Added start of ItemsControl.

Perspex/Application.cs

@@ -6,12 +6,15 @@
 
 namespace Perspex
 {
+    using Perspex.Controls;
     using Perspex.Input;
     using Perspex.Styling;
     using Splat;
 
     public class Application
     {
+        private DataTemplates dataTemplates;
+
         private Styles styles;
 
         public Application()
@@ -27,6 +30,24 @@ namespace Perspex
             private set;
         }
 
+        public DataTemplates DataTemplates
+        {
+            get
+            {
+                if (this.dataTemplates == null)
+                {
+                    this.dataTemplates = new DataTemplates();
+                }
+
+                return this.dataTemplates;
+            }
+
+            set
+            {
+                this.dataTemplates = value;
+            }
+        }
+
         public IFocusManager FocusManager
         {
             get;

Perspex/Controls/ContentPresenter.cs

@@ -46,6 +46,11 @@ namespace Perspex.Controls
             set { this.SetValue(ContentProperty, value); }
         }
 
+        IEnumerable<IVisual> IVisual.ExistingVisualChildren
+        {
+            get { return Enumerable.Repeat(this.visualChild, this.visualChild != null ? 1 : 0); }
+        }
+
         IEnumerable<IVisual> IVisual.VisualChildren
         {
             get
@@ -154,35 +159,5 @@ namespace Perspex.Controls
 
             return new Size();
         }
-
-        private DataTemplate FindDataTemplate(object content)
-        {
-            ILogical node = this;
-
-            while (node != null)
-            {
-                Control control = node as Control;
-
-                if (control != null)
-                {
-                    foreach (DataTemplate dt in control.DataTemplates.Reverse())
-                    {
-                        if (dt.Match(content))
-                        {
-                            return dt;
-                        }
-                    }
-                }
-
-                node = node.LogicalParent;
-
-                if (node == null && control != null)
-                {
-                    node = control.TemplatedParent as ILogical;
-                }
-            }
-
-            return null;
-        }
     }
 }

Perspex/Controls/Control.cs

@@ -208,5 +208,48 @@ namespace Perspex.Controls
                 }
             });
         }
+
+        protected DataTemplate FindDataTemplate(object content)
+        {
+            ILogical node = this;
+
+            while (node != null)
+            {
+                Control control = node as Control;
+
+                if (control != null)
+                {
+                    foreach (DataTemplate dt in control.DataTemplates.Reverse())
+                    {
+                        if (dt.Match(content))
+                        {
+                            return dt;
+                        }
+                    }
+                }
+
+                node = node.LogicalParent;
+
+                if (node == null && control != null)
+                {
+                    node = control.TemplatedParent as ILogical;
+                }
+            }
+
+            foreach (DataTemplate dt in Application.Current.DataTemplates.Reverse())
+            {
+                if (dt.Match(content))
+                {
+                    return dt;
+                }
+            }
+
+            return null;
+        }
+
+        protected DataTemplate GetDataTemplate(object content)
+        {
+            return this.FindDataTemplate(content) ?? DataTemplate.Default;
+        }
     }
 }

Perspex/Controls/DataTemplate.cs

@@ -11,6 +11,9 @@ namespace Perspex.Controls
 
     public class DataTemplate
     {
+        public static readonly DataTemplate Default =
+            new DataTemplate(typeof(object), o => new TextBox { Text = o.ToString() });
+
         public DataTemplate(Type type, Func<object, IVisual> build)
             : this(o => type.GetTypeInfo().IsAssignableFrom(o.GetType().GetTypeInfo()), build)
         {
@@ -18,6 +21,9 @@ namespace Perspex.Controls
 
         public DataTemplate(Func<object, bool> match, Func<object, IVisual> build)
         {
+            Contract.Requires<ArgumentNullException>(match != null);
+            Contract.Requires<ArgumentNullException>(build != null);
+
             this.Match = match;
             this.Build = build;
         }

