Adds proper layout measurement for the ReactTextViewManager.

In order to leverage the CSSNode class to its fullest, various view managers need to override the measurement algorithm to determine the proper width and height needed for a view.

For now, we needed to move the measurement of FrameworkElements to the dispatcher thread, as WinRT does not have any text formatter or other hooks for determining the size of text without mimicking the element itself.  Issue #106 covers this.

ReactNative/ReactNative.csproj

@@ -244,13 +244,13 @@
     <Compile Include="UIManager\UIViewOperationQueue.cs" />
     <Compile Include="UIManager\ViewAtIndex.cs" />
     <Compile Include="UIManager\ViewGroupManager.cs" />
-    <Compile Include="UIManager\ViewGroupManager.Generic.cs" />
+    <Compile Include="UIManager\PanelViewGroupManager.cs" />
     <Compile Include="UIManager\ViewManager.cs" />
     <Compile Include="UIManager\ViewManager.Generic.cs" />
     <Compile Include="UIManager\ViewManagerRegistry.cs" />
+    <Compile Include="Views\Scroll\ReactScrollViewManager.cs" />
     <Compile Include="Views\ViewManagersPropertyCache.cs" />
     <Compile Include="UIManager\ViewProperties.cs" />
-	<Compile Include="Views\Text\InlineManager.cs" />
     <Compile Include="Views\Text\ReactRawTextManager.cs" />
     <Compile Include="Views\Text\ReactTextShadowNode.cs" />
     <Compile Include="Views\Text\ReactTextViewManager.cs" />
@@ -262,8 +262,8 @@
     <Compile Include="Views\View\ReactPanel.cs" />
     <Compile Include="Views\View\ReactViewManager.cs" />
     <Compile Include="Views\TextInput\ReactTextInputManager.cs" />
-	<Compile Include="Modules\Toast\ToastHelper.cs" />
-	<Compile Include="Modules\Toast\ToastModule.cs" />
+    <Compile Include="Modules\Toast\ToastHelper.cs" />
+    <Compile Include="Modules\Toast\ToastModule.cs" />
     <EmbeddedResource Include="Properties\ReactNative.rd.xml" />
   </ItemGroup>
   <ItemGroup>

ReactNative/Shell/MainReactPackage.cs

@@ -2,6 +2,7 @@
 using ReactNative.Modules.Core;
 using ReactNative.Modules.WebSocket;
 using ReactNative.UIManager;
+using ReactNative.Views.Scroll;
 using ReactNative.Views.Text;
 using ReactNative.Views.TextInput;
 using ReactNative.Views.View;
@@ -39,7 +40,7 @@ public IReadOnlyList<ViewManager> CreateViewManagers(
                 //new ReactProgressBarViewManager(),
                 new ReactRawTextManager(),
                 //new RecyclerViewBackedScrollViewManager(),
-                //new ReactScrollViewManager(),
+                new ReactScrollViewManager(),
                 //new ReactSwitchManager(),
                 new ReactTextInputManager(),
                 new ReactTextViewManager(),

ReactNative/UIManager/NativeViewHierarchyManager.cs

@@ -133,8 +133,23 @@ public void UpdateLayout(int parentTag, int tag, int x, int y, int width, int he
                 .With("tag", tag))
             {
                 var viewToUpdate = ResolveView(tag);
-                // TODO: call viewToUpdate.Measure()
-                //throw new NotImplementedException();
+
+                var parentViewManager = default(ViewManager);
+                var parentViewGroupManager = default(ViewGroupManager);
+                if (!_tagsToViewManagers.TryGetValue(parentTag, out parentViewManager) || 
+                    (parentViewGroupManager = parentViewManager as ViewGroupManager) == null)
+                {
+                    throw new InvalidOperationException(
+                        string.Format(
+                            CultureInfo.InvariantCulture,
+                            "Trying to use view with tag '{0}' as a parent, but its manager doesn't extend ViewGroupManager.",
+                            tag));
+                }
+
+                if (!parentViewGroupManager.NeedsCustomLayoutForChildren)
+                {
+                    UpdateLayout(viewToUpdate, x, y, width, height);
+                }
             }
         }
 
@@ -189,7 +204,7 @@ public void ManageChildren(int tag, int[] indicesToRemove, ViewAtIndex[] viewsTo
             }
 
             var viewGroupManager = (ViewGroupManager)viewManager;
-            var viewToManage = (Panel)_tagsToViews[tag];
+            var viewToManage = _tagsToViews[tag];
 
             var lastIndexToRemove = viewGroupManager.GetChildCount(viewToManage);
             if (indicesToRemove != null)
@@ -513,5 +528,13 @@ private void DropView(FrameworkElement view)
             _tagsToViews.Remove(tag);
             _tagsToViewManagers.Remove(tag);
         }
+
+        private void UpdateLayout(FrameworkElement viewToUpdate, int x, int y, int width, int height)
+        {
+            viewToUpdate.Width = width;
+            viewToUpdate.Height = height;
+            Canvas.SetLeft(viewToUpdate, x);
+            Canvas.SetTop(viewToUpdate, y);
+        }
     }
 }

