Add getSurfaceProps helper method to SurfaceManager (facebook#48487)

Summary:
Pull Request resolved: facebook#48487

[Changelog] [Internal] - Add getSurfaceProps helper method to SurfaceManager

When reload a reactHost we need to know which surface properties have been applied when starting the surface. This adds a utility function for that.

Reviewed By: rshest

Differential Revision: D67822459

fbshipit-source-id: 6d1f182514ed6e7ae8e31d3e1ca052c93bac2843

Author: christophpurrer

packages/react-native/ReactCommon/react/renderer/scheduler/SurfaceManager.cpp

@@ -89,6 +89,22 @@ std::unordered_set<SurfaceId> SurfaceManager::getRunningSurfaces()
   return surfaceIds;
 }
 
+std::optional<SurfaceManager::SurfaceProps> SurfaceManager::getSurfaceProps(
+    SurfaceId surfaceId) const noexcept {
+  std::optional<SurfaceManager::SurfaceProps> surfaceProps;
+
+  visit(surfaceId, [&](const SurfaceHandler& surfaceHandler) {
+    surfaceProps = SurfaceManager::SurfaceProps{
+        surfaceId,
+        surfaceHandler.getModuleName(),
+        surfaceHandler.getProps(),
+        surfaceHandler.getLayoutConstraints(),
+        surfaceHandler.getLayoutContext()};
+  });
+
+  return surfaceProps;
+}
+
 Size SurfaceManager::measureSurface(
     SurfaceId surfaceId,
     const LayoutConstraints& layoutConstraints,

packages/react-native/ReactCommon/react/renderer/scheduler/SurfaceManager.h

@@ -8,6 +8,7 @@
 #pragma once
 
 #include <mutex>
+#include <optional>
 #include <shared_mutex>
 #include <unordered_map>
 
@@ -29,6 +30,15 @@ class SurfaceManager final {
   explicit SurfaceManager(const Scheduler& scheduler) noexcept;
   ~SurfaceManager() noexcept;
 
+  /* SurfaceProps contain information about running surfaces */
+  struct SurfaceProps {
+    SurfaceId surfaceId;
+    std::string moduleName;
+    folly::dynamic props;
+    LayoutConstraints layoutConstraints;
+    LayoutContext layoutContext;
+  };
+
 #pragma mark - Surface Management
 
   void startSurface(
@@ -46,6 +56,9 @@ class SurfaceManager final {
 
   std::unordered_set<SurfaceId> getRunningSurfaces() const noexcept;
 
+  std::optional<SurfaceManager::SurfaceProps> getSurfaceProps(
+      SurfaceId surfaceId) const noexcept;
+
   Size measureSurface(
       SurfaceId surfaceId,
       const LayoutConstraints& layoutConstraints,