Style away the hours.

Perspex.UnitTests/Styling/SelectorTests.cs

@@ -17,11 +17,106 @@ namespace Perspex.UnitTests.Styling
     [TestClass]
     public class SelectorTests
     {
+        [TestMethod]
+        public void Class_Matches_Control_With_Class()
+        {
+            var control = new Control1
+            {
+                Classes = new Classes { "foo" },
+            };
+
+            var target = control.Select().Class("foo");
+
+            CollectionAssert.AreEqual(new[] { true }, target.GetActivator().Take(1).ToEnumerable().ToArray());
+        }
+
+        [TestMethod]
+        public void Class_Doesnt_Match_Control_Without_Class()
+        {
+            var control = new Control1
+            {
+                Classes = new Classes { "bar" },
+            };
+
+            var target = control.Select().Class("foo");
+
+            CollectionAssert.AreEqual(new[] { false }, target.GetActivator().Take(1).ToEnumerable().ToArray());
+        }
+
+        [TestMethod]
+        public void Class_Tracks_Additions()
+        {
+            var control = new Control1();
+
+            var target = control.Select().Class("foo");
+            var activator = target.GetActivator();
+
+            CollectionAssert.AreEqual(new[] { false }, activator.Take(1).ToEnumerable().ToArray());
+            control.Classes.Add("foo");
+            CollectionAssert.AreEqual(new[] { true }, activator.Take(1).ToEnumerable().ToArray());
+        }
+
+        [TestMethod]
+        public void Class_Tracks_Removals()
+        {
+            var control = new Control1
+            {
+                Classes = new Classes { "foo" },
+            };
+
+            var target = control.Select().Class("foo");
+            var activator = target.GetActivator();
+
+            CollectionAssert.AreEqual(new[] { true }, activator.Take(1).ToEnumerable().ToArray());
+            control.Classes.Remove("foo");
+            CollectionAssert.AreEqual(new[] { false }, activator.Take(1).ToEnumerable().ToArray());
+        }
+
+        [TestMethod]
+        public void Id_Matches_Control_With_Correct_Id()
+        {
+            var control = new Control1 { Id = "foo" };
+            var target = control.Select().Id("foo");
+
+            CollectionAssert.AreEqual(new[] { true }, target.GetActivator().Take(1).ToEnumerable().ToArray());
+        }
+
+        [TestMethod]
+        public void Id_Doesnt_Match_Control_Of_Wrong_Id()
+        {
+            var control = new Control1 { Id = "foo" };
+            var target = control.Select().Id("bar");
+
+            CollectionAssert.AreEqual(new[] { false }, target.GetActivator().Take(1).ToEnumerable().ToArray());
+        }
+
+        [TestMethod]
+        public void When_Id_Matches_Control_Other_Selectors_Are_Subscribed()
+        {
+            var control = new Control1 { Id = "foo" };
+            var target = control.Select().Id("foo").SubscribeCheck();
+
+            var result = target.GetActivator().ToEnumerable().Take(1).ToArray();
+
+            Assert.AreEqual(1, control.SubscribeCheckObservable.SubscribedCount);
+        }
+
+        [TestMethod]
+        public void When_Id_Doesnt_Match_Control_Other_Selectors_Are_Not_Subscribed()
+        {
+            var control = new Control1 { Id = "foo" };
+            var target = control.Select().Id("bar").SubscribeCheck();
+
+            var result = target.GetActivator().ToEnumerable().Take(1).ToArray();
+
+            Assert.AreEqual(0, control.SubscribeCheckObservable.SubscribedCount);
+        }
+
         [TestMethod]
         public void OfType_Matches_Control_Of_Correct_Type()
         {
-            var control = new Class1();
-            var target = control.Select().OfType<Class1>();
+            var control = new Control1();
+            var target = control.Select().OfType<Control1>();
 
             CollectionAssert.AreEqual(new[] { true }, target.GetActivator().Take(1).ToEnumerable().ToArray());
         }
@@ -29,8 +124,8 @@ namespace Perspex.UnitTests.Styling
         [TestMethod]
         public void OfType_Doesnt_Match_Control_Of_Wrong_Type()
         {
-            var control = new Class2();
-            var target = control.Select().OfType<Class1>();
+            var control = new Control2();
+            var target = control.Select().OfType<Control1>();
 
