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 _image;}
            set
            {
                _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()
        //{
        //    if (this.Width < _drawRect.Width)
        //    {
        //        this.Left = (_drawRect.Width - this.Width) / 2;
        //        hScrollBar1.Enabled = false;
        //    }
        //    else
        //    {
        //        if (this.Left > 0)
        //            this.Left = 0;
        //        hScrollBar1.Minimum = 0;
        //        hScrollBar1.Maximum = this.Width - _drawRect.Width;
        //        hScrollBar1.SmallChange = 1;
        //        hScrollBar1.LargeChange = 10;
        //        hScrollBar1.Enabled = true;
        //    }
        //    if (this.Height < _drawRect.Height)
        //    {
        //        this.Top = (_drawRect.Height - this.Height) / 2;
        //        vScrollBar1.Enabled = false;
        //    }
        //    else
        //    {
        //        if (this.Top > 0)
        //            this.Top = 0;
        //        vScrollBar1.Minimum = 0;
        //        vScrollBar1.Maximum = this.Height - _drawRect.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 + _drawRect.Location.X, e.Location.Y + _drawRect.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
                    _drawRect = new Rectangle(_drawRect.X + ClientRectangle.Width / 4, _drawRect.Y + ClientRectangle.Height / 4, _drawRect.Width / 2, _drawRect.Height / 2);
                }
                else
                {
                    //Do the reverse of above
                    _drawRect = new Rectangle(_drawRect.X - ClientRectangle.Width / 4, _drawRect.Y - ClientRectangle.Height / 4, ClientRectangle.Width, ClientRectangle.Height);
                }
                //Calculate Draw Rectangle by calling the resize event.
                panBox_Resize(null, EventArgs.Empty);
            }
        }

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

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

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

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

                if (_drawRect.Location.Y > _image.Height - _drawRect.Height + Padding.Bottom)
                    _drawRect.Location = new Point(_drawRect.Location.X, _image.Height - _drawRect.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)
                {
                    _drawRect = new Rectangle(_drawRect.Location.X, _drawRect.Location.Y, ClientRectangle.Width / 2, ClientRectangle.Height / 2);
                }
                else
                    _drawRect = new Rectangle(_drawRect.Location.X, _drawRect.Location.Y, ClientRectangle.Width, ClientRectangle.Height);

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

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

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

                if (_drawRect.Location.Y > _image.Height - _drawRect.Height + Padding.Bottom)
                    _drawRect.Location = new Point(_drawRect.Location.X, _image.Height - _drawRect.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, _drawRect, 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, _drawRect.Left, -vScrollBar1.Value, 1);
        //    _drawRect.Location = new Point(start.X - ee.Location.X, start.Y - ee.Location.Y);

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

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

        //    if (_drawRect.Location.X > _image.Width - _drawRect.Width + Padding.Right)
        //        _drawRect.Location = new Point(_image.Width - _drawRect.Width + Padding.Right, _drawRect.Location.Y);

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

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

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

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

        //    if (_drawRect.Location.X > _image.Width - _drawRect.Width + Padding.Right)
        //        _drawRect.Location = new Point(_image.Width - _drawRect.Width + Padding.Right, _drawRect.Location.Y);

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

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