WIP

Perspex.Controls/ColumnDefinition.cs

@@ -21,6 +21,11 @@ namespace Perspex.Controls
         {
         }
 
+        public ColumnDefinition(double value, GridUnitType type)
+        {
+            this.Width = new GridLength(value, type);
+        }
+
         public ColumnDefinition(GridLength width)
         {
             this.Width = width;

Perspex.Controls/Control.cs

@@ -203,13 +203,6 @@ namespace Perspex.Controls
 
         protected virtual DataTemplate FindDataTemplate(object content)
         {
-            Control control = content as Control;
-
-            if (control != null)
-            {
-                return new DataTemplate(x => control);
-            }
-
             // TODO: This needs to traverse the logical tree, not the visual.
             foreach (var i in this.GetVisualAncestors().OfType<Control>())
             {
@@ -238,9 +231,22 @@ namespace Perspex.Controls
             return null;
         }
 
-        protected DataTemplate GetDataTemplate(object content)
+        protected Control ApplyDataTemplate(object content)
         {
-            return this.FindDataTemplate(content) ?? DataTemplate.Default;
+            DataTemplate result = this.FindDataTemplate(content);
+
+            if (result != null)
+            {
+                return result.Build(content);
+            }
+            else if (content is Control)
+            {
+                return (Control)content;
+            }
+            else
+            {
+                return DataTemplate.Default.Build(content);
+            }
         }
     }
 }

Perspex.Controls/ItemsControl.cs

@@ -90,7 +90,7 @@ namespace Perspex.Controls
 
         protected virtual Control CreateItemControlOverride(object item)
         {
-            return (item as Control) ?? this.GetDataTemplate(item).Build(item);
+            return this.ApplyDataTemplate(item);
         }
 
         private void ItemsChanged(Tuple<IEnumerable, IEnumerable> value)

Perspex.Controls/ItemsPresenter.cs

@@ -68,7 +68,7 @@ namespace Perspex.Controls
             }
             else
             {
-                return this.GetDataTemplate(item).Build(item) as Control;
+                return this.ApplyDataTemplate(item);
             }
         }
          

Perspex.Controls/Panel.cs

@@ -7,7 +7,7 @@
 namespace Perspex.Controls
 {
     using System;
-    using System.Collections.Generic;
+    using System.Collections.Specialized;
     using System.Linq;
 
     /// <summary>
@@ -24,6 +24,7 @@ namespace Perspex.Controls
                 if (this.children == null)
                 {
                     this.children = new Controls();
+                    this.children.CollectionChanged += ChildrenChanged;
                 }
 
                 return this.children;
@@ -35,11 +36,41 @@ namespace Perspex.Controls
 
                 if (this.children != value)
                 {
+                    if (this.children != null)
+                    {
+                        this.children.CollectionChanged -= ChildrenChanged;
+                    }
+
                     this.children = value;
                     this.ClearVisualChildren();
-                    this.AddVisualChildren(value);
+
+                    if (this.children != null)
+                    {
+                        this.children.CollectionChanged += ChildrenChanged;
+                        this.AddVisualChildren(value);
+                    }
                 }
             }
         }
+
+        private void ChildrenChanged(object sender, NotifyCollectionChangedEventArgs e)
+        {
+            // TODO: Handle Move and Replace.
+            switch (e.Action)
+            {
+                case NotifyCollectionChangedAction.Add:
+                    this.AddVisualChildren(e.NewItems.OfType<Visual>());
+                    break;
+
+                case NotifyCollectionChangedAction.Remove:
+                    this.RemoveVisualChildren(e.OldItems.OfType<Visual>());
+                    break;
+
+                case NotifyCollectionChangedAction.Reset:
+                    this.ClearVisualChildren();
+                    this.AddVisualChildren(this.children);
+                    break;
+            }
+        }
     }
 }

Perspex.Controls/TabStrip.cs

@@ -36,7 +36,7 @@ namespace Perspex.Controls
             {
                 result = new TabItem
                 {
-                    Content = this.GetDataTemplate(item).Build(item),
+                    Content = this.ApplyDataTemplate(item),
                 };
             }
 

