fix: account for Android font weight adjustment in text measurement

Author: TorinAsakura

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManager.java

@@ -93,6 +93,7 @@
 import com.facebook.react.views.text.PreparedLayout;
 import com.facebook.react.views.text.ReactTextViewManager;
 import com.facebook.react.views.text.ReactTextViewManagerCallback;
+import com.facebook.react.views.text.ReactTypefaceUtils;
 import com.facebook.react.views.text.TextEffectRegistry;
 import com.facebook.react.views.text.TextLayoutManager;
 import java.util.ArrayList;
@@ -553,6 +554,7 @@ private NativeArray measureLines(
     return (NativeArray)
         TextLayoutManager.measureLines(
             mReactApplicationContext.getAssets(),
+            ReactTypefaceUtils.getFontWeightAdjustment(mReactApplicationContext),
             attributedString,
             paragraphAttributes,
             PixelUtil.toPixelFromDIP(width),
@@ -639,6 +641,7 @@ public long measureText(
 
     return TextLayoutManager.measureText(
         mReactApplicationContext.getAssets(),
+        ReactTypefaceUtils.getFontWeightAdjustment(mReactApplicationContext),
         attributedString,
         paragraphAttributes,
         getYogaSize(minWidth, maxWidth),
@@ -666,6 +669,7 @@ public PreparedLayout prepareTextLayout(
 
     return TextLayoutManager.createPreparedLayout(
         mReactApplicationContext.getAssets(),
+        ReactTypefaceUtils.getFontWeightAdjustment(mReactApplicationContext),
         attributedString,
         paragraphAttributes,
         getYogaSize(minWidth, maxWidth),

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/text/ReactTextViewManager.kt

@@ -158,6 +158,7 @@ public constructor(
     val spanned: Spannable =
         TextLayoutManager.getOrCreateSpannableForText(
             view.context.assets,
+            ReactTypefaceUtils.getFontWeightAdjustment(view.context),
             attributedString,
             reactTextViewManagerCallback,
             TextEffectRegistry.current,

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/text/ReactTypefaceUtils.kt

@@ -7,14 +7,22 @@
 
 package com.facebook.react.views.text
 
+import android.content.Context
+import android.content.res.Configuration
 import android.content.res.AssetManager
 import android.graphics.Typeface
+import android.os.Build
 import com.facebook.react.bridge.ReadableArray
 import com.facebook.react.common.ReactConstants
 import com.facebook.react.common.assets.ReactFontManager
+import kotlin.math.max
+import kotlin.math.min
 
 public object ReactTypefaceUtils {
 
+  private const val FONT_WEIGHT_MIN = 1
+  private const val FONT_WEIGHT_MAX = 1000
+
   @JvmStatic
   public fun parseFontWeight(fontWeightString: String?): Int =
       when (fontWeightString) {
@@ -110,4 +118,33 @@ public object ReactTypefaceUtils {
       ReactFontManager.getInstance().getTypeface(fontFamilyName, typefaceStyle, assetManager)
     }
   }
+
+  @JvmStatic
+  public fun getFontWeightAdjustment(context: Context): Int =
+      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+        context.resources.configuration.fontWeightAdjustment
+      } else {
+        0
+      }
+
+  @JvmStatic
+  public fun applyFontWeightAdjustment(
+      typeface: Typeface?,
+      fontWeightAdjustment: Int,
+  ): Typeface? {
+    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.S || fontWeightAdjustment == 0) {
+      return typeface
+    }
+
+    if (fontWeightAdjustment == Configuration.FONT_WEIGHT_ADJUSTMENT_UNDEFINED) {
+      return typeface
+    }
+
+    val baseTypeface = typeface ?: Typeface.DEFAULT
+    val adjustedWeight =
+        min(max(baseTypeface.weight + fontWeightAdjustment, FONT_WEIGHT_MIN), FONT_WEIGHT_MAX)
+    val italic = baseTypeface.style and Typeface.ITALIC != 0
+
+    return Typeface.create(baseTypeface, adjustedWeight, italic)
+  }
 }