Added ItemsControl.ItemTemplate property.

src/Avalonia.Controls/DropDown.cs

@@ -68,7 +68,10 @@ namespace Avalonia.Controls
         /// <inheritdoc/>
         protected override IItemContainerGenerator CreateItemContainerGenerator()
         {
-            return new ItemContainerGenerator<DropDownItem>(this, DropDownItem.ContentProperty);
+            return new ItemContainerGenerator<DropDownItem>(
+                this,
+                DropDownItem.ContentProperty,
+                DropDownItem.ContentTemplateProperty);
         }
 
         /// <inheritdoc/>

src/Avalonia.Controls/Generators/IItemContainerGenerator.cs

@@ -18,6 +18,11 @@ namespace Avalonia.Controls.Generators
         /// </summary>
         IEnumerable<ItemContainer> Containers { get; }
 
+        /// <summary>
+        /// Gets or sets the data template used to display the items in the control.
+        /// </summary>
+        IDataTemplate ItemTemplate { get; set; }
+
         /// <summary>
         /// Signalled whenever new containers are materialized.
         /// </summary>

src/Avalonia.Controls/Generators/ItemContainerGenerator.cs

@@ -37,6 +37,11 @@ namespace Avalonia.Controls.Generators
         /// <inheritdoc/>
         public event EventHandler<ItemContainerEventArgs> Dematerialized;
 
+        /// <summary>
+        /// Gets or sets the data template used to display the items in the control.
+        /// </summary>
+        public IDataTemplate ItemTemplate { get; set; }
+
         /// <summary>
         /// Gets the owner control.
         /// </summary>
@@ -156,7 +161,7 @@ namespace Avalonia.Controls.Generators
         /// <returns>The created container control.</returns>
         protected virtual IControl CreateContainer(object item)
         {
-            var result = Owner.MaterializeDataTemplate(item);
+            var result = Owner.MaterializeDataTemplate(item, ItemTemplate);
 
             if (result != null && !(item is IControl))
             {

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

@@ -19,15 +19,18 @@ namespace Avalonia.Controls.Generators
         /// </summary>
         /// <param name="owner">The owner control.</param>
         /// <param name="contentProperty">The container's Content property.</param>
+        /// <param name="contentTemplateProperty">The container's ContentTemplate property.</param>
         public ItemContainerGenerator(
             IControl owner, 
-            AvaloniaProperty contentProperty)
+            AvaloniaProperty contentProperty,
+            AvaloniaProperty contentTemplateProperty)
             : base(owner)
         {
             Contract.Requires<ArgumentNullException>(owner != null);
             Contract.Requires<ArgumentNullException>(contentProperty != null);
 
             ContentProperty = contentProperty;
+            ContentTemplateProperty = contentTemplateProperty;
         }
 
         /// <summary>
@@ -35,6 +38,11 @@ namespace Avalonia.Controls.Generators
         /// </summary>
         protected AvaloniaProperty ContentProperty { get; }
 
+        /// <summary>
+        /// Gets the container's ContentTemplate property.
+        /// </summary>
+        protected AvaloniaProperty ContentTemplateProperty { get; }
+
         /// <inheritdoc/>
         protected override IControl CreateContainer(object item)
         {
@@ -51,6 +59,12 @@ namespace Avalonia.Controls.Generators
             else
             {
                 var result = new T();
+
+                if (ContentTemplateProperty != null)
+                {
+                    result.SetValue(ContentTemplateProperty, ItemTemplate);
+                }
+
                 result.SetValue(ContentProperty, item);
 
                 if (!(item is IControl))

src/Avalonia.Controls/Generators/TreeItemContainerGenerator.cs

@@ -20,16 +20,18 @@ namespace Avalonia.Controls.Generators
         /// </summary>
         /// <param name="owner">The owner control.</param>
         /// <param name="contentProperty">The container's Content property.</param>
+        /// <param name="contentTemplateProperty">The container's ContentTemplate property.</param>
         /// <param name="itemsProperty">The container's Items property.</param>
         /// <param name="isExpandedProperty">The container's IsExpanded property.</param>
         /// <param name="index">The container index for the tree</param>
         public TreeItemContainerGenerator(
             IControl owner,
             AvaloniaProperty contentProperty,
+            AvaloniaProperty contentTemplateProperty,
             AvaloniaProperty itemsProperty,
             AvaloniaProperty isExpandedProperty,
             TreeContainerIndex index)
-            : base(owner, contentProperty)
+            : base(owner, contentProperty, contentTemplateProperty)
         {
             Contract.Requires<ArgumentNullException>(owner != null);
             Contract.Requires<ArgumentNullException>(contentProperty != null);

src/Avalonia.Controls/ItemsControl.cs

@@ -41,6 +41,12 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<ITemplate<IPanel>> ItemsPanelProperty =
             AvaloniaProperty.Register<ItemsControl, ITemplate<IPanel>>(nameof(ItemsPanel), DefaultPanel);
 