Perspex.Controls/TreeView.cs

@@ -40,7 +40,13 @@ namespace Perspex.Controls
 
         private TreeDataTemplate GetTreeDataTemplate(object item)
         {
-            DataTemplate template = this.GetDataTemplate(item);
+            DataTemplate template = this.FindDataTemplate(item);
+
+            if (template == null)
+            {
+                template = DataTemplate.Default;
+            }
+
             TreeDataTemplate treeTemplate = template as TreeDataTemplate;
 
             if (treeTemplate == null)

Perspex.Diagnostics/DevTools.cs

@@ -0,0 +1,47 @@
+// -----------------------------------------------------------------------
+// <copyright file="DevTools.cs" company="Steven Kirk">
+// Copyright 2014 MIT Licence. See licence.md for more information.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace Perspex.Diagnostics
+{
+    using Perspex.Controls;
+
+    public class DevTools : Decorator
+    {
+        public static readonly PerspexProperty<Control> RootProperty =
+            PerspexProperty.Register<DevTools, Control>("Root");
+
+        public DevTools()
+        {
+            this.Content = new Grid
+            {
+                ColumnDefinitions = new ColumnDefinitions
+                {
+                    new ColumnDefinition(1, GridUnitType.Star),
+                    new ColumnDefinition(3, GridUnitType.Star),
+                },
+                Children = new Controls
+                {
+                    new TreeView
+                    {
+                        DataTemplates = new DataTemplates
+                        {
+                            new TreeDataTemplate<IVisual>(
+                                x => new TextBlock {Text = x.GetType().Name },
+                                x => x.VisualChildren),
+                        },
+                        [TreeView.ItemsProperty] = this[DevTools.RootProperty],
+                    }
+                }
+            };
+        }
+
+        public Control Root
+        {
+            get { return this.GetValue(RootProperty); }
+            set { this.SetValue(RootProperty, value); }
+        }
+    }
+}

Perspex.Diagnostics/Perspex.Diagnostics.csproj

@@ -65,6 +65,7 @@
     </ProjectReference>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="DevTools.cs" />
     <Compile Include="Debug.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>

Perspex.Input/InputElement.cs

@@ -47,10 +47,14 @@ namespace Perspex.Input
 
         public InputElement()
         {
-            this.GotFocus += (s, e) => this.IsFocused = true;
-            this.LostFocus += (s, e) => this.IsFocused = false;
-            this.PointerEnter += (s, e) => this.IsPointerOver = true;
-            this.PointerLeave += (s, e) => this.IsPointerOver = false;
+            this.GotFocus += (_, e) => this.OnGotFocus(e);
+            this.LostFocus += (_, e) => this.OnLostFocus(e);
+            this.KeyDown += (_, e) => this.OnKeyDown(e);
+            this.PreviewKeyDown += (_, e) => this.OnPreviewKeyDown(e);
+            this.PointerEnter += (_, e) => this.OnPointerEnter(e);
+            this.PointerLeave += (_, e) => this.OnPointerLeave(e);
+            this.PointerPressed += (_, e) => this.OnPointerPressed(e);
+            this.PointerReleased += (_, e) => this.OnPointerReleased(e);
         }
 
         public event EventHandler<RoutedEventArgs> GotFocus
@@ -71,6 +75,12 @@ namespace Perspex.Input
             remove { this.RemoveHandler(KeyDownEvent, value); }
         }
 
+        public event EventHandler<KeyEventArgs> PreviewKeyDown
+        {
+            add { this.AddHandler(PreviewKeyDownEvent, value); }
+            remove { this.RemoveHandler(PreviewKeyDownEvent, value); }
+        }
+
         public event EventHandler<PointerEventArgs> PointerEnter
         {
             add { this.AddHandler(PointerEnterEvent, value); }
@@ -117,5 +127,41 @@ namespace Perspex.Input
         {
             Locator.Current.GetService<IFocusManager>().Focus(this);
         }
+
+        protected virtual void OnGotFocus(RoutedEventArgs e)
+        {
+            this.IsFocused = true;
+        }
+
+        protected virtual void OnLostFocus(RoutedEventArgs e)
+        {
+            this.IsFocused = false;
+        }
+
+        protected virtual void OnKeyDown(KeyEventArgs e)
+        {
+        }
+
+        protected virtual void OnPreviewKeyDown(KeyEventArgs e)
+        {
+        }
+
+        protected virtual void OnPointerEnter(PointerEventArgs e)
+        {
+            this.IsPointerOver = true;
+        }
+
+        protected virtual void OnPointerLeave(PointerEventArgs e)
+        {
+            this.IsPointerOver = false;
+        }
+
+        protected virtual void OnPointerPressed(PointerEventArgs e)
+        {
+        }
+
+        protected virtual void OnPointerReleased(PointerEventArgs e)
+        {
+        }
     }
 }

