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

   1
   2 //
   3 // Permission is hereby granted, free of charge, to any person obtaining
   4 // a copy of this software and associated documentation files (the
   5 // "Software"), to deal in the Software without restriction, including
   6 // without limitation the rights to use, copy, modify, merge, publish,
   7 // distribute, sublicense, and/or sell copies of the Software, and to
   8 // permit persons to whom the Software is furnished to do so, subject to
   9 // the following conditions:
  10 //
  11 // The above copyright notice and this permission notice shall be
  12 // included in all copies or substantial portions of the Software.
  13 //
  14 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  15 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  16 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  17 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  18 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  19 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  20 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  21 //
  22 /**
  23  * Namespace: System.Web.UI.WebControls
  24  * Class:     WebColorConverter
  25  *
  26  * Author:  Gaurav Vaish, Gonzalo Paniagua Javier
  27  * Maintainer: gvaish@iitk.ac.in
  28  * Contact: <my_scripts2001@yahoo.com>, <gvaish@iitk.ac.in>, <gonzalo@ximian.com>
  29  * Implementation: yes
  30  * Status:  100%
  31  *
  32  * (C) Gaurav Vaish (2002)
  33  * (c) 2002 Ximian, Inc. (http://www.ximian.com)
  34  */
  35
  36 using System;
  37 using System.Globalization;
  38 using System.ComponentModel;
  39 using System.Drawing;
  40 using System.Web;
  41 using System.Web.UI;
  42
  43 namespace System.Web.UI.WebControls
  44 {
  45         public class WebColorConverter : ColorConverter
  46         {
  47                 public override object ConvertFrom (ITypeDescriptorContext context,
  48                                                     CultureInfo culture,
  49                                                     object value)
  50                 {
  51                         if (value is string) {
  52                                 string val = ((string) value).Trim ();
  53                                 if(val == String.Empty || val.Length == 0)
  54                                         return Color.Empty;
  55
  56                                 NumberStyles style = (val [0] == '#') ? NumberStyles.HexNumber :
  57                                                                        NumberStyles.None;
  58
  59                                 try {
  60                                         int n = Int32.Parse (val.Substring (1), style);
  61                                         return Color.FromArgb (n);
  62                                 } catch {
  63                                         Color c = Color.FromName (val);
  64                                         if (c.A != 0 || c.R != 0 || c.B != 0 || c.G != 0)
  65                                                 return c;
  66                                 }
  67                         }
  68
  69                         return base.ConvertFrom(context, culture, value);
  70                 }
  71
  72                 public override object ConvertTo (ITypeDescriptorContext context,
  73                                                   CultureInfo culture,
  74                                                   object value,
  75                                                   Type destinationType)
  76                 {
  77                         if (destinationType == null)
  78                                 throw new ArgumentNullException ("destinationType");
  79
  80                         if (destinationType == typeof (String) && value != null) {
  81                                 Color c = (Color) value;
  82                                 if (c == Color.Empty)
  83                                         return String.Empty;
  84
  85                                 if (c.IsNamedColor || c.IsSystemColor)
  86                                         return c.Name;
  87
  88                                 return String.Format ("#{0:X2}{1:X2}{2:X2}{3:X2}", c.A, c.R, c.G, c.B);
  89                         }
  90
  91                         return base.ConvertTo(context, culture, value, destinationType);
  92                 }
  93         }
  94 }
  95