Add color parsing logic

1 files changed, 32 insertions, 1 deletions

diff --git a/Xamarin.PropertyEditing/Drawing/CommonColor.cs b/Xamarin.PropertyEditing/Drawing/CommonColor.cs
index 08578d4..a4bdaa8 100644
--- a/Xamarin.PropertyEditing/Drawing/CommonColor.cs
+++ b/Xamarin.PropertyEditing/Drawing/CommonColor.cs
@@ -1,5 +1,7 @@
 using System;
 using System.ComponentModel;
+using System.Linq;
+using System.Text.RegularExpressions;
 
 namespace Xamarin.PropertyEditing.Drawing
 {
@@ -522,6 +524,35 @@ namespace Xamarin.PropertyEditing.Drawing
 			+ (left.g - right.g) * (left.g - right.g)
 			+ (left.b - right.b) * (left.b - right.b);
 
+		public static bool TryParse (string value, out CommonColor color)
+		{
+			if (Regex.IsMatch(value, @"^#(([A-Fa-f0-9]{2}){3}|[A-Fa-f0-9]{3}|[A-Fa-f0-9]{4}|([A-Fa-f0-9]{2}){4})$")) {
+				var hex =  value.Substring (1);
+				switch (hex.Length) {
+				case 3:
+					hex = hex.Select (c => $"{c}{c}").Aggregate ((a, b) => (a + b));
+					goto case 6;
+				case 6:
+					hex = hex + "ff";
+					goto case 8;
+				case 4:
+					hex = hex.Select (c => $"{c}{c}").Aggregate ((a, b) => (a + b));
+					goto case 8;
+				case 8:
+					var  v = Convert.ToInt32 (hex, 16);
+					color = new CommonColor (
+						r: (byte)(v >> 24),
+						g: (byte)(v >> 16),
+						b: (byte)(v >> 8),
+						a: (byte) v);
+
+					return true;
+				}
+			}
+			color = CommonColor.Black;
+			return false;
+		}
+
 		public override int GetHashCode ()
 		{
 			var hashCode = 466501756;
@@ -536,7 +567,7 @@ namespace Xamarin.PropertyEditing.Drawing
 
 		public override string ToString ()
 		{
-			return $"#{A:X2}{R:X2}{G:X2}{B:X2}";
+			return $"#{R:X2}{G:X2}{B:X2}{A:X2}";
 		}
 	}
 }