ReactNative/UIManager/NativeViewHierarchyOptimizer.cs

@@ -79,7 +79,7 @@ public void HandleCreateView(
             _uiViewOperationQueue.EnqueueCreateView(
                     themedContext,
                     node.ReactTag,
-                    node.ViewClassName,
+                    node.ViewClass,
                     initialProperties);
 #else
             var isLayoutOnly = node.ViewClass == ViewProperties.ViewClassName
@@ -376,7 +376,7 @@ private void ApplyLayoutRecursive(ReactShadowNode node, int x, int y)
             if (!node.IsLayoutOnly && node.NativeParent != null)
             {
                 _uiViewOperationQueue.EnqueueUpdateLayout(
-                    node.Parent.ReactTag,
+                    node.NativeParent.ReactTag,
                     node.ReactTag,
                     x,
                     y,

ReactNative/UIManager/ViewGroupManager.Generic.cs → ReactNative/UIManager/PanelViewGroupManager.cs

@@ -9,7 +9,7 @@ namespace ReactNative.UIManager
     /// extending <see cref="Panel"/>.
     /// </summary>
     /// <typeparam name="TPanel">Type of panel.</typeparam>
-    public abstract class ViewGroupManager<TPanel> : ViewGroupManager
+    public abstract class PanelViewGroupManager<TPanel> : ViewGroupManager
         where TPanel : Panel
     {
         /// <summary>
@@ -53,6 +53,57 @@ public sealed override void UpdateExtraData(FrameworkElement root, object extraD
             UpdateExtraData((TPanel)root, extraData);
         }
 
+        /// <summary>
+        /// Gets the number of children in the view group.
+        /// </summary>
+        /// <param name="parent">The view group.</param>
+        /// <returns>The number of children.</returns>
+        public sealed override int GetChildCount(FrameworkElement parent)
+        {
+            return GetChildCount((TPanel)parent);
+        }
+
+        /// <summary>
+        /// Gets the child at the given index.
+        /// </summary>
+        /// <param name="parent">The parent view.</param>
+        /// <param name="index">The index.</param>
+        /// <returns>The child view.</returns>
+        public sealed override FrameworkElement GetChildAt(FrameworkElement parent, int index)
+        {
+            return GetChildAt((TPanel)parent, index);
+        }
+
+        /// <summary>
+        /// Adds a child at the given index.
+        /// </summary>
+        /// <param name="parent">The parent view.</param>
+        /// <param name="child">The child view.</param>
+        /// <param name="index">The index.</param>
+        public sealed override void AddView(FrameworkElement parent, FrameworkElement child, int index)
+        {
+            AddView((TPanel)parent, child, index);
+        }
+
+        /// <summary>
+        /// Removes the child at the given index.
+        /// </summary>
+        /// <param name="parent">The view group.</param>
+        /// <param name="index">The index.</param>
+        public override void RemoveChildAt(FrameworkElement parent, int index)
+        {
+            RemoveChildAt((TPanel)parent, index);
+        }
+
+        /// <summary>
+        /// Removes all children from the view group.
+        /// </summary>
+        /// <param name="parent">The view group.</param>
+        public override void RemoveAllChildren(FrameworkElement parent)
+        {
+            RemoveAllChildren((TPanel)parent);
+        }
+
         /// <summary>
         /// Subclasses can override this method to install custom event 
         /// emitters on the given view.
@@ -172,5 +223,56 @@ protected virtual void ReceiveCommand(TPanel view, int commandId, JArray args)
         protected virtual void UpdateExtraData(TPanel root, object extraData)
         {
         }
+
+        /// <summary>
+        /// Gets the number of children in the view group.
+        /// </summary>
+        /// <param name="parent">The view group.</param>
+        /// <returns>The number of children.</returns>
+        protected virtual int GetChildCount(TPanel parent)
+        {
+            return parent.Children.Count;
+        }
+
+        /// <summary>
+        /// Gets the child at the given index.
+        /// </summary>
+        /// <param name="parent">The parent view.</param>
+        /// <param name="index">The index.</param>
+        /// <returns>The child view.</returns>
+        protected virtual FrameworkElement GetChildAt(TPanel parent, int index)
+        {
+            return (FrameworkElement)parent.Children[index];
+        }
+
+        /// <summary>
+        /// Adds a child at the given index.
+        /// </summary>
+        /// <param name="parent">The parent view.</param>
+        /// <param name="child">The child view.</param>
+        /// <param name="index">The index.</param>
+        protected virtual void AddView(TPanel parent, FrameworkElement child, int index)
+        {
+            parent.Children.Insert(index, child);
+        }
+
+        /// <summary>
+        /// Removes the child at the given index.
+        /// </summary>
+        /// <param name="parent">The view group.</param>
+        /// <param name="index">The index.</param>
+        protected virtual void RemoveChildAt(TPanel parent, int index)
+        {
+            parent.Children.RemoveAt(index);
+        }
+
+        /// <summary>
+        /// Removes all children from the view group.
+        /// </summary>
+        /// <param name="parent">The view group.</param>
+        protected virtual void RemoveAllChildren(TPanel parent)
+        {
+            parent.Children.Clear();
+        }
     }
 }

