From b803d713e83b4f36906dfc0b4962eef737ff1790 Mon Sep 17 00:00:00 2001
From: Nick Gerleman <ngerlem@meta.com>
Date: Wed, 25 Feb 2026 20:02:20 -0800
Subject: [PATCH] Refactor ParagraphComponentDescriptor to support subclassing
 (#55634)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/55634

Extract ParagraphComponentDescriptor logic into a template base class BaseParagraphComponentDescriptor<ShadowNodeT> so that other paragraph-like component descriptors can reuse the same TextLayoutManager wiring. Remove `final` from ParagraphShadowNode to allow subclassing. Move TextLayoutManagerKey from extern linkage in .cpp to constexpr in the new header.

This is a pure refactor with no behavioral change.

Changelog:
[Internal]

Reviewed By: cortinico

Differential Revision: D93829402
---
 .../text/BaseParagraphComponentDescriptor.h   | 49 +++++++++++++++++++
 .../text/ParagraphComponentDescriptor.cpp     | 14 ------
 .../text/ParagraphComponentDescriptor.h       | 31 ++----------
 .../components/text/ParagraphShadowNode.h     |  2 +-
 4 files changed, 53 insertions(+), 43 deletions(-)
 create mode 100644 packages/react-native/ReactCommon/react/renderer/components/text/BaseParagraphComponentDescriptor.h
 delete mode 100644 packages/react-native/ReactCommon/react/renderer/components/text/ParagraphComponentDescriptor.cpp

diff --git a/packages/react-native/ReactCommon/react/renderer/components/text/BaseParagraphComponentDescriptor.h b/packages/react-native/ReactCommon/react/renderer/components/text/BaseParagraphComponentDescriptor.h
new file mode 100644
index 000000000000..8c7c8aab798f
--- /dev/null
+++ b/packages/react-native/ReactCommon/react/renderer/components/text/BaseParagraphComponentDescriptor.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+#include <react/renderer/core/ConcreteComponentDescriptor.h>
+#include <react/renderer/textlayoutmanager/TextLayoutManager.h>
+#include <react/utils/ContextContainer.h>
+
+namespace facebook::react {
+
+constexpr const char *const TextLayoutManagerKey = "TextLayoutManager";
+
+template <typename ShadowNodeT>
+class BaseParagraphComponentDescriptor : public ConcreteComponentDescriptor<ShadowNodeT> {
+ public:
+  explicit BaseParagraphComponentDescriptor(const ComponentDescriptorParameters &parameters)
+      : ConcreteComponentDescriptor<ShadowNodeT>(parameters),
+        textLayoutManager_(getManagerByName<TextLayoutManager>(this->contextContainer_, TextLayoutManagerKey))
+  {
+  }
+
+  ComponentName getComponentName() const override
+  {
+    return ShadowNodeT::Name();
+  }
+
+ protected:
+  void adopt(ShadowNode &shadowNode) const override
+  {
+    ConcreteComponentDescriptor<ShadowNodeT>::adopt(shadowNode);
+
+    auto &paragraphShadowNode = static_cast<ShadowNodeT &>(shadowNode);
+
+    // `ParagraphShadowNode` uses `TextLayoutManager` to measure text content
+    // and communicate text rendering metrics to mounting layer.
+    paragraphShadowNode.setTextLayoutManager(textLayoutManager_);
+  }
+
+ private:
+  // Every `ParagraphShadowNode` has a reference to a shared `TextLayoutManager`
+  const std::shared_ptr<const TextLayoutManager> textLayoutManager_;
+};
+
+} // namespace facebook::react
diff --git a/packages/react-native/ReactCommon/react/renderer/components/text/ParagraphComponentDescriptor.cpp b/packages/react-native/ReactCommon/react/renderer/components/text/ParagraphComponentDescriptor.cpp
deleted file mode 100644
index ee4e014b6564..000000000000
--- a/packages/react-native/ReactCommon/react/renderer/components/text/ParagraphComponentDescriptor.cpp
+++ /dev/null
@@ -1,14 +0,0 @@
-/*
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-#include "ParagraphComponentDescriptor.h"
-
-namespace facebook::react {
-
-extern const char TextLayoutManagerKey[] = "TextLayoutManager";
-
-} // namespace facebook::react
diff --git a/packages/react-native/ReactCommon/react/renderer/components/text/ParagraphComponentDescriptor.h b/packages/react-native/ReactCommon/react/renderer/components/text/ParagraphComponentDescriptor.h
index 3ed1a2a7aefc..3f64c6e8cb7a 100644
--- a/packages/react-native/ReactCommon/react/renderer/components/text/ParagraphComponentDescriptor.h
+++ b/packages/react-native/ReactCommon/react/renderer/components/text/ParagraphComponentDescriptor.h
@@ -7,41 +7,16 @@
 
 #pragma once
 
+#include <react/renderer/components/text/BaseParagraphComponentDescriptor.h>
 #include <react/renderer/components/text/ParagraphShadowNode.h>
-#include <react/renderer/core/ConcreteComponentDescriptor.h>
-#include <react/renderer/textlayoutmanager/TextLayoutManager.h>
-#include <react/utils/ContextContainer.h>
 
 namespace facebook::react {
-
-extern const char TextLayoutManagerKey[];
-
 /*
  * Descriptor for <Paragraph> component.
  */
-class ParagraphComponentDescriptor final : public ConcreteComponentDescriptor<ParagraphShadowNode> {
+class ParagraphComponentDescriptor final : public BaseParagraphComponentDescriptor<ParagraphShadowNode> {
  public:
-  explicit ParagraphComponentDescriptor(const ComponentDescriptorParameters &parameters)
-      : ConcreteComponentDescriptor<ParagraphShadowNode>(parameters),
-        textLayoutManager_(getManagerByName<TextLayoutManager>(contextContainer_, TextLayoutManagerKey))
-  {
-  }
-
- protected:
-  void adopt(ShadowNode &shadowNode) const override
-  {
-    ConcreteComponentDescriptor::adopt(shadowNode);
-
-    auto &paragraphShadowNode = static_cast<ParagraphShadowNode &>(shadowNode);
-
-    // `ParagraphShadowNode` uses `TextLayoutManager` to measure text content
-    // and communicate text rendering metrics to mounting layer.
-    paragraphShadowNode.setTextLayoutManager(textLayoutManager_);
-  }
-
- private:
-  // Every `ParagraphShadowNode` has a reference to a shared `TextLayoutManager`
-  const std::shared_ptr<const TextLayoutManager> textLayoutManager_;
+  using BaseParagraphComponentDescriptor::BaseParagraphComponentDescriptor;
 };
 
 } // namespace facebook::react
diff --git a/packages/react-native/ReactCommon/react/renderer/components/text/ParagraphShadowNode.h b/packages/react-native/ReactCommon/react/renderer/components/text/ParagraphShadowNode.h
index e8510a7705df..704088cbaae6 100644
--- a/packages/react-native/ReactCommon/react/renderer/components/text/ParagraphShadowNode.h
+++ b/packages/react-native/ReactCommon/react/renderer/components/text/ParagraphShadowNode.h
@@ -26,7 +26,7 @@ extern const char ParagraphComponentName[];
  * containing and displaying text. Text content is represented as nested <Text>
  * and <RawText> components.
  */
-class ParagraphShadowNode final
+class ParagraphShadowNode
     : public ConcreteViewShadowNode<ParagraphComponentName, ParagraphProps, ParagraphEventEmitter, ParagraphState>,
       public BaseTextShadowNode {
  public: