Return TargetType from Selector.

src/Perspex.Styling/Styling/Selector.cs

@@ -37,22 +37,33 @@ namespace Perspex.Styling
     public class Selector
     {
         private readonly Func<IStyleable, SelectorMatch> _evaluate;
-
+        private readonly Type _targetType;
         private readonly bool _inTemplate;
-
         private readonly bool _stopTraversal;
-
         private string _description;
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Selector"/> class.
+        /// </summary>
         public Selector()
         {
             _evaluate = _ => SelectorMatch.True;
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Selector"/> class.
+        /// </summary>
+        /// <param name="previous">The previous selector.</param>
+        /// <param name="evaluate">The evaluator function.</param>
+        /// <param name="selectorString">The string representation of the selector.</param>
+        /// <param name="targetType">The target type, if available.</param>
+        /// <param name="inTemplate">Whether to match in a control template.</param>
+        /// <param name="stopTraversal">Whether to stop traversal at this point.</param>
         public Selector(
             Selector previous,
             Func<IStyleable, SelectorMatch> evaluate,
             string selectorString,
+            Type targetType = null,
             bool inTemplate = false,
             bool stopTraversal = false)
             : this()
@@ -62,25 +73,49 @@ namespace Perspex.Styling
             Previous = previous;
             _evaluate = evaluate;
             SelectorString = selectorString;
+            _targetType = targetType;
             _inTemplate = inTemplate || previous._inTemplate;
             _stopTraversal = stopTraversal;
         }
 
+        /// <summary>
+        /// Gets the previous selector.
+        /// </summary>
         public Selector Previous
         {
-            get; }
+            get;
+        }
 
+        /// <summary>
+        /// Gets a string representation of the selector.
+        /// </summary>
         public string SelectorString
         {
             get;
-            set;
         }
 
+        /// <summary>
+        /// Gets the target type of the selector, if available.
+        /// </summary>
+        public Type TargetType
+        {
+            get { return _targetType ?? MovePrevious()?.TargetType; }
+        }
+
+        /// <summary>
+        /// Returns the previous selector if traversal is not stopped.
+        /// </summary>
+        /// <returns>The previous selector.</returns>
         public Selector MovePrevious()
         {
             return _stopTraversal ? null : Previous;
         }
 
+        /// <summary>
+        /// Tries to match the selector with a control.
+        /// </summary>
+        /// <param name="control">The control.</param>
+        /// <returns>A <see cref="SelectorMatch"/>.</returns>
         public SelectorMatch Match(IStyleable control)
         {
             List<IObservable<bool>> inputs = new List<IObservable<bool>>();
@@ -117,6 +152,10 @@ namespace Perspex.Styling
             }
         }
 
+        /// <summary>
+        /// Gets a string representation of the selector.
+        /// </summary>
+        /// <returns>The string representation of the selector.</returns>
         public override string ToString()
         {
             if (_description == null)

src/Perspex.Styling/Styling/Selectors.cs

@@ -8,8 +8,16 @@ using System.Reflection;
 
 namespace Perspex.Styling
 {
+    /// <summary>
+    /// Extension methods for <see cref="Selector"/>.
+    /// </summary>
     public static class Selectors
     {
+        /// <summary>
+        /// Returns a selector which matches a previous selector's child.
+        /// </summary>
+        /// <param name="previous">The previous selector.</param>
+        /// <returns>The selector.</returns>
         public static Selector Child(this Selector previous)
         {
             Contract.Requires<ArgumentNullException>(previous != null);
@@ -17,6 +25,12 @@ namespace Perspex.Styling
             return new Selector(previous, x => MatchChild(x, previous), " < ", stopTraversal: true);
         }
 
+        /// <summary>
+        /// Returns a selector which matches a control's style class.
+        /// </summary>
+        /// <param name="previous">The previous selector.</param>
+        /// <param name="name">The name of the style class.</param>
+        /// <returns>The selector.</returns>
         public static Selector Class(this Selector previous, string name)
         {
             Contract.Requires<ArgumentNullException>(previous != null);
@@ -25,6 +39,11 @@ namespace Perspex.Styling
             return new Selector(previous, x => MatchClass(x, name), name[0] == ':' ? name : '.' + name);
         }
 
+        /// <summary>
+        /// Returns a selector which matches a descendent of a previous selector.
+        /// </summary>
+        /// <param name="previous">The previous selector.</param>
+        /// <returns>The selector.</returns>
         public static Selector Descendent(this Selector previous)
         {
             Contract.Requires<ArgumentNullException>(previous != null);
@@ -32,18 +51,36 @@ namespace Perspex.Styling
             return new Selector(previous, x => MatchDescendent(x, previous), " ", stopTraversal: true);
         }
 
+        /// <summary>
+        /// Returns a selector which matches a type or a derived type.
+        /// </summary>
+        /// <param name="previous">The previous selector.</param>
+        /// <param name="type">The type.</param>
+        /// <returns>The selector.</returns>
         public static Selector Is(this Selector previous, Type type)
         {
             Contract.Requires<ArgumentNullException>(previous != null);
 
