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) 2004,2006,2008 Novell, Inc (http://www.novell.com)
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System.Collections;
  32 using System.ComponentModel;
  33 using System.Globalization;
  34 using System.Text;
  35 using System.ComponentModel.Design.Serialization;
  36 using System.Reflection;
  37
  38 namespace System.Drawing
  39 {
  40         public class ColorConverter : TypeConverter
  41         {
  42                 static StandardValuesCollection cached;
  43                 static object creatingCached = new object ();
  44
  45                 public ColorConverter () { }
  46
  47                 public override bool CanConvertFrom (ITypeDescriptorContext context, Type sourceType)
  48                 {
  49                         if (sourceType == typeof (string))
  50                                 return true;
  51
  52                         return base.CanConvertFrom (context, sourceType);
  53                 }
  54
  55                 public override bool CanConvertTo (ITypeDescriptorContext context, Type destinationType)
  56                 {
  57                         if (destinationType == typeof (InstanceDescriptor))
  58                                 return true;
  59
  60                         return base.CanConvertTo (context, destinationType);
  61                 }
  62
  63                 internal static Color StaticConvertFromString (ITypeDescriptorContext context, string s, CultureInfo culture)
  64                 {
  65                         if (culture == null)
  66                                 culture = CultureInfo.InvariantCulture;
  67
  68                         s = s.Trim ();
  69
  70                         if (s.Length == 0)
  71                                 return Color.Empty;
  72
  73                         // Try to process both NamedColor and SystemColors from the KnownColor enumeration
  74                         if (Char.IsLetter (s [0])) {
  75                                 KnownColor kc;
  76                                 try {
  77                                         kc = (KnownColor) Enum.Parse (typeof (KnownColor), s, true);
  78                                 }
  79                                 catch (Exception e) {
  80                                         // whatever happens MS throws an basic Exception
  81                                         string msg = Locale.GetText ("Invalid color name '{0}'.", s);
  82                                         throw new Exception (msg, new FormatException (msg, e));
  83                                 }
  84                                 return KnownColors.FromKnownColor (kc);
  85                         }
  86
  87                         String numSeparator = culture.TextInfo.ListSeparator;
  88                         Color result = Color.Empty;
  89
  90                         if (s.IndexOf (numSeparator) == -1) {
  91                                 bool sharp = (s[0] == '#');
  92                                 int start = sharp ? 1 : 0;
  93                                 bool hex = false;
  94                                 // deal with #hex, 0xhex and #0xhex
  95                                 if ((s.Length > start + 1) && (s[start] == '0')) {
  96                                         hex = ((s[start + 1] == 'x') || (s[start + 1] == 'X'));
  97                                         if (hex)
  98                                                 start += 2;
  99                                 }
 100
 101                                 if (sharp || hex) {
 102                                         s = s.Substring (start);
 103                                         int argb;
 104                                         try {
 105                                                 argb = Int32.Parse (s, NumberStyles.HexNumber);
 106                                         }
 107                                         catch (Exception e) {
 108                                                 // whatever happens MS throws an basic Exception
 109                                                 string msg = Locale.GetText ("Invalid Int32 value '{0}'.", s);
 110                                                 throw new Exception (msg, e);
 111                                         }
 112
 113                                         // note that the default alpha value for a 6 hex digit (i.e. when none are present) is
 114                                         // 0xFF while shorter string defaults to 0xFF - unless both # an 0x are specified
 115                                         if ((s.Length < 6) || ((s.Length == 6) && sharp && hex))
 116                                                 argb &= 0x00FFFFFF;
 117                                         else if ((argb >> 24) == 0)
 118                                                 argb |= unchecked((int)0xFF000000);
 119                                         result = Color.FromArgb (argb);
 120                                 }
 121                         }
 122
 123                         if (result.IsEmpty) {
 124                                 Int32Converter converter = new Int32Converter ();
 125                                 String [] components = s.Split (numSeparator.ToCharArray ());
 126
 127                                 // MS seems to convert the indivual component to int before
 128                                 // checking the number of components
 129                                 int[] numComponents = new int[components.Length];
 130                                 for (int i = 0; i < numComponents.Length; i++) {
 131                                         numComponents[i] = (int) converter.ConvertFrom (context,
 132                                                 culture, components[i]);
 133                                 }
 134
 135                                 switch (components.Length) {
 136                                         case 1:
 137                                                 result = Color.FromArgb (numComponents[0]);
 138                                                 break;
 139                                         case 3:
 140                                                 result = Color.FromArgb (numComponents[0], numComponents[1],
 141                                                         numComponents[2]);
 142                                                 break;
 143                                         case 4:
