src/XSF/Xamarin.Forms.Core/ColorTypeConverter.cs

   1 using System;
   2 using System.Linq;
   3 using System.Globalization;
   4 using Xamarin.Forms.Internals;
   5
   6 namespace Xamarin.Forms
   7 {
   8         [Xaml.ProvideCompiled("Xamarin.Forms.Core.XamlC.ColorTypeConverter")]
   9         [Xaml.TypeConversion(typeof(Color))]
  10         public class ColorTypeConverter : TypeConverter
  11         {
  12                 // Supported inputs
  13                 // HEX          #rgb, #argb, #rrggbb, #aarrggbb
  14                 // RGB          rgb(255,0,0), rgb(100%,0%,0%)                                   values in range 0-255 or 0%-100%
  15                 // RGBA         rgba(255, 0, 0, 0.8), rgba(100%, 0%, 0%, 0.8)   opacity is 0.0-1.0
  16                 // HSL          hsl(120, 100%, 50%)                                                             h is 0-360, s and l are 0%-100%
  17                 // HSLA         hsla(120, 100%, 50%, .8)                                                opacity is 0.0-1.0
  18                 // Predefined color                                                                                     case insensitive
  19                 public override object ConvertFromInvariantString(string value)
  20                 {
  21                         if (value != null)
  22                         {
  23                                 value = value.Trim();
  24                                 if (value.StartsWith("#", StringComparison.Ordinal))
  25                                         return Color.FromHex(value);
  26
  27                                 if (value.StartsWith("rgba", StringComparison.OrdinalIgnoreCase)) {
  28                                         var op = value.IndexOf('(');
  29                                         var cp = value.LastIndexOf(')');
  30                                         if (op < 0 || cp < 0 || cp < op)
  31                                                 throw new InvalidOperationException($"Cannot convert \"{value}\" into {typeof(Color)}");
  32                                         var quad = value.Substring(op + 1, cp - op - 1).Split(',');
  33                                         if (quad.Length != 4)
  34                                                 throw new InvalidOperationException($"Cannot convert \"{value}\" into {typeof(Color)}");
  35                                         var r = ParseColorValue(quad[0], 255, acceptPercent: true);
  36                                         var g = ParseColorValue(quad[1], 255, acceptPercent: true);
  37                                         var b = ParseColorValue(quad[2], 255, acceptPercent: true);
  38                                         var a = ParseOpacity(quad[3]);
  39                                         return new Color(r, g, b, a);
  40                                 }
  41
  42                                 if (value.StartsWith("rgb", StringComparison.OrdinalIgnoreCase)) {
  43                                         var op = value.IndexOf('(');
  44                                         var cp = value.LastIndexOf(')');
  45                                         if (op < 0 || cp < 0 || cp < op)
  46                                                 throw new InvalidOperationException($"Cannot convert \"{value}\" into {typeof(Color)}");
  47                                         var triplet = value.Substring(op + 1, cp - op - 1).Split(',');
  48                                         if (triplet.Length != 3)
  49                                                 throw new InvalidOperationException($"Cannot convert \"{value}\" into {typeof(Color)}");
  50                                         var r = ParseColorValue(triplet[0], 255, acceptPercent: true);
  51                                         var g = ParseColorValue(triplet[1], 255, acceptPercent: true);
  52                                         var b = ParseColorValue(triplet[2], 255, acceptPercent: true);
  53                                         return new Color(r, g, b);
  54                                 }
  55
  56                                 if (value.StartsWith("hsla", StringComparison.OrdinalIgnoreCase)) {
  57                                         var op = value.IndexOf('(');
  58                                         var cp = value.LastIndexOf(')');
  59                                         if (op < 0 || cp < 0 || cp < op)
  60                                                 throw new InvalidOperationException($"Cannot convert \"{value}\" into {typeof(Color)}");
  61                                         var quad = value.Substring(op + 1, cp - op - 1).Split(',');
  62                                         if (quad.Length != 4)
  63                                                 throw new InvalidOperationException($"Cannot convert \"{value}\" into {typeof(Color)}");
  64                                         var h = ParseColorValue(quad[0], 360, acceptPercent: false);
  65                                         var s = ParseColorValue(quad[1], 100, acceptPercent: true);
  66                                         var l = ParseColorValue(quad[2], 100, acceptPercent: true);
  67                                         var a = ParseOpacity(quad[3]);