+        /// <summary>
+        /// Defines the <see cref="ItemTemplate"/> property.
+        /// </summary>
+        public static readonly StyledProperty<IDataTemplate> ItemTemplateProperty =
+            AvaloniaProperty.Register<ItemsControl, IDataTemplate>(nameof(ItemTemplate));
+
         /// <summary>
         /// Defines the <see cref="MemberSelector"/> property.
         /// </summary>
@@ -65,6 +71,7 @@ namespace Avalonia.Controls
         {
             PseudoClasses.Add(":empty");
             SubscribeToItems(_items);
+            ItemTemplateProperty.Changed.AddClassHandler<ItemsControl>(x => x.ItemTemplateChanged);
         }
 
         /// <summary>
@@ -80,6 +87,7 @@ namespace Avalonia.Controls
 
                     if (_itemContainerGenerator != null)
                     {
+                        _itemContainerGenerator.ItemTemplate = ItemTemplate;
                         _itemContainerGenerator.Materialized += (_, e) => OnContainersMaterialized(e);
                         _itemContainerGenerator.Dematerialized += (_, e) => OnContainersDematerialized(e);
                     }
@@ -108,6 +116,15 @@ namespace Avalonia.Controls
             set { SetValue(ItemsPanelProperty, value); }
         }
 
+        /// <summary>
+        /// Gets or sets the data template used to display the items in the control.
+        /// </summary>
+        public IDataTemplate ItemTemplate
+        {
+            get { return GetValue(ItemTemplateProperty); }
+            set { SetValue(ItemTemplateProperty, value); }
+        }
+
         /// <summary>
         /// Selects a member from <see cref="Items"/> to use as the list item.
         /// </summary>
@@ -354,7 +371,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Subscribes to an <see cref="Items"/> collection.
         /// </summary>
-        /// <param name="items"></param>
+        /// <param name="items">The items collection.</param>
         private void SubscribeToItems(IEnumerable items)
         {
             PseudoClasses.Set(":empty", items == null || items.Count() == 0);
@@ -366,5 +383,18 @@ namespace Avalonia.Controls
                 incc.CollectionChanged += ItemsCollectionChanged;
             }
         }
+
+        /// <summary>
+        /// Called when the <see cref="ItemTemplate"/> changes.
+        /// </summary>
+        /// <param name="e">The event args.</param>
+        private void ItemTemplateChanged(AvaloniaPropertyChangedEventArgs e)
+        {
+            if (_itemContainerGenerator != null)
+            {
+                _itemContainerGenerator.ItemTemplate = (IDataTemplate)e.NewValue;
+                // TODO: Rebuild the item containers.
+            }
+        }
     }
 }

src/Avalonia.Controls/ListBox.cs

@@ -41,7 +41,10 @@ namespace Avalonia.Controls
         /// <inheritdoc/>
         protected override IItemContainerGenerator CreateItemContainerGenerator()
         {
-            return new ItemContainerGenerator<ListBoxItem>(this, ListBoxItem.ContentProperty);
+            return new ItemContainerGenerator<ListBoxItem>(
+                this, 
+                ListBoxItem.ContentProperty,
+                ListBoxItem.ContentTemplateProperty);
         }
 
         /// <inheritdoc/>

src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs

@@ -27,6 +27,12 @@ namespace Avalonia.Controls.Presenters
         public static readonly StyledProperty<ITemplate<IPanel>> ItemsPanelProperty =
             ItemsControl.ItemsPanelProperty.AddOwner<ItemsPresenterBase>();
 
+        /// <summary>
+        /// Defines the <see cref="ItemTemplate"/> property.
+        /// </summary>
+        public static readonly StyledProperty<IDataTemplate> ItemTemplateProperty =
+            ItemsControl.ItemTemplateProperty.AddOwner<ItemsPresenterBase>();
+
         /// <summary>
         /// Defines the <see cref="MemberSelector"/> property.
         /// </summary>
@@ -122,6 +128,15 @@ namespace Avalonia.Controls.Presenters
             set { SetValue(ItemsPanelProperty, value); }
         }
 
