Keep BaseTextAttributes as part of AttributedString

packages/react-native/ReactCommon/react/renderer/attributedstring/AttributedString.cpp

@@ -91,6 +91,11 @@ void AttributedString::prependAttributedString(
       attributedString.fragments_.end());
 }
 
+void AttributedString::setBaseTextAttributes(
+    const TextAttributes& defaultAttributes) {
+  baseAttributes_ = defaultAttributes;
+}
+
 const Fragments& AttributedString::getFragments() const {
   return fragments_;
 }
@@ -107,6 +112,10 @@ std::string AttributedString::getString() const {
   return string;
 }
 
+const TextAttributes& AttributedString::getBaseTextAttributes() const {
+  return baseAttributes_;
+}
+
 bool AttributedString::isEmpty() const {
   return fragments_.empty();
 }

packages/react-native/ReactCommon/react/renderer/attributedstring/AttributedString.h

@@ -75,6 +75,12 @@ class AttributedString : public Sealable, public DebugStringConvertible {
   void appendAttributedString(const AttributedString& attributedString);
   void prependAttributedString(const AttributedString& attributedString);
 
+  /*
+   * Sets attributes which would apply to hypothetical text not included in the
+   * AttributedString.
+   */
+  void setBaseTextAttributes(const TextAttributes& defaultAttributes);
+
   /*
    * Returns a read-only reference to a list of fragments.
    */
@@ -90,6 +96,8 @@ class AttributedString : public Sealable, public DebugStringConvertible {
    */
   std::string getString() const;
 
+  const TextAttributes& getBaseTextAttributes() const;
+
   /*
    * Returns `true` if the string is empty (has no any fragments).
    */
@@ -113,6 +121,7 @@ class AttributedString : public Sealable, public DebugStringConvertible {
 
  private:
   Fragments fragments_;
+  TextAttributes baseAttributes_;
 };
 
 } // namespace facebook::react

packages/react-native/ReactCommon/react/renderer/attributedstring/conversions.h

@@ -871,6 +871,7 @@ constexpr static MapBuffer::Key AS_KEY_HASH = 0;
 constexpr static MapBuffer::Key AS_KEY_STRING = 1;
 constexpr static MapBuffer::Key AS_KEY_FRAGMENTS = 2;
 constexpr static MapBuffer::Key AS_KEY_CACHE_ID = 3;
+constexpr static MapBuffer::Key AS_KEY_BASE_ATTRIBUTES = 4;
 
 // constants for Fragment serialization
 constexpr static MapBuffer::Key FR_KEY_STRING = 0;
@@ -1117,6 +1118,9 @@ inline MapBuffer toMapBuffer(const AttributedString& attributedString) {
   // TODO: This truncates half the hash
   builder.putInt(AS_KEY_HASH, static_cast<int>(hash));
   builder.putString(AS_KEY_STRING, attributedString.getString());
+  builder.putMapBuffer(
+      AS_KEY_BASE_ATTRIBUTES,
+      toMapBuffer(attributedString.getBaseTextAttributes()));
   auto fragmentsMap = fragmentsBuilder.build();
   builder.putMapBuffer(AS_KEY_FRAGMENTS, fragmentsMap);
   return builder.build();

packages/react-native/ReactCommon/react/renderer/components/text/ParagraphShadowNode.cpp

@@ -58,6 +58,7 @@ const Content& ParagraphShadowNode::getContent(
   auto attributedString = AttributedString{};
   auto attachments = Attachments{};
   buildAttributedString(textAttributes, *this, attributedString, attachments);
+  attributedString.setBaseTextAttributes(textAttributes);
 
   content_ = Content{
       attributedString, getConcreteProps().paragraphAttributes, attachments};

packages/react-native/ReactCommon/react/renderer/components/textinput/platform/android/react/renderer/components/androidtextinput/AndroidTextInputShadowNode.cpp

@@ -64,6 +64,7 @@ AttributedString AndroidTextInputShadowNode::getAttributedString() const {
   auto attachments = BaseTextShadowNode::Attachments{};
   BaseTextShadowNode::buildAttributedString(
       childTextAttributes, *this, attributedString, attachments);
+  attributedString.setBaseTextAttributes(childTextAttributes);
 
   // BaseTextShadowNode only gets children. We must detect and prepend text
   // value attributes manually.

packages/react-native/ReactCommon/react/renderer/components/textinput/platform/ios/react/renderer/components/iostextinput/TextInputShadowNode.cpp

@@ -88,6 +88,7 @@ AttributedString TextInputShadowNode::getAttributedString(
   auto attachments = Attachments{};
   BaseTextShadowNode::buildAttributedString(
       textAttributes, *this, attributedString, attachments);
+  attributedString.setBaseTextAttributes(textAttributes);
 
   return attributedString;
 }