Merge branch 'master' of https://github.com/Perspex/Perspex

samples/TestApplication/GalleryStyle.cs

@@ -107,13 +107,10 @@ namespace TestApplication
                     new Deck
                     {
                         Name = "deck",
-                        DataTemplates = new DataTemplates
+                        MemberSelector = control.ContentSelector,
-                        {
-                            new DataTemplate<TabItem>(x => (Control)control.MaterializeDataTemplate(x.Content)),
-                        },
                         [~Deck.TransitionProperty] = control[~TabControl.TransitionProperty],
-                        [!ItemsControl.ItemsProperty] = control[!ItemsControl.ItemsProperty],
+                        [!Deck.ItemsProperty] = control[!ItemsControl.ItemsProperty],
-                        [!SelectingItemsControl.SelectedItemProperty] = control[!SelectingItemsControl.SelectedItemProperty],
+                        [!Deck.SelectedItemProperty] = control[!SelectingItemsControl.SelectedItemProperty],
                         [Grid.ColumnProperty] = 1,
                     }
                 }

samples/TestApplication/TestApplication.csproj

@@ -84,6 +84,10 @@
       <Project>{FB05AC90-89BA-4F2F-A924-F37875FB547C}</Project>
       <Name>Perspex.Cairo</Name>
     </ProjectReference>
+    <ProjectReference Include="..\..\src\Gtk\Perspex.Gtk\Perspex.Gtk.csproj">
+      <Project>{54f237d5-a70a-4752-9656-0c70b1a7b047}</Project>
+      <Name>Perspex.Gtk</Name>
+    </ProjectReference>
     <ProjectReference Include="..\..\src\Perspex.Animation\Perspex.Animation.csproj">
       <Project>{D211E587-D8BC-45B9-95A4-F297C8FA5200}</Project>
       <Name>Perspex.Animation</Name>

src/Gtk/Perspex.Cairo/Media/FormattedTextImpl.cs

@@ -25,7 +25,7 @@ namespace Perspex.Cairo.Media
             FontWeight fontWeight)
         {
             Contract.Requires<NullReferenceException>(context != null);
-
+            Contract.Requires<NullReferenceException> (text != null);
             Layout = new Pango.Layout(context);
             _text = text;
             Layout.SetText(text);

src/Gtk/Perspex.Gtk/GtkPlatform.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Reactive.Disposables;
+using System.Threading;
 using Perspex.Controls.Platform;
 using Perspex.Input.Platform;
 using Perspex.Input;
@@ -51,6 +52,12 @@ namespace Perspex.Gtk
             Gtk.Application.RunIteration();
         }
 
+        public void RunLoop(CancellationToken cancellationToken)
+        {
+            while (!cancellationToken.IsCancellationRequested)
+                Gtk.Application.RunIteration();
+        }
+
         public IDisposable StartTimer(TimeSpan interval, Action tick)
         {
             var result = true;
@@ -65,8 +72,13 @@ namespace Perspex.Gtk
             return Disposable.Create(() => result = false);
         }
 
-        public void Wake()
+
+
+        public void Signal()
         {
+            Gtk.Application.Invoke(delegate { Signaled?.Invoke(); });
         }
+
+        public event Action Signaled;
     }
 }

src/Markup/Perspex.Markup.Xaml/Converters/TimeSpanTypeConverter.cs

@@ -26,7 +26,7 @@ namespace Perspex.Markup.Xaml.Converters
             if (!valueStr.Contains(":"))
             {
                 // shorthand seconds format (ie. "0.25")
-                var secs = double.Parse(valueStr);
+                var secs = double.Parse(valueStr, CultureInfo.InvariantCulture);
                 return TimeSpan.FromSeconds(secs);
             }
 

src/Perspex.Base/Perspex.Base.csproj

@@ -72,9 +72,10 @@
     <Compile Include="Threading\Dispatcher.cs" />
     <Compile Include="Threading\DispatcherPriority.cs" />
     <Compile Include="Threading\DispatcherTimer.cs" />
-    <Compile Include="Threading\MainLoop.cs" />
+    <Compile Include="Threading\JobRunner.cs" />
     <Compile Include="Threading\PerspexScheduler.cs" />
     <Compile Include="Threading\PerspexSynchronizationContext.cs" />
+    <Compile Include="Threading\SingleThreadDispatcher.cs" />
     <Compile Include="Utilities\MathUtilities.cs" />
     <Compile Include="Utilities\TypeUtilities.cs" />
   </ItemGroup>

src/Perspex.Base/Platform/IPclPlatformWrapper.cs

@@ -10,5 +10,7 @@ namespace Perspex.Platform
     public interface IPclPlatformWrapper
     {
         Assembly[] GetLoadedAssemblies();
+        void PostThreadPoolItem(Action cb);
+        IDisposable StartSystemTimer(TimeSpan interval, Action tick);
     }
 }

src/Perspex.Base/Platform/IPlatformThreadingInterface.cs

@@ -2,6 +2,7 @@
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
 using System;
+using System.Threading;
 
 namespace Perspex.Platform
 {
@@ -10,16 +11,7 @@ namespace Perspex.Platform
     /// </summary>
     public interface IPlatformThreadingInterface
     {
-        /// <summary>
+        void RunLoop(CancellationToken cancellationToken);
-        /// Checks whether there are messages waiting to be processed.
-        /// </summary>
-        /// <returns>True if there are messages waiting, otherwise false.</returns>
-        bool HasMessages();
-
-        /// <summary>
-        /// Process a single message from the windowing system, blocking until one is available.
-        /// </summary>
-        void ProcessMessage();
 
         /// <summary>
         /// Starts a timer.
@@ -32,6 +24,9 @@ namespace Perspex.Platform
         /// <summary>
         /// Sends a message that causes <see cref="ProcessMessage"/> to exit.
         /// </summary>
-        void Wake();
+        void Signal();
+
+        event Action Signaled;
+
     }
 }

src/Perspex.Base/Threading/Dispatcher.cs

@@ -4,7 +4,7 @@
 using System;
 using System.Threading;
 using System.Threading.Tasks;
-using Perspex.Win32.Threading;
+using Perspex.Platform;
 
 namespace Perspex.Threading
 {
@@ -17,21 +17,19 @@ namespace Perspex.Threading
     /// </remarks>
     public class Dispatcher
     {
-        private static readonly Dispatcher s_instance = new Dispatcher();
+        private readonly IPlatformThreadingInterface _platform;
+        private readonly JobRunner _jobRunner;
 
-        private readonly MainLoop _mainLoop = new MainLoop();
+        public static Dispatcher UIThread { get; } =
+            new Dispatcher(PerspexLocator.Current.GetService<IPlatformThreadingInterface>());
 
-        /// <summary>
+        public Dispatcher(IPlatformThreadingInterface platform)
-        /// Initializes a new instance of the <see cref="Dispatcher"/> class.
-        /// </summary>
-        private Dispatcher()
         {
+            _platform = platform;
+            _jobRunner = new JobRunner(platform);
+            _platform.Signaled += _jobRunner.RunJobs;
         }
 
-        /// <summary>
-        /// Gets the <see cref="Dispatcher"/> for the UI thread.
-        /// </summary>
-        public static Dispatcher UIThread => s_instance;
 
         /// <summary>
         /// Runs the dispatcher's main loop.
@@ -41,7 +39,9 @@ namespace Perspex.Threading
         /// </param>
         public void MainLoop(CancellationToken cancellationToken)
         {
-            _mainLoop.Run(cancellationToken);
+            var platform = PerspexLocator.Current.GetService<IPlatformThreadingInterface>();
+            cancellationToken.Register(platform.Signal);
+            platform.RunLoop(cancellationToken);
         }
 
         /// <summary>
@@ -49,7 +49,7 @@ namespace Perspex.Threading
         /// </summary>
         public void RunJobs()
         {
-            _mainLoop.RunJobs();
+            _jobRunner.RunJobs();
         }
 
         /// <summary>
@@ -60,7 +60,7 @@ namespace Perspex.Threading
         /// <returns>A task that can be used to track the method's execution.</returns>
         public Task InvokeAsync(Action action, DispatcherPriority priority = DispatcherPriority.Normal)
         {
-            return _mainLoop.InvokeAsync(action, priority);
+            return _jobRunner.InvokeAsync(action, priority);
         }
 
         /// <summary>
@@ -70,7 +70,7 @@ namespace Perspex.Threading
         /// <param name="priority">The priority with which to invoke the method.</param>
         internal void Post(Action action, DispatcherPriority priority = DispatcherPriority.Normal)
         {
-            _mainLoop.Post(action, priority);
+            _jobRunner.Post(action, priority);
         }
     }
 }

src/Perspex.Base/Threading/DispatcherTimer.cs

@@ -24,17 +24,6 @@ namespace Perspex.Threading
         public DispatcherTimer()
         {
             _priority = DispatcherPriority.Normal;
-            Dispatcher = Dispatcher.UIThread;
-        }
-
-        /// <summary>
-        /// Initializes a new instance of the <see cref="DispatcherTimer"/> class.
-        /// </summary>
-        /// <param name="priority">The priority to use.</param>
-        public DispatcherTimer(DispatcherPriority priority)
-        {
-            _priority = priority;
-            Dispatcher = Dispatcher.UIThread;
         }
 
         /// <summary>
@@ -42,10 +31,9 @@ namespace Perspex.Threading
         /// </summary>
         /// <param name="priority">The priority to use.</param>
         /// <param name="dispatcher">The dispatcher to use.</param>
-        public DispatcherTimer(DispatcherPriority priority, Dispatcher dispatcher)
+        public DispatcherTimer(DispatcherPriority priority)
         {
             _priority = priority;
-            Dispatcher = dispatcher;
         }
 
         /// <summary>
@@ -55,10 +43,9 @@ namespace Perspex.Threading
         /// <param name="priority">The priority to use.</param>
         /// <param name="dispatcher">The dispatcher to use.</param>
         /// <param name="callback">The event to call when the timer ticks.</param>
-        public DispatcherTimer(TimeSpan interval, DispatcherPriority priority, EventHandler callback, Dispatcher dispatcher)
+        public DispatcherTimer(TimeSpan interval, DispatcherPriority priority, EventHandler callback)
         {
             _priority = priority;
-            Dispatcher = dispatcher;
             Interval = interval;
             Tick += callback;
         }
@@ -79,13 +66,6 @@ namespace Perspex.Threading
         /// </summary>
         public event EventHandler Tick;
 
-        /// <summary>
-        /// Gets the dispatcher that the timer uses.
-        /// </summary>
-        public Dispatcher Dispatcher
-        {
-            get; }
-
         /// <summary>
         /// Gets or sets the interval at which the timer ticks.
         /// </summary>
@@ -197,7 +177,7 @@ namespace Perspex.Threading
         /// </summary>
         private void InternalTick()
         {
-            Dispatcher.Post(RaiseTick, _priority);
+            Dispatcher.UIThread.Post(RaiseTick, _priority);
         }
 
         /// <summary>

src/Perspex.Base/Threading/MainLoop.cs → src/Perspex.Base/Threading/JobRunner.cs

@@ -6,41 +6,20 @@ using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using Perspex.Platform;
-using Perspex.Threading;
 
-namespace Perspex.Win32.Threading
+namespace Perspex.Threading
 {
     /// <summary>
     /// A main loop in a <see cref="Dispatcher"/>.
     /// </summary>
-    internal class MainLoop
+    internal class JobRunner
     {
-        private static readonly IPlatformThreadingInterface s_platform;
+        private readonly IPlatformThreadingInterface _platform;
-
         private readonly Queue<Job> _queue = new Queue<Job>();
 
-        /// <summary>
+        public JobRunner(IPlatformThreadingInterface platform)
-        /// Initializes static members of the <see cref="MainLoop"/> class.
-        /// </summary>
-        static MainLoop()
         {
-            s_platform = PerspexLocator.Current.GetService<IPlatformThreadingInterface>();
+            _platform = platform;
-        }
-
-        /// <summary>
-        /// Runs the main loop.
-        /// </summary>
-        /// <param name="cancellationToken">
-        /// A cancellation token used to exit the main loop.
-        /// </param>
-        public void Run(CancellationToken cancellationToken)
-        {
-            while (!cancellationToken.IsCancellationRequested)
-            {
-                RunJobs();
-
-                s_platform.ProcessMessage();
-            }
         }
 
         /// <summary>
@@ -48,21 +27,15 @@ namespace Perspex.Win32.Threading
         /// </summary>
         public void RunJobs()
         {
-            Job job = null;
+            while (true)
-
-            while (job != null || _queue.Count > 0)
             {
-                if (job == null)
+                Job job;
-                {
-                    lock (_queue)
-                    {
-                        job = _queue.Dequeue();
-                    }
-                }
 
-                if (job.Priority < DispatcherPriority.Input && s_platform.HasMessages())
+                lock (_queue)
                 {
-                    break;
+                    if (_queue.Count == 0)
+                        return;
+                    job = _queue.Dequeue();
                 }
 
                 if (job.TaskCompletionSource == null)
@@ -81,8 +54,6 @@ namespace Perspex.Win32.Threading
                         job.TaskCompletionSource.SetException(e);
                     }
                 }
-
-                job = null;
             }
         }
 
@@ -113,11 +84,14 @@ namespace Perspex.Win32.Threading
 
         private void AddJob(Job job)
         {
+            var needWake = false;
             lock (_queue)
             {
+                needWake = _queue.Count == 0;
                 _queue.Enqueue(job);
             }
-            s_platform.Wake();
+            if (needWake)
+                _platform.Signal();
         }
 
         /// <summary>

src/Perspex.Base/Threading/PerspexScheduler.cs

@@ -7,7 +7,7 @@ using System.Reactive.Concurrency;
 namespace Perspex.Threading
 {
     /// <summary>
-    /// A reactive scheduler that uses Perspex's <see cref="Dispatcher.UIThread"/>.
+    /// A reactive scheduler that uses Perspex's <see cref="Dispatcher"/>.
     /// </summary>
     public class PerspexScheduler : LocalScheduler
     {

src/Perspex.Base/Threading/PerspexSynchronizationContext.cs

@@ -36,7 +36,7 @@ namespace Perspex.Threading
         /// <inheritdoc/>
         public override void Post(SendOrPostCallback d, object state)
         {
-            Dispatcher.UIThread.Post(() => d(state));
+           Dispatcher.UIThread.Post(() => d(state));
         }
 
