From c70abb393fb1d7410d5a092a331de4919a5ad0ea Mon Sep 17 00:00:00 2001
From: Valentin Shergin <shergin@fb.com>
Date: Sun, 30 Sep 2018 22:01:51 -0700
Subject: [PATCH] Fabric: Enabling view hierarchy flattening (for <View>
 component only for now)

Summary: This change implements `onLayoutOnly` for regular bare <View> component (*not* for its descendants!) After this view flattening is actually starting working for all platforms.

Reviewed By: mdvacca

Differential Revision: D9511001

fbshipit-source-id: 3562dd1b7570a064150f100cc2e1bc4220b81290
---
 .../fabric/components/view/ViewShadowNode.cpp | 27 +++++++++++++++++++
 .../fabric/components/view/ViewShadowNode.h   | 15 ++++++++---
 .../view/accessibility/AccessibilityProps.h   |  2 +-
 3 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/ReactCommon/fabric/components/view/ViewShadowNode.cpp b/ReactCommon/fabric/components/view/ViewShadowNode.cpp
index 2beb57c8d71..07636a5276f 100644
--- a/ReactCommon/fabric/components/view/ViewShadowNode.cpp
+++ b/ReactCommon/fabric/components/view/ViewShadowNode.cpp
@@ -12,5 +12,32 @@ namespace react {
 
 const char ViewComponentName[] = "View";
 
+bool ViewShadowNode::isLayoutOnly() const {
+#ifdef ANDROID
+  // This feature is not properly tested on Android yet.
+  return false;
+#else
+  const auto &viewProps = *std::static_pointer_cast<const ViewProps>(props_);
+
+  return
+    // Event listeners
+    !viewProps.onLayout &&
+    // Generic Props
+    viewProps.nativeId.empty() &&
+    // Accessibility Props
+    !viewProps.accessible &&
+    // Style Props
+    viewProps.yogaStyle.overflow == YGOverflowVisible &&
+    viewProps.opacity == 1.0 &&
+    !viewProps.backgroundColor &&
+    !viewProps.foregroundColor &&
+    !viewProps.shadowColor &&
+    viewProps.transform == Transform {} &&
+    viewProps.zIndex == 0 &&
+    // Layout Metrics
+    getLayoutMetrics().borderWidth == EdgeInsets {};
+#endif
+}
+
 } // namespace react
 } // namespace facebook
diff --git a/ReactCommon/fabric/components/view/ViewShadowNode.h b/ReactCommon/fabric/components/view/ViewShadowNode.h
index effac24c4fb..9dedb15aa99 100644
--- a/ReactCommon/fabric/components/view/ViewShadowNode.h
+++ b/ReactCommon/fabric/components/view/ViewShadowNode.h
@@ -15,12 +15,21 @@ namespace react {
 
 extern const char ViewComponentName[];
 
-using ViewShadowNode =
-  ConcreteViewShadowNode<
+/*
+ * `ShadowNode` for <View> component.
+ */
+class ViewShadowNode final:
+  public ConcreteViewShadowNode<
     ViewComponentName,
     ViewProps,
     ViewEventEmitter
-  >;
+  > {
+
+public:
+  using ConcreteViewShadowNode::ConcreteViewShadowNode;
+
+  bool isLayoutOnly() const;
+};
 
 } // namespace react
 } // namespace facebook
diff --git a/ReactCommon/fabric/components/view/accessibility/AccessibilityProps.h b/ReactCommon/fabric/components/view/accessibility/AccessibilityProps.h
index f50d4553cbe..5533667a637 100644
--- a/ReactCommon/fabric/components/view/accessibility/AccessibilityProps.h
+++ b/ReactCommon/fabric/components/view/accessibility/AccessibilityProps.h
@@ -29,7 +29,7 @@ public:
 
 #pragma mark - Props
 
-  const bool accessible {true};
+  const bool accessible {false};
   const std::vector<std::string> accessibilityActions {};
   const std::string accessibilityLabel {""};
   const AccessibilityTraits accessibilityTraits {AccessibilityTraits::None};