 144                                                 result = Color.FromArgb (numComponents[0], numComponents[1],
 145                                                         numComponents[2], numComponents[3]);
 146                                                 break;
 147                                         default:
 148                                                 throw new ArgumentException (s + " is not a valid color value.");
 149                                 }
 150                         }
 151
 152                         if (!result.IsEmpty) {
 153                                 // Look for a named or system color with those values
 154                                 Color known = KnownColors.FindColorMatch (result);
 155                                 if (!known.IsEmpty)
 156                                         return known;
 157                         }
 158
 159                         return result;
 160                 }
 161
 162
 163                 public override object ConvertFrom (ITypeDescriptorContext context,
 164                                                     CultureInfo culture,
 165                                                     object value)
 166                 {
 167                         string s = value as string;
 168                         if (s == null)
 169                                 return base.ConvertFrom (context, culture, value);
 170
 171                         return StaticConvertFromString (context, s, culture);
 172                 }
 173
 174                 public override object ConvertTo (ITypeDescriptorContext context,
 175                                                   CultureInfo culture,
 176                                                   object value,
 177                                                   Type destinationType)
 178                 {
 179                         if (value is Color) {
 180                                 Color color = (Color) value;
 181                                 if (destinationType == typeof (string)) {
 182                                         if (color == Color.Empty)
 183                                                 return string.Empty;
 184
 185                                         if (color.IsKnownColor || color.IsNamedColor)
 186                                                 return color.Name;
 187
 188                                         String numSeparator = culture.TextInfo.ListSeparator;
 189
 190                                         StringBuilder sb = new StringBuilder ();
 191                                         if (color.A != 255) {
 192                                                 sb.Append (color.A);
 193                                                 sb.Append (numSeparator);
 194                                                 sb.Append (" ");
 195                                         }
 196                                         sb.Append (color.R);
 197                                         sb.Append (numSeparator);
 198                                         sb.Append (" ");
 199
 200                                         sb.Append (color.G);
 201                                         sb.Append (numSeparator);
 202                                         sb.Append (" ");
 203
 204                                         sb.Append (color.B);
 205                                         return sb.ToString ();
 206                                 } else if (destinationType == typeof (InstanceDescriptor)) {
 207                                         if (color.IsEmpty) {
 208                                                 return new InstanceDescriptor (typeof (Color).GetField ("Empty"), null);
 209                                         } else if (color.IsSystemColor) {
 210                                                 return new InstanceDescriptor (typeof (SystemColors).GetProperty (color.Name), null);
 211                                         } else if (color.IsKnownColor){
 212                                                 return new InstanceDescriptor (typeof (Color).GetProperty (color.Name), null);
 213                                         } else {
 214                                                 MethodInfo met = typeof(Color).GetMethod ("FromArgb", new Type[] { typeof(int), typeof(int), typeof(int), typeof(int) } );
 215                                                 return new InstanceDescriptor (met, new object[] {color.A, color.R, color.G, color.B });
 216                                         }
 217                                 }
 218                         }
 219
 220                         return base.ConvertTo (context, culture, value, destinationType);
 221                 }
 222
 223                 public override StandardValuesCollection GetStandardValues (ITypeDescriptorContext context)
 224                 {
 225                         lock (creatingCached) {
 226                                 if (cached != null)
 227                                         return cached;
 228 #if TARGET_JVM
 229                                 Color [] colors = new Color [KnownColors.Values.Length - 1];
 230                                 Array.Copy (KnownColors.Values, 1, colors, 0, colors.Length);
 231 #else
 232                                 Array colors = Array.CreateInstance (typeof (Color), KnownColors.ArgbValues.Length - 1);
 233                                 for (int i=1; i < KnownColors.ArgbValues.Length; i++) {
 234                                         colors.SetValue (KnownColors.FromKnownColor ((KnownColor)i), i - 1);
 235                                 }
 236 #endif
 237
 238                                 Array.Sort (colors, 0, colors.Length, new CompareColors ());
 239                                 cached = new StandardValuesCollection (colors);
 240                         }
 241
 242                         return cached;
 243                 }
 244
 245                 public override bool GetStandardValuesSupported (ITypeDescriptorContext context)
 246                 {
 247                         return true;
 248                 }
 249
 250                 sealed class CompareColors : IComparer {
 251
 252                         public int Compare (object x, object y)
 253                         {
 254                                 return String.Compare (((Color) x).Name, ((Color) y).Name);
 255                         }
 256                 }
 257         }
 258 }