         /// <inheritdoc/>

src/Perspex.Base/Threading/SingleThreadDispatcher.cs

@@ -0,0 +1,58 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using Perspex.Platform;
+
+namespace Perspex.Threading
+{
+    public class SingleThreadDispatcher : Dispatcher
+    {
+        class ThreadingInterface : IPlatformThreadingInterface
+        {
+            private AutoResetEvent _evnt = new AutoResetEvent(false);
+            private JobRunner _timerJobRunner;
+
+            public ThreadingInterface()
+            {
+                _timerJobRunner = new JobRunner(this);
+            }
+
+            public void RunLoop(CancellationToken cancellationToken)
+            {
+                while (!cancellationToken.IsCancellationRequested)
+                {
+                    _evnt.WaitOne();
+                    if (cancellationToken.IsCancellationRequested)
+                        return;
+                    Signaled?.Invoke();
+                    _timerJobRunner.RunJobs();
+                }
+            }
+
+            public IDisposable StartTimer(TimeSpan interval, Action tick)
+                => PerspexLocator.Current.GetService<IPclPlatformWrapper>().StartSystemTimer(interval,
+                    () => _timerJobRunner.Post(tick, DispatcherPriority.Normal));
+
+            public void Signal() => _evnt.Set();
+
+            public event Action Signaled;
+        }
+
+        public SingleThreadDispatcher() : base(new ThreadingInterface())
+        {
+        }
+
+        public static Dispatcher StartNew(CancellationToken token)
+        {
+            var dispatcher = new SingleThreadDispatcher();
+            PerspexLocator.Current.GetService<IPclPlatformWrapper>().PostThreadPoolItem(() =>
+            {
+                dispatcher.MainLoop(token);
+            });
+            return dispatcher;
+        }
+    }
+}

src/Perspex.Controls/Generators/IItemContainerGenerator.cs

@@ -25,12 +25,12 @@ namespace Perspex.Controls.Generators
         /// The index of the first item of the data in the containing collection.
         /// </param>
         /// <param name="items">The items.</param>
-        /// <param name="itemTemplate">An optional item template.</param>
+        /// <param name="selector">An optional member selector.</param>
         /// <returns>The created controls.</returns>
         IList<IControl> CreateContainers(
             int startingIndex,
             IEnumerable items,
-            IDataTemplate itemTemplate);
+            IMemberSelector selector);
 
         /// <summary>
         /// Removes a set of created containers from the index and returns the removed controls.

src/Perspex.Controls/Generators/ItemContainerGenerator.cs

@@ -45,12 +45,12 @@ namespace Perspex.Controls.Generators
         /// The index of the first item of the data in the containing collection.
         /// </param>
         /// <param name="items">The items.</param>
-        /// <param name="itemTemplate">An optional item template.</param>
+        /// <param name="selector">An optional member selector.</param>
         /// <returns>The created container controls.</returns>
         public IList<IControl> CreateContainers(
             int startingIndex,
             IEnumerable items,
-            IDataTemplate itemTemplate)
+            IMemberSelector selector)
         {
             Contract.Requires<ArgumentNullException>(items != null);
 
@@ -59,7 +59,8 @@ namespace Perspex.Controls.Generators
 
             foreach (var item in items)
             {
-                IControl container = CreateContainer(item, itemTemplate);
+                var i = selector != null ? selector.Select(item) : item;
+                var container = CreateContainer(i);
                 result.Add(container);
             }
 
@@ -141,24 +142,10 @@ namespace Perspex.Controls.Generators
         /// Creates the container for an item.
         /// </summary>
         /// <param name="item">The item.</param>
-        /// <param name="itemTemplate">An optional item template.</param>
         /// <returns>The created container control.</returns>
-        protected virtual IControl CreateContainer(object item, IDataTemplate itemTemplate)
+        protected virtual IControl CreateContainer(object item)
         {
-            if (item == null)
+            return Owner.MaterializeDataTemplate(item);
-            {
-                return null;
-            }
-            else if (itemTemplate != null && itemTemplate.Match(item))
-            {
-                var result = itemTemplate.Build(item);
-                result.DataContext = item;
-                return result;
-            }
-            else
-            {
-                return Owner.MaterializeDataTemplate(item);
-            }
         }
 
         /// <summary>

src/Perspex.Controls/Generators/ItemContainerGenerator`1.cs

@@ -21,17 +21,24 @@ namespace Perspex.Controls.Generators
         }
 
         /// <inheritdoc/>
-        protected override IControl CreateContainer(object item, IDataTemplate itemTemplate)
+        protected override IControl CreateContainer(object item)
         {
-            T result = item as T;
+            var container = item as T;
 
-            if (result == null)
+            if (item == null)
             {
-                result = new T();
+                return null;
+            }
+            else if (container != null)
+            {
+                return container;
+            }
+            else
+            {
+                var result = new T();
                 result.Content = Owner.MaterializeDataTemplate(item);
+                return result;
             }
-
-            return result;
         }
     }
 }

src/Perspex.Controls/Generators/TreeItemContainerGenerator.cs

@@ -46,9 +46,12 @@ namespace Perspex.Controls.Generators
         /// The index of the first item of the data in the containing collection.
         /// </param>
         /// <param name="items">The items.</param>
-        /// <param name="itemTemplate">An optional item template.</param>
+        /// <param name="selector">An optional member selector.</param>
         /// <returns>The created container controls.</returns>
-        public IList<IControl> CreateContainers(int startingIndex, IEnumerable items, IDataTemplate itemTemplate)
+        public IList<IControl> CreateContainers(
+            int startingIndex, 
+            IEnumerable items,
+            IMemberSelector selector)
         {
             Contract.Requires<ArgumentNullException>(items != null);
 
@@ -57,8 +60,9 @@ namespace Perspex.Controls.Generators
 
             foreach (var item in items)
             {
-                var container = CreateContainer(item, itemTemplate);
+                var i = selector != null ? selector.Select(item) : item;
-                _containers.Add(item, container);
+                var container = CreateContainer(i);
+                _containers.Add(i, container);
                 result.Add(container);
             }
 
@@ -156,9 +160,8 @@ namespace Perspex.Controls.Generators
         /// Creates the container for an item.
         /// </summary>
         /// <param name="item">The item.</param>
-        /// <param name="itemTemplate">An optional item template.</param>
         /// <returns>The created container control.</returns>
-        protected virtual T CreateContainer(object item, IDataTemplate itemTemplate)
+        protected virtual T CreateContainer(object item)
         {
             T result = item as T;
 

src/Perspex.Controls/ItemsControl.cs

@@ -33,13 +33,19 @@ namespace Perspex.Controls
         /// Defines the <see cref="Items"/> property.
         /// </summary>
         public static readonly PerspexProperty<IEnumerable> ItemsProperty =
-            PerspexProperty.Register<ItemsControl, IEnumerable>("Items");
+            PerspexProperty.Register<ItemsControl, IEnumerable>(nameof(Items));
 
