De-duplicate building Spannable on Android (#39630)

Summary:
A first step in my work on https://github.com/react-native-community/discussions-and-proposals/issues/695

De-duplicate the code for creating `Spannable` on Android. I'm planning to add quite serious new features to this module. This would be really hard with the current level of code duplication.

## Changelog:

[INTERNAL] [CHANGED] - De-duplicate building `Spannable` on Android

Pull Request resolved: https://github.com/facebook/react-native/pull/39630

Test Plan: I tried to ensure that the refactored code is relatively easy to prove to be equivalent to the original duplicated one, but there's always a risk of a human mistake in this process. So far, I have been testing this by ensuring that nothing broke in the `Text` example section in RNTester.

Reviewed By: mdvacca

Differential Revision: D51016244

Pulled By: NickGerleman

fbshipit-source-id: e9f873c01b2af0685c7b0943aebea170c997d22e

packages/react-native/ReactAndroid/api/ReactAndroid.api

@@ -1686,6 +1686,7 @@ public final class com/facebook/react/common/MapBuilder$Builder {
 
 public class com/facebook/react/common/ReactConstants {
 	public static final field TAG Ljava/lang/String;
+	public static final field UNSET I
 	public fun <init> ()V
 }
 
@@ -1764,7 +1765,6 @@ public class com/facebook/react/common/assets/ReactFontManager {
 public class com/facebook/react/common/assets/ReactFontManager$TypefaceStyle {
 	public static final field BOLD I
 	public static final field NORMAL I
-	public static final field UNSET I
 	public fun <init> (I)V
 	public fun <init> (II)V
 	public fun <init> (IZ)V
@@ -1906,6 +1906,7 @@ public class com/facebook/react/config/ReactFeatureFlags {
 	public static field enableMountHooks Z
 	public static field enableOnDemandReactChoreographer Z
 	public static field enableRemoveDeleteTreeInstruction Z
+	public static field enableSpannableBuildingUnification Z
 	public static field enableTextSpannableCache Z
 	public static field enableViewRecycling Z
 	public static field excludeYogaFromRawProps Z
@@ -6785,7 +6786,7 @@ public class com/facebook/react/views/text/ReactBackgroundColorSpan : android/te
 	public fun <init> (I)V
 }
 
-public abstract class com/facebook/react/views/text/ReactBaseTextShadowNode : com/facebook/react/uimanager/LayoutShadowNode {
+public abstract class com/facebook/react/views/text/ReactBaseTextShadowNode : com/facebook/react/uimanager/LayoutShadowNode, com/facebook/react/views/text/BasicTextAttributeProvider {
 	public static final field DEFAULT_TEXT_SHADOW_COLOR I
 	public static final field PROP_SHADOW_COLOR Ljava/lang/String;
 	public static final field PROP_SHADOW_OFFSET Ljava/lang/String;
@@ -6793,7 +6794,6 @@ public abstract class com/facebook/react/views/text/ReactBaseTextShadowNode : co
 	public static final field PROP_SHADOW_OFFSET_WIDTH Ljava/lang/String;
 	public static final field PROP_SHADOW_RADIUS Ljava/lang/String;
 	public static final field PROP_TEXT_TRANSFORM Ljava/lang/String;
-	public static final field UNSET I
 	protected field mAccessibilityRole Lcom/facebook/react/uimanager/ReactAccessibilityDelegate$AccessibilityRole;
 	protected field mAdjustsFontSizeToFit Z
 	protected field mBackgroundColor I
@@ -6824,6 +6824,22 @@ public abstract class com/facebook/react/views/text/ReactBaseTextShadowNode : co
 	protected field mTextShadowRadius F
 	public fun <init> ()V
 	public fun <init> (Lcom/facebook/react/views/text/ReactTextViewManagerCallback;)V
+	public fun getAccessibilityRole ()Lcom/facebook/react/uimanager/ReactAccessibilityDelegate$AccessibilityRole;
+	public fun getBackgroundColor ()I
+	public fun getColor ()I
+	public fun getFontFamily ()Ljava/lang/String;
+	public fun getFontFeatureSettings ()Ljava/lang/String;
+	public fun getFontStyle ()I
+	public fun getFontWeight ()I
+	public fun getRole ()Lcom/facebook/react/uimanager/ReactAccessibilityDelegate$Role;
+	public fun getTextShadowColor ()I
+	public fun getTextShadowOffsetDx ()F
+	public fun getTextShadowOffsetDy ()F
+	public fun getTextShadowRadius ()F
+	public fun isBackgroundColorSet ()Z
+	public fun isColorSet ()Z
+	public fun isLineThroughTextDecorationSet ()Z
+	public fun isUnderlineTextDecorationSet ()Z
 	public fun setAccessibilityRole (Ljava/lang/String;)V
 	public fun setAdjustFontSizeToFit (Z)V
 	public fun setAllowFontScaling (Z)V
@@ -7084,12 +7100,19 @@ public class com/facebook/react/views/text/ReactVirtualTextViewManager$$PropsSet
 	public fun setProperty (Lcom/facebook/react/views/text/ReactVirtualTextViewManager;Landroid/view/View;Ljava/lang/String;Ljava/lang/Object;)V
 }
 