             CollectionAssert.AreEqual(new[] { false }, target.GetActivator().Take(1).ToEnumerable().ToArray());
         }
@@ -38,8 +133,8 @@ namespace Perspex.UnitTests.Styling
         [TestMethod]
         public void When_OfType_Matches_Control_Other_Selectors_Are_Subscribed()
         {
-            var control = new Class1();
-            var target = control.Select().OfType<Class1>().SubscribeCheck();
+            var control = new Control1();
+            var target = control.Select().OfType<Control1>().SubscribeCheck();
 
             var result = target.GetActivator().ToEnumerable().Take(1).ToArray();
 
@@ -49,19 +144,19 @@ namespace Perspex.UnitTests.Styling
         [TestMethod]
         public void When_OfType_Doesnt_Match_Control_Other_Selectors_Are_Not_Subscribed()
         {
-            var control = new Class1();
-            var target = control.Select().OfType<Class2>().SubscribeCheck();
+            var control = new Control1();
+            var target = control.Select().OfType<Control2>().SubscribeCheck();
 
             var result = target.GetActivator().ToEnumerable().Take(1).ToArray();
 
             Assert.AreEqual(0, control.SubscribeCheckObservable.SubscribedCount);
         }
 
-        public class Class1 : SubscribeCheck
+        public class Control1 : SubscribeCheck
         {
         }
 
-        public class Class2 : SubscribeCheck
+        public class Control2 : SubscribeCheck
         {
         }
     }

Perspex.UnitTests/Styling/SubscribeCheck.cs

@@ -8,6 +8,7 @@ namespace Perspex.UnitTests.Styling
 {
     using System;
     using System.Reactive.Disposables;
+    using Perspex.Controls;
     using Perspex.Styling;
     using Match = Perspex.Styling.Match;
 
@@ -27,20 +28,20 @@ namespace Perspex.UnitTests.Styling
     {
         public SubscribeCheck()
         {
-            this.Classes = Classes;
+            this.Classes = new Classes();
             this.SubscribeCheckObservable = new TestObservable();
         }
 
-        public Classes Classes
-        {
-            get;
-            private set;
-        }
+        public string Id { get; set; }
+
+        public Classes Classes { get; set; }
+
+        public TestObservable SubscribeCheckObservable { get; private set; }
 
-        public TestObservable SubscribeCheckObservable
+        public TemplatedControl TemplatedParent
         {
             get;
-            private set;
+            set;
         }
 
         public virtual void SetValue(PerspexProperty property, object value, IObservable<bool> activator)

Perspex/ControlTemplate.cs

@@ -1,25 +1,55 @@
-namespace Perspex
+// -----------------------------------------------------------------------
+// <copyright file="ControlTemplate.cs" company="Steven Kirk">
+// Copyright 2014 MIT Licence. See licence.md for more information.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace Perspex
 {
     using System;
+    using System.Diagnostics.Contracts;
+    using System.Linq;
     using Perspex.Controls;
 
     public class ControlTemplate
     {
+        private Func<TemplatedControl, Control> build;
+
         public ControlTemplate(Func<TemplatedControl, Control> build)
         {
-            this.Build = build;
+            Contract.Requires<NullReferenceException>(build != null);
+
+            this.build = build;
         }
 
-        public Func<TemplatedControl, Control> Build
+        public Control Build(TemplatedControl templatedParent)
         {
-            get;
-            private set;
+            Contract.Requires<NullReferenceException>(templatedParent != null);
+
+            Control root = this.build(templatedParent);
+            this.SetTemplatedParent(root, templatedParent);
+            return root;
         }
 
         public static ControlTemplate Create<TControl>(Func<TControl, Control> build)
             where TControl : TemplatedControl
         {
+            Contract.Requires<NullReferenceException>(build != null);
+
             return new ControlTemplate(c => build((TControl)c));
         }
+
+        private void SetTemplatedParent(Control control, TemplatedControl templatedParent)
+        {
+            Contract.Requires<NullReferenceException>(control != null);
+            Contract.Requires<NullReferenceException>(templatedParent != null);
+
+            control.TemplatedParent = templatedParent;
+
+            foreach (Control child in control.VisualChildren.OfType<Control>())
+            {
+                this.SetTemplatedParent(child, templatedParent);
+            }
+        }
     }
 }

Perspex/Controls/Control.cs

@@ -70,13 +70,15 @@ namespace Perspex.Controls
         internal static readonly PerspexProperty<Control> ParentPropertyRW =
             PerspexProperty.Register<Control, Control>("Parent");
 
+        private Classes classes;
+
         private Styles styles;
 
         public Control()
         {
-            this.Classes = new Classes();
-            this.Classes.BeforeChanged.Subscribe(x => this.BeginDeferStyleChanges());
-            this.Classes.AfterChanged.Subscribe(x => this.EndDeferStyleChanges());
+            this.classes = new Classes();
+            this.classes.BeforeChanged.Subscribe(x => this.BeginDeferStyleChanges());
+            this.classes.AfterChanged.Subscribe(x => this.EndDeferStyleChanges());
 
             this.GetObservableWithHistory(ParentPropertyRW).Subscribe(this.ParentChanged);
 
@@ -145,8 +147,21 @@ namespace Perspex.Controls
 
         public Classes Classes
         {
-            get;
-            private set;
+            get 
+            { 
+                return this.classes; 
+            }
+            
+            set
+            {
+                if (this.classes != value)
+                {
+                    this.BeginDeferStyleChanges();
+                    this.classes.Clear();
+                    this.classes.Add(value);
+                    this.EndDeferStyleChanges();
+                }
+            }
         }
 
         public Brush Foreground
@@ -203,6 +218,12 @@ namespace Perspex.Controls
             }
         }
 
+        public TemplatedControl TemplatedParent
+        {
+            get;
+            internal set;
+        }
+
         public VerticalAlignment VerticalAlignment
         {
             get { return this.GetValue(VerticalAlignmentProperty); }

Perspex/Styling/IStyleable.cs

@@ -19,6 +19,16 @@ namespace Perspex.Styling
         /// </summary>
         Classes Classes { get; }
 
+        /// <summary>
+        /// Gets the ID of the control.
+        /// </summary>
+        string Id { get; }
+
+        /// <summary>
+        /// Gets the template parent of this element if the control comes from a template.
+        /// </summary>
+        TemplatedControl TemplatedParent { get; }
+
         /// <summary>
         /// Binds a <see cref="PerspexProperty"/> to a style.
         /// </summary>

Perspex/Styling/Match.cs

@@ -26,6 +26,12 @@ namespace Perspex.Styling
             private set;
         }
 
+        public bool InTemplate
+        {
+            get;
+            set;
+        }
+
         public List<IObservable<bool>> Observables
         {
             get;

Perspex/Styling/Selectors.cs

@@ -38,6 +38,37 @@ namespace Perspex.Styling
             return match;
         }
 
+        public static Match Id(this Match match, string id)
+        {
+            Contract.Requires<ArgumentNullException>(match != null);
+
+            if (!match.InTemplate)
+            {
+                match.Observables.Add(Observable.Return(
+                    match.Control.TemplatedParent == null &&
+                    match.Control.Id == id));
+            }
+            else
+            {
+                match.Observables.Add(Observable.Return(
+                    match.Control.TemplatedParent != null &&
+                    match.Control.Id == id));
+            }
+
+            match.SelectorString += '#' + id;
+            return match;
+        }
+
+        public static Match InTemplateOf<T>(this Match match)
+        {
+            Contract.Requires<ArgumentNullException>(match != null);
+
+            match.Observables.Add(Observable.Return(match.Control.TemplatedParent is T));
+            match.InTemplate = true;
+            match.SelectorString += '%' + typeof(T).Name;
+            return match;
+        }
+
         public static Match OfType<T>(this Match match)
         {
             Contract.Requires<ArgumentNullException>(match != null);

Perspex/Visual.cs

@@ -14,6 +14,8 @@ namespace Perspex
 
     public abstract class Visual : PerspexObject
     {
+        private string id;
+
         private Visual visualParent;
 
         public Rect Bounds
@@ -22,6 +24,29 @@ namespace Perspex
             protected set;
         }
 
+        public string Id
+        {
+            get
+            {
+                return this.id;
+            }
+
+            set
+            {
+                if (this.id != null)
+                {
+                    throw new InvalidOperationException("ID already set.");
+                }
+
+                if (this.visualParent != null)
+                {
+                    throw new InvalidOperationException("Cannot set ID : control already added to tree.");
+                }
+
+                this.id = value;
+            }
+        }
+
         public virtual IEnumerable<Visual> VisualChildren
         {
             get { return Enumerable.Empty<Visual>(); }