         /// <summary>
         /// Defines the <see cref="ItemsPanel"/> property.
         /// </summary>
         public static readonly PerspexProperty<ITemplate<IPanel>> ItemsPanelProperty =
-            PerspexProperty.Register<ItemsControl, ITemplate<IPanel>>("ItemsPanel", defaultValue: DefaultPanel);
+            PerspexProperty.Register<ItemsControl, ITemplate<IPanel>>(nameof(ItemsPanel), DefaultPanel);
+
+        /// <summary>
+        /// Defines the <see cref="MemberSelector"/> property.
+        /// </summary>
+        public static readonly PerspexProperty<IMemberSelector> MemberSelectorProperty =
+            PerspexProperty.Register<ItemsControl, IMemberSelector>(nameof(MemberSelector));
 
         private IItemContainerGenerator _itemContainerGenerator;
 
@@ -94,6 +100,15 @@ namespace Perspex.Controls
             set { SetValue(ItemsPanelProperty, value); }
         }
 
+        /// <summary>
+        /// Selects a member from <see cref="Items"/> to use as the list item.
+        /// </summary>
+        public IMemberSelector MemberSelector
+        {
+            get { return GetValue(MemberSelectorProperty); }
+            set { SetValue(MemberSelectorProperty, value); }
+        }
+
         /// <summary>
         /// Gets the items presenter control.
         /// </summary>

src/Perspex.Controls/Perspex.Controls.csproj

@@ -71,6 +71,7 @@
     <Compile Include="Canvas.cs" />
     <Compile Include="Templates\ControlTemplate`2.cs" />
     <Compile Include="Templates\DataTemplate`1.cs" />
+    <Compile Include="Templates\FuncMemberSelector.cs" />
     <Compile Include="Templates\IControlTemplate.cs" />
     <Compile Include="Templates\FuncTemplate`2.cs" />
     <Compile Include="Templates\FuncTemplate`1.cs" />
@@ -122,6 +123,7 @@
     <Compile Include="Primitives\Thumb.cs" />
     <Compile Include="RequestBringIntoViewEventArgs.cs" />
     <Compile Include="Shapes\Ellipse.cs" />
+    <Compile Include="Templates\IMemberSelector.cs" />
     <Compile Include="Templates\ITemplate`2.cs" />
     <Compile Include="Templates\ITemplate`1.cs" />
     <Compile Include="Templates\ITreeDataTemplate.cs" />

src/Perspex.Controls/Presenters/ContentPresenter.cs

@@ -97,7 +97,7 @@ namespace Perspex.Controls.Presenters
         {
             var old = Child;
             var content = Content;
-            var result = content != null ? this.MaterializeDataTemplate(content) : null;
+            var result = this.MaterializeDataTemplate(content);
             var logicalHost = this.FindReparentingHost();
             var logicalChildren = logicalHost?.LogicalChildren ?? LogicalChildren;
 

src/Perspex.Controls/Presenters/DeckPresenter.cs

@@ -30,6 +30,12 @@ namespace Perspex.Controls.Presenters
         /// </summary>
         public static readonly PerspexProperty<ITemplate<IPanel>> ItemsPanelProperty =
             ItemsControl.ItemsPanelProperty.AddOwner<DeckPresenter>();
+        
+        /// <summary>
+        /// Defines the <see cref="MemberSelector"/> property.
+        /// </summary>
+        public static readonly PerspexProperty<IMemberSelector> MemberSelectorProperty =
+            ItemsControl.MemberSelectorProperty.AddOwner<DeckPresenter>();
 
         /// <summary>
         /// Defines the <see cref="SelectedIndex"/> property.
@@ -101,6 +107,15 @@ namespace Perspex.Controls.Presenters
             set { SetValue(ItemsPanelProperty, value); }
         }
 
+        /// <summary>
+        /// Selects a member from <see cref="Items"/> to use as the list item.
+        /// </summary>
+        public IMemberSelector MemberSelector
+        {
+            get { return GetValue(MemberSelectorProperty); }
+            set { SetValue(MemberSelectorProperty, value); }
+        }
+
         /// <summary>
         /// Gets or sets the index of the selected page.
         /// </summary>
@@ -181,7 +196,7 @@ namespace Perspex.Controls.Presenters
             if (toIndex != -1)
             {
                 var item = Items.Cast<object>().ElementAt(toIndex);
-                to = generator.CreateContainers(toIndex, new[] { item }, null).FirstOrDefault();
+                to = generator.CreateContainers(toIndex, new[] { item }, MemberSelector).FirstOrDefault();
 
                 if (to != null)
                 {

src/Perspex.Controls/Presenters/ItemsPresenter.cs

@@ -28,6 +28,12 @@ namespace Perspex.Controls.Presenters
         public static readonly PerspexProperty<ITemplate<IPanel>> ItemsPanelProperty =
             ItemsControl.ItemsPanelProperty.AddOwner<ItemsPresenter>();
 
+        /// <summary>
+        /// Defines the <see cref="MemberSelector"/> property.
+        /// </summary>
+        public static readonly PerspexProperty<IMemberSelector> MemberSelectorProperty =
+            ItemsControl.MemberSelectorProperty.AddOwner<ItemsPresenter>();
+
         private bool _createdPanel;
 
         private IItemContainerGenerator _generator;
@@ -96,6 +102,15 @@ namespace Perspex.Controls.Presenters
             set { SetValue(ItemsPanelProperty, value); }
         }
 
+        /// <summary>
+        /// Selects a member from <see cref="Items"/> to use as the list item.
+        /// </summary>
+        public IMemberSelector MemberSelector
+        {
+            get { return GetValue(MemberSelectorProperty); }
+            set { SetValue(MemberSelectorProperty, value); }
+        }
+
         /// <summary>
         /// Gets the panel used to display the items.
         /// </summary>
@@ -171,8 +186,7 @@ namespace Perspex.Controls.Presenters
         {
             if (items != null)
             {
-                Panel.Children.AddRange(
+                Panel.Children.AddRange(ItemContainerGenerator.CreateContainers(0, Items, MemberSelector));
-                    ItemContainerGenerator.CreateContainers(0, Items, null));
 
                 INotifyCollectionChanged incc = items as INotifyCollectionChanged;
 
@@ -229,7 +243,7 @@ namespace Perspex.Controls.Presenters
                 {
                     case NotifyCollectionChangedAction.Add:
                         Panel.Children.AddRange(
-                            generator.CreateContainers(e.NewStartingIndex, e.NewItems, null));
+                            generator.CreateContainers(e.NewStartingIndex, e.NewItems, MemberSelector));
                         break;
 
                     case NotifyCollectionChangedAction.Remove:

src/Perspex.Controls/TabControl.cs

@@ -4,6 +4,7 @@
 using Perspex.Animation;
 using Perspex.Controls.Presenters;
 using Perspex.Controls.Primitives;
+using Perspex.Controls.Templates;
 
 namespace Perspex.Controls
 {
@@ -24,6 +25,9 @@ namespace Perspex.Controls
         public static readonly PerspexProperty<IPageTransition> TransitionProperty =
             Deck.TransitionProperty.AddOwner<TabControl>();
 
