mcs/class/System.Web/System.Web.UI.WebControls/WebColorConverter.cs

   1 // Permission is hereby granted, free of charge, to any person obtaining
   2 // a copy of this software and associated documentation files (the
   3 // "Software"), to deal in the Software without restriction, including
   4 // without limitation the rights to use, copy, modify, merge, publish,
   5 // distribute, sublicense, and/or sell copies of the Software, and to
   6 // permit persons to whom the Software is furnished to do so, subject to
   7 // the following conditions:
   8 //
   9 // The above copyright notice and this permission notice shall be
  10 // included in all copies or substantial portions of the Software.
  11 //
  12 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  13 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  14 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  15 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  16 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  17 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  18 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  19 //
  20 // Copyright (c) 2005 Novell, Inc. (http://www.novell.com)
  21 //
  22 // Authors:
  23 //      Peter Bartok    (pbartok@novell.com)
  24 //
  25 //
  26
  27 using System.Drawing;
  28 using System.Globalization;
  29 using System.ComponentModel;
  30 using System.Security.Permissions;
  31
  32 namespace System.Web.UI.WebControls {
  33
  34         // CAS
  35         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  36         [AspNetHostingPermission (SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  37         public class WebColorConverter : ColorConverter {
  38
  39                 // Converts from string to Color
  40                 public override object ConvertFrom (ITypeDescriptorContext context, CultureInfo culture, object value)
  41                 {
  42                         if (value is string)
  43                         {
  44                                 string  s;
  45
  46                                 s = ((string)value).Trim();
  47                                 if (s.Length == 0)
  48                                 {
  49                                         return Color.Empty;
  50                                 }
  51
  52                                 if (culture == null) {
  53                                         culture = CultureInfo.InvariantCulture;
  54                                 }
  55
  56                                 if (s[0] == '#')
  57                                 {
  58                                         // Hex
  59
  60                                         // MS throws a generic exception, wrapping the specific exception, who knows why...
  61                                         try
  62                                         {
  63                                                 if (s.Length == 7)
  64                                                 {
  65                                                         int     v;
  66                                                         v = Int32.Parse(s.Substring(1), NumberStyles.HexNumber, culture);
  67
  68                                                         return Color.FromArgb(255, (v >> 16) & 0xff, (v >> 8) & 0xff, v & 0xff);
  69                                                 }
  70                                                 else
  71                                                 {
  72                                                         return Color.FromArgb(Int32.Parse(s.Substring(1), NumberStyles.HexNumber, culture));
  73                                                 }
  74                                         }
  75
  76                                         catch (FormatException e)
  77                                         {
  78                                                 throw new Exception(s + "is not a valid color value", e);
  79                                         }
  80                                         catch (System.OverflowException e)
  81                                         {
  82                                                 throw new Exception(s + " is not a valid color value", e);
  83                                         }
  84                                 }
  85                                 else
  86                                 {
  87                                         // Name or decimal
  88                                         int     n = 0;
  89
  90                                         try
  91                                         {
  92                                                 n = Int32.Parse(s, NumberStyles.Integer, culture);
  93                                         }
  94
  95                                         catch (FormatException e)
  96                                         {
  97                                                 Color c;
  98
  99                                                 c = Color.FromName(s);
 100                                                 if ((c.A != 0) || (c.R != 0) || (c.G != 0) || (c.B != 0))
 101                                                 {
 102                                                         return c;
 103                                                 }
 104
 105                                                 throw new Exception(s + " is not a valid color value", e);
 106                                         }
 107
 108                                         catch (System.OverflowException e)
 109                                         {
 110                                                 throw new Exception(s + " is not a valid color value", e);
 111                                         }
 112
 113                                         catch
 114                                         {
 115                                                 throw;
 116                                         }
 117
 118                                         return Color.FromArgb(n);
 119                                 }
 120                         }
 121                         return base.ConvertFrom (context, culture, value);
 122                 }
 123
 124                 // Converts from Color to string
 125                 public override object ConvertTo (ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
 126                 {
 127                         if (!(value is Color) || destinationType != typeof (string))
 128                                 return base.ConvertTo (context, culture, value, destinationType);
 129
 130                         Color c = (Color) value;
 131
 132                         if (culture == null)
 133                                 culture = CultureInfo.InvariantCulture;
 134
 135                         string s = c.ToKnownColor ().ToString ();
 136                         if (s != "0")
 137                                 return s;
 138
 139                         return String.Format (culture, "#{0:X2}{1:X2}{2:X2}", c.R, c.G, c.B);
 140                 }
 141         }
 142 }