Perspex/Controls/ItemsControl.cs

@@ -0,0 +1,99 @@
+// -----------------------------------------------------------------------
+// <copyright file="ItemsControl.cs" company="Steven Kirk">
+// Copyright 2014 MIT Licence. See licence.md for more information.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace Perspex.Controls
+{
+    using System;
+    using System.Collections;
+    using System.Collections.Generic;
+    using System.Linq;
+    using Perspex.Layout;
+
+    public class ItemsControl : Control, IVisual
+    {
+        private static readonly ItemsPanelTemplate defaultPanel =
+            new ItemsPanelTemplate(() => new StackPanel { Orientation = Orientation.Vertical });
+
+        public static readonly PerspexProperty<IEnumerable> ItemsProperty =
+            PerspexProperty.Register<ItemsControl, IEnumerable>("Items");
+
+        public static readonly PerspexProperty<ItemsPanelTemplate> ItemsPanelProperty =
+            PerspexProperty.Register<ItemsControl, ItemsPanelTemplate>("ItemsPanel", defaultValue: defaultPanel);
+
+        private Panel panel;
+
+        public ItemsControl()
+        {
+            this.GetObservable(ItemsProperty).Subscribe(this.ItemsChanged);
+        }
+
+        public IEnumerable Items
+        {
+            get { return this.GetValue(ItemsProperty); }
+            set { this.SetValue(ItemsProperty, value); }
+        }
+
+        public ItemsPanelTemplate ItemsPanel
+        {
+            get { return this.GetValue(ItemsPanelProperty); }
+            set { this.SetValue(ItemsPanelProperty, value); }
+        }
+
+        IEnumerable<IVisual> IVisual.ExistingVisualChildren
+        {
+            get { return Enumerable.Repeat(this.panel, this.panel != null ? 1 : 0); }
+        }
+
+        IEnumerable<IVisual> IVisual.VisualChildren
+        {
+            get { return Enumerable.Repeat(this.GetPanel(), 1); }
+        }
+
+        protected override Size MeasureOverride(Size availableSize)
+        {
+            Panel panel = this.GetPanel();
+            panel.Measure(availableSize);
+            return panel.DesiredSize.Value;
+        }
+
+        protected override Size ArrangeOverride(Size finalSize)
+        {
+            this.GetPanel().Arrange(new Rect(finalSize));
+            return finalSize;
+        }
+
+        private IEnumerable<Control> CreateItems(IEnumerable items)
+        {
+            if (items != null)
+            {
+                return items
+                    .Cast<object>()
+                    .Select(x => this.GetDataTemplate(x).Build(x))
+                    .OfType<Control>();
+            }
+            else
+            {
+                return Enumerable.Empty<Control>();
+            }
+        }
+
+        private Panel GetPanel()
+        {
+            if (this.panel == null)
+            {
+                this.panel = this.ItemsPanel.Build();
+                this.panel.Children = new PerspexList<Control>(this.CreateItems(this.Items));
+            }
+
+            return this.panel;
+        }
+
+        private void ItemsChanged(IEnumerable items)
+        {
+            this.GetPanel().Children = new PerspexList<Control>(this.CreateItems(items));
+        }
+    }
+}

Perspex/Controls/ItemsPanelTemplate.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Perspex.Controls
+{
+    public class ItemsPanelTemplate
+    {
+        public ItemsPanelTemplate(Func<Panel> build)
+        {
+            Contract.Requires<ArgumentNullException>(build != null);
+
+            this.Build = build;
+        }
+
+        public Func<Panel> Build { get; private set; }
+    }
+}

Perspex/Controls/Panel.cs

@@ -53,7 +53,7 @@ namespace Perspex.Controls
 
         IEnumerable<IVisual> IVisual.VisualChildren
         {
-            get { return this.children; }
+            get { return this.children ?? Enumerable.Empty<IVisual>(); }
         }
     }
 }

Perspex/Perspex.csproj

@@ -70,6 +70,8 @@
   <ItemGroup>
     <Compile Include="Application.cs" />
     <Compile Include="BindingExtensions.cs" />
+    <Compile Include="Controls\ItemsPanelTemplate.cs" />
+    <Compile Include="Controls\ItemsControl.cs" />
     <Compile Include="Controls\DataTemplate.cs" />
     <Compile Include="Controls\DataTemplates.cs" />
     <Compile Include="Controls\CheckBox.cs" />

Perspex/PerspexList.cs

@@ -16,10 +16,13 @@ namespace Perspex
     {
         public PerspexList()
         {
-            this.Changed = Observable.FromEvent<NotifyCollectionChangedEventHandler, NotifyCollectionChangedEventArgs>(
-                handler => (sender, e) => handler(e),
-                handler => this.CollectionChanged += handler,
-                handler => this.CollectionChanged -= handler);
+            this.Initialize();
+        }
+
+        public PerspexList(IEnumerable<T> items)
+            : base(items)
+        {
+            this.Initialize();
         }
 
         public IObservable<NotifyCollectionChangedEventArgs> Changed
@@ -35,5 +38,13 @@ namespace Perspex
                 this.Add(item);
             }
         }
+
+        private void Initialize()
+        {
+            this.Changed = Observable.FromEvent<NotifyCollectionChangedEventHandler, NotifyCollectionChangedEventArgs>(
+                handler => (sender, e) => handler(e),
+                handler => this.CollectionChanged += handler,
+                handler => this.CollectionChanged -= handler);
+        }
     }
 }

TestApplication/Program.cs

@@ -36,6 +36,12 @@ namespace TestApplication
         }
     }
 
+    class Item
+    {
+        public string Name { get; set; }
+        public string Value { get; set; }
+    }
+
     class Program
     {
         static void Main(string[] args)
@@ -76,23 +82,38 @@ namespace TestApplication
                             Source = new Bitmap("github_icon.png"),
                             Width = 200,
                         },
-                        new ContentControl
+                        new ItemsControl
                         {
                             DataTemplates = new DataTemplates
                             {
-                                new DataTemplate<string>(o => new Border
+                                new DataTemplate<Item>(o => new Border
                                 {
                                     Background = Brushes.Red,
                                     BorderBrush = Brushes.Black,
-                                    BorderThickness = 2,
-                                    Content = new TextBlock
+                                    BorderThickness = 1,
+                                    Content = new StackPanel
                                     {
-                                        Text = o,
+                                        Orientation = Orientation.Vertical,
+                                        Children = new PerspexList<Control>
+                                        {
+                                            new TextBlock
+                                            {
+                                                Text = o.Name,
+                                            },
+                                            new TextBlock
+                                            {
+                                                Text = o.Value,
+                                            }
+                                        },
                                     }
                                 }),
                             },
-                            Content = "Data Template",
-                        },
+                            Items = new[]
+                            {
+                                new Item { Name = "Foo", Value = "Bar" },
+                                new Item { Name = "Buzz", Value = "Aldrin" },
+                            },
+                        }
                     }
                 }
             };