+        private static readonly IMemberSelector s_contentSelector =
+            new FuncMemberSelector<object, object>(SelectContent);
+
         /// <summary>
         /// Initializes static members of the <see cref="TabControl"/> class.
         /// </summary>
@@ -34,6 +38,14 @@ namespace Perspex.Controls
             SelectedIndexProperty.Changed.AddClassHandler<TabControl>(x => x.SelectedIndexChanged);
         }
 
+        /// <summary>
+        /// Gets an <see cref="IMemberSelector"/> that selects the content of a <see cref="TabItem"/>.
+        /// </summary>
+        public IMemberSelector ContentSelector
+        {
+            get { return s_contentSelector; }
+        }
+
         /// <summary>
         /// Gets the <see cref="SelectingItemsControl.SelectedItem"/> as a <see cref="TabItem"/>.
         /// </summary>
@@ -65,6 +77,25 @@ namespace Perspex.Controls
             return control is DeckPresenter;
         }
 
+        /// <summary>
+        /// Selects the content of a tab item.
+        /// </summary>
+        /// <param name="o">The tab item.</param>
+        /// <returns>The content.</returns>
+        private static object SelectContent(object o)
+        {
+            var content = o as IContentControl;
+
+            if (content != null)
+            {
+                return content.Content;
+            }
+            else
+            {
+                return o;
+            }       
+        }
+
         /// <summary>
         /// Called when the <see cref="SelectingItemsControl.SelectedIndex"/> property changes.
         /// </summary>

src/Perspex.Controls/Templates/DataTemplateExtensions.cs

@@ -19,28 +19,37 @@ namespace Perspex.Controls.Templates
         /// <returns>The data materialized as a control.</returns>
         public static IControl MaterializeDataTemplate(this IControl control, object data)
         {
-            IDataTemplate template = control.FindDataTemplate(data);
+            if (data == null)
-            IControl result;
-
-            if (template != null)
             {
-                result = template.Build(data);
+                return null;
+            }
+            else
+            {
+                var asControl = data as IControl;
 
-                if (result != null && result.DataContext == null)
+                if (asControl != null)
+                {
+                    return asControl;
+                }
+                else
                 {
+                    IDataTemplate template = control.FindDataTemplate(data);
+                    IControl result;
+
+                    if (template != null)
+                    {
+                        result = template.Build(data);
+                    }
+                    else
+                    {
+                        result = DataTemplate.Default.Build(data);
+                    }
+
                     result.DataContext = data;
+
+                    return result;
                 }
             }
-            else if (data is IControl)
-            {
-                result = (IControl)data;
-            }
-            else
-            {
-                result = DataTemplate.Default.Build(data);
-            }
-
-            return result;
         }
 
         /// <summary>

src/Perspex.Controls/Templates/FuncMemberSelector.cs

@@ -0,0 +1,35 @@
+// Copyright (c) The Perspex Project. All rights reserved.
+// Licensed under the MIT license. See licence.md file in the project root for full license information.
+
+using System;
+
+namespace Perspex.Controls.Templates
+{
+    /// <summary>
+    /// Selects a member of an object using a <see cref="Func{TObject, TMember}"/>.
+    /// </summary>
+    public class FuncMemberSelector<TObject, TMember> : IMemberSelector
+    {
+        private Func<TObject, TMember> _selector;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="FuncMemberSelector{TObject, TMember}"/>
+        /// class.
+        /// </summary>
+        /// <param name="selector">The selector.</param>
+        public FuncMemberSelector(Func<TObject, TMember> selector)
+        {
+            this._selector = selector;
+        }
+
+        /// <summary>
+        /// Selects a member of an object.
+        /// </summary>
+        /// <param name="o">The obeject.</param>
+        /// <returns>The selected member.</returns>
+        public object Select(object o)
+        {
+            return (o is TObject) ? _selector((TObject)o) : default(TMember);
+        }
+    }
+}

src/Perspex.Controls/Templates/IMemberSelector.cs

@@ -0,0 +1,18 @@
+// Copyright (c) The Perspex Project. All rights reserved.
+// Licensed under the MIT license. See licence.md file in the project root for full license information.
+
+namespace Perspex.Controls.Templates
+{
+    /// <summary>
+    /// Selects a member of an object.
+    /// </summary>
+    public interface IMemberSelector
+    {
+        /// <summary>
+        /// Selects a member of an object.
+        /// </summary>
+        /// <param name="o">The obeject.</param>
+        /// <returns>The selected member.</returns>
+        object Select(object o);
+    }
+}

src/Perspex.Controls/TopLevel.cs

@@ -43,11 +43,6 @@ namespace Perspex.Controls
         public static readonly PerspexProperty<IInputElement> PointerOverElementProperty =
             PerspexProperty.Register<TopLevel, IInputElement>(nameof(IInputRoot.PointerOverElement));
 
-        /// <summary>
-        /// The dispatcher for the window.
-        /// </summary>
-        private readonly Dispatcher _dispatcher;
-
         /// <summary>
         /// The render manager for the window.s
         /// </summary>
@@ -126,8 +121,6 @@ namespace Perspex.Controls
 
             Size clientSize = ClientSize = PlatformImpl.ClientSize;
 
-            _dispatcher = Dispatcher.UIThread;
-
             if (renderInterface != null)
             {
                 _renderer = renderInterface.CreateRenderer(PlatformImpl.Handle, clientSize.Width, clientSize.Height);
@@ -404,7 +397,7 @@ namespace Perspex.Controls
         /// </summary>
         private void HandleLayoutNeeded()
         {
-            _dispatcher.InvokeAsync(LayoutManager.ExecuteLayoutPass, DispatcherPriority.Render);
+            Dispatcher.UIThread.InvokeAsync(LayoutManager.ExecuteLayoutPass, DispatcherPriority.Render);
         }
 
         /// <summary>
@@ -420,7 +413,7 @@ namespace Perspex.Controls
         /// </summary>
         private void HandleRenderNeeded()
         {
-            _dispatcher.InvokeAsync(
+            Dispatcher.UIThread.InvokeAsync(
                 () => PlatformImpl.Invalidate(new Rect(ClientSize)),
                 DispatcherPriority.Render);
         }

src/Perspex.HtmlRenderer/HtmlControl.cs

@@ -563,7 +563,7 @@ namespace Perspex.Controls.Html
             if (CheckAccess())
                 OnLoadComplete(e);
             else
-                Dispatcher.Invoke(new Action<HtmlLinkClickedEventArgs>(OnLinkClicked), e);
+                Dispatcher.UIThread.Invoke(new Action<HtmlLinkClickedEventArgs>(OnLinkClicked), e);
 
