Fixed failing tests.

Perspex.Base/Collections/PerspexReadOnlyListView.cs

@@ -38,7 +38,7 @@ namespace Perspex.Collections
 
         public int Count
         {
-            get { return this.source.Count; }
+            get { return this.source?.Count ?? 0; }
         }
 
         public IPerspexReadOnlyList<T> Source
@@ -169,7 +169,7 @@ namespace Perspex.Collections
 
         public int Count
         {
-            get { return this.source.Count; }
+            get { return this.source?.Count ?? 0; }
         }
 
         public IPerspexReadOnlyList<TIn> Source

Perspex.Controls/Generators/ItemContainerGenerator.cs

@@ -85,14 +85,17 @@ namespace Perspex.Controls.Generators
                 {
                     Control container = this.CreateContainerOverride(item);
 
-                    if (container.DataContext == null)
+                    if (container != null)
                     {
-                        container.DataContext = item;
+                        if (container.DataContext == null)
+                        {
+                            container.DataContext = item;
+                        }
+
+                        container.TemplatedParent = null;
+                        this.AddInternal(item, container);
+                        result.Add(container);
                     }
-
-                    container.TemplatedParent = null;
-                    this.AddInternal(item, container);
-                    result.Add(container);
                 }
             }
             finally

Perspex.Controls/Presenters/DeckPresenter.cs

@@ -135,9 +135,13 @@ namespace Perspex.Controls.Presenters
 
                 if (value.Item2 != null)
                 {
-                    to = generator.Generate(new[] { value.Item2 }).Single();
-                    this.Panel.Children.Add(to);
-                    toIndex = this.Items.IndexOf(value.Item2);
+                    to = generator.Generate(new[] { value.Item2 }).FirstOrDefault();
+
+                    if (to != null)
+                    {
+                        this.Panel.Children.Add(to);
+                        toIndex = this.Items.IndexOf(value.Item2);
+                    }
                 }
 
                 if (this.Transition != null)

Perspex.Controls/Primitives/TabStrip.cs

@@ -27,7 +27,8 @@ namespace Perspex.Controls.Primitives
 
         public TabStrip()
         {
-            this.BindTwoWay(SelectedTabProperty, this, SelectingItemsControl.SelectedItemProperty);
+            this.GetObservable(SelectedItemProperty).Subscribe(x => this.SelectedTab = x as TabItem);
+            this.GetObservable(SelectedTabProperty).Subscribe(x => this.SelectedItem = x as TabItem);
         }
 
         public TabItem SelectedTab

Perspex.Controls/TabControl.cs

@@ -35,14 +35,15 @@ namespace Perspex.Controls
 
         public TabControl()
         {
+            this.BindTwoWay(SelectedTabProperty, this, SelectingItemsControl.SelectedItemProperty);
+
             this.GetObservable(SelectedItemProperty).Subscribe(x =>
             {
                 ContentControl c = x as ContentControl;
                 object content = (c != null) ? c.Content : c;
+                this.SetValue(SelectedTabProperty, x);
                 this.SetValue(SelectedContentProperty, content);
             });
-
-            this.BindTwoWay(SelectedTabProperty, this, SelectingItemsControl.SelectedItemProperty);
         }
 
         public object SelectedContent
@@ -73,11 +74,13 @@ namespace Perspex.Controls
             // Don't handle keypresses.
         }
 
+        Deck deck;
+
         protected override void OnTemplateApplied()
         {
             base.OnTemplateApplied();
 
-            var deck = this.GetTemplateChild<Deck>("deck");
+            this.deck = this.GetTemplateChild<Deck>("deck");
             this.logicalChildren.Source = ((ILogical)deck).LogicalChildren;
         }
     }

Perspex.Themes.Default/TabControlStyle.cs

@@ -47,7 +47,7 @@ namespace Perspex.Themes.Default
                     {
                         Name = "tabStrip",
                         [~TabStrip.ItemsProperty] = control[~TabControl.ItemsProperty],
-                        [~~TabStrip.SelectedItemProperty] = control[~~TabControl.SelectedItemProperty],
+                        [!!TabStrip.SelectedItemProperty] = control[!!TabControl.SelectedItemProperty],
                     },
                     new Deck
                     {
@@ -57,7 +57,7 @@ namespace Perspex.Themes.Default
                             new DataTemplate<TabItem>(x => control.MaterializeDataTemplate(x.Content)),
                         },
                         [~Deck.ItemsProperty] = control[~TabControl.ItemsProperty],
-                        [!Deck.SelectedItemProperty] = control[!TabControl.SelectedItemProperty],
+                        [~Deck.SelectedItemProperty] = control[~TabControl.SelectedItemProperty],
                         [~Deck.TransitionProperty] = control[~TabControl.TransitionProperty],
                         [Grid.RowProperty] = 1,
                     }