+public class com/facebook/react/views/text/SetSpanOperation {
+	protected field end I
+	protected field start I
+	protected field what Lcom/facebook/react/views/text/ReactSpan;
+	public fun execute (Landroid/text/SpannableStringBuilder;I)V
+}
+
 public class com/facebook/react/views/text/ShadowStyleSpan : android/text/style/CharacterStyle, com/facebook/react/views/text/ReactSpan {
 	public fun <init> (FFFI)V
 	public fun updateDrawState (Landroid/text/TextPaint;)V
 }
 
-public class com/facebook/react/views/text/TextAttributeProps {
+public class com/facebook/react/views/text/TextAttributeProps : com/facebook/react/views/text/EffectiveTextAttributeProvider {
 	public static final field TA_KEY_ACCESSIBILITY_ROLE S
 	public static final field TA_KEY_ALIGNMENT S
 	public static final field TA_KEY_ALLOW_FONT_SCALING S
@@ -7117,7 +7140,6 @@ public class com/facebook/react/views/text/TextAttributeProps {
 	public static final field TA_KEY_TEXT_SHADOW_OFFSET_DY S
 	public static final field TA_KEY_TEXT_SHADOW_RADIUS S
 	public static final field TA_KEY_TEXT_TRANSFORM S
-	public static final field UNSET I
 	protected field mAccessibilityRole Lcom/facebook/react/uimanager/ReactAccessibilityDelegate$AccessibilityRole;
 	protected field mAllowFontScaling Z
 	protected field mBackgroundColor I
@@ -7149,13 +7171,32 @@ public class com/facebook/react/views/text/TextAttributeProps {
 	protected field mTextTransform Lcom/facebook/react/views/text/TextTransform;
 	public static fun fromMapBuffer (Lcom/facebook/react/common/mapbuffer/MapBuffer;)Lcom/facebook/react/views/text/TextAttributeProps;
 	public static fun fromReadableMap (Lcom/facebook/react/uimanager/ReactStylesDiffMap;)Lcom/facebook/react/views/text/TextAttributeProps;
+	public fun getAccessibilityRole ()Lcom/facebook/react/uimanager/ReactAccessibilityDelegate$AccessibilityRole;
+	public fun getBackgroundColor ()I
+	public fun getColor ()I
+	public fun getEffectiveFontSize ()I
+	public fun getEffectiveLetterSpacing ()F
 	public fun getEffectiveLineHeight ()F
+	public fun getFontFamily ()Ljava/lang/String;
+	public fun getFontFeatureSettings ()Ljava/lang/String;
+	public fun getFontStyle ()I
+	public fun getFontWeight ()I
 	public static fun getHyphenationFrequency (Ljava/lang/String;)I
 	public static fun getJustificationMode (Lcom/facebook/react/uimanager/ReactStylesDiffMap;I)I
 	public static fun getLayoutDirection (Ljava/lang/String;)I
 	public fun getLetterSpacing ()F
+	public fun getRole ()Lcom/facebook/react/uimanager/ReactAccessibilityDelegate$Role;
 	public static fun getTextAlignment (Lcom/facebook/react/uimanager/ReactStylesDiffMap;ZI)I
 	public static fun getTextBreakStrategy (Ljava/lang/String;)I
+	public fun getTextShadowColor ()I
+	public fun getTextShadowOffsetDx ()F
+	public fun getTextShadowOffsetDy ()F
+	public fun getTextShadowRadius ()F
+	public fun getTextTransform ()Lcom/facebook/react/views/text/TextTransform;
+	public fun isBackgroundColorSet ()Z
+	public fun isColorSet ()Z
+	public fun isLineThroughTextDecorationSet ()Z
+	public fun isUnderlineTextDecorationSet ()Z
 }
 
 public class com/facebook/react/views/text/TextAttributes {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/common/ReactConstants.java