ReactNative/UIManager/RootViewManager.cs

@@ -1,11 +1,9 @@
-using Windows.UI.Xaml;
-
-namespace ReactNative.UIManager
+namespace ReactNative.UIManager
 {
     /// <summary>
     /// View manager for react root view components.
     /// </summary>
-    public class RootViewManager : ViewGroupManager
+    public class RootViewManager : PanelViewGroupManager<SizeMonitoringPanel>
     {
         /// <summary>
         /// The name of the react root view.
@@ -23,7 +21,7 @@ public override string Name
         /// </summary>
         /// <param name="reactContext">The react context.</param>
         /// <returns>The view instance.</returns>
-        protected override FrameworkElement CreateViewInstance(ThemedReactContext reactContext)
+        protected override SizeMonitoringPanel CreateViewInstanceCore(ThemedReactContext reactContext)
         {
             return new SizeMonitoringPanel();
         }

ReactNative/UIManager/UIImplementation.cs

@@ -463,6 +463,8 @@ public void MeasureLayoutRelativeToParent(int tag, ICallback errorCallback, ICal
         /// <param name="batchId">The batch identifier.</param>
         public void DispatchViewUpdates(EventDispatcher eventDispatcher, int batchId)
         {
+            DispatcherHelpers.AssertOnDispatcher();
+
             foreach (var tag in _shadowNodeRegistry.RootNodeTags)
             {
                 var cssRoot = _shadowNodeRegistry.GetNode(tag);
@@ -472,7 +474,7 @@ public void DispatchViewUpdates(EventDispatcher eventDispatcher, int batchId)
             }
 
             _nativeViewHierarchyOptimizer.OnBatchComplete();
-            _operationsQueue.DispatchViewUpdates(batchId);
+            _operationsQueue.ExecuteOperations(batchId);
         }
 
         /// <summary>

ReactNative/UIManager/UIManagerModule.cs

@@ -387,13 +387,16 @@ public void OnBatchComplete()
         {
             var batchId = _batchId++;
 
-            using (Tracer.Trace(Tracer.TRACE_TAG_REACT_BRIDGE, "onBatchCompleteUI")
-                .With("BatchId", batchId))
+            Context.RunOnDispatcherQueueThread(() =>
             {
-                _uiImplementation.DispatchViewUpdates(_eventDispatcher, batchId);
-            }
-
-            // TODO: coordinate with UI operations?
+                using (Tracer.Trace(Tracer.TRACE_TAG_REACT_BRIDGE, "onBatchCompleteUI")
+                    .With("BatchId", batchId))
+                {
+                    _uiImplementation.DispatchViewUpdates(_eventDispatcher, batchId);
+                }
+            });
+
+            // TODO: coordinate with UI operations a la choreographer?
             _eventDispatcher.OnBatchComplete();
         }
 

ReactNative/UIManager/UIViewOperationQueue.cs

@@ -312,8 +312,10 @@ public void EnqueueFindTargetForTouch(
         /// Dispatches the view updates.
         /// </summary>
         /// <param name="batchId">The batch identifier.</param>
-        internal void DispatchViewUpdates(int batchId)
+        internal void ExecuteOperations(int batchId)
         {
+            DispatcherHelpers.AssertOnDispatcher();
+
             var operations = default(IList<Action>);
             lock (_operationsLock)
             {
@@ -324,20 +326,17 @@ internal void DispatchViewUpdates(int batchId)
                 }
             }
 
-            _reactContext.RunOnDispatcherQueueThread(() =>
+            using (Tracer.Trace(Tracer.TRACE_TAG_REACT_BRIDGE, "DispatchUI")
+                .With("BatchId", batchId))
             {
-                using (Tracer.Trace(Tracer.TRACE_TAG_REACT_BRIDGE, "DispatchUI")
-                    .With("BatchId", batchId))
+                if (operations != null)
                 {
-                    if (operations != null)
+                    foreach (var operation in operations)
                     {
-                        foreach (var operation in operations)
-                        {
-                            operation();
-                        }
+                        operation();
                     }
                 }
-            });
+            }
         }
 
         private void EnqueueOperation(Action action)