Renamed RelativeUnit values.

Percent -> Relative, Pixels -> Absolute.

src/Perspex.HtmlRenderer/Adapters/PerspexAdapter.cs

@@ -77,8 +77,8 @@ namespace TheArtOfDev.HtmlRenderer.Perspex.Adapters
             double y = angle <= 45 ? Math.Max(0.5 - angle / 90, 0) : angle > 135 ? Math.Abs(1.5 - angle / 90) : 0;
             return new BrushAdapter(new LinearGradientBrush
             {
-                StartPoint = new RelativePoint(x, y, RelativeUnit.Percent), 
-                EndPoint = new RelativePoint(1 - x, 1 - y, RelativeUnit.Percent),
+                StartPoint = new RelativePoint(x, y, RelativeUnit.Relative), 
+                EndPoint = new RelativePoint(1 - x, 1 - y, RelativeUnit.Relative),
                 GradientStops =
                 {
                     new GradientStop(startColor, 0),

src/Perspex.SceneGraph/RelativePoint.cs

@@ -1,6 +1,10 @@
 // Copyright (c) The Perspex Project. All rights reserved.
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
+using System;
+using System.Globalization;
+using System.Linq;
+
 namespace Perspex
 {
     /// <summary>
@@ -10,14 +14,14 @@ namespace Perspex
     public enum RelativeUnit
     {
         /// <summary>
-        /// The point is expressed as a percentage of the containing element's size.
+        /// The point is expressed as a fraction of the containing element's size.
         /// </summary>
-        Percent,
+        Relative,
 
         /// <summary>
-        /// The origin's point is in pixels.
+        /// The point is absolute (i.e. in pixels).
         /// </summary>
-        Pixels,
+        Absolute,
     }
 
     /// <summary>
@@ -28,17 +32,17 @@ namespace Perspex
         /// <summary>
         /// A point at the top left of the containing element.
         /// </summary>
-        public static readonly RelativePoint TopLeft = new RelativePoint(0, 0, RelativeUnit.Percent);
+        public static readonly RelativePoint TopLeft = new RelativePoint(0, 0, RelativeUnit.Relative);
 
         /// <summary>
         /// A point at the center of the containing element.
         /// </summary>
-        public static readonly RelativePoint Center = new RelativePoint(0.5, 0.5, RelativeUnit.Percent);
+        public static readonly RelativePoint Center = new RelativePoint(0.5, 0.5, RelativeUnit.Relative);
 
         /// <summary>
         /// A point at the bottom right of the containing element.
         /// </summary>
-        public static readonly RelativePoint BottomRight = new RelativePoint(1, 1, RelativeUnit.Percent);
+        public static readonly RelativePoint BottomRight = new RelativePoint(1, 1, RelativeUnit.Relative);
 
         private Point _point;
 
@@ -83,9 +87,48 @@ namespace Perspex
         /// <returns>The origin point in pixels.</returns>
         public Point ToPixels(Size size)
         {
-            return _unit == RelativeUnit.Pixels ?
+            return _unit == RelativeUnit.Absolute ?
                 _point :
                 new Point(_point.X * size.Width, _point.Y * size.Height);
         }
+
+        /// <summary>
+        /// Parses a <see cref="RelativePoint"/> string.
+        /// </summary>
+        /// <param name="s">The string.</param>
+        /// <param name="culture">The current culture.</param>
+        /// <returns>The parsed <see cref="RelativePoint"/>.</returns>
+        public static RelativePoint Parse(string s, CultureInfo culture)
+        {
+            var parts = s.Split(new[] { ',', ' ' }, StringSplitOptions.RemoveEmptyEntries)
+                .Select(x => x.Trim())
+                .ToList();
+
+            if (parts.Count == 2)
+            {
+                var unit = RelativeUnit.Absolute;
+
+                if (parts[0].EndsWith("%"))
+                {
+                    if (!parts[1].EndsWith("%"))
+                    {
+                        throw new FormatException("If one coordinate is relative, both must be.");
+                    }
+
+                    parts[0] = parts[0].TrimEnd('%');
+                    parts[1] = parts[1].TrimEnd('%');
+                    unit = RelativeUnit.Relative;
+                }
+
+                return new RelativePoint(
+                    double.Parse(parts[0], culture), 
+                    double.Parse(parts[1], culture),
+                    unit);
+            }
+            else
+            {
+                throw new FormatException("Invalid Point.");
+            }
+        }
     }
 }

src/Perspex.SceneGraph/RelativeRect.cs

@@ -11,7 +11,7 @@ namespace Perspex
         /// <summary>
         /// A rectangle that represents 100% of an area.
         /// </summary>
-        public static readonly RelativeRect Fill = new RelativeRect(0, 0, 1, 1, RelativeUnit.Percent);
+        public static readonly RelativeRect Fill = new RelativeRect(0, 0, 1, 1, RelativeUnit.Relative);
 