@@ -10,4 +10,12 @@ package com.facebook.react.common;
 public class ReactConstants {
 
   public static final String TAG = "ReactNative";
+
+  /**
+   * Some types have built-in support for representing a "missing" or "unset" value, for example NaN
+   * in the case of floating point numbers or null in the case of object references. Integers don't
+   * have such a special value. When an integer represent an inherently non-negative value, we use a
+   * special negative value to mark it as "unset".
+   */
+  public static final int UNSET = -1;
 }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/common/assets/ReactFontManager.java

@@ -15,6 +15,7 @@ import android.util.SparseArray;
 import androidx.annotation.Nullable;
 import androidx.core.content.res.ResourcesCompat;
 import com.facebook.infer.annotation.Nullsafe;
+import com.facebook.react.common.ReactConstants;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -167,8 +168,6 @@ public class ReactFontManager {
 
     public static final int BOLD = 700;
     public static final int NORMAL = 400;
-    public static final int UNSET = -1;
-
     private static final int MIN_WEIGHT = 1;
     private static final int MAX_WEIGHT = 1000;
 
@@ -177,11 +176,11 @@ public class ReactFontManager {
 
     public TypefaceStyle(int weight, boolean italic) {
       mItalic = italic;
-      mWeight = weight == UNSET ? NORMAL : weight;
+      mWeight = weight == ReactConstants.UNSET ? NORMAL : weight;
     }
 
     public TypefaceStyle(int style) {
-      if (style == UNSET) {
+      if (style == ReactConstants.UNSET) {
         style = Typeface.NORMAL;
       }
 
@@ -194,12 +193,13 @@ public class ReactFontManager {
      * existing weight bit in `style` will be used.
      */
     public TypefaceStyle(int style, int weight) {
-      if (style == UNSET) {
+      if (style == ReactConstants.UNSET) {
         style = Typeface.NORMAL;
       }
 
       mItalic = (style & Typeface.ITALIC) != 0;
-      mWeight = weight == UNSET ? (style & Typeface.BOLD) != 0 ? BOLD : NORMAL : weight;
+      mWeight =
+          weight == ReactConstants.UNSET ? (style & Typeface.BOLD) != 0 ? BOLD : NORMAL : weight;
     }
 
     public int getNearestStyle() {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/config/ReactFeatureFlags.java

@@ -173,4 +173,7 @@ public class ReactFeatureFlags {
    *  when there is work to do.
    */
   public static boolean enableOnDemandReactChoreographer = false;
+
+  /** Enables the new unified {@link android.text.Spannable} building logic. */
+  public static boolean enableSpannableBuildingUnification = false;
 }

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

@@ -0,0 +1,48 @@
+/*
+ * 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.
+ */
+
+package com.facebook.react.views.text
+
+import com.facebook.react.uimanager.ReactAccessibilityDelegate
+
+/**
+ * Interface for an entity providing basic text attributes of a text node/fragment. "Basic" means
+ * that they can be provided trivially, without processing the parent element.
+ */
+internal interface BasicTextAttributeProvider {
+  val role: ReactAccessibilityDelegate.Role?
+
+  val accessibilityRole: ReactAccessibilityDelegate.AccessibilityRole?
+
+  val isBackgroundColorSet: Boolean
+
+  val backgroundColor: Int
+
+  val isColorSet: Boolean
+
+  val color: Int
+
+  val fontStyle: Int
+
+  val fontWeight: Int
+
+  val fontFamily: String?
+
+  val fontFeatureSettings: String?
+
+  val isUnderlineTextDecorationSet: Boolean
+
+  val isLineThroughTextDecorationSet: Boolean
+
+  val textShadowOffsetDx: Float
+
+  val textShadowOffsetDy: Float
+
+  val textShadowRadius: Float
+
+  val textShadowColor: Int
+}

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

@@ -14,6 +14,7 @@ import android.text.TextPaint;
 import android.text.style.MetricAffectingSpan;
 import androidx.annotation.Nullable;
 import com.facebook.infer.annotation.Nullsafe;
+import com.facebook.react.common.ReactConstants;
 import com.facebook.react.common.assets.ReactFontManager;
 
 @Nullsafe(Nullsafe.Mode.LOCAL)
@@ -61,13 +62,11 @@ public class CustomStyleSpan extends MetricAffectingSpan implements ReactSpan {
   }
 
   public int getStyle() {
-    return mStyle == ReactFontManager.TypefaceStyle.UNSET ? Typeface.NORMAL : mStyle;
+    return mStyle == ReactConstants.UNSET ? Typeface.NORMAL : mStyle;
   }
 
   public int getWeight() {
-    return mWeight == ReactFontManager.TypefaceStyle.UNSET
-        ? ReactFontManager.TypefaceStyle.NORMAL
-        : mWeight;
+    return mWeight == ReactConstants.UNSET ? ReactFontManager.TypefaceStyle.NORMAL : