Make TabControl logical child test pass.

And simplified logic in selecting ContentControl logical child.

Perspex.Base/Collections/PerspexReadOnlyListView.cs

@@ -94,7 +94,9 @@ namespace Perspex.Collections
 
         public IEnumerator<T> GetEnumerator()
         {
-            return this.source.GetEnumerator();
+            return (this.source != null) ? 
+                this.source.GetEnumerator() : 
+                Enumerable.Empty<T>().GetEnumerator();
         }
 
         IEnumerator IEnumerable.GetEnumerator()

Perspex.Controls/ContentControl.cs

@@ -24,11 +24,7 @@ namespace Perspex.Controls
         public static readonly PerspexProperty<VerticalAlignment> VerticalContentAlignmentProperty =
             PerspexProperty.Register<ContentControl, VerticalAlignment>("VerticalContentAlignment");
 
-        private SingleItemPerspexList<ILogical> logicalChild = new SingleItemPerspexList<ILogical>();
-
-        private ContentPresenter presenter;
-
-        private IDisposable presenterSubscription;
+        private PerspexReadOnlyListView<ILogical> logicalChildren = new PerspexReadOnlyListView<ILogical>();
 
         public ContentControl()
         {
@@ -55,26 +51,23 @@ namespace Perspex.Controls
 
         IReadOnlyPerspexList<ILogical> ILogical.LogicalChildren
         {
-            get { return this.logicalChild; }
+            get { return this.logicalChildren; }
         }
 
         protected override void OnTemplateApplied()
         {
-            if (this.presenterSubscription != null)
-            {
-                this.presenterSubscription.Dispose();
-                this.presenterSubscription = null;
-            }
-
             // We allow ContentControls without ContentPresenters in the template. This can be
             // useful for e.g. a simple ToggleButton that displays an image. There's no need to
             // have a ContentPresenter in the visual tree for that.
-            this.presenter = this.FindTemplateChild<ContentPresenter>("contentPresenter");
+            var presenter = this.FindTemplateChild<ContentPresenter>("contentPresenter");
 
-            if (this.presenter != null)
+            if (presenter != null)
+            {
+                this.logicalChildren.Source = ((ILogical)presenter).LogicalChildren;
+            }
+            else
             {
-                this.presenterSubscription = this.presenter.ChildObservable
-                    .Subscribe(x => this.logicalChild.SingleItem = x);
+                this.logicalChildren.Source = null;
             }
         }
 

Perspex.Controls/DropDown.cs

@@ -27,11 +27,7 @@ namespace Perspex.Controls
         public static readonly PerspexProperty<bool> IsDropDownOpenProperty =
             PerspexProperty.Register<DropDown, bool>("IsDropDownOpen");
 
-        private SingleItemPerspexList<ILogical> logicalChild = new SingleItemPerspexList<ILogical>();
-
-        private ContentPresenter presenter;
-
-        private IDisposable presenterSubscription;
+        private PerspexReadOnlyListView<ILogical> logicalChildren = new PerspexReadOnlyListView<ILogical>();
 
         public DropDown()
         {
@@ -65,26 +61,23 @@ namespace Perspex.Controls
 
         IReadOnlyPerspexList<ILogical> ILogical.LogicalChildren
         {
-            get { return this.logicalChild; }
+            get { return this.logicalChildren; }
         }
 
         protected override void OnTemplateApplied()
         {
-            if (this.presenterSubscription != null)
+            var presenter = this.FindTemplateChild<ContentPresenter>("contentPresenter");
+
+            if (presenter != null)
             {
-                this.presenterSubscription.Dispose();
-                this.presenterSubscription = null;
+                this.logicalChildren.Source = ((ILogical)presenter).LogicalChildren;
             }
-
-            this.presenter = this.FindTemplateChild<ContentPresenter>("contentPresenter");
-
-            if (this.presenter != null)
+            else
             {
-                this.presenterSubscription = this.presenter.ChildObservable
-                    .Subscribe(x => this.logicalChild.SingleItem = x);
+                this.logicalChildren.Source = null;
             }
         }
-        
+
         private void SetContentParent(Tuple<object, object> change)
         {
             var control1 = change.Item1 as Control;

Perspex.Controls/Presenters/ContentPresenter.cs

@@ -10,19 +10,18 @@ namespace Perspex.Controls.Presenters
     using System.Linq;
     using System.Reactive.Linq;
     using System.Reactive.Subjects;
+    using Perspex.Collections;
     using Perspex.Controls.Primitives;
     using Perspex.Media;
 
-    public class ContentPresenter : Control, IVisual, IPresenter
+    public class ContentPresenter : Control, IVisual, ILogical, IPresenter
     {
         public static readonly PerspexProperty<object> ContentProperty =
             ContentControl.ContentProperty.AddOwner<ContentPresenter>();
 
         private bool createdChild;
 
-        private Control child;
-
-        private BehaviorSubject<Control> childObservable = new BehaviorSubject<Control>(null);
+        private SingleItemPerspexList<ILogical> logicalChild = new SingleItemPerspexList<ILogical>();
 
         public ContentPresenter()
         {
@@ -31,31 +30,7 @@ namespace Perspex.Controls.Presenters
 
         public Control Child
         {
-            get
-            {
-                return this.child;
-            }
-
-            private set
-            {
-                if (this.child != value)
-                {
-                    this.ClearVisualChildren();
-                    this.child = value;
-
-                    if (value != null)
-                    {
-                        this.AddVisualChild(value);
-                    }
-
-                    this.childObservable.OnNext(value);
-                }
-            }
-        }
-
-        public IObservable<Control> ChildObservable
-        {
-            get { return this.childObservable; }
+            get { return (Control)this.logicalChild.SingleItem; }
         }
 
         public object Content
@@ -64,6 +39,11 @@ namespace Perspex.Controls.Presenters
             set { this.SetValue(ContentProperty, value); }
         }
 
+        IReadOnlyPerspexList<ILogical> ILogical.LogicalChildren
+        {
+            get { return this.logicalChild; }
+        }
+
         public override sealed void ApplyTemplate()
         {
             if (!this.createdChild)
@@ -79,10 +59,12 @@ namespace Perspex.Controls.Presenters
 
         protected override Size MeasureOverride(Size availableSize)
         {
-            if (this.child != null)
+            var child = this.Child;
+
+            if (child != null)
             {
-                this.child.Measure(availableSize);
-                return this.child.DesiredSize.Value;
+                child.Measure(availableSize);
+                return child.DesiredSize.Value;
             }
 
             return new Size();
@@ -124,17 +106,18 @@ namespace Perspex.Controls.Presenters
                     }
                 }
 
-                var foo = this.TemplatedParent as TemplatedControl;
+                var templatedParent = this.TemplatedParent as TemplatedControl;
 
-                if (foo != null)
+                if (templatedParent != null)
                 {
-                    foo = foo.TemplatedParent as TemplatedControl;
+                    templatedParent = templatedParent.TemplatedParent as TemplatedControl;
                 }
 
-                result.TemplatedParent = foo;
+                result.TemplatedParent = templatedParent;
+                this.AddVisualChild(result);
             }
 
-            this.Child = result;
+            this.logicalChild.SingleItem = result;
             this.createdChild = true;
         }
     }

Perspex.Controls/TabControl.cs

@@ -15,7 +15,7 @@ namespace Perspex.Controls
     using Perspex.Controls.Primitives;
     using Perspex.Controls.Templates;
 
-    public class TabControl : SelectingItemsControl
+    public class TabControl : SelectingItemsControl, ILogical
     {
         public static readonly PerspexProperty<object> SelectedContentProperty =
             PerspexProperty.Register<TabControl, object>("SelectedContent");
@@ -50,6 +50,11 @@ namespace Perspex.Controls
             set { this.SetValue(SelectedTabProperty, value); }
         }
 
+        IReadOnlyPerspexList<ILogical> ILogical.LogicalChildren
+        {
+            get { return this.logicalChildren; }
+        }
+
         protected override void OnTemplateApplied()
         {
             var presenter = this.GetTemplateChild<ContentPresenter>("contentPresenter");

Tests/Perspex.Controls.UnitTests/ContentControlTests.cs

@@ -150,13 +150,20 @@ namespace Perspex.Controls.UnitTests
         [Fact]
         public void Clearing_Content_Should_Remove_From_LogicalChildren()
         {
-            var contentControl = new ContentControl();
+            var target = new ContentControl();
             var child = new Control();
 
-            contentControl.Content = child;
-            contentControl.Content = null;
+            target.Template = this.GetTemplate();
+            target.Content = child;
+            target.ApplyTemplate();
+
+            target.Content = null;
+
+            // Need to call ApplyTemplate on presenter for LogocalChildren to be updated.
+            var presenter = target.GetTemplateChildren().Single(x => x.Id == "contentPresenter");
+            presenter.ApplyTemplate();
 
-            Assert.Equal(new ILogical[0], ((ILogical)contentControl).LogicalChildren.ToList());
+            Assert.Equal(new ILogical[0], ((ILogical)target).LogicalChildren.ToList());
         }
 
         [Fact]

Tests/Perspex.Controls.UnitTests/ContentPresenterTests.cs

@@ -0,0 +1,86 @@
+// -----------------------------------------------------------------------
+// <copyright file="ContentPresenterTests.cs" company="Steven Kirk">
+// Copyright 2014 MIT Licence. See licence.md for more information.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace Perspex.Controls.UnitTests
+{
+    using System;
+    using System.Collections.Specialized;
+    using System.Linq;
+    using Moq;
+    using Perspex.Controls;
+    using Perspex.Controls.Presenters;
+    using Perspex.Controls.Templates;
+    using Perspex.Layout;
+    using Perspex.Platform;
+    using Perspex.Styling;
+    using Perspex.VisualTree;
+    using Ploeh.AutoFixture;
+    using Ploeh.AutoFixture.AutoMoq;
+    using Splat;
+    using Xunit;
+
+    public class ContentPresenterTests
+    {
+        [Fact]
+        public void Setting_Content_Should_Make_Control_Appear_In_LogicalChildren()
+        {
+            var target = new ContentPresenter();
+            var child = new Control();
+
+            target.Content = child;
+            target.ApplyTemplate();
+
+            Assert.Equal(new[] { child }, ((ILogical)target).LogicalChildren.ToList());
+        }
+
+        [Fact]
+        public void Clearing_Content_Should_Remove_From_LogicalChildren()
+        {
+            var target = new ContentPresenter();
+            var child = new Control();
+
+            target.Content = child;
+            target.Content = null;
+
+            Assert.Equal(new ILogical[0], ((ILogical)target).LogicalChildren.ToList());
+        }
+
+        [Fact]
+        public void Changing_Content_Should_Fire_LogicalChildren_CollectionChanged()
+        {
+            var target = new ContentPresenter();
+            var child = new Control();
+            var called = false;
+
+            ((ILogical)target).LogicalChildren.CollectionChanged += (s, e) =>
+                called = e.Action == NotifyCollectionChangedAction.Add;
+
+            target.Content = child;
+            target.ApplyTemplate();
+
+            Assert.True(called);
+        }
+
+        [Fact]
+        public void Clearing_Content_Should_Fire_LogicalChildren_CollectionChanged()
+        {
+            var target = new ContentPresenter();
+            var child = new Control();
+            var called = false;
+
+            target.Content = child;
+            target.ApplyTemplate();
+
+            ((ILogical)target).LogicalChildren.CollectionChanged += (s, e) =>
+                called = e.Action == NotifyCollectionChangedAction.Remove;
+
+            target.Content = null;
+            target.ApplyTemplate();
+
+            Assert.True(called);
+        }
+    }
+}

Tests/Perspex.Controls.UnitTests/DropDownTests.cs

@@ -154,6 +154,7 @@ namespace Perspex.Controls.UnitTests
 
             target.Content = child;
             target.Content = null;
+            target.ApplyTemplate();
 
             Assert.Equal(new ILogical[0], ((ILogical)target).LogicalChildren.ToList());
         }

Tests/Perspex.Controls.UnitTests/Perspex.Controls.UnitTests.csproj

@@ -79,6 +79,7 @@
     <Otherwise />
   </Choose>
   <ItemGroup>
+    <Compile Include="ContentPresenterTests.cs" />
     <Compile Include="DropDownTests.cs" />
     <Compile Include="ScrollContentPresenterTests.cs" />
     <Compile Include="ScrollViewerTests.cs" />

Tests/Perspex.Controls.UnitTests/TabControlTests.cs

@@ -136,7 +136,7 @@ namespace Perspex.Controls.UnitTests
             target.ApplyTemplate();
 
             Assert.Equal(1, target.GetLogicalChildren().Count());
-            Assert.Equal("Foo", ((TabItem)target.GetLogicalChildren().First()).Id);
+            Assert.Equal("Foo", ((TextBlock)target.GetLogicalChildren().First()).Id);
         }
 
         private Control CreateTabControlTemplate(TabControl parent)