using System;
using System.Drawing;
using System.Windows.Forms;

namespace ChildForms
{
    public partial class DDPanBox : UserControl
    {
        //if true were at 2:1 false then 1:1
        bool zoom = false;
        bool dragging = false; //Tells us if our image has been clicked on.
        Point start = new Point(); //Keep initial click for accurate panning.
        //private Image _image;
        //private Rectangle _drawRect;


        public Image Image
        {
            get {return this.pictureBox2.Image; }
            set
            {
                //_image = value;
                this.pictureBox2.Image = value;
                //Calculate Draw Rectangle by calling the resize event.
                panBox_Resize(this, EventArgs.Empty);
            }
        }

        //public Rectangle DrawRect
        //{
        //    get { return _drawRect; }
        //    set { _drawRect = value; }
        //}

        public static Rectangle DeflateRect(Rectangle rect, Padding padding)
        {
            rect.X += padding.Left;
            rect.Y += padding.Top;
            rect.Width -= padding.Horizontal;
            rect.Height -= padding.Vertical;
            return rect;

        }

        public void ClearImage(Graphics g)
        {
            g.Clear(Color.Black);

            //picBox.Refresh();
            //this.Image.Dispose();
            //this.Image = null;
            //this.Refresh();
            //Graphics g = Graphics.FromImage(_image);
            //Color c = Color.FromArgb(52, 52, 52);
            //g.Clear(c);
            //this.Invalidate();
            //this.Refresh();

        }


        public DDPanBox()
        {
            InitializeComponent();
            //Set up double buffering and a little extra.
            this.SetStyle(ControlStyles.UserPaint | ControlStyles.OptimizedDoubleBuffer |
            ControlStyles.AllPaintingInWmPaint | ControlStyles.SupportsTransparentBackColor,
            true);

            //set the part of the source image to be drawn.
            //DrawRect = DeflateRect(ClientRectangle, Padding);
            //_drawRect = ClientRectangle;

            //Subscribe to our event handlers.
            this.MouseDown += new MouseEventHandler(panBox_MouseDown);
            this.MouseMove += new MouseEventHandler(panBox_MouseMove);
            this.MouseUp += new MouseEventHandler(panBox_MouseUp);
            this.Resize += new EventHandler(panBox_Resize);
        }

        private void ScrollAdjust()
        {
            //using (pictureBox2)
            //{
            if (pictureBox2.Width < pictureBox1.Width)
            {
                pictureBox2.Left = (pictureBox1.Width - pictureBox2.Width) / 2;
                hScrollBar1.Enabled = false;
            }
            else
            {
                if (pictureBox2.Left > 0)
                    pictureBox2.Left = 0;
                hScrollBar1.Minimum = 0;
                hScrollBar1.Maximum = pictureBox2.Width - pictureBox1.Width;
                hScrollBar1.SmallChange = 1;
                hScrollBar1.LargeChange = 10;
                hScrollBar1.Enabled = true;
            }
            if (pictureBox2.Height < pictureBox1.Height)
            {
                pictureBox2.Top = (pictureBox1.Height - pictureBox2.Height) / 2;
                vScrollBar1.Enabled = false;
            }
            else
            {
                if (pictureBox2.Top > 0)
                    pictureBox2.Top = 0;
                vScrollBar1.Minimum = 0;
                vScrollBar1.Maximum = pictureBox2.Height - pictureBox1.Height;
                vScrollBar1.SmallChange = 1;
                vScrollBar1.LargeChange = 10;
                vScrollBar1.Enabled = true;
            }
            //}
        }


        void panBox_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                dragging = true;
                //offset new point by original one so we know where in the image we are.
                start = new Point(e.Location.X + pictureBox1.Location.X, e.Location.Y + pictureBox1.Location.Y);
                Cursor = Cursors.SizeAll; //just for looks.
            }
            else if (e.Button == MouseButtons.Right)
            {
                zoom = !zoom;
                if (zoom)
                {
                    // modify the drawrect to a smaller rectangle to zoom, and center it in previous drawrect
                    // pictureBox1 = new Rectangle(pictureBox1.X + ClientRectangle.Width / 4, pictureBox1.Y + ClientRectangle.Height / 4, pictureBox1.Width / 2, pictureBox1.Height / 2);
                    pictureBox1.Left = pictureBox1.Left + ClientRectangle.Width / 4;
                    pictureBox1.Top = pictureBox1.Top + ClientRectangle.Height / 4;
                    pictureBox1.Width = pictureBox1.Width / 2;
                    pictureBox1.Height = pictureBox1.Height / 2;
                }
                else
                {
                    //Do the reverse of above
                    //pictureBox1 = new Rectangle(pictureBox1.X - ClientRectangle.Width / 4, pictureBox1.Y - ClientRectangle.Height / 4, ClientRectangle.Width, ClientRectangle.Height);

                    pictureBox1.Left = pictureBox1.Left - ClientRectangle.Width / 4;
                    pictureBox1.Top = pictureBox1.Top - ClientRectangle.Height / 4;
                    pictureBox1.Width = pictureBox1.Width;
                    pictureBox1.Height = pictureBox1.Height;