         }
 
@@ -572,7 +572,7 @@ namespace Perspex.Controls.Html
             if (CheckAccess())
                 OnLinkClicked(e);
             else
-                Dispatcher.Invoke(new Action<HtmlLinkClickedEventArgs>(OnLinkClicked), e);
+                Dispatcher.UIThread.Invoke(new Action<HtmlLinkClickedEventArgs>(OnLinkClicked), e);
         }
 
         private void OnRenderError(object sender, HtmlRenderErrorEventArgs e)
@@ -580,7 +580,7 @@ namespace Perspex.Controls.Html
             if (CheckAccess())
                 OnRenderError(e);
             else
-                Dispatcher.Invoke(new Action<HtmlRenderErrorEventArgs>(OnRenderError), e);
+                Dispatcher.UIThread.Invoke(new Action<HtmlRenderErrorEventArgs>(OnRenderError), e);
         }
 
         private void OnStylesheetLoad(object sender, HtmlStylesheetLoadEventArgs e)
@@ -588,7 +588,7 @@ namespace Perspex.Controls.Html
             if (CheckAccess())
                 OnStylesheetLoad(e);
             else
-                Dispatcher.Invoke(new Action<HtmlStylesheetLoadEventArgs>(OnStylesheetLoad), e);
+                Dispatcher.UIThread.Invoke(new Action<HtmlStylesheetLoadEventArgs>(OnStylesheetLoad), e);
         }
 
         private void OnImageLoad(object sender, HtmlImageLoadEventArgs e)
@@ -596,7 +596,7 @@ namespace Perspex.Controls.Html
             if (CheckAccess())
                 OnImageLoad(e);
             else
-                Dispatcher.Invoke(new Action<HtmlImageLoadEventArgs>(OnImageLoad), e);
+                Dispatcher.UIThread.Invoke(new Action<HtmlImageLoadEventArgs>(OnImageLoad), e);
         }
 
         private void OnRefresh(object sender, HtmlRefreshEventArgs e)
@@ -604,7 +604,7 @@ namespace Perspex.Controls.Html
             if (CheckAccess())
                 OnRefresh(e);
             else
-                Dispatcher.Invoke(new Action<HtmlRefreshEventArgs>(OnRefresh), e);
+                Dispatcher.UIThread.Invoke(new Action<HtmlRefreshEventArgs>(OnRefresh), e);
         }
         */
     }

src/Perspex.SceneGraph/Media/FormattedText.cs

@@ -29,6 +29,9 @@ namespace Perspex.Media
             TextAlignment textAlignment,
             FontWeight fontWeight)
         {
+            //TODO: Find out why it was null in the first place. Demo project - AvalonStudio
+            //https://github.com/VitalElement/AvalonStudio/commit/787fb9396feb74e6ca6bd4e08436269a349df9c6
+            text = text ?? "";
             Text = text;
             FontFamilyName = fontFamilyName;
             FontSize = fontSize;

src/Perspex.SceneGraph/Thickness.cs

@@ -38,8 +38,6 @@ namespace Perspex
         /// <param name="uniformLength">The length that should be applied to all sides.</param>
         public Thickness(double uniformLength)
         {
-            Contract.Requires<ArgumentException>(uniformLength >= 0);
-
             _left = _top = _right = _bottom = uniformLength;
         }
 
@@ -50,9 +48,6 @@ namespace Perspex
         /// <param name="vertical">The thickness on the top and bottom.</param>
         public Thickness(double horizontal, double vertical)
         {
-            Contract.Requires<ArgumentException>(horizontal >= 0);
-            Contract.Requires<ArgumentException>(vertical >= 0);
-
             _left = _right = horizontal;
             _top = _bottom = vertical;
         }
@@ -66,11 +61,6 @@ namespace Perspex
         /// <param name="bottom">The thickness on the bottom.</param>
         public Thickness(double left, double top, double right, double bottom)
         {
-            Contract.Requires<ArgumentException>(left >= 0);
-            Contract.Requires<ArgumentException>(top >= 0);
-            Contract.Requires<ArgumentException>(right >= 0);
-            Contract.Requires<ArgumentException>(bottom >= 0);
-
             _left = left;
             _top = top;
             _right = right;

src/Perspex.Themes.Default/DeckStyle.cs

@@ -42,6 +42,7 @@ namespace Perspex.Themes.Default
             return new DeckPresenter
             {
                 Name = "itemsPresenter",
+                MemberSelector = control.MemberSelector,
                 [~ItemsPresenter.ItemsProperty] = control[~ItemsControl.ItemsProperty],
                 [~ItemsPresenter.ItemsPanelProperty] = control[~ItemsControl.ItemsPanelProperty],
                 [~DeckPresenter.SelectedIndexProperty] = control[~SelectingItemsControl.SelectedIndexProperty],

src/Perspex.Themes.Default/DropDownStyle.cs

@@ -128,6 +128,7 @@ namespace Perspex.Themes.Default
                                 Padding = new Thickness(4),
                                 Child = new ItemsPresenter
                                 {
+                                    MemberSelector = control.MemberSelector,
                                     [~ItemsPresenter.ItemsProperty] = control[~ItemsControl.ItemsProperty],
                                 }
                             },

src/Perspex.Themes.Default/ItemsControlStyle.cs

@@ -42,6 +42,7 @@ namespace Perspex.Themes.Default
             return new ItemsPresenter
             {
                 Name = "itemsPresenter",
+                MemberSelector = control.MemberSelector,
                 [~ItemsPresenter.ItemsProperty] = control[~ItemsControl.ItemsProperty],
                 [~ItemsPresenter.ItemsPanelProperty] = control[~ItemsControl.ItemsPanelProperty],
             };

src/Perspex.Themes.Default/ListBoxStyle.cs

@@ -53,6 +53,7 @@ namespace Perspex.Themes.Default
                     Content = new ItemsPresenter
                     {
                         Name = "itemsPresenter",
+                        MemberSelector = control.MemberSelector,
                         [~ItemsPresenter.ItemsProperty] = control[~ItemsControl.ItemsProperty],
                         [~ItemsPresenter.ItemsPanelProperty] = control[~ItemsControl.ItemsPanelProperty],
                     }

src/Perspex.Themes.Default/TabControlStyle.cs

@@ -59,12 +59,9 @@ namespace Perspex.Themes.Default
                     new Deck
                     {
                         Name = "deck",
-                        DataTemplates = new DataTemplates
+                        MemberSelector = new FuncMemberSelector<TabItem, object>(x => x.Content),
-                        {
+                        [!Deck.ItemsProperty] = control[!ItemsControl.ItemsProperty],
-                            new DataTemplate<TabItem>(x => (Control)control.MaterializeDataTemplate(x.Content)),
+                        [!Deck.SelectedItemProperty] = control[!SelectingItemsControl.SelectedItemProperty],
-                        },
-                        [!ItemsControl.ItemsProperty] = control[!ItemsControl.ItemsProperty],
-                        [!SelectingItemsControl.SelectedItemProperty] = control[!SelectingItemsControl.SelectedItemProperty],
                         [~Deck.TransitionProperty] = control[~TabControl.TransitionProperty],
                         [Grid.RowProperty] = 1,
                     }

src/Perspex.Themes.Default/TreeViewStyle.cs

@@ -54,6 +54,7 @@ namespace Perspex.Themes.Default
                     Content = new ItemsPresenter
                     {
                         Name = "itemsPresenter",
+                        MemberSelector = control.MemberSelector,
                         [~ItemsPresenter.ItemsProperty] = control[~ItemsControl.ItemsProperty],
                         [~ItemsPresenter.ItemsPanelProperty] = control[~ItemsControl.ItemsPanelProperty],
                     }

src/Windows/Perspex.Win32/Win32Platform.cs

@@ -8,6 +8,7 @@ using System.ComponentModel;
 using System.Diagnostics.CodeAnalysis;
 using System.Reactive.Disposables;
 using System.Runtime.InteropServices;
+using System.Threading;
 using Perspex.Controls.Platform;
 using Perspex.Input;
 using Perspex.Platform;
@@ -79,6 +80,17 @@ namespace Perspex.Win32
             UnmanagedMethods.DispatchMessage(ref msg);
         }
 
