Implement ScrollView.keyboardDismissMode

Summary: Changelog: [internal]

Reviewed By: shergin

Differential Revision: D24648120

fbshipit-source-id: 718be95dc87217fa6745535a3760ec23cc390444

React/Fabric/Mounting/ComponentViews/ScrollView/RCTScrollViewComponentView.mm

@@ -28,6 +28,18 @@
 
 static CGFloat const kClippingLeeway = 44.0;
 
+static UIScrollViewKeyboardDismissMode RCTUIKeyboardDismissModeFromProps(ScrollViewProps const &props)
+{
+  switch (props.keyboardDismissMode) {
+    case ScrollViewKeyboardDismissMode::None:
+      return UIScrollViewKeyboardDismissModeNone;
+    case ScrollViewKeyboardDismissMode::OnDrag:
+      return UIScrollViewKeyboardDismissModeOnDrag;
+    case ScrollViewKeyboardDismissMode::Interactive:
+      return UIScrollViewKeyboardDismissModeInteractive;
+  }
+}
+
 static void RCTSendPaperScrollEvent_DEPRECATED(UIScrollView *scrollView, NSInteger tag)
 {
   static uint16_t coalescingKey = 0;
@@ -150,7 +162,6 @@ - (void)updateProps:(Props::Shared const &)props oldProps:(Props::Shared const &
   MAP_SCROLL_VIEW_PROP(decelerationRate);
   MAP_SCROLL_VIEW_PROP(directionalLockEnabled);
   // MAP_SCROLL_VIEW_PROP(indicatorStyle);
-  // MAP_SCROLL_VIEW_PROP(keyboardDismissMode);
   MAP_SCROLL_VIEW_PROP(maximumZoomScale);
   MAP_SCROLL_VIEW_PROP(minimumZoomScale);
   MAP_SCROLL_VIEW_PROP(scrollEnabled);
@@ -219,6 +230,10 @@ - (void)updateProps:(Props::Shared const &)props oldProps:(Props::Shared const &
   MAP_SCROLL_VIEW_PROP(disableIntervalMomentum);
   MAP_SCROLL_VIEW_PROP(snapToInterval);
 
+  if (oldScrollViewProps.keyboardDismissMode != newScrollViewProps.keyboardDismissMode) {
+    scrollView.keyboardDismissMode = RCTUIKeyboardDismissModeFromProps(newScrollViewProps);
+  }
+
   // MAP_SCROLL_VIEW_PROP(scrollIndicatorInsets);
 
   [super updateProps:props oldProps:oldProps];