+        /// <summary>
+        /// Gets or sets the data template used to display the items in the control.
+        /// </summary>
+        public IDataTemplate ItemTemplate
+        {
+            get { return GetValue(ItemTemplateProperty); }
+            set { SetValue(ItemTemplateProperty, value); }
+        }
+
         /// <summary>
         /// Selects a member from <see cref="Items"/> to use as the list item.
         /// </summary>

src/Avalonia.Controls/Primitives/TabStrip.cs

@@ -20,7 +20,10 @@ namespace Avalonia.Controls.Primitives
 
         protected override IItemContainerGenerator CreateItemContainerGenerator()
         {
-            return new ItemContainerGenerator<TabStripItem>(this, ContentControl.ContentProperty);
+            return new ItemContainerGenerator<TabStripItem>(
+                this,
+                ContentControl.ContentProperty,
+                ContentControl.ContentTemplateProperty);
         }
 
         /// <inheritdoc/>

src/Avalonia.Controls/TreeView.cs

@@ -96,6 +96,7 @@ namespace Avalonia.Controls
             var result = new TreeItemContainerGenerator<TreeViewItem>(
                 this,
                 TreeViewItem.HeaderProperty,
+                null,
                 TreeViewItem.ItemsProperty,
                 TreeViewItem.IsExpandedProperty,
                 new TreeContainerIndex());

src/Avalonia.Controls/TreeViewItem.cs

@@ -80,6 +80,7 @@ namespace Avalonia.Controls
             return new TreeItemContainerGenerator<TreeViewItem>(
                 this,
                 TreeViewItem.HeaderProperty,
+                null,
                 TreeViewItem.ItemsProperty,
                 TreeViewItem.IsExpandedProperty,
                 _treeView?.ItemContainerGenerator.Index ?? new TreeContainerIndex());

src/Avalonia.Themes.Default/ContextMenu.xaml

@@ -13,6 +13,7 @@
         <ItemsPresenter Name="PART_ItemsPresenter"
                         Items="{TemplateBinding Items}"
                         ItemsPanel="{TemplateBinding ItemsPanel}"
+                        ItemTemplate="{TemplateBinding ItemTemplate}"
                         KeyboardNavigation.TabNavigation="Continue"/>
       </Border>
     </ControlTemplate>

src/Avalonia.Themes.Default/DropDown.xaml

@@ -38,6 +38,7 @@
                       BorderThickness="1">
                 <ItemsPresenter Name="PART_ItemsPresenter"
                                 Items="{TemplateBinding Items}" 
+                                ItemTemplate="{TemplateBinding ItemTemplate}"
                                 MemberSelector="{TemplateBinding MemberSelector}"/>
               </Border>
             </Popup>

src/Avalonia.Themes.Default/ItemsControl.xaml

@@ -4,6 +4,7 @@
       <ItemsPresenter Name="PART_ItemsPresenter"
                       Items="{TemplateBinding Items}"
                       ItemsPanel="{TemplateBinding ItemsPanel}"
+                      ItemTemplate="{TemplateBinding ItemTemplate}"
                       MemberSelector="{TemplateBinding MemberSelector}"/>
     </ControlTemplate>
   </Setter>

src/Avalonia.Themes.Default/ListBox.xaml

@@ -11,6 +11,7 @@
           <ItemsPresenter Name="PART_ItemsPresenter"
                           Items="{TemplateBinding Items}"
                           ItemsPanel="{TemplateBinding ItemsPanel}"
+                          ItemTemplate="{TemplateBinding ItemTemplate}"
                           Margin="{TemplateBinding Padding}"
                           MemberSelector="{TemplateBinding MemberSelector}"/>
         </ScrollViewer>

src/Avalonia.Themes.Default/Menu.xaml

@@ -8,6 +8,7 @@
         <ItemsPresenter Name="PART_ItemsPresenter" 
                         Items="{TemplateBinding Items}" 
                         ItemsPanel="{TemplateBinding ItemsPanel}"
+                        ItemTemplate="{TemplateBinding ItemTemplate}"
                         KeyboardNavigation.TabNavigation="Continue"/>
       </Border>
     </ControlTemplate>

src/Avalonia.Themes.Default/MenuItem.xaml

@@ -53,6 +53,7 @@
                     <ItemsPresenter Name="PART_ItemsPresenter"
                                     Items="{TemplateBinding Items}"
                                     ItemsPanel="{TemplateBinding ItemsPanel}"
+                                    ItemTemplate="{TemplateBinding ItemTemplate}"
                                     Margin="2"
                                     MemberSelector="{TemplateBinding MemberSelector}"/>
                     <Rectangle Name="iconSeparator"
@@ -99,6 +100,7 @@
                     <ItemsPresenter Name="PART_ItemsPresenter"
                                     Items="{TemplateBinding Items}"
                                     ItemsPanel="{TemplateBinding ItemsPanel}"
+                                    ItemTemplate="{TemplateBinding ItemTemplate}"
                                     Margin="2"
                                     MemberSelector="{TemplateBinding MemberSelector}"/>
                     <Rectangle Name="iconSeparator"

