Add some tests for the Color class

Testing/Tests/ColorTests.cs

@@ -0,0 +1,161 @@
+//
+// Colors.cs
+//
+// Author:
+//       Lluis Sanchez <lluis@xamarin.com>
+//
+// Copyright (c) 2013 Xamarin Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+using System;
+using Xwt.Drawing;
+using NUnit.Framework;
+
+namespace Xwt
+{
+	[TestFixture]
+	public class ColorTests
+	{
+		[Test]
+		public void Red ()
+		{
+			var c = new Color ();
+			c.Red = 1;
+			Assert.AreEqual (1d, c.Red);
+			Assert.AreEqual (0d, c.Green);
+			Assert.AreEqual (0d, c.Blue);
+			Assert.AreEqual (0d, c.Alpha);
+		}
+
+		[Test]
+		public void Green ()
+		{
+			var c = new Color ();
+			c.Green = 1;
+			Assert.AreEqual (1d, c.Green);
+			Assert.AreEqual (0d, c.Red);
+			Assert.AreEqual (0d, c.Blue);
+			Assert.AreEqual (0d, c.Alpha);
+		}
+		
+		[Test]
+		public void Blue ()
+		{
+			var c = new Color ();
+			c.Blue = 1;
+			Assert.AreEqual (1d, c.Blue);
+			Assert.AreEqual (0d, c.Green);
+			Assert.AreEqual (0d, c.Red);
+			Assert.AreEqual (0d, c.Alpha);
+		}
+		
+		[Test]
+		public void Alpha ()
+		{
+			var c = new Color ();
+			c.Alpha = 1;
+			Assert.AreEqual (1d, c.Alpha);
+			Assert.AreEqual (0d, c.Green);
+			Assert.AreEqual (0d, c.Blue);
+			Assert.AreEqual (0d, c.Red);
+		}
+		
+		[Test]
+		public void Constructor ()
+		{
+			var c = new Color (0.1d, 0.2d, 0.3d);
+			Assert.AreEqual (0.1d, c.Red);
+			Assert.AreEqual (0.2d, c.Green);
+			Assert.AreEqual (0.3d, c.Blue);
+			Assert.AreEqual (1d, c.Alpha);
+		}
+
+		[Test]
+		public void ConstructorWithAlpha ()
+		{
+			var c = new Color (0.1d, 0.2d, 0.3d, 0.4d);
+			Assert.AreEqual (0.1d, c.Red);
+			Assert.AreEqual (0.2d, c.Green);
+			Assert.AreEqual (0.3d, c.Blue);
+			Assert.AreEqual (0.4d, c.Alpha);
+		}
+		
+		[Test]
+		public void FromBytes ()
+		{
+			var c = Color.FromBytes (255, 255, 255);
+			Assert.AreEqual (1d, c.Red);
+			Assert.AreEqual (1d, c.Green);
+			Assert.AreEqual (1d, c.Blue);
+			Assert.AreEqual (1d, c.Alpha);
+			c = Color.FromBytes (128, 128, 128);
+			Assert.AreEqual (128, (int)(c.Red * 255));
+			Assert.AreEqual (128, (int)(c.Green * 255));
+			Assert.AreEqual (128, (int)(c.Blue * 255));
+			Assert.AreEqual (1, c.Alpha);
+		}
+		
+		[Test]
+		public void ParseColor ()
+		{
+			Color c;
+			Assert.IsTrue (Color.TryParse ("#3a02b9", out c));
+			Assert.AreEqual (0x3a, (int)(c.Red * 255));
+			Assert.AreEqual (0x02, (int)(c.Green * 255));
+			Assert.AreEqual (0xb9, (int)(c.Blue * 255));
+			Assert.AreEqual (1d, c.Alpha);
+		}
+		
+		[Test]
+		public void ParseColorWithAlpha ()
+		{
+			Color c;
+			Assert.IsTrue (Color.TryParse ("#3a02b9dd", out c));
+			Assert.AreEqual (0x3a, (int)(c.Red * 255));
+			Assert.AreEqual (0x02, (int)(c.Green * 255));
+			Assert.AreEqual (0xb9, (int)(c.Blue * 255));
+			Assert.AreEqual (0xdd, (int)(c.Alpha * 255));
+		}
+		
+		[Test]
+		public void ParseColorFailures ()
+		{
+			Color c;
+			Assert.IsFalse (Color.TryParse ("#3a02b9ddff", out c));
+			Assert.IsFalse (Color.TryParse ("3a02b9dd", out c));
+			Assert.IsFalse (Color.TryParse ("#3a02b9j", out c));
+		}
+
+		[Test]
+		public void Equality ()
+		{
+			var c1 = new Color (1, 0, 0);
+			var c2 = new Color (1, 0, 0);
+			Assert.IsTrue (c1 == c2);
+			Assert.IsTrue (c1.Equals (c2));
+			Assert.IsFalse (c1 != c2);
+
+			c1 = new Color (0.9, 0, 0);
+			Assert.IsFalse (c1 == c2);
+			Assert.IsFalse (c1.Equals (c2));
+			Assert.IsTrue (c1 != c2);
+		}
+	}
+}
+

Xwt/Xwt.Drawing/Color.cs

@@ -205,9 +205,12 @@ namespace Xwt.Drawing
 		
 		public static bool TryParse (string name, out Color color)
 		{
+			if (name == null)
+				throw new ArgumentNullException ("name");
+
 			uint val;
-			if (!TryParseColourFromHex (name, out val)) {
-				color = Colors.White;
+			if (name.Length == 0 || !TryParseColourFromHex (name, out val)) {
+				color = default (Color);
 				return false;
 			}
 			color = Color.FromBytes ((byte)(val >> 24), (byte)((val >> 16) & 0xff), (byte)((val >> 8) & 0xff), (byte)(val & 0xff));
@@ -219,7 +222,7 @@ namespace Xwt.Drawing
 		{
 			val = 0;
 			
-			if (str.Length > 9)
+			if (str[0] != '#' || str.Length > 9)
 				return false;
 			
 			if (!uint.TryParse (str.Substring (1), System.Globalization.NumberStyles.HexNumber, null, out val))

Xwt/Xwt.Drawing/Context.cs

@@ -34,7 +34,6 @@ namespace Xwt.Drawing
 	{
 		ContextBackendHandler handler;
 		Pattern pattern;
-		Font font;
 		double globalAlpha = 1;
 		Stack<double> alphaStack = new Stack<double> ();