  68                                         return Color.FromHsla(h, s, l, a);
  69                                 }
  70
  71                                 if (value.StartsWith("hsl", StringComparison.OrdinalIgnoreCase)) {
  72                                         var op = value.IndexOf('(');
  73                                         var cp = value.LastIndexOf(')');
  74                                         if (op < 0 || cp < 0 || cp < op)
  75                                                 throw new InvalidOperationException($"Cannot convert \"{value}\" into {typeof(Color)}");
  76                                         var triplet = value.Substring(op + 1, cp - op - 1).Split(',');
  77                                         if (triplet.Length != 3)
  78                                                 throw new InvalidOperationException($"Cannot convert \"{value}\" into {typeof(Color)}");
  79                                         var h = ParseColorValue(triplet[0], 360, acceptPercent: false);
  80                                         var s = ParseColorValue(triplet[1], 100, acceptPercent: true);
  81                                         var l = ParseColorValue(triplet[2], 100, acceptPercent: true);
  82                                         return Color.FromHsla(h, s, l);
  83                                 }
  84
  85                                 string[] parts = value.Split('.');
  86                                 if (parts.Length == 1 || (parts.Length == 2 && parts[0] == "Color"))
  87                                 {
  88                                         string color = parts[parts.Length - 1];
  89                                         switch (color.ToLowerInvariant()) {
  90                                         case "default": return Color.Default;
  91                                         case "accent": return Color.Accent;
  92                                         case "aliceblue": return Color.AliceBlue;
  93                                         case "antiquewhite": return Color.AntiqueWhite;
  94                                         case "aqua": return Color.Aqua;
  95                                         case "aquamarine": return Color.Aquamarine;
  96                                         case "azure": return Color.Azure;
  97                                         case "beige": return Color.Beige;
  98                                         case "bisque": return Color.Bisque;
  99                                         case "black": return Color.Black;
 100                                         case "blanchedalmond": return Color.BlanchedAlmond;
 101                                         case "blue": return Color.Blue;
 102                                         case "blueViolet": return Color.BlueViolet;
 103                                         case "brown": return Color.Brown;
 104                                         case "burlywood": return Color.BurlyWood;
 105                                         case "cadetblue": return Color.CadetBlue;
 106                                         case "chartreuse": return Color.Chartreuse;
 107                                         case "chocolate": return Color.Chocolate;
 108                                         case "coral": return Color.Coral;
 109                                         case "cornflowerblue": return Color.CornflowerBlue;
 110                                         case "cornsilk": return Color.Cornsilk;
 111                                         case "crimson": return Color.Crimson;
 112                                         case "cyan": return Color.Cyan;
 113                                         case "darkblue": return Color.DarkBlue;
 114                                         case "darkcyan": return Color.DarkCyan;
 115                                         case "darkgoldenrod": return Color.DarkGoldenrod;
 116                                         case "darkgray": return Color.DarkGray;
 117                                         case "darkgreen": return Color.DarkGreen;
 118                                         case "darkkhaki": return Color.DarkKhaki;
 119                                         case "darkmagenta": return Color.DarkMagenta;
 120                                         case "darkolivegreen": return Color.DarkOliveGreen;
 121                                         case "darkorange": return Color.DarkOrange;
 122                                         case "darkorchid": return Color.DarkOrchid;
 123                                         case "darkred": return Color.DarkRed;
 124                                         case "darksalmon": return Color.DarkSalmon;
 125                                         case "darkseagreen": return Color.DarkSeaGreen;
 126                                         case "darkslateblue": return Color.DarkSlateBlue;
 127                                         case "darkslategray": return Color.DarkSlateGray;
 128                                         case "darkturquoise": return Color.DarkTurquoise;
 129                                         case "darkviolet": return Color.DarkViolet;
 130                                         case "deeppink": return Color.DeepPink;
 131                                         case "deepskyblue": return Color.DeepSkyBlue;
