Fabric: LayoutableShadowNode::getTransform

Summary:
`LayoutableShadowNode::getTransform` returns a transform object that represents transformations that will/should
be applied on top of regular layout metrics by mounting layer.

Reviewed By: mdvacca

Differential Revision: D15219262

fbshipit-source-id: e7aeb85b5f7e2fce3f8faf9dfcaee5dae3217d36

ReactCommon/fabric/components/view/ConcreteViewShadowNode.h

@@ -117,6 +117,10 @@ class ConcreteViewShadowNode : public ConcreteShadowNode<
     return clonedChildShadowNode.get();
   }
 
+  Transform getTransform() const override {
+    return BaseShadowNode::getProps()->transform;
+  }
+
 #pragma mark - DebugStringConvertible
 
 #if RN_DEBUG_STRING_CONVERTIBLE

ReactCommon/fabric/core/layout/LayoutableShadowNode.cpp

@@ -36,6 +36,10 @@ bool LayoutableShadowNode::LayoutableShadowNode::isLayoutOnly() const {
   return false;
 }
 
+Transform LayoutableShadowNode::getTransform() const {
+  return Transform::Identity();
+}
+
 LayoutMetrics LayoutableShadowNode::getRelativeLayoutMetrics(
     const LayoutableShadowNode &ancestorLayoutableShadowNode) const {
   auto &ancestorShadowNode =

ReactCommon/fabric/core/layout/LayoutableShadowNode.h

@@ -17,6 +17,7 @@
 #include <react/core/Sealable.h>
 #include <react/core/ShadowNode.h>
 #include <react/debug/DebugStringConvertible.h>
+#include <react/graphics/Transform.h>
 
 namespace facebook {
 namespace react {
@@ -64,6 +65,14 @@ class LayoutableShadowNode : public virtual Sealable {
    */
   virtual bool isLayoutOnly() const;
 
+  /*
+   * Returns a transform object that represents transformations that will/should
+   * be applied on top of regular layout metrics by mounting layer.
+   * The `transform` value modifies a coordinate space of a layout system.
+   * Default implementation returns `Identity` transform.
+   */
+  virtual Transform getTransform() const;
+
   /*
    * Returns layout metrics relatively to the given ancestor node.
    */