Make ContentControl child be logical child.

The control this is created by the ContentPresenter now appears as the
logical child of the parent ContentControl.

Perspex.Controls.UnitTests/ContentControlTests.cs

@@ -125,11 +125,28 @@ namespace Perspex.Controls.UnitTests
             var target = new ContentControl();
             var child = new Control();
 
+            target.Template = this.GetTemplate();
             target.Content = child;
+            target.ApplyTemplate();
 
             CollectionAssert.AreEqual(new[] { child }, ((ILogical)target).LogicalChildren.ToList());
         }
 
+        [TestMethod]
+        public void Setting_Content_To_String_Should_Make_TextBlock_Appear_In_LogicalChildren()
+        {
+            var target = new ContentControl();
+            var child = new Control();
+
+            target.Template = this.GetTemplate();
+            target.Content = "Foo";
+            target.ApplyTemplate();
+
+            var logical = (ILogical)target;
+            Assert.AreEqual(1, logical.LogicalChildren.Count);
+            Assert.IsInstanceOfType(logical.LogicalChildren[0], typeof(TextBlock));
+        }
+
         [TestMethod]
         public void Clearing_Content_Should_Remove_From_LogicalChildren()
         {
@@ -152,7 +169,13 @@ namespace Perspex.Controls.UnitTests
             ((ILogical)contentControl).LogicalChildren.CollectionChanged += (s, e) =>
                 called = e.Action == NotifyCollectionChangedAction.Add;
 
+            contentControl.Template = this.GetTemplate();
             contentControl.Content = child;
+            contentControl.ApplyTemplate();
+
+            // Need to call ApplyTemplate on presenter for CollectionChanged to be called.
+            var presenter = contentControl.GetTemplateControls().Single(x => x.Id == "presenter");
+            presenter.ApplyTemplate();
 
             Assert.IsTrue(called);
         }
@@ -164,13 +187,19 @@ namespace Perspex.Controls.UnitTests
             var child = new Control();
             var called = false;
 
+            contentControl.Template = this.GetTemplate();
             contentControl.Content = child;
+            ApplyTemplate(contentControl);
 
             ((ILogical)contentControl).LogicalChildren.CollectionChanged += (s, e) =>
                 called = e.Action == NotifyCollectionChangedAction.Remove;
 
             contentControl.Content = null;
 
+            // Need to call ApplyTemplate on presenter for CollectionChanged to be called.
+            var presenter = contentControl.GetTemplateControls().Single(x => x.Id == "presenter");
+            presenter.ApplyTemplate();
+
             Assert.IsTrue(called);
         }
 
@@ -182,13 +211,19 @@ namespace Perspex.Controls.UnitTests
             var child2 = new Control();
             var called = false;
 
+            contentControl.Template = this.GetTemplate();
             contentControl.Content = child1;
+            contentControl.ApplyTemplate();
 
             ((ILogical)contentControl).LogicalChildren.CollectionChanged += (s, e) =>
                 called = e.Action == NotifyCollectionChangedAction.Replace;
 
             contentControl.Content = child2;
 
+            // Need to call ApplyTemplate on presenter for CollectionChanged to be called.
+            var presenter = contentControl.GetTemplateControls().Single(x => x.Id == "presenter");
+            presenter.ApplyTemplate();
+
             Assert.IsTrue(called);
         }
 
@@ -206,6 +241,7 @@ namespace Perspex.Controls.UnitTests
                     Background = new Perspex.Media.SolidColorBrush(0xffffffff),
                     Content = new ContentPresenter
                     {
+                        Id = "presenter",
                         [~ContentPresenter.ContentProperty] = parent[~ContentControl.ContentProperty],
                     }
                 };

Perspex.Controls/ContentControl.cs

@@ -8,6 +8,7 @@ namespace Perspex.Controls
 {
     using System;
     using Perspex.Collections;
+    using Perspex.Controls.Presenters;
     using Perspex.Controls.Primitives;
     using Perspex.Layout;
 
