using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace DPumpHydr.WinFrmUI.Volute
{
    public partial class DesignDraw1 : UserControl
    {
        public DesignDraw1()
        {
            Point start = new Point(20, 120);
            Point control1 = new Point(40, 90);
            Point control2 = new Point(60, 150);
            Point end1 = new Point(100, 180);
            Point control3 = new Point(120, 170);
            Point control4 = new Point(135, 190);
            Point end2 = new Point(150, 220);

            screenPoints = new List<Point> { start, control1, control2, end1, control3, control4, end2 };
        }
        List<Point> screenPoints;
        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);




            Graphics g = e.Graphics;
            if (_dragPointNO >= 0)
            {
                using (Pen penUn = new Pen(Color.Gray, 2f))
                using (SolidBrush penSelect = new SolidBrush(Color.Red))
                {
                    for (int i = 0; i < screenPoints.Count; i++)
                    {
                        var pt = screenPoints[i];
                        if (i == _dragPointNO)
                            g.FillEllipse(penSelect, pt.X - 4f, pt.Y - 4f, 8, 8);
                        else
                            g.DrawEllipse(penUn, pt.X - 4f, pt.Y - 4f, 8, 8);
                    }

                }
            }
            else
            {

                using (SolidBrush penBrush = new SolidBrush(Color.Black))
                {
                    foreach (var pt in screenPoints)
                    {
                        g.FillEllipse(penBrush, pt.X - 4f, pt.Y - 4f, 8, 8);
                    }
                }

            }


            using (Pen penCurve = new Pen(Color.Blue, 2f))
            {
                g.DrawBeziers(penCurve, screenPoints.ToArray());
            }

        }
        int _dragPointNO = -1;
        protected override void OnMouseClick(MouseEventArgs e)
        {
            base.OnMouseClick(e);

        }

        protected override void OnMouseUp(MouseEventArgs e)
        {
            base.OnMouseUp(e);

            this.Cursor = Cursors.Default;
            if (_dragPointNO >= 0)
            {
                //鼠标未移除控件范围
                if (this.ClientRectangle.Contains(e.Location))
                {
                    screenPoints[_dragPointNO] = e.Location;
                    Invalidate();
                }
            }
            _dragPointNO = -1;
        }
        protected override void OnMouseDown(MouseEventArgs e)
        {
            base.OnMouseDown(e);

            _dragPointNO = -1;
            this.Cursor = Cursors.Default;
            //判断是否在点周围
            Rectangle r = new Rectangle(e.X - 5, e.Y - 5, 10, 10);
            for (int i = 0; i < screenPoints.Count; i++)
            {
                if (r.Contains(screenPoints[i]))
                {
                    _dragPointNO = i;
                    this.Cursor = Cursors.Hand;
                    Invalidate();
                    break;
                }
            }
        }

        protected override void OnMouseMove(MouseEventArgs e)
        {
            base.OnMouseMove(e);

            if (_dragPointNO >= 0)
            {
                //鼠标未移除控件范围
                if (this.ClientRectangle.Contains(e.Location))
                {
                    screenPoints[_dragPointNO] = e.Location;
                    Invalidate();
                }
            }
        }
    }
}