+        public void RunLoop(CancellationToken cancellationToken)
+        {
+            while (!cancellationToken.IsCancellationRequested)
+            {
+                UnmanagedMethods.MSG msg;
+                UnmanagedMethods.GetMessage(out msg, IntPtr.Zero, 0, 0);
+                UnmanagedMethods.TranslateMessage(ref msg);
+                UnmanagedMethods.DispatchMessage(ref msg);
+            }
+        }
+
         public IDisposable StartTimer(TimeSpan interval, Action callback)
         {
             UnmanagedMethods.TimerProc timerDelegate =
@@ -100,18 +112,27 @@ namespace Perspex.Win32
             });
         }
 
-        public void Wake()
+        private static readonly int SignalW = unchecked((int) 0xdeadbeaf);
+        private static readonly int SignalL = unchecked((int)0x12345678);
+
+        public void Signal()
         {
-            //UnmanagedMethods.PostMessage(
+            UnmanagedMethods.PostMessage(
-            //    this.hwnd,
+                _hwnd,
-            //    (int)UnmanagedMethods.WindowsMessage.WM_DISPATCH_WORK_ITEM,
+                (int) UnmanagedMethods.WindowsMessage.WM_DISPATCH_WORK_ITEM,
-            //    IntPtr.Zero,
+                new IntPtr(SignalW),
-            //    IntPtr.Zero);
+                new IntPtr(SignalL));
         }
 
+        public event Action Signaled;
+
         [SuppressMessage("Microsoft.StyleCop.CSharp.NamingRules", "SA1305:FieldNamesMustNotUseHungarianNotation", Justification = "Using Win32 naming for consistency.")]
         private IntPtr WndProc(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam)
         {
+            if (msg == (int) UnmanagedMethods.WindowsMessage.WM_DISPATCH_WORK_ITEM && wParam.ToInt64() == SignalW && lParam.ToInt64() == SignalL)
+            {
+                Signaled?.Invoke();
+            }
             return UnmanagedMethods.DefWindowProc(hWnd, msg, wParam, lParam);
         }
 

src/Windows/Perspex.Win32/WindowImpl.cs

@@ -1,4 +1,4 @@
-// Copyright (c) The Perspex Project. All rights reserved.
+// Copyright (c) The Perspex Project. All rights reserved.
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
 using Perspex.Input;
@@ -306,6 +306,21 @@ namespace Perspex.Win32
                     }
 
                     break;
+
+                case UnmanagedMethods.WindowsMessage.WM_NCLBUTTONDOWN:
+                case UnmanagedMethods.WindowsMessage.WM_NCRBUTTONDOWN:
+                case UnmanagedMethods.WindowsMessage.WM_NCMBUTTONDOWN:
+                    e = new RawMouseEventArgs(
+                        WindowsMouseDevice.Instance,
+                        timestamp,
+                        _owner,
+                        msg == (int)UnmanagedMethods.WindowsMessage.WM_NCLBUTTONDOWN
+                            ? RawMouseEventType.LeftButtonDown
+                            : msg == (int)UnmanagedMethods.WindowsMessage.WM_NCRBUTTONDOWN
+                                ? RawMouseEventType.RightButtonDown
+                                : RawMouseEventType.MiddleButtonDown,
+                        new Point(0, 0), GetMouseModifiers(wParam));
+                    break;
                 case UnmanagedMethods.WindowsMessage.WM_LBUTTONDOWN:
                 case UnmanagedMethods.WindowsMessage.WM_RBUTTONDOWN:
                 case UnmanagedMethods.WindowsMessage.WM_MBUTTONDOWN:
@@ -320,7 +335,7 @@ namespace Perspex.Win32
                                 : RawMouseEventType.MiddleButtonDown,
                         new Point((uint) lParam & 0xffff, (uint) lParam >> 16), GetMouseModifiers(wParam));
                     break;
-
+                    
                 case UnmanagedMethods.WindowsMessage.WM_LBUTTONUP:
                 case UnmanagedMethods.WindowsMessage.WM_RBUTTONUP:
                 case UnmanagedMethods.WindowsMessage.WM_MBUTTONUP:
@@ -406,6 +421,10 @@ namespace Perspex.Win32
             if (e != null && Input != null)
             {
                 Input(e);
+
+                if (msg >= 161 && msg <= 173)
+                    return UnmanagedMethods.DefWindowProc(hWnd, msg, wParam, lParam);
+
                 return IntPtr.Zero;
             }
 

tests/Perspex.Controls.UnitTests/ContentControlTests.cs

@@ -262,6 +262,30 @@ namespace Perspex.Controls.UnitTests
             Assert.Equal("Bar", ((TextBlock)target.Presenter.Child).Text);
         }
 
+        [Fact]
+        public void DataContext_Should_Be_Set_For_Templated_Data()
+        {
+            var target = new ContentControl();
+
+            target.Template = GetTemplate();
+            target.Content = "Foo";
+            target.ApplyTemplate();
+
+            Assert.Equal("Foo", target.Presenter.Child.DataContext);
+        }
+
+        [Fact]
+        public void DataContext_Should_Not_Be_Set_For_Control_Data()
+        {
+            var target = new ContentControl();
+
+            target.Template = GetTemplate();
+            target.Content = new TextBlock();
+            target.ApplyTemplate();
+
+            Assert.Null(target.Presenter.Child.DataContext);
+        }
+
         private ControlTemplate GetTemplate()
         {
             return new ControlTemplate<ContentControl>(parent =>

tests/Perspex.Controls.UnitTests/ItemsControlTests.cs

@@ -6,6 +6,7 @@ using System.Linq;
 using Perspex.Collections;
 using Perspex.Controls.Presenters;
 using Perspex.Controls.Templates;
+using Perspex.LogicalTree;
 using Perspex.Styling;
 using Perspex.VisualTree;
 using Xunit;
@@ -287,6 +288,70 @@ namespace Perspex.Controls.UnitTests
             Assert.Equal(target, ((ILogical)child).LogicalParent);
         }
 