-            return new Selector(previous, x => MatchIs(x, type), type.Name);
+            return new Selector(previous, x => MatchIs(x, type), type.Name, type);
         }
 
+        /// <summary>
+        /// Returns a selector which matches a type or a derived type.
+        /// </summary>
+        /// <typeparam name="T">The type.</typeparam>
+        /// <param name="previous">The previous selector.</param>
+        /// <returns>The selector.</returns>
         public static Selector Is<T>(this Selector previous) where T : IStyleable
         {
             return previous.Is(typeof(T));
         }
 
+        /// <summary>
+        /// Returns a selector which matches a control's Name.
+        /// </summary>
+        /// <param name="previous">The previous selector.</param>
+        /// <param name="name">The name.</param>
+        /// <returns>The selector.</returns>
         public static Selector Name(this Selector previous, string name)
         {
             Contract.Requires<ArgumentNullException>(previous != null);
@@ -51,18 +88,38 @@ namespace Perspex.Styling
             return new Selector(previous, x => MatchName(x, name), '#' + name);
         }
 
+        /// <summary>
+        /// Returns a selector which matches a type.
+        /// </summary>
+        /// <param name="previous">The previous selector.</param>
+        /// <param name="type">The type.</param>
+        /// <returns>The selector.</returns>
         public static Selector OfType(this Selector previous, Type type)
         {
             Contract.Requires<ArgumentNullException>(previous != null);
 
-            return new Selector(previous, x => MatchOfType(x, type), type.Name);
+            return new Selector(previous, x => MatchOfType(x, type), type.Name, type);
         }
 
+        /// <summary>
+        /// Returns a selector which matches a type.
+        /// </summary>
+        /// <typeparam name="T">The type.</typeparam>
+        /// <param name="previous">The previous selector.</param>
+        /// <returns>The selector.</returns>
         public static Selector OfType<T>(this Selector previous) where T : IStyleable
         {
             return previous.OfType(typeof(T));
         }
 
+        /// <summary>
+        /// Returns a selector which matches a control with the specified property value.
+        /// </summary>
+        /// <typeparam name="T">The property type.</typeparam>
+        /// <param name="previous">The previous selector.</param>
+        /// <param name="property">The property.</param>
+        /// <param name="value">The property value.</param>
+        /// <returns>The selector.</returns>
         public static Selector PropertyEquals<T>(this Selector previous, PerspexProperty<T> property, object value)
         {
             Contract.Requires<ArgumentNullException>(previous != null);
@@ -71,6 +128,11 @@ namespace Perspex.Styling
             return new Selector(previous, x => MatchPropertyEquals(x, property, value), $"[{property.Name}={value}]");
         }
 
+        /// <summary>
+        /// Returns a selector which enters a lookless control's template.
+        /// </summary>
+        /// <param name="previous">The previous selector.</param>
+        /// <returns>The selector.</returns>
         public static Selector Template(this Selector previous)
         {
             Contract.Requires<ArgumentNullException>(previous != null);

tests/Perspex.Styling.UnitTests/SelectorTests_Multiple.cs

@@ -6,7 +6,6 @@ using System.Collections.Generic;
 using System.Linq;
 using Perspex.Controls;
 using Perspex.Controls.Templates;
-using Perspex.Styling;
 using Xunit;
 
 namespace Perspex.Styling.UnitTests
@@ -50,5 +49,66 @@ namespace Perspex.Styling.UnitTests
             control.Classes.Remove("foo");
             Assert.Equal(new[] { false, true, false }, values);
         }
+
+        [Fact]
+        public void TargetType_OfType()
+        {
+            var selector = new Selector().OfType<Button>();
+
+            Assert.Equal(typeof(Button), selector.TargetType);
+        }
+
+        [Fact]
+        public void TargetType_OfType_Class()
+        {
+            var selector = new Selector()
+                .OfType<Button>()
+                .Class("foo");
+
+            Assert.Equal(typeof(Button), selector.TargetType);
+        }
+
+        [Fact]
+        public void TargetType_Is_Class()
+        {
+            var selector = new Selector()
+                .Is<Button>()
+                .Class("foo");
+
+            Assert.Equal(typeof(Button), selector.TargetType);
+        }
+
+        [Fact]
+        public void TargetType_Child()
+        {
+            var selector = new Selector()
+                .OfType<Button>()
+                .Child()
+                .OfType<TextBlock>();
+
+            Assert.Equal(typeof(TextBlock), selector.TargetType);
+        }
+
+        [Fact]
+        public void TargetType_Descendent()
+        {
+            var selector = new Selector()
+                .OfType<Button>()
+                .Descendent()
+                .OfType<TextBlock>();
+
+            Assert.Equal(typeof(TextBlock), selector.TargetType);
+        }
+
+        [Fact]
+        public void TargetType_Template()
+        {
+            var selector = new Selector()
+                .OfType<Button>()
+                .Template()
+                .OfType<TextBlock>();
+
+            Assert.Equal(typeof(TextBlock), selector.TargetType);
+        }
     }
 }