         /// <summary>
         /// Initializes a new instance of the <see cref="RelativeRect"/> structure.
@@ -90,7 +90,7 @@ namespace Perspex
         /// <returns>The origin point in pixels.</returns>
         public Rect ToPixels(Size size)
         {
-            return Unit == RelativeUnit.Pixels ?
+            return Unit == RelativeUnit.Absolute ?
                 Rect :
                 new Rect(
                     Rect.X * size.Width,

tests/Perspex.RenderTests/Media/LinearGradientBrushTests.cs

@@ -34,8 +34,8 @@ namespace Perspex.Direct2D1.RenderTests.Media
                 {
                     Background = new LinearGradientBrush
                     {
-                        StartPoint = new RelativePoint(0, 0.5, RelativeUnit.Percent),
-                        EndPoint = new RelativePoint(1, 0.5, RelativeUnit.Percent),
+                        StartPoint = new RelativePoint(0, 0.5, RelativeUnit.Relative),
+                        EndPoint = new RelativePoint(1, 0.5, RelativeUnit.Relative),
                         GradientStops =
                         {
                             new GradientStop { Color = Colors.Red, Offset = 0 },
@@ -61,8 +61,8 @@ namespace Perspex.Direct2D1.RenderTests.Media
                 {
                     Background = new LinearGradientBrush
                     {
-                        StartPoint = new RelativePoint(0.5, 0, RelativeUnit.Percent),
-                        EndPoint = new RelativePoint(0.5, 1, RelativeUnit.Percent),
+                        StartPoint = new RelativePoint(0.5, 0, RelativeUnit.Relative),
+                        EndPoint = new RelativePoint(0.5, 1, RelativeUnit.Relative),
                         GradientStops =
                         {
                             new GradientStop { Color = Colors.Red, Offset = 0 },

tests/Perspex.RenderTests/Media/VisualBrushTests.cs

@@ -288,7 +288,7 @@ namespace Perspex.Direct2D1.RenderTests.Media
                 {
                     Fill = new VisualBrush
                     {
-                        SourceRect = new RelativeRect(40, 40, 100, 100, RelativeUnit.Pixels),
+                        SourceRect = new RelativeRect(40, 40, 100, 100, RelativeUnit.Absolute),
                         Visual = new Border
                         {
                             Width = 180,
@@ -329,7 +329,7 @@ namespace Perspex.Direct2D1.RenderTests.Media
                 {
                     Fill = new VisualBrush
                     {
-                        DestinationRect = new RelativeRect(92, 92, 92, 92, RelativeUnit.Pixels),
+                        DestinationRect = new RelativeRect(92, 92, 92, 92, RelativeUnit.Absolute),
                         Visual = new Border
                         {
                             Width = 180,
@@ -370,8 +370,8 @@ namespace Perspex.Direct2D1.RenderTests.Media
                 {
                     Fill = new VisualBrush
                     {
-                        SourceRect = new RelativeRect(40, 40, 100, 100, RelativeUnit.Pixels),
-                        DestinationRect = new RelativeRect(92, 92, 92, 92, RelativeUnit.Pixels),
+                        SourceRect = new RelativeRect(40, 40, 100, 100, RelativeUnit.Absolute),
+                        DestinationRect = new RelativeRect(92, 92, 92, 92, RelativeUnit.Absolute),
                         Visual = new Border
                         {
                             Width = 180,
@@ -412,8 +412,8 @@ namespace Perspex.Direct2D1.RenderTests.Media
                 {
                     Fill = new VisualBrush
                     {
-                        SourceRect = new RelativeRect(0.22, 0.22, 0.56, 0.56, RelativeUnit.Percent),
-                        DestinationRect = new RelativeRect(0.5, 0.5, 0.5, 0.5, RelativeUnit.Percent),
+                        SourceRect = new RelativeRect(0.22, 0.22, 0.56, 0.56, RelativeUnit.Relative),
+                        DestinationRect = new RelativeRect(0.5, 0.5, 0.5, 0.5, RelativeUnit.Relative),
                         Visual = new Border
                         {
                             Width = 180,
@@ -456,7 +456,7 @@ namespace Perspex.Direct2D1.RenderTests.Media
                     {
                         Stretch = Stretch.None,
                         TileMode = TileMode.Tile,
-                        DestinationRect = new RelativeRect(0.25, 0.25, 0.5, 0.5, RelativeUnit.Percent),
+                        DestinationRect = new RelativeRect(0.25, 0.25, 0.5, 0.5, RelativeUnit.Relative),
                         Visual = new Border
                         {
                             Width = 92,
@@ -543,7 +543,7 @@ namespace Perspex.Direct2D1.RenderTests.Media
                     {
                         Stretch = Stretch.None,
                         TileMode = TileMode.FlipX,
-                        DestinationRect = new RelativeRect(0, 0, 0.5, 0.5, RelativeUnit.Percent),
+                        DestinationRect = new RelativeRect(0, 0, 0.5, 0.5, RelativeUnit.Relative),
                         Visual = new Border
                         {
                             Width = 92,
@@ -586,7 +586,7 @@ namespace Perspex.Direct2D1.RenderTests.Media
                     {
                         Stretch = Stretch.None,
                         TileMode = TileMode.FlipY,
-                        DestinationRect = new RelativeRect(0, 0, 0.5, 0.5, RelativeUnit.Percent),
+                        DestinationRect = new RelativeRect(0, 0, 0.5, 0.5, RelativeUnit.Relative),
                         Visual = new Border
                         {
                             Width = 92,
@@ -629,7 +629,7 @@ namespace Perspex.Direct2D1.RenderTests.Media
                     {
                         Stretch = Stretch.None,
                         TileMode = TileMode.FlipXY,
-                        DestinationRect = new RelativeRect(0, 0, 0.5, 0.5, RelativeUnit.Percent),
+                        DestinationRect = new RelativeRect(0, 0, 0.5, 0.5, RelativeUnit.Relative),
                         Visual = new Border
                         {
                             Width = 92,