Extract TextLayoutManager::baseline()

Summary:
This is shared between platforms using a very strange pattern. Let's just extract this into its own function. Not considering breaking, since TextLayoutManager is internal interface.

Changelog: [internal]

Differential Revision: D73555465

Author: NickGerleman

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

@@ -214,8 +214,9 @@ Float ParagraphShadowNode::baseline(
   }
 
   AttributedStringBox attributedStringBox{attributedString};
-  return textLayoutManager_->baseline(
-      attributedStringBox, getConcreteProps().paragraphAttributes, size);
+
+  return LineMeasurement::baseline(textLayoutManager_->measureLines(
+      attributedStringBox, getConcreteProps().paragraphAttributes, size));
 }
 
 void ParagraphShadowNode::layout(LayoutContext layoutContext) {

packages/react-native/ReactCommon/react/renderer/components/textinput/BaseTextInputShadowNode.h

@@ -106,8 +106,8 @@ class BaseTextInputShadowNode : public ConcreteViewShadowNode<
                    &(YogaLayoutableShadowNode::yogaNode_), YGEdgeTop);
 
     AttributedStringBox attributedStringBox{attributedString};
-    return textLayoutManager_->baseline(
-               attributedStringBox, props.paragraphAttributes, size) +
+    return LineMeasurement::baseline(textLayoutManager_->measureLines(
+               attributedStringBox, props.paragraphAttributes, size)) +
         top;
   }
 

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

@@ -92,10 +92,10 @@ Float AndroidTextInputShadowNode::baseline(
       YGNodeLayoutGetPadding(&yogaNode_, YGEdgeTop);
 
   AttributedStringBox attributedStringBox{attributedString};
-  return textLayoutManager_->baseline(
+  return LineMeasurement::baseline(textLayoutManager_->measureLines(
              attributedStringBox,
              getConcreteProps().paragraphAttributes,
-             size) +
+             size)) +
       top;
 }
 

packages/react-native/ReactCommon/react/renderer/textlayoutmanager/TextLayoutManager.cpp

@@ -69,15 +69,6 @@ class TextLayoutManager {
       const ParagraphAttributes& paragraphAttributes,
       const Size& size) const;
 
-  /*
-   * Calculates baseline of `attributedString` using native text rendering
-   * infrastructure.
-   */
-  Float baseline(
-      const AttributedStringBox& attributedStringBox,
-      const ParagraphAttributes& paragraphAttributes,
-      const Size& size) const;
-
 #ifdef __APPLE__
   /*
    * Returns an opaque pointer to platform-specific TextLayoutManager.

packages/react-native/ReactCommon/react/renderer/textlayoutmanager/TextLayoutManager.h

@@ -35,6 +35,13 @@ struct LineMeasurement {
   LineMeasurement(const folly::dynamic& data);
 
   bool operator==(const LineMeasurement& rhs) const;
+
+  static inline Float baseline(const std::vector<LineMeasurement>& lines) {
+    if (lines.empty()) {
+      return lines[0].ascender;
+    }
+    return 0;
+  }
 };
 
 using LinesMeasurements = std::vector<LineMeasurement>;