mcs/class/System.Drawing/System.Drawing/ColorConverter.cs

   1 //
   2 // System.Drawing.ColorConverter
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //      Ravindra (rkumar@novell.com)
   7 //
   8 // Copyright (C) 2002 Ximian, Inc.  http://www.ximian.com
   9 // Copyright (C) 2004 Novell, Inc.  http://www.novell.com
  10 //
  11
  12 //
  13 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  14 //
  15 // Permission is hereby granted, free of charge, to any person obtaining
  16 // a copy of this software and associated documentation files (the
  17 // "Software"), to deal in the Software without restriction, including
  18 // without limitation the rights to use, copy, modify, merge, publish,
  19 // distribute, sublicense, and/or sell copies of the Software, and to
  20 // permit persons to whom the Software is furnished to do so, subject to
  21 // the following conditions:
  22 //
  23 // The above copyright notice and this permission notice shall be
  24 // included in all copies or substantial portions of the Software.
  25 //
  26 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  27 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  28 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  29 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  30 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  31 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  32 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  33 //
  34
  35 using System;
  36 using System.Collections;
  37 using System.ComponentModel;
  38 using System.Globalization;
  39 using System.Text;
  40 using System.ComponentModel.Design.Serialization;
  41 using System.Reflection;
  42
  43 namespace System.Drawing
  44 {
  45         public class ColorConverter : TypeConverter
  46         {
  47                 static StandardValuesCollection cached;
  48                 static object creatingCached = new object ();
  49
  50                 public ColorConverter () { }
  51
  52                 public override bool CanConvertFrom (ITypeDescriptorContext context, Type sourceType)
  53                 {
  54                         if (sourceType == typeof (string))
  55                                 return true;
  56
  57                         return base.CanConvertFrom (context, sourceType);
  58                 }
  59
  60                 public override bool CanConvertTo (ITypeDescriptorContext context, Type destinationType)
  61                 {
  62                         if (destinationType == typeof (InstanceDescriptor))
  63                                 return true;
  64
  65                         return base.CanConvertTo (context, destinationType);
  66                 }
  67
  68                 public override object ConvertFrom (ITypeDescriptorContext context,
  69                                                     CultureInfo culture,
  70                                                     object value)
  71                 {
  72                         string s = value as string;
  73                         if (s == null)
  74                                 return base.ConvertFrom (context, culture, value);
  75
  76                         s = s.Trim ();
  77
  78                         if (s.Length == 0) {
  79                                 return Color.Empty;
  80                         }
  81
  82                         object named = Color.NamedColors [s];
  83                         if (named != null)
  84                                 return (Color) named;
  85
  86                         named = Color.SystemColors [s];
  87                         if (named != null)
  88                                 return (Color) named;
  89
  90                         String numSeparator = culture.TextInfo.ListSeparator;
  91
  92                         Int32Converter converter = new Int32Converter ();
  93
  94                         object result = null;
  95
  96                         if (s.IndexOf (numSeparator) == -1) {
  97                                 if ((s.Length == 8 && (s.StartsWith ("0x") || s.StartsWith ("0X")))
  98                                         || (s.Length == 7 && s.StartsWith ("#"))) {
  99                                         result = Color.FromArgb (-16777216 | (int) converter.
