mcs/class/System.Drawing/System.Drawing/ColorTranslator.cs

   1 //
   2 // System.Drawing.ColorTranslator.cs
   3 //
   4 // (C) 2001 Ximian, Inc.  http://www.ximian.com
   5 //
   6 // Dennis Hayes (dennish@raytek.com)
   7 // Inital Implimentation 3/25/2002
   8 // All conversions based on best guess, will improve over time
   9 //
  10 using System;
  11 namespace System.Drawing {
  12         public sealed class ColorTranslator{
  13
  14                 private ColorTranslator ()
  15                 {
  16                 }
  17
  18                 // From converisons
  19                 /// <summary>
  20                 ///
  21                 /// </summary>
  22                 /// <param name="HtmlFromColor"></param>
  23                 /// <returns></returns>
  24                 public static Color FromHtml(string HtmlFromColor){
  25                         // If first char is "#"
  26                                 //convert "#RRGGBB" to int and use Color.FromARGB(int) to create color
  27                         // else //it is a color name
  28                         //If there is a single digit at the end of the name, remove it.
  29                         // Call Color.FromKnownColor(HtmlFromColor)
  30
  31                         //At least some Html strings match .NET Colors,
  32                         // so this should work for those colors.
  33                         // .NET colors, XWindows colors, and WWWC web colors
  34                         // are (according to Charles Pretziod) base the same
  35                         //colors, so many shouold work if any do.
  36                         if (HtmlFromColor[0] != '#')
  37                         {
  38                                 int length = HtmlFromColor.Length;
  39                                 for (int i = length - 1; i >= 0; i--)
  40                                 {
  41                                         if (!Char.IsDigit (HtmlFromColor[i]))
  42                                                 break;
  43                                         length--;
  44                                 }
  45
  46                                 return Color.FromName(HtmlFromColor.Substring (0, length));
  47                         }
  48
  49                         int pos = 0, index = 0;
  50                         int[] rgb = new int[] {0, 0, 0};
  51
  52                         string specifier = HtmlFromColor.Substring (1).ToLower ();
  53                         if (specifier.Length != 6)
  54                                 return Color.Empty;
  55
  56                         foreach (char c in specifier)
  57                         {
  58                                 rgb[index] *= 16;
  59
  60                                 if (Char.IsDigit (c))
  61                                         rgb[index] += Int32.Parse (c.ToString ());
  62                                 else if (c <= 'f' && c >= 'a')
  63                                         rgb[index] += 10 + (c - 'a');
  64                                 else
  65                                         return Color.Empty;
  66
  67                                 pos++;
  68                                 if ((pos % 2) == 0)
  69                                         index++;
  70                         }
  71
  72                         return Color.FromArgb (rgb[0], rgb[1], rgb[2]);
  73                 }
  74
  75                 /// <summary>
  76                 ///
  77                 /// </summary>
  78                 /// <param name="OLEFromColor"></param>
  79                 /// <returns></returns>
  80                 public static Color FromOle(int OLEFromColor){
  81                         //int newcolor;
  82                         //TODO: swap RB bytes i.e. AARRGGBB to AABBGGRR
  83                         //return Color.FromArgb(newcolor);
  84                         return Color.Empty;
  85                 }
  86
  87                 /// <summary>
  88                 ///
  89                 /// </summary>
  90                 /// <param name="Win32FromColor"></param>
  91                 /// <returns></returns>
  92                 public static Color FromWin32(int Win32FromColor){
  93                         //int newcolor;
  94                         //TODO: swap RB bytes i.e. AARRGGBB to AABBGGRR
  95                         //return Color.FromArgb(newcolor);
  96                         return Color.Empty;
  97                 }
  98
  99                 // To conversions
 100                 public static string ToHtml (Color c)
 101                 {
 102                         if (c.IsEmpty)
 103                                 return "";
 104
 105                         string result;
 106
 107                         if (c.IsNamedColor)
 108                                 result = c.Name;
 109                         else
 110                                 result = String.Format ("#{0:X2}{1:X2}{2:X2}", c.R, c.G, c.B);
 111
 112                         return result;
 113                 }
 114                 /// <summary>
 115                 /// converts from BGR to RGB
 116                 /// </summary>
 117                 /// <param name="OleToColor"></param>
 118                 /// <returns></returns>
 119                 public static int ToOle(Color FromColor){
 120                         // TODO: Swap red and blue(from argb), convert to int(toargb)
 121                         // Same as ToWin32
 122                         return (Color.FromArgb(FromColor.B,FromColor.G,FromColor.R)).ToArgb();
 123                 }
 124
 125                 /// <summary>
 126                 /// converts from RGB to BGR
 127                 /// </summary>
 128                 /// <param name="Win32ToColor"></param>
 129                 /// <returns></returns>
 130                 public static int ToWin32(Color FromColor){
 131                         // TODO: Swap red and blue(from argb), convert to int(toargb)
 132                         // Same as ToOle
 133                         return (Color.FromArgb(FromColor.B,FromColor.G,FromColor.R)).ToArgb();
 134                 }
 135         }
 136 }
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