Perspex.SceneGraph/Visual.cs

@@ -143,6 +143,18 @@ namespace Perspex
             this.visualChildren.Remove(visual);
         }
 
+        protected void RemoveVisualChildren(IEnumerable<Visual> visuals)
+        {
+            Contract.Requires<ArgumentNullException>(visuals != null);
+
+            this.EnsureVisualChildrenCreated();
+
+            foreach (var v in visuals)
+            {
+                this.visualChildren.Remove(v);
+            }
+        }
+
         protected void SetVisualBounds(Rect bounds)
         {
             this.bounds = bounds;

Perspex.Windows/Perspex.Windows.csproj

@@ -78,6 +78,10 @@
       <Project>{d2221c82-4a25-4583-9b43-d791e3f6820c}</Project>
       <Name>Perspex.Controls</Name>
     </ProjectReference>
+    <ProjectReference Include="..\Perspex.Diagnostics\Perspex.Diagnostics.csproj">
+      <Project>{7062ae20-5dcc-4442-9645-8195bdece63e}</Project>
+      <Name>Perspex.Diagnostics</Name>
+    </ProjectReference>
     <ProjectReference Include="..\Perspex.Input\Perspex.Input.csproj">
       <Project>{62024b2d-53eb-4638-b26b-85eeaa54866e}</Project>
       <Name>Perspex.Input</Name>

Perspex.Windows/Window.cs

@@ -12,6 +12,7 @@ namespace Perspex.Windows
     using System.Reactive.Linq;
     using System.Runtime.InteropServices;
     using Perspex.Controls;
+    using Perspex.Diagnostics;
     using Perspex.Input;
     using Perspex.Input.Raw;
     using Perspex.Layout;
@@ -114,6 +115,22 @@ namespace Perspex.Windows
             UnmanagedMethods.ShowWindow(this.Handle, 4);
         }
 
+        protected override void OnPreviewKeyDown(KeyEventArgs e)
+        {
+            if (e.Key == Key.F12)
+            {
+                Window window = new Window
+                {
+                    Content = new DevTools
+                    {
+                        Root = this,
+                    },
+                };
+
+                window.Show();
+            }
+        }
+
         private Control DefaultTemplate(Window c)
         {
             Border border = new Border();

TestApplication/Program.cs

@@ -179,7 +179,6 @@ namespace TestApplication
                         new TabItem
                         {
                             Header = "Lists",
-                            IsSelected = true,
                             Content = new StackPanel
                             {
                                 Orientation = Orientation.Horizontal,
@@ -218,22 +217,20 @@ namespace TestApplication
                 }
             };
 
-            System.Console.Write(Perspex.Diagnostics.Debug.PrintVisualTree(window));
+            //var treeView = window.FindControl<TreeView>("treeView");
+            //var newTreeViewItemText = window.FindControl<TextBox>("newTreeViewItemText");
+            //var addTreeViewItem = window.FindControl<Button>("addTreeViewItem");
 
-            ////var treeView = window.FindControl<TreeView>("treeView");
-            ////var newTreeViewItemText = window.FindControl<TextBox>("newTreeViewItemText");
-            ////var addTreeViewItem = window.FindControl<Button>("addTreeViewItem");
-
-            ////addTreeViewItem.Click += (s, e) =>
-            ////{
-            ////    if (treeView.SelectedItem != null)
-            ////    {
-            ////        ((Node)treeView.SelectedItem).Children.Add(new Node
-            ////        {
-            ////            Name = newTreeViewItemText.Text,
-            ////        });
-            ////    }
-            ////};
+            //addTreeViewItem.Click += (s, e) =>
+            //{
+            //    if (treeView.SelectedItem != null)
+            //    {
+            //        ((Node)treeView.SelectedItem).Children.Add(new Node
+            //        {
+            //            Name = newTreeViewItemText.Text,
+            //        });
+            //    }
+            //};
 
             window.Show();
             Application.Current.Run(window);