 132                                         case "dimgray": return Color.DimGray;
 133                                         case "dodgerblue": return Color.DodgerBlue;
 134                                         case "firebrick": return Color.Firebrick;
 135                                         case "floralwhite": return Color.FloralWhite;
 136                                         case "forestgreen": return Color.ForestGreen;
 137                                         case "fuchsia": return Color.Fuchsia;
 138                                         case "gainsboro": return Color.Gainsboro;
 139                                         case "ghostwhite": return Color.GhostWhite;
 140                                         case "gold": return Color.Gold;
 141                                         case "goldenrod": return Color.Goldenrod;
 142                                         case "gray": return Color.Gray;
 143                                         case "green": return Color.Green;
 144                                         case "greenyellow": return Color.GreenYellow;
 145                                         case "honeydew": return Color.Honeydew;
 146                                         case "hotpink": return Color.HotPink;
 147                                         case "indianred": return Color.IndianRed;
 148                                         case "indigo": return Color.Indigo;
 149                                         case "ivory": return Color.Ivory;
 150                                         case "khaki": return Color.Khaki;
 151                                         case "lavender": return Color.Lavender;
 152                                         case "lavenderblush": return Color.LavenderBlush;
 153                                         case "lawngreen": return Color.LawnGreen;
 154                                         case "lemonchiffon": return Color.LemonChiffon;
 155                                         case "lightblue": return Color.LightBlue;
 156                                         case "lightcoral": return Color.LightCoral;
 157                                         case "lightcyan": return Color.LightCyan;
 158                                         case "lightgoldenrodyellow": return Color.LightGoldenrodYellow;
 159                                         case "lightgrey":
 160                                         case "lightgray": return Color.LightGray;
 161                                         case "lightgreen": return Color.LightGreen;
 162                                         case "lightpink": return Color.LightPink;
 163                                         case "lightsalmon": return Color.LightSalmon;
 164                                         case "lightseagreen": return Color.LightSeaGreen;
 165                                         case "lightskyblue": return Color.LightSkyBlue;
 166                                         case "lightslategray": return Color.LightSlateGray;
 167                                         case "lightsteelblue": return Color.LightSteelBlue;
 168                                         case "lightyellow": return Color.LightYellow;
 169                                         case "lime": return Color.Lime;
 170                                         case "limegreen": return Color.LimeGreen;
 171                                         case "linen": return Color.Linen;
 172                                         case "magenta": return Color.Magenta;
 173                                         case "maroon": return Color.Maroon;
 174                                         case "mediumaquamarine": return Color.MediumAquamarine;
 175                                         case "mediumblue": return Color.MediumBlue;
 176                                         case "mediumorchid": return Color.MediumOrchid;
 177                                         case "mediumpurple": return Color.MediumPurple;
 178                                         case "mediumseagreen": return Color.MediumSeaGreen;
 179                                         case "mediumslateblue": return Color.MediumSlateBlue;
 180                                         case "mediumspringgreen": return Color.MediumSpringGreen;
 181                                         case "mediumturquoise": return Color.MediumTurquoise;
 182                                         case "mediumvioletred": return Color.MediumVioletRed;
 183                                         case "midnightblue": return Color.MidnightBlue;
 184                                         case "mintcream": return Color.MintCream;
 185                                         case "mistyrose": return Color.MistyRose;
 186                                         case "moccasin": return Color.Moccasin;
 187                                         case "navajowhite": return Color.NavajoWhite;
 188                                         case "navy": return Color.Navy;
 189                                         case "oldlace": return Color.OldLace;
 190                                         case "olive": return Color.Olive;
 191                                         case "olivedrab": return Color.OliveDrab;