+        [Fact]
+        public void DataContexts_Should_Be_Correctly_Set()
+        {
+            var items = new object[]
+            {
+                "Foo",
+                new Item("Bar"),
+                new TextBlock { Text = "Baz" },
+                new ListBoxItem { Content = "Qux" },
+            };
+
+            var target = new ItemsControl
+            {
+                Template = GetTemplate(),
+                DataContext = "Base",
+                DataTemplates = new DataTemplates
+                {
+                    new DataTemplate<Item>(x => new Button { Content = x })
+                },
+                Items = items,
+            };
+
+            target.ApplyTemplate();
+
+            var dataContexts = target.Presenter.Panel.Children
+                .Cast<Control>()
+                .Select(x => x.DataContext)
+                .ToList();
+
+            Assert.Equal(
+                new object[] { items[0], items[1], "Base", "Base" },
+                dataContexts);
+        }
+
+        [Fact]
+        public void MemberSelector_Should_Select_Member()
+        {
+            var target = new ItemsControl
+            {
+                Template = GetTemplate(),
+                Items = new[] { new Item("Foo"), new Item("Bar") },
+                MemberSelector = new FuncMemberSelector<Item, string>(x => x.Value),
+            };
+
+            target.ApplyTemplate();
+
+            var text = target.Presenter.Panel.Children
+                .Cast<TextBlock>()
+                .Select(x => x.Text)
+                .ToList();
+
+            Assert.Equal(new[] { "Foo", "Bar" }, text);
+        }
+
+        private class Item
+        {
+            public Item(string value)
+            {
+                Value = value;
+            }
+
+            public string Value { get; }
+        }
+
         private ControlTemplate GetTemplate()
         {
             return new ControlTemplate<ItemsControl>(parent =>
@@ -297,6 +362,7 @@ namespace Perspex.Controls.UnitTests
                     Child = new ItemsPresenter
                     {
                         Name = "itemsPresenter",
+                        MemberSelector = parent.MemberSelector,
                         [~ItemsPresenter.ItemsProperty] = parent[~ItemsControl.ItemsProperty],
                     }
                 };

tests/Perspex.Controls.UnitTests/Presenters/ItemsPresenterTests.cs

@@ -101,12 +101,12 @@ namespace Perspex.Controls.UnitTests.Presenters
 
             target.ApplyTemplate();
 
-            var text = target.Panel.Children.OfType<TextBlock>().Select(x => x.Text).ToList();
+            var text = target.Panel.Children.Cast<TextBlock>().Select(x => x.Text).ToList();
             Assert.Equal(new[] { "foo", "bar" }, text);
 
             items.RemoveAt(1);
 
-            text = target.Panel.Children.OfType<TextBlock>().Select(x => x.Text).ToList();
+            text = target.Panel.Children.Cast<TextBlock>().Select(x => x.Text).ToList();
             Assert.Equal(new[] { "foo", "bar" }, text);
         }
 
@@ -174,6 +174,55 @@ namespace Perspex.Controls.UnitTests.Presenters
             Assert.Equal(target.Panel, child);
         }
 
+        [Fact]
+        public void MemberSelector_Should_Select_Member()
+        {
+            var target = new ItemsPresenter
+            {
+                Items = new[] { new Item("Foo"), new Item("Bar") },
+                MemberSelector = new FuncMemberSelector<Item, string>(x => x.Value),
+            };
+
+            target.ApplyTemplate();
+
+            var text = target.Panel.Children
+                .Cast<TextBlock>()
+                .Select(x => x.Text)
+                .ToList();
+
+            Assert.Equal(new[] { "Foo", "Bar" }, text);
+        }
+
+        [Fact]
+        public void MemberSelector_Should_Set_DataContext()
+        {
+            var items = new[] { new Item("Foo"), new Item("Bar") };
+            var target = new ItemsPresenter
+            {
+                Items = items,
+                MemberSelector = new FuncMemberSelector<Item, string>(x => x.Value),
+            };
+
+            target.ApplyTemplate();
+
+            var dataContexts = target.Panel.Children
+                .Cast<TextBlock>()
+                .Select(x => x.DataContext)
+                .ToList();
+
+            Assert.Equal(new[] { "Foo", "Bar" }, dataContexts);
+        }
+
+        private class Item
+        {
+            public Item(string value)
+            {
+                Value = value;
+            }
+
+            public string Value { get; }
+        }
+
         private class TestItem : ContentControl
         {
         }

tests/Perspex.Controls.UnitTests/TabControlTests.cs

@@ -130,6 +130,46 @@ namespace Perspex.Controls.UnitTests
             Assert.Same(target.SelectedTab, target.SelectedItem);
         }
 
+        [Fact]
+        public void DataContexts_Should_Be_Correctly_Set()
+        {
+            var items = new object[]
+            {
+                "Foo",
+                new Item("Bar"),
+                new TextBlock { Text = "Baz" },
+                new TabItem { Content = "Qux" },
+            };
+
+            var target = new TabControl
+            {
+                Template = new ControlTemplate<TabControl>(CreateTabControlTemplate),
+                DataContext = "Base",
+                DataTemplates = new DataTemplates
+                {
+                    new DataTemplate<Item>(x => new Button { Content = x })
+                },
+                Items = items,
+            };
+
+            target.ApplyTemplate();
+
+            var dataContext = ((TextBlock)target.GetLogicalChildren().Single()).DataContext;
+            Assert.Equal(items[0], dataContext);
+
+            target.SelectedIndex = 1;
+            dataContext = ((Button)target.GetLogicalChildren().Single()).DataContext;
+            Assert.Equal(items[1], dataContext);
+
+            target.SelectedIndex = 2;
+            dataContext = ((TextBlock)target.GetLogicalChildren().Single()).DataContext;
+            Assert.Equal("Base", dataContext);
+
+            target.SelectedIndex = 3;
+            dataContext = ((TextBlock)target.GetLogicalChildren().Single()).DataContext;
+            Assert.Equal("Qux", dataContext);
+        }
+
         private Control CreateTabControlTemplate(TabControl parent)
         {
             return new StackPanel
@@ -147,10 +187,7 @@ namespace Perspex.Controls.UnitTests
                     {
                         Name = "deck",
                         Template = new ControlTemplate<Deck>(CreateDeckTemplate),
-                        DataTemplates = new DataTemplates
+                        MemberSelector = parent.ContentSelector,
-                        {
-                            new DataTemplate<TabItem>(x => (Control)parent.MaterializeDataTemplate(x.Content)),
-                        },
                         [!ItemsControl.ItemsProperty] = parent[!ItemsControl.ItemsProperty],
                         [!SelectingItemsControl.SelectedItemProperty] = parent[!SelectingItemsControl.SelectedItemProperty],
                     }
@@ -172,11 +209,22 @@ namespace Perspex.Controls.UnitTests
             return new DeckPresenter
             {
                 Name = "itemsPresenter",
-                [!ItemsPresenter.ItemsProperty] = control[!ItemsControl.ItemsProperty],
+                [!DeckPresenter.ItemsProperty] = control[!ItemsControl.ItemsProperty],
-                [!ItemsPresenter.ItemsPanelProperty] = control[!ItemsControl.ItemsPanelProperty],
+                [!DeckPresenter.ItemsPanelProperty] = control[!ItemsControl.ItemsPanelProperty],
+                [!DeckPresenter.MemberSelectorProperty] = control[!ItemsControl.MemberSelectorProperty],
                 [!DeckPresenter.SelectedIndexProperty] = control[!SelectingItemsControl.SelectedIndexProperty],
                 [~DeckPresenter.TransitionProperty] = control[~Deck.TransitionProperty],
             };
         }
+
+        private class Item
+        {
+            public Item(string value)
+            {
+                Value = value;
+            }
+
+            public string Value { get; }
+        }
     }
 }