Make ItemsControl templated.

Perspex/Controls/ControlTemplate.cs

@@ -7,8 +7,6 @@
 namespace Perspex.Controls
 {
     using System;
-    using System.Linq;
-    using Perspex.Controls;
 
     public class ControlTemplate
     {

Perspex/Controls/DataTemplate.cs

@@ -12,7 +12,7 @@ namespace Perspex.Controls
     public class DataTemplate
     {
         public static readonly DataTemplate Default =
-            new DataTemplate(typeof(object), o => new TextBox { Text = o.ToString() });
+            new DataTemplate(typeof(object), o => new TextBlock { Text = o.ToString() });
 
         public DataTemplate(Type type, Func<object, IVisual> build)
             : this(o => type.GetTypeInfo().IsAssignableFrom(o.GetType().GetTypeInfo()), build)

Perspex/Controls/ItemsControl.cs

@@ -6,13 +6,9 @@
 
 namespace Perspex.Controls
 {
-    using System;
     using System.Collections;
-    using System.Collections.Generic;
-    using System.Linq;
-    using Perspex.Layout;
 
-    public class ItemsControl : Control, IVisual
+    public class ItemsControl : TemplatedControl
     {
         private static readonly ItemsPanelTemplate defaultPanel =
             new ItemsPanelTemplate(() => new StackPanel { Orientation = Orientation.Vertical });
@@ -23,11 +19,8 @@ namespace Perspex.Controls
         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
@@ -41,59 +34,5 @@ namespace Perspex.Controls
             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/ItemsPresenter.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 ItemsPresenter : Control, IVisual
+    {
+        public static readonly PerspexProperty<IEnumerable> ItemsProperty =
+            PerspexProperty.Register<ItemsControl, IEnumerable>("Items");
+
+        public static readonly PerspexProperty<ItemsPanelTemplate> ItemsPanelProperty =
+            PerspexProperty.Register<ItemsControl, ItemsPanelTemplate>("ItemsPanel");
+
+        private Panel panel;
+
+        public ItemsPresenter()
+        {
+            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.ItemsPanel != null)
+            {
+                this.panel = this.ItemsPanel.Build();
+                this.ItemsChanged(this.Items);
+            }
+
+            return this.panel;
+        }
+
+        private void ItemsChanged(IEnumerable items)
+        {
+            if (this.panel != null)
+            {
+                this.panel.Children = new PerspexList<Control>(this.CreateItems(items));
+            }
+        }
+    }
+}

Perspex/Perspex.csproj

@@ -70,6 +70,7 @@
   <ItemGroup>
     <Compile Include="Application.cs" />
     <Compile Include="BindingExtensions.cs" />
+    <Compile Include="Controls\ItemsPresenter.cs" />
     <Compile Include="Controls\ItemsPanelTemplate.cs" />
     <Compile Include="Controls\ItemsControl.cs" />
     <Compile Include="Controls\DataTemplate.cs" />
@@ -126,6 +127,7 @@
     <Compile Include="Media\Geometry.cs" />
     <Compile Include="Media\Stretch.cs" />
     <Compile Include="Themes\Default\ContentControlStyle.cs" />
+    <Compile Include="Themes\Default\ItemsControlStyle.cs" />
     <Compile Include="Vector.cs" />
     <Compile Include="Rendering\RenderManager.cs" />
     <Compile Include="Rendering\IRenderManager.cs" />

Perspex/Themes/Default/DefaultTheme.cs

@@ -15,7 +15,9 @@ namespace Perspex.Themes.Default
             this.Add(new ButtonStyle());
             this.Add(new CheckBoxStyle());
             this.Add(new ContentControlStyle());
+            this.Add(new ItemsControlStyle());
             this.Add(new TextBoxStyle());
+            this.Add(new ItemsControlStyle());
         }
     }
 }

Perspex/Themes/Default/ItemsControlStyle.cs

@@ -0,0 +1,41 @@
+// -----------------------------------------------------------------------
+// <copyright file="ItemsControlStyle.cs" company="Steven Kirk">
+// Copyright 2014 MIT Licence. See licence.md for more information.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace Perspex.Themes.Default
+{
+    using System;
+    using System.Linq;
+    using Perspex.Controls;
+    using Perspex.Media;
+    using Perspex.Shapes;
+    using Perspex.Styling;
+
+    public class ItemsControlStyle : Styles
+    {
+        public ItemsControlStyle()
+        {
+            this.AddRange(new[]
+            {
+                new Style(x => x.OfType<ItemsControl>())
+                {
+                    Setters = new[]
+                    {
+                        new Setter(Button.TemplateProperty, ControlTemplate.Create<ItemsControl>(this.Template)),
+                    },
+                },
+            });
+        }
+
+        private Control Template(ItemsControl control)
+        {
+            return new ItemsPresenter
+            {
+                [~ItemsPresenter.ItemsProperty] = control[~ItemsControl.ItemsProperty],
+                [~ItemsPresenter.ItemsPanelProperty] = control[~ItemsControl.ItemsPanelProperty],
+            };
+        }
+    }
+}