 100                                                 ConvertFromString (context, culture, s));
 101                                 }
 102                                 else if ((s.Length == 5 && (s.StartsWith ("0x") || s.StartsWith ("0X")))
 103                                         || (s.Length == 4 && s.StartsWith ("#"))) {
 104                                         int i = (int) converter.ConvertFromString (context, culture, s);
 105                                         i = ((i & 0xf00) << 12) | ((i & 0xf00) << 8) |
 106                                                 ((i & 0xf0) << 8) | ((i & 0xf0) << 4) |
 107                                                 ((i & 0xf) << 4) | (i & 0xf);
 108                                         result = Color.FromArgb ( -16777216 | i );
 109                                 }
 110                         }
 111
 112                         if (result == null) {
 113                                 String [] components = s.Split (numSeparator.ToCharArray ());
 114
 115                                 // MS seems to convert the indivual component to int before
 116                                 // checking the number of components
 117                                 int[] numComponents = new int[components.Length];
 118                                 for (int i = 0; i < numComponents.Length; i++) {
 119                                         numComponents[i] = (int) converter.ConvertFrom (context,
 120                                                 culture, components[i]);
 121                                 }
 122
 123                                 switch (components.Length) {
 124                                         case 1:
 125                                                 result = Color.FromArgb (numComponents[0]);
 126                                                 break;
 127                                         case 3:
 128                                                 result = Color.FromArgb (numComponents[0], numComponents[1],
 129                                                         numComponents[2]);
 130                                                 break;
 131                                         case 4:
 132                                                 result = Color.FromArgb (numComponents[0], numComponents[1],
 133                                                         numComponents[2], numComponents[3]);
 134                                                 break;
 135                                         default:
 136                                                 throw new ArgumentException (s + " is not a valid color value.");
 137                                 }
 138                         }
 139
 140                         if (result != null) {
 141                                 Color resultColor = (Color) result;
 142
 143                                 // Look for a named or system color with those values
 144                                 foreach (Color c in Color.NamedColors.Values) {
 145                                         if (c == resultColor)
 146                                                 return c;
 147                                 }
 148
 149                                 foreach (Color c in Color.SystemColors.Values) {
 150                                         if (c == resultColor)
 151                                                 return c;
 152                                 }
 153                         }
 154
 155                         return result;
 156                 }
 157
 158                 public override object ConvertTo (ITypeDescriptorContext context,
 159                                                   CultureInfo culture,
 160                                                   object value,
 161                                                   Type destinationType)
 162                 {
 163                         if ((destinationType == typeof (string)) && (value is Color)) {
 164                                 Color color = (Color) value;
 165
 166                                 if (color == Color.Empty) {
 167                                         return string.Empty;
 168                                 }
 169
 170                                 if (color.IsKnownColor) {
 171                                         return color.Name;
 172                                 }
 173
 174                                 if (color.IsNamedColor)
 175                                         return color.Name;
 176
 177                                 String numSeparator = culture.TextInfo.ListSeparator;
 178
 179                                 StringBuilder sb = new StringBuilder ();
 180                                 if (color.A != 255) {
 181                                         sb.Append (color.A);
 182                                         sb.Append (numSeparator);
 183                                         sb.Append (" ");
 184                                 }
 185                                 sb.Append (color.R);
 186                                 sb.Append (numSeparator);
 187                                 sb.Append (" ");
 188
 189                                 sb.Append (color.G);
 190                                 sb.Append (numSeparator);
 191                                 sb.Append (" ");
 192
 193                                 sb.Append (color.B);
 194                                 return sb.ToString ();
 195                         }
 196
 197                         if (destinationType == typeof (InstanceDescriptor) && value is Color) {
 198                                 Color c = (Color)value;
 199                                 if (c.IsKnownColor){
 200                                         return new InstanceDescriptor (typeof (SystemColors).GetProperty (c.Name), null);
 201                                 } else {
 202                                         MethodInfo met = typeof(Color).GetMethod ("FromArgb", new Type[] { typeof(int), typeof(int), typeof(int), typeof(int) } );
 203                                         return new InstanceDescriptor (met, new object[] {c.A, c.R, c.G, c.B });
 204                                 }
 205                         }
 206
 207                         return base.ConvertTo (context, culture, value, destinationType);
 208                 }
 209
 210                 public override StandardValuesCollection GetStandardValues (ITypeDescriptorContext context)
 211                 {
 212                         if (cached != null)
 213                                 return cached;
 214
 215                         lock (creatingCached)
 216                         {
 217                                 if (cached != null)
 218                                         return cached;
 219
 220                                 ICollection named = (ICollection) Color.NamedColors.Values;
 221                                 ICollection system = (ICollection) Color.SystemColors.Values;
 222                                 Array colors = Array.CreateInstance (typeof (Color), named.Count + system.Count);
 223                                 named.CopyTo (colors, 0);
 224                                 system.CopyTo (colors, named.Count);
 225                                 Array.Sort (colors, 0, colors.Length, new CompareColors ());
 226                                 cached = new StandardValuesCollection (colors);
 227                         }
 228
 229                         return cached;
 230                 }
 231
 232                 public override bool GetStandardValuesSupported (ITypeDescriptorContext context)
 233                 {
 234                         return true;
 235                 }
 236
 237                 class CompareColors : IComparer
 238                 {
 239                         public int Compare (object x, object y)
 240                         {
 241                                 return String.Compare (((Color) x).Name, ((Color) y).Name);
 242                         }
 243                 }
 244         }
 245 }