 192                                         case "orange": return Color.Orange;
 193                                         case "orangered": return Color.OrangeRed;
 194                                         case "orchid": return Color.Orchid;
 195                                         case "palegoldenrod": return Color.PaleGoldenrod;
 196                                         case "palegreen": return Color.PaleGreen;
 197                                         case "paleturquoise": return Color.PaleTurquoise;
 198                                         case "palevioletred": return Color.PaleVioletRed;
 199                                         case "papayawhip": return Color.PapayaWhip;
 200                                         case "peachpuff": return Color.PeachPuff;
 201                                         case "peru": return Color.Peru;
 202                                         case "pink": return Color.Pink;
 203                                         case "plum": return Color.Plum;
 204                                         case "powderblue": return Color.PowderBlue;
 205                                         case "purple": return Color.Purple;
 206                                         case "red": return Color.Red;
 207                                         case "rosybrown": return Color.RosyBrown;
 208                                         case "royalblue": return Color.RoyalBlue;
 209                                         case "saddlebrown": return Color.SaddleBrown;
 210                                         case "salmon": return Color.Salmon;
 211                                         case "sandybrown": return Color.SandyBrown;
 212                                         case "seagreen": return Color.SeaGreen;
 213                                         case "seashell": return Color.SeaShell;
 214                                         case "sienna": return Color.Sienna;
 215                                         case "silver": return Color.Silver;
 216                                         case "skyblue": return Color.SkyBlue;
 217                                         case "slateblue": return Color.SlateBlue;
 218                                         case "slategray": return Color.SlateGray;
 219                                         case "snow": return Color.Snow;
 220                                         case "springgreen": return Color.SpringGreen;
 221                                         case "steelblue": return Color.SteelBlue;
 222                                         case "tan": return Color.Tan;
 223                                         case "teal": return Color.Teal;
 224                                         case "thistle": return Color.Thistle;
 225                                         case "tomato": return Color.Tomato;
 226                                         case "transparent": return Color.Transparent;
 227                                         case "turquoise": return Color.Turquoise;
 228                                         case "violet": return Color.Violet;
 229                                         case "wheat": return Color.Wheat;
 230                                         case "white": return Color.White;
 231                                         case "whitesmoke": return Color.WhiteSmoke;
 232                                         case "yellow": return Color.Yellow;
 233                                         case "yellowgreen": return Color.YellowGreen;
 234                                         }
 235                                         var field = typeof(Color).GetFields().FirstOrDefault(fi => fi.IsStatic && string.Equals(fi.Name, color, StringComparison.OrdinalIgnoreCase));
 236                                         if (field != null)
 237                                                 return (Color)field.GetValue(null);
 238                                         var property = typeof(Color).GetProperties().FirstOrDefault(pi => string.Equals(pi.Name, color, StringComparison.OrdinalIgnoreCase) && pi.CanRead && pi.GetMethod.IsStatic);
 239                                         if (property != null)
 240                                                 return (Color)property.GetValue(null, null);
 241                                 }
 242                         }
 243
 244                         throw new InvalidOperationException($"Cannot convert \"{value}\" into {typeof(Color)}");
 245                 }
 246
 247                 static double ParseColorValue(string elem, int maxValue, bool acceptPercent)
 248                 {
 249                         elem = elem.Trim();
 250                         if (elem.EndsWith("%", StringComparison.Ordinal) && acceptPercent) {
 251                                 maxValue = 100;
 252                                 elem = elem.Substring(0, elem.Length - 1);
 253                         }
 254                         return double.Parse(elem, NumberStyles.Number, CultureInfo.InvariantCulture).Clamp(0, maxValue) / maxValue;
 255                 }
 256
 257                 static double ParseOpacity(string elem)
 258                 {
 259                         return double.Parse(elem, NumberStyles.Number, CultureInfo.InvariantCulture).Clamp(0, 1);
 260                 }
 261         }
 262 }