                }
                //Calculate Draw Rectangle by calling the resize event.
                panBox_Resize(null, EventArgs.Empty);
            }
        }

        void panBox_MouseMove(object sender, MouseEventArgs e)
        {
            if (dragging)
            {
                pictureBox1.Location = new Point(start.X - e.Location.X, start.Y - e.Location.Y);

                if (pictureBox1.Location.X < 0 - Padding.Left)
                    pictureBox1.Location = new Point(0 - Padding.Left, pictureBox1.Location.Y);

                if (pictureBox1.Location.Y < 0 - Padding.Top)
                    pictureBox1.Location = new Point(pictureBox1.Location.X, 0 - Padding.Top);

                if (pictureBox1.Location.X > Image.Width - pictureBox1.Width + Padding.Right)
                    pictureBox1.Location = new Point(Image.Width - pictureBox1.Width + Padding.Right, pictureBox1.Location.Y);

                if (pictureBox1.Location.Y > Image.Height - pictureBox1.Height + Padding.Bottom)
                    pictureBox1.Location = new Point(pictureBox1.Location.X, Image.Height - pictureBox1.Height + Padding.Bottom);

                this.Refresh();
            }
        }

        void panBox_MouseUp(object sender, MouseEventArgs e)
        {
            dragging = false;
            Cursor = Cursors.Default;
        }

        void panBox_Resize(object sender, EventArgs e)
        {
            if (Image != null)
            {
                if (zoom)
                {
                    pictureBox1.Width = ClientRectangle.Width / 2;
                    pictureBox1.Height = ClientRectangle.Height / 2;
                }
                else
                {
                    pictureBox1.Width = ClientRectangle.Width;
                    pictureBox1.Height = ClientRectangle.Height;
                }

                if (pictureBox1.Location.X < 0 - Padding.Left)
                    pictureBox1.Location = new Point(0 - Padding.Left, pictureBox1.Location.Y);

                if (pictureBox1.Location.Y < 0 - Padding.Top)
                    pictureBox1.Location = new Point(pictureBox1.Location.X, 0 - Padding.Top);

                if (pictureBox1.Location.X > Image.Width - pictureBox1.Width + Padding.Right)
                    pictureBox1.Location = new Point(Image.Width - pictureBox1.Width + Padding.Right, pictureBox1.Location.Y);

                if (pictureBox1.Location.Y > Image.Height - pictureBox1.Height + Padding.Bottom)
                    pictureBox1.Location = new Point(pictureBox1.Location.X, Image.Height - pictureBox1.Height + Padding.Bottom);

                this.Refresh();
            }
        }

        //protected override void OnPaint(PaintEventArgs e)
        //{
        //    if (Image != null)
        //    {
        //        e.Graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
        //        e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
        //        e.Graphics.DrawImage(Image, ClientRectangle, pictureBox1, GraphicsUnit.Pixel);

        //        if (zoom)
        //            e.Graphics.DrawString("Zoom 2:1", this.Font, Brushes.White, new PointF(15F, 15F));
        //        else
        //            e.Graphics.DrawString("Zoom 1:1", this.Font, Brushes.White, new PointF(15F, 15F));
        //    }

        //    base.OnPaint(e);
        //}

        private void vScrollBar1_Scroll(object sender, ScrollEventArgs e)
        {
            MouseEventArgs ee = new MouseEventArgs(MouseButtons, 1, pictureBox1.Left, -vScrollBar1.Value, 1);
            pictureBox1.Location = new Point(start.X - ee.Location.X, start.Y - ee.Location.Y);

            if (pictureBox1.Location.X < 0 - Padding.Left)
                pictureBox1.Location = new Point(0 - Padding.Left, pictureBox1.Location.Y);

            if (pictureBox1.Location.Y < 0 - Padding.Top)
                pictureBox1.Location = new Point(pictureBox1.Location.X, 0 - Padding.Top);

            if (pictureBox1.Location.X > Image.Width - pictureBox1.Width + Padding.Right)
                pictureBox1.Location = new Point(Image.Width - pictureBox1.Width + Padding.Right, pictureBox1.Location.Y);

            if (pictureBox1.Location.Y > Image.Height - pictureBox1.Height + Padding.Bottom)
                pictureBox1.Location = new Point(pictureBox1.Location.X, Image.Height - pictureBox1.Height + Padding.Bottom);
            this.Refresh();
        }

        private void hScrollBar1_Scroll(object sender, ScrollEventArgs e)
        {
            MouseEventArgs ee = new MouseEventArgs(MouseButtons, 1, -hScrollBar1.Value, pictureBox1.Top, 1);
            pictureBox1.Location = new Point(start.X - ee.Location.X, start.Y - ee.Location.Y);

            if (pictureBox1.Location.X < 0 - Padding.Left)
                pictureBox1.Location = new Point(0 - Padding.Left, pictureBox1.Location.Y);

            if (pictureBox1.Location.Y < 0 - Padding.Top)
                pictureBox1.Location = new Point(pictureBox1.Location.X, 0 - Padding.Top);

            if (pictureBox1.Location.X > Image.Width - pictureBox1.Width + Padding.Right)
                pictureBox1.Location = new Point(Image.Width - pictureBox1.Width + Padding.Right, pictureBox1.Location.Y);

            if (pictureBox1.Location.Y > Image.Height - pictureBox1.Height + Padding.Bottom)
                pictureBox1.Location = new Point(pictureBox1.Location.X, Image.Height - pictureBox1.Height + Padding.Bottom);
            this.Refresh();
        }

        private void DDPanBox_Resize(object sender, EventArgs e)
        {
            ScrollAdjust();
        }
    }
}