphicalObject
    {
        Form form;
        Point ptCenter;
        int halfside;   
        Color color;

        Color clrText = Color .DarkGray;
        string str = "";
        double angle = 0.0;
        Font font = new Font ("Times New Roman", 12, FontStyle .Bold | FontStyle .Italic);

        double compensation;    // used only between MouseDown and MouseUp; calculated and used only OUTSIDE !!!

        // ------------------------------------------------- 
        public ColoredSquare (Form formParent, Point pt, int half, Color clr, string text)
        {
            form = formParent;
            ptCenter = pt;
            halfside = Math .Max (Math .Abs (half), 2);
            color = clr;
            str = text;
        }
        // ------------------------------------------------- 
        public ColoredSquare (Form formParent, Point pt, int half, Color clr)
            : this (formParent, pt, half, clr, "")
        {
        }
        // -------------------------------------------------        Center
        public Point Center
        {
            get { return (ptCenter); }
            set
            {
                ptCenter = value;
                DefineCover ();
            }
        }
        // -------------------------------------------------        Side
        public int Side
        {
            get { return (2 * halfside); }
            set
            {
                halfside = Math .Max (Math .Abs (value) / 2, 2);
                DefineCover ();
            }
        }
        // -------------------------------------------------        Color
        public Color Color
        {
            get { return (color); }
            set { color = value; }
        }
        // -------------------------------------------------        TextColor
        public Color TextColor
        {
            get { return (clrText); }
            set { clrText = value; }
        }
        // -------------------------------------------------        Text
        public string Text
        {
            get { return (str); }
            set
            {
                str = value;
                DefineCover ();
            }
        }
        // -------------------------------------------------        TextAngle
        public double TextAngle
        {
            get { return (angle); }
            set
            {
                angle = Auxi_Common .LimitedRadian (value);
                DefineCover ();
            }
        }
        // -------------------------------------------------        Font
        public Font Font
        {
            get { return (font); }
            set
            {
                font = value;
                DefineCover ();
            }
        }
        // -------------------------------------------------        StartRotation
        public void StartRotation (Point ptMouse)
        {
            double angleMouse = -Math .Atan2 (ptMouse .Y - ptCenter .Y, ptMouse .X - ptCenter .X);
            compensation = Auxi_Common .LimitedRadian (angleMouse - angle);
        }
        // -------------------------------------------------        Draw
        public void Draw (Graphics grfx)
        {
            Rectangle rc = new Rectangle (ptCenter .X - halfside, ptCenter .Y - halfside, 2 * halfside, 2 * halfside);
            grfx .FillRectangle (new SolidBrush (color), rc);
            Auxi_Drawing .DrawText (grfx, str, font, angle, clrText, ptCenter, TextBasis .M);
        }
        // -------------------------------------------------        DefineCover
        public override void DefineCover ()
        {
            Rectangle rc = new Rectangle (ptCenter .X - halfside, ptCenter .Y - halfside, 2 * halfside, 2 * halfside);
            if (str .Length > 0)
            {
                SizeF sizef = Auxi_Geometry .MeasureString (form, str, font);
                Point [] corners = Auxi_Geometry .TextCorners (sizef .Width, sizef .Height, angle, ptCenter, TextBasis .M);
                PointF [] cornersF = new PointF [corners .Length];
                for (int i = 0; i < corners .Length; i++)
                {
                    cornersF [i] = new PointF (corners [i] .X, corners [i] .Y);
                }
                CoverNode [] nodes = new CoverNode [2] {new CoverNode (0, cornersF, Cursors.Hand), 
                                                        new CoverNode (1, rc) };    //Auxi_Geometry .CornersOfRectangle (rc)
                cover = new Cover (nodes);
            }
            else
            {
                cover = new Cover (rc, Resizing .None);
            }
        }
        // -------------------------------------------------
        public override void Move (int cx, int cy)
        {
            ptCenter += new Size (cx, cy);
        }
        // -------------------------------------------------        MoveNode
        public override bool MoveNode (int i, int cx, int cy, Point ptMouse, MouseButtons catcher)
        {
            bool bRet = false;

            if (catcher == MouseButtons .Left)
            {
                Move (cx, cy);
                bRet = true;
            }
            else if (catcher == MouseButtons .Right && i == 0 && str .Length > 0)
            {
                double angleMouse = -Math .Atan2 (ptMouse .Y - ptCenter .Y, ptMouse .X - ptCenter .X);
                angle = Auxi_Common .LimitedRadian (angleMouse - compensation);      // Compensation
                bRet = true;
            }
            return (bRet);
        }

    }
}