Tests/Perspex.Controls.UnitTests/TabControlTests.cs

@@ -6,11 +6,11 @@
 
 namespace Perspex.Controls.UnitTests
 {
-    using System.Linq;
     using Perspex.Controls.Presenters;
     using Perspex.Controls.Primitives;
+    using Perspex.Controls.Templates;
     using Perspex.LogicalTree;
-    using Perspex.Styling;
+    using System.Linq;
     using Xunit;
 
     public class TabControlTests
@@ -18,50 +18,30 @@ namespace Perspex.Controls.UnitTests
         [Fact]
         public void First_Tab_Should_Be_Selected_By_Default()
         {
+            TabItem selected;
             var target = new TabControl
             {
                 Template = ControlTemplate.Create<TabControl>(this.CreateTabControlTemplate),
                 Items = new[]
                 {
-                    new TabItem
-                    {
-                        Name = "first"
-                    },
-                    new TabItem
-                    {
-                        Name = "second"
-                    },
-                }
-            };
-
-            target.ApplyTemplate();
-
-            Assert.NotNull(target.SelectedTab);
-            Assert.Equal(target.SelectedTab, target.SelectedItem);
-        }
-
-        [Fact]
-        public void First_Tab_Content_Should_Be_Displayed_By_Default()
-        {
-            var target = new TabControl
-            {
-                Template = ControlTemplate.Create<TabControl>(this.CreateTabControlTemplate),
-                Items = new[]
-                {
-                    new TabItem
+                    (selected = new TabItem
                     {
-                        Content = new TextBlock(),
-                    },
+                        Name = "first",
+                        Content = "foo",
+                    }),
                     new TabItem
                     {
-                        Content = new Border(),
+                        Name = "second",
+                        Content = "bar",
                     },
                 }
             };
 
             target.ApplyTemplate();
 
-            Assert.IsType<TextBlock>(target.SelectedContent);
+            Assert.Equal(selected, target.SelectedItem);
+            Assert.Equal(selected, target.SelectedTab);
+            Assert.Equal("foo", target.SelectedContent);
         }
 
         [Fact]
@@ -124,11 +104,11 @@ namespace Perspex.Controls.UnitTests
                 {
                     new TabItem
                     {
-                        Content = new TextBlock { Name = "Foo" }
+                        Content = "foo"
                     },
                     new TabItem
                     {
-                        Content = new TextBlock { Name = "Foo" }
+                        Content = "bar"
                     },
                 },
             };
@@ -136,7 +116,7 @@ namespace Perspex.Controls.UnitTests
             target.ApplyTemplate();
 
             Assert.Equal(1, target.GetLogicalChildren().Count());
-            Assert.Equal("Foo", ((TextBlock)target.GetLogicalChildren().First()).Name);
+            Assert.Equal("foo", ((TextBlock)target.GetLogicalChildren().First()).Text);
         }
 
         private Control CreateTabControlTemplate(TabControl parent)
@@ -155,8 +135,13 @@ namespace Perspex.Controls.UnitTests
                     new Deck
                     {
                         Name = "deck",
+                        Template = ControlTemplate.Create<Deck>(this.CreateDeckTemplate),
+                        DataTemplates = new DataTemplates
+                        {
+                            new DataTemplate<TabItem>(x => parent.MaterializeDataTemplate(x.Content)),
+                        },
                         [~Deck.ItemsProperty] = parent[~TabControl.ItemsProperty],
-                        [!Deck.SelectedItemProperty] = parent[!TabControl.SelectedItemProperty],
+                        [~Deck.SelectedItemProperty] = parent[~TabControl.SelectedItemProperty],
                     }
                 }
             };
@@ -170,5 +155,17 @@ namespace Perspex.Controls.UnitTests
                 [~ItemsPresenter.ItemsProperty] = parent[~TabStrip.ItemsProperty],
             };
         }
+
+        private Control CreateDeckTemplate(Deck control)
+        {
+            return new DeckPresenter
+            {
+                Name = "itemsPresenter",
+                [~ItemsPresenter.ItemsProperty] = control[~Deck.ItemsProperty],
+                [~ItemsPresenter.ItemsPanelProperty] = control[~Deck.ItemsPanelProperty],
+                [~DeckPresenter.SelectedItemProperty] = control[~Deck.SelectedItemProperty],
+                [~DeckPresenter.TransitionProperty] = control[~Deck.TransitionProperty],
+            };
+        }
     }
 }