From 3dd92513c55032c201111cfbb4efce4484eda605 Mon Sep 17 00:00:00 2001
From: Valentin Shergin <shergin@fb.com>
Date: Tue, 23 Mar 2021 13:39:21 -0700
Subject: [PATCH] Fabric: Aligning `UIManager::startSurface` and
 `UIManager::stopSurface` signatures

Summary:
In the previous diff, we moved the destruction of a ShadowTree object from `UIManager::stopSurface` method. And the next logical step is to align `UIManager::startSurface` method with the symmetrical approach. Now `stopSurface` accepts a unique pointer to a ShadowTree and `stopSurface` returns it back to the caller; this way we can avoid returning a raw pointer from `startSurface`.

Changelog: [Internal] Fabric-specific internal change.

Reviewed By: sammy-SC

Differential Revision: D27010533

fbshipit-source-id: b9211fb7e67763cc190d6b8c86cb866d20c6693d
---
 .../react/renderer/scheduler/SurfaceHandler.cpp    | 12 ++++++++----
 ReactCommon/react/renderer/uimanager/UIManager.cpp | 14 ++++----------
 ReactCommon/react/renderer/uimanager/UIManager.h   |  8 +++-----
 3 files changed, 15 insertions(+), 19 deletions(-)

diff --git a/ReactCommon/react/renderer/scheduler/SurfaceHandler.cpp b/ReactCommon/react/renderer/scheduler/SurfaceHandler.cpp
index fead649c5ed..e022b69309e 100644
--- a/ReactCommon/react/renderer/scheduler/SurfaceHandler.cpp
+++ b/ReactCommon/react/renderer/scheduler/SurfaceHandler.cpp
@@ -68,12 +68,16 @@ void SurfaceHandler::start() const noexcept {
       parameters = parameters_;
     }
 
-    link_.shadowTree = &link_.uiManager->startSurface(
+    auto shadowTree = std::make_unique<ShadowTree>(
         parameters.surfaceId,
-        parameters.moduleName,
-        parameters.props,
         parameters.layoutConstraints,
-        parameters.layoutContext);
+        parameters.layoutContext,
+        *link_.uiManager);
+
+    link_.shadowTree = shadowTree.get();
+
+    link_.uiManager->startSurface(
+        std::move(shadowTree), parameters.moduleName, parameters.props);
 
     link_.status = Status::Running;
 
diff --git a/ReactCommon/react/renderer/uimanager/UIManager.cpp b/ReactCommon/react/renderer/uimanager/UIManager.cpp
index 1ede96f843c..5a8044b6ee1 100644
--- a/ReactCommon/react/renderer/uimanager/UIManager.cpp
+++ b/ReactCommon/react/renderer/uimanager/UIManager.cpp
@@ -146,17 +146,13 @@ void UIManager::setIsJSResponder(
   }
 }
 
-ShadowTree const &UIManager::startSurface(
-    SurfaceId surfaceId,
+void UIManager::startSurface(
+    ShadowTree::Unique &&shadowTree,
     std::string const &moduleName,
-    folly::dynamic const &props,
-    LayoutConstraints const &layoutConstraints,
-    LayoutContext const &layoutContext) const {
+    folly::dynamic const &props) const {
   SystraceSection s("UIManager::startSurface");
 
-  auto shadowTree = std::make_unique<ShadowTree>(
-      surfaceId, layoutConstraints, layoutContext, *this);
-  auto shadowTreePointer = shadowTree.get();
+  auto surfaceId = shadowTree->getSurfaceId();
   shadowTreeRegistry_.add(std::move(shadowTree));
 
   runtimeExecutor_([=](jsi::Runtime &runtime) {
@@ -167,8 +163,6 @@ ShadowTree const &UIManager::startSurface(
 
     uiManagerBinding->startSurface(runtime, surfaceId, moduleName, props);
   });
-
-  return *shadowTreePointer;
 }
 
 ShadowTree::Unique UIManager::stopSurface(SurfaceId surfaceId) const {
diff --git a/ReactCommon/react/renderer/uimanager/UIManager.h b/ReactCommon/react/renderer/uimanager/UIManager.h
index 723b7a23a6d..a6fa5b7db88 100644
--- a/ReactCommon/react/renderer/uimanager/UIManager.h
+++ b/ReactCommon/react/renderer/uimanager/UIManager.h
@@ -85,12 +85,10 @@ class UIManager final : public ShadowTreeDelegate {
 
 #pragma mark - Surface Start & Stop
 
-  ShadowTree const &startSurface(
-      SurfaceId surfaceId,
+  void startSurface(
+      ShadowTree::Unique &&shadowTree,
       std::string const &moduleName,
-      folly::dynamic const &props,
-      LayoutConstraints const &layoutConstraints,
-      LayoutContext const &layoutContext) const;
+      folly::dynamic const &props) const;
 
   ShadowTree::Unique stopSurface(SurfaceId surfaceId) const;