fix(ScrollView): 'scrollEnabled' prop should only disable scroll, not touch (microsoft#767)

rozele · web-flow · commit ff99a1cbdfbf · 2016-10-11T14:28:11.000-04:00
Using the IsEnabled property disabled touch in addition to scroll. We'll need to keep some state about the current horizontal scroll status, but we can easily work around this by just disabling horizontal and vertical scroll. Fixes microsoft#764
diff --git a/ReactWindows/ReactNative/Views/Scroll/ReactScrollViewManager.cs b/ReactWindows/ReactNative/Views/Scroll/ReactScrollViewManager.cs
@@ -18,6 +18,9 @@ public class ReactScrollViewManager : ViewParentManager<ScrollViewer>
     {
         private const int CommandScrollTo = 1;
 
+        private readonly IDictionary<ScrollViewer, ScrollViewerData> _scrollViewerData =
+            new Dictionary<ScrollViewer, ScrollViewerData>();
+
         /// <summary>
         /// The name of the view manager.
         /// </summary>
@@ -99,7 +102,16 @@ public void SetBackgroundColor(ScrollViewer view, uint color)
         [ReactProp("scrollEnabled", DefaultBoolean = true)]
         public void SetEnabled(ScrollViewer view, bool enabled)
         {
-            view.IsEnabled = enabled;
+            if (enabled)
+            {
+                view.VerticalScrollMode = ScrollMode.Auto;
+                view.HorizontalScrollMode = _scrollViewerData[view].HorizontalScrollMode;
+            }
+            else
+            {
+                view.VerticalScrollMode = ScrollMode.Disabled;
+                view.HorizontalScrollMode = ScrollMode.Disabled;
+            }
         }
 
         /// <summary>
@@ -112,9 +124,11 @@ public void SetEnabled(ScrollViewer view, bool enabled)
         [ReactProp("horizontal")]
         public void SetHorizontal(ScrollViewer view, bool horizontal)
         {
-            view.HorizontalScrollMode = horizontal
+            var horizontalScrollMode = horizontal
                 ? ScrollMode.Auto
                 : ScrollMode.Disabled;
+
+            view.HorizontalScrollMode = _scrollViewerData[view].HorizontalScrollMode = horizontalScrollMode;
         }
 
         /// <summary>
@@ -255,6 +269,8 @@ public override void RemoveChildAt(ScrollViewer parent, int index)
         /// <param name="view">The view.</param>
         public override void OnDropViewInstance(ThemedReactContext reactContext, ScrollViewer view)
         {
+            _scrollViewerData.Remove(view);
+
             view.ViewChanging -= OnViewChanging;
             view.DirectManipulationStarted -= OnDirectManipulationStarted;
             view.DirectManipulationCompleted -= OnDirectManipulationCompleted;
@@ -292,13 +308,19 @@ public override void ReceiveCommand(ScrollViewer view, int commandId, JArray arg
         /// <returns>The view instance.</returns>
         protected override ScrollViewer CreateViewInstance(ThemedReactContext reactContext)
         {
-            return new ScrollViewer
+            var scrollViewerData = new ScrollViewerData();
+
+            var scrollViewer = new ScrollViewer
             {
                 HorizontalScrollBarVisibility = ScrollBarVisibility.Hidden,
                 HorizontalScrollMode = ScrollMode.Disabled,
                 VerticalScrollBarVisibility = ScrollBarVisibility.Hidden,
                 VerticalScrollMode = ScrollMode.Auto,
             };
+
+            _scrollViewerData.Add(scrollViewer, scrollViewerData);
+
+            return scrollViewer;
         }
 
         /// <summary>
@@ -453,5 +475,10 @@ public override void Dispatch(RCTEventEmitter eventEmitter)
                 eventEmitter.receiveEvent(ViewTag, EventName, _data);
             }
         }
+
+        class ScrollViewerData
+        {
+            public ScrollMode HorizontalScrollMode = ScrollMode.Disabled;
+        }
     }
 }