@@ -24,6 +25,10 @@ namespace Perspex.Controls
 
         private SingleItemPerspexList<ILogical> logicalChild = new SingleItemPerspexList<ILogical>();
 
+        private ContentPresenter presenter;
+
+        private IDisposable presenterSubscription;
+
         public ContentControl()
         {
             this.GetObservableWithHistory(ContentProperty).Subscribe(x =>
@@ -40,8 +45,6 @@ namespace Perspex.Controls
                 {
                     control2.Parent = this;
                 }
-
-                this.logicalChild.SingleItem = control2;
             });
         }
 
@@ -67,5 +70,18 @@ namespace Perspex.Controls
             get { return this.GetValue(VerticalContentAlignmentProperty); }
             set { this.SetValue(VerticalContentAlignmentProperty, value); }
         }
+
+        protected override void OnTemplateApplied()
+        {
+            if (this.presenterSubscription != null)
+            {
+                this.presenterSubscription.Dispose();
+                this.presenterSubscription = null;
+            }
+
+            this.presenter = this.GetTemplateChild<ContentPresenter>("presenter");
+            this.presenterSubscription = this.presenter.ChildObservable
+                .Subscribe(x => this.logicalChild.SingleItem = x);
+        }
     }
 }

Perspex.Controls/Presenters/ContentPresenter.cs

@@ -9,8 +9,8 @@ namespace Perspex.Controls.Presenters
     using System;
     using System.Linq;
     using System.Reactive.Linq;
+    using System.Reactive.Subjects;
     using Perspex.Controls.Primitives;
-    using Perspex.Layout;
 
     public class ContentPresenter : Control, IVisual
     {
@@ -19,11 +19,44 @@ namespace Perspex.Controls.Presenters
 
         private bool createdChild;
 
+        private Control child;
+
+        private BehaviorSubject<Control> childObservable = new BehaviorSubject<Control>(null);
+
         public ContentPresenter()
         {
             this.GetObservable(ContentProperty).Skip(1).Subscribe(this.ContentChanged);
         }
 
+        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; }
+        }
+
         public object Content
         {
             get { return this.GetValue(ContentProperty); }
@@ -45,12 +78,10 @@ namespace Perspex.Controls.Presenters
 
         protected override Size MeasureOverride(Size availableSize)
         {
-            Control child = ((IVisual)this).VisualChildren.SingleOrDefault() as Control;
-
-            if (child != null)
+            if (this.child != null)
             {
-                child.Measure(availableSize);
-                return child.DesiredSize.Value;
+                this.child.Measure(availableSize);
+                return this.child.DesiredSize.Value;
             }
 
             return new Size();
@@ -64,13 +95,13 @@ namespace Perspex.Controls.Presenters
 
         private void CreateChild()
         {
+            Control result = null;
             object content = this.Content;
 
             this.ClearVisualChildren();
 
             if (content != null)
             {
-                Control result;
 
                 if (content is Control)
                 {
@@ -101,9 +132,9 @@ namespace Perspex.Controls.Presenters
                 }
 
                 result.TemplatedParent = foo;
-                this.AddVisualChild(result);
             }
 
+            this.Child = result;
             this.createdChild = true;
         }
     }

Perspex.Themes.Default/ContentControlStyle.cs

@@ -31,7 +31,8 @@ namespace Perspex.Themes.Default
         private Control Template(ContentControl control)
         {
             return new ContentPresenter
-            {
+            { 
+                Id = "presenter",
                 [~ContentPresenter.ContentProperty] = control[~ContentControl.ContentProperty],
             };
         }

Perspex.Themes.Default/WindowStyle.cs

@@ -37,6 +37,7 @@ namespace Perspex.Themes.Default
                 [~Border.BackgroundProperty] = control[~Window.BackgroundProperty],
                 Content = new ContentPresenter
                 {
+                    Id = "presenter",
                     [~ContentPresenter.ContentProperty] = control[~Window.ContentProperty],
                 }
             };