src/Avalonia.Themes.Default/TabStrip.xaml

@@ -5,7 +5,8 @@
         <ItemsPresenter Name="PART_ItemsPresenter"
                         MemberSelector="{TemplateBinding MemberSelector}"
                         Items="{TemplateBinding Items}"
-                        ItemsPanel="{TemplateBinding ItemsPanel}"/>
+                        ItemsPanel="{TemplateBinding ItemsPanel}"
+                        ItemTemplate="{TemplateBinding ItemTemplate}"/>
       </ControlTemplate>
     </Setter>
     <Setter Property="ItemsPanel">

tests/Avalonia.Controls.UnitTests/Generators/ItemContainerGeneratorTypedTests.cs

@@ -14,7 +14,7 @@ namespace Avalonia.Controls.UnitTests.Generators
         {
             var items = new[] { "foo", "bar", "baz" };
             var owner = new Decorator();
-            var target = new ItemContainerGenerator<ListBoxItem>(owner, ListBoxItem.ContentProperty);
+            var target = new ItemContainerGenerator<ListBoxItem>(owner, ListBoxItem.ContentProperty, null);
             var containers = target.Materialize(0, items, null);
             var result = containers
                 .Select(x => x.ContainerControl)

tests/Avalonia.Controls.UnitTests/ItemsControlTests.cs

@@ -14,6 +14,22 @@ namespace Avalonia.Controls.UnitTests
 {
     public class ItemsControlTests
     {
+        [Fact]
+        public void Should_Use_ItemTemplate_To_Create_Control()
+        {
+            var target = new ItemsControl
+            {
+                Template = GetTemplate(),
+                ItemTemplate = new FuncDataTemplate<string>(_ => new Canvas()),
+            };
+
+            target.Items = new[] { "Foo" };
+            target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
+
+            Assert.IsType<Canvas>(target.Presenter.Panel.Children[0]);
+        }
+
         [Fact]
         public void Panel_Should_Have_TemplatedParent_Set_To_ItemsControl()
         {

tests/Avalonia.Controls.UnitTests/ListBoxTests.cs

@@ -14,6 +14,27 @@ namespace Avalonia.Controls.UnitTests
 {
     public class ListBoxTests
     {
+        [Fact]
+        public void Should_Use_ItemTemplate_To_Create_Item_Content()
+        {
+            var target = new ListBox
+            {
+                Template = new FuncControlTemplate(CreateListBoxTemplate),
+                ItemTemplate = new FuncDataTemplate<string>(_ => new Canvas()),
+            };
+
+            target.Items = new[] { "Foo" };
+            target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
+
+            var container = (ListBoxItem)target.Presenter.Panel.Children[0];
+            container.Template = ListBoxItemTemplate();
+            container.ApplyTemplate();
+            ((ContentPresenter)container.Presenter).UpdateChild();
+
+            Assert.IsType<Canvas>(container.Presenter.Child);
+        }
+
         [Fact]
         public void ListBox_Should_Find_ItemsPresenter_In_ScrollViewer()
         {
@@ -123,6 +144,7 @@ namespace Avalonia.Controls.UnitTests
             {
                 Name = "PART_ContentPresenter",
                 [!ContentPresenter.ContentProperty] = parent[!ListBoxItem.ContentProperty],
+                [!ContentPresenter.ContentTemplateProperty] = parent[!ListBoxItem.ContentTemplateProperty],
             });
         }
 

tests/Avalonia.Controls.UnitTests/Presenters/CarouselPresenterTests.cs

@@ -201,7 +201,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
         {
             protected override IItemContainerGenerator CreateItemContainerGenerator()
             {
-                return new ItemContainerGenerator<TestItem>(this, TestItem.ContentProperty);
+                return new ItemContainerGenerator<TestItem>(this, TestItem.ContentProperty, null);
             }
         }
     }

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

@@ -54,7 +54,8 @@ namespace Avalonia.Controls.UnitTests.Presenters
 
             target.ItemContainerGenerator = new ItemContainerGenerator<ListBoxItem>(
                 target, 
-                ListBoxItem.ContentProperty);
+                ListBoxItem.ContentProperty,
+                null);
             target.ApplyTemplate();
 
             Assert.Equal(2, target.Panel.Children.Count);
@@ -332,7 +333,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
         {
             protected override IItemContainerGenerator CreateItemContainerGenerator()
             {
-                return new ItemContainerGenerator<TestItem>(this, TestItem.ContentProperty);
+                return new ItemContainerGenerator<TestItem>(this, TestItem.ContentProperty, null);
             }
         }
     }