From f5a856e109768d2e1c7328316a8aaa0f5f01c2c2 Mon Sep 17 00:00:00 2001
From: Steven Kirk <steven.kirk@tricycleinc.com>
Date: Fri, 26 Dec 2014 22:31:22 +0000
Subject: [PATCH] Make ItemsControl items be logical children.

---
 Perspex.Controls/Control.cs                   |  4 +-
 Perspex.Controls/ItemsControl.cs              | 43 ++++++++++++++++++-
 Perspex.Controls/Panel.cs                     |  9 +++-
 Perspex.Controls/Presenters/ItemsPresenter.cs |  2 +-
 4 files changed, 54 insertions(+), 4 deletions(-)

diff --git a/Perspex.Controls/Control.cs b/Perspex.Controls/Control.cs
index 2b5a8b5075..1e4bff5d94 100644
--- a/Perspex.Controls/Control.cs
+++ b/Perspex.Controls/Control.cs
@@ -38,6 +38,8 @@ namespace Perspex.Controls
         public static readonly RoutedEvent<RequestBringIntoViewEventArgs> RequestBringIntoViewEvent =
             RoutedEvent.Register<Control, RequestBringIntoViewEventArgs>("RequestBringIntoView", RoutingStrategy.Bubble);
 
+        private static readonly IReadOnlyPerspexList<ILogical> EmptyChildren = new SingleItemPerspexList<ILogical>();
+
         private Classes classes = new Classes();
 
         private DataTemplates dataTemplates;
@@ -167,7 +169,7 @@ namespace Perspex.Controls
 
         IReadOnlyPerspexList<ILogical> ILogical.LogicalChildren
         {
-            get { throw new NotImplementedException(); }
+            get { return EmptyChildren; }
         }
 
         public void BringIntoView()
diff --git a/Perspex.Controls/ItemsControl.cs b/Perspex.Controls/ItemsControl.cs
index 1d8d92b8e4..133fa41559 100644
--- a/Perspex.Controls/ItemsControl.cs
+++ b/Perspex.Controls/ItemsControl.cs
@@ -11,10 +11,13 @@ namespace Perspex.Controls
     using System.ComponentModel;
     using System.Diagnostics.CodeAnalysis;
     using System.Linq;
+    using Perspex.Collections;
     using Perspex.Controls.Generators;
+    using Perspex.Controls.Presenters;
     using Perspex.Controls.Primitives;
+    using Perspex.VisualTree;
 
-    public class ItemsControl : TemplatedControl
+    public class ItemsControl : TemplatedControl, ILogical
     {
         [SuppressMessage("Microsoft.StyleCop.CSharp.NamingRules", "SA1202:ElementsMustBeOrderedByAccess", Justification = "Needs to be before or a NullReferenceException is thrown.")]
         private static readonly ItemsPanelTemplate DefaultPanel =
@@ -28,6 +31,10 @@ namespace Perspex.Controls
 
         private ItemContainerGenerator itemContainerGenerator;
 
+        private PerspexReadOnlyListView<IVisual, ILogical> logicalChildren;
+
+        private ItemsPresenter presenter;
+
         public ItemsControl()
         {
             this.GetObservableWithHistory(ItemsProperty).Subscribe(this.ItemsChanged);
@@ -58,11 +65,45 @@ namespace Perspex.Controls
             set { this.SetValue(ItemsPanelProperty, value); }
         }
 
+        IReadOnlyPerspexList<ILogical> ILogical.LogicalChildren
+        {
+            get
+            {
+                if (this.logicalChildren == null)
+                {
+                    this.logicalChildren = new PerspexReadOnlyListView<IVisual, ILogical>(
+                        new PerspexList<IVisual>(), 
+                        x => (ILogical)x);
+                }
+
+                return this.logicalChildren;
+            }
+        }
+
         protected virtual ItemContainerGenerator CreateItemContainerGenerator()
         {
             return new ItemContainerGenerator(this);
         }
 
+        protected override void OnTemplateApplied()
+        {
+            if (this.logicalChildren != null)
+            {
+                this.logicalChildren.Dispose();
+                this.logicalChildren = null;
+            }
+
+            this.presenter = this.FindTemplateChild<ItemsPresenter>("presenter");
+
+            if (presenter != null)
+            {
+                var panel = (IVisual)this.presenter.GetVisualChildren().Single();
+                this.logicalChildren = new PerspexReadOnlyListView<IVisual, ILogical>(
+                    panel.VisualChildren,
+                    x => (ILogical)x);
+            }
+        }
+
         private void ItemsChanged(Tuple<IEnumerable, IEnumerable> value)
         {
             INotifyPropertyChanged inpc = value.Item1 as INotifyPropertyChanged;
diff --git a/Perspex.Controls/Panel.cs b/Perspex.Controls/Panel.cs
index d449f4da05..4a1db10ac6 100644
--- a/Perspex.Controls/Panel.cs
+++ b/Perspex.Controls/Panel.cs
@@ -62,6 +62,13 @@ namespace Perspex.Controls
 
         private void ChildrenChanged(object sender, NotifyCollectionChangedEventArgs e)
         {
+            var logicalParent = (Control)this;
+
+            while (logicalParent.TemplatedParent != null)
+            {
+                logicalParent = (Control)logicalParent.TemplatedParent;
+            }
+
             // TODO: Handle Move and Replace.
             switch (e.Action)
             {
@@ -70,7 +77,7 @@ namespace Perspex.Controls
 
                     foreach (var child in e.NewItems.OfType<Control>())
                     {
-                        child.Parent = this;
+                        child.Parent = logicalParent;
                     }
 
                     break;
diff --git a/Perspex.Controls/Presenters/ItemsPresenter.cs b/Perspex.Controls/Presenters/ItemsPresenter.cs
index 8830122696..b2de51a674 100644
--- a/Perspex.Controls/Presenters/ItemsPresenter.cs
+++ b/Perspex.Controls/Presenters/ItemsPresenter.cs
@@ -26,7 +26,7 @@ namespace Perspex.Controls.Presenters
 
         public ItemsPresenter()
         {
-            this.GetObservableWithHistory(ItemsProperty).Skip(1).Subscribe(this.ItemsChanged);
+            this.GetObservableWithHistory(ItemsProperty).Subscribe(this.ItemsChanged);
         }
 
         public IEnumerable Items