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

namespace Owf.Controls
{
	public partial class DigitalDisplayControl : UserControl
	{
		private Color _digitColor = Color.GreenYellow;
		[Browsable(true), DefaultValue("Color.GreenYellow")]
		public Color DigitColor
		{
			get { return _digitColor; }
			set { _digitColor = value; Invalidate(); }
		}

		private string _digitText = "88.88";
		[Browsable(true), DefaultValue("88.88")]
		public string DigitText
		{
			get { return _digitText; }
			set { _digitText = value; Invalidate(); }
		}

		public DigitalDisplayControl()
		{
			this.SetStyle(ControlStyles.DoubleBuffer, true);
			this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);
			this.SetStyle(ControlStyles.ResizeRedraw, true);
			this.SetStyle(ControlStyles.UserPaint, true);
			this.SetStyle(ControlStyles.SupportsTransparentBackColor, true);
			InitializeComponent();
			this.BackColor = Color.Transparent;
		}

		private void DigitalGauge_Paint(object sender, PaintEventArgs e)
		{
			e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;

			SevenSegmentHelper sevenSegmentHelper = new SevenSegmentHelper(e.Graphics);

			SizeF digitSizeF = sevenSegmentHelper.GetStringSize(_digitText, Font);
			float scaleFactor = Math.Min(ClientSize.Width / digitSizeF.Width, ClientSize.Height / digitSizeF.Height);
			Font font = new Font(Font.FontFamily, scaleFactor * Font.SizeInPoints);
			digitSizeF = sevenSegmentHelper.GetStringSize(_digitText, font);

			using (SolidBrush brush = new SolidBrush(_digitColor))
			{
				using (SolidBrush lightBrush = new SolidBrush(Color.FromArgb(20, _digitColor)))
				{
					sevenSegmentHelper.DrawDigits(
						_digitText, font, brush, lightBrush,
						(ClientSize.Width - digitSizeF.Width) / 2,
						(ClientSize.Height - digitSizeF.Height) / 2);
				}
			}
		}
	}

	public class SevenSegmentHelper
	{
		Graphics _graphics;

		// Indicates what segments are illuminated for all 10 digits
		static byte[,] _segmentData = {{1, 1, 1, 0, 1, 1, 1},
							 {0, 0, 1, 0, 0, 1, 0},  
							 {1, 0, 1, 1, 1, 0, 1},  
							 {1, 0, 1, 1, 0, 1, 1},  
							 {0, 1, 1, 1, 0, 1, 0},  
							 {1, 1, 0, 1, 0, 1, 1},  
							 {1, 1, 0, 1, 1, 1, 1},  
							 {1, 0, 1, 0, 0, 1, 0},  
							 {1, 1, 1, 1, 1, 1, 1},  
							 {1, 1, 1, 1, 0, 1, 1}}; 

		// Points that define each of the seven segments
		readonly Point[][] _segmentPoints = new Point[7][];

		public SevenSegmentHelper(Graphics graphics)
		{
			this._graphics = graphics;
			_segmentPoints[0] = new Point[] {new Point( 3,  2), new Point(39,  2), new Point(31, 10), new Point(11, 10)};
			_segmentPoints[1] = new Point[] {new Point( 2,  3), new Point(10, 11), new Point(10, 31), new Point( 2, 35)};
			_segmentPoints[2] = new Point[] {new Point(40,  3), new Point(40, 35), new Point(32, 31), new Point(32, 11)};
			_segmentPoints[3] = new Point[] {new Point( 3, 36), new Point(11, 32), new Point(31, 32), new Point(39, 36), new Point(31, 40), new Point(11, 40)};
			_segmentPoints[4] = new Point[] {new Point( 2, 37), new Point(10, 41), new Point(10, 61), new Point( 2, 69)};
			_segmentPoints[5] = new Point[] {new Point(40, 37), new Point(40, 69), new Point(32, 61), new Point(32, 41)};
			_segmentPoints[6] = new Point[] {new Point(11, 62), new Point(31, 62), new Point(39, 70), new Point( 3, 70)};
		}

		public SizeF GetStringSize(string text, Font font)
		{
			SizeF sizef = new SizeF(0, _graphics.DpiX * font.SizeInPoints / 72);

			for (int i = 0; i < text.Length; i++)
			{
				if (Char.IsDigit(text[i]))
					sizef.Width += 42 * _graphics.DpiX * font.SizeInPoints / 72 / 72;
				else if (text[i] == ':' || text[i] == '.')
					sizef.Width += 12 * _graphics.DpiX * font.SizeInPoints / 72 / 72;
			}
			return sizef;
		}

		public void DrawDigits(string text, Font font, Brush brush, Brush brushLight, float x, float y)
		{
			for (int cnt = 0; cnt < text.Length; cnt++)
			{
				// For digits 0-9
				if (Char.IsDigit(text[cnt]))
					x = DrawDigit(text[cnt] - '0', font, brush, brushLight, x, y);
				// For colon :
				else if (text[cnt] == ':')
					x = DrawColon(font, brush, x, y);
				// For dot .
				else if (text[cnt] == '.')
					x = DrawDot(font, brush, x, y);
			}
		}

		private float DrawDigit(int num, Font font, Brush brush, Brush brushLight, float x, float y)
		{
			for (int cnt = 0; cnt < _segmentPoints.Length; cnt++)
			{
				if (_segmentData[num, cnt] == 1)
				{
					FillPolygon(_segmentPoints[cnt], font, brush, x, y);
				}
				else
				{
					FillPolygon(_segmentPoints[cnt], font, brushLight, x, y);
				}
			}
			return x + 42 * _graphics.DpiX * font.SizeInPoints / 72 / 72;
		}

		private float DrawDot(Font font, Brush brush, float x, float y)
		{
			Point[][] dotPoints = new Point[1][];

			dotPoints[0] = new Point[] {new Point( 2, 64), new Point( 6, 61),
                                new Point(10, 64), new Point( 6, 69)};

			for (int cnt = 0; cnt < dotPoints.Length; cnt++)
			{
				FillPolygon(dotPoints[cnt], font, brush, x, y);
			}
			return x + 12 * _graphics.DpiX * font.SizeInPoints / 72 / 72;
		}

		private float DrawColon(Font font, Brush brush, float x, float y)
		{
			Point[][] colonPoints = new Point[2][];

			colonPoints[0] = new Point[] {new Point( 2, 21), new Point( 6, 17), new Point(10, 21), new Point( 6, 25)};
			colonPoints[1] = new Point[] {new Point( 2, 51), new Point( 6, 47), new Point(10, 51), new Point( 6, 55)};

			for (int cnt = 0; cnt < colonPoints.Length; cnt++)
			{
				FillPolygon(colonPoints[cnt], font, brush, x, y);
			}
			return x + 12 * _graphics.DpiX * font.SizeInPoints / 72 / 72;
		}

		private void FillPolygon(Point[] polygonPoints, Font font, Brush brush, float x, float y)
		{
			PointF[] polygonPointsF = new PointF[polygonPoints.Length];

			for (int cnt = 0; cnt < polygonPoints.Length; cnt++)
			{
				polygonPointsF[cnt].X = x + polygonPoints[cnt].X * _graphics.DpiX * font.SizeInPoints / 72 / 72;
				polygonPointsF[cnt].Y = y + polygonPoints[cnt].Y * _graphics.DpiY * font.SizeInPoints / 72 / 72;
			}
			_graphics.FillPolygon(brush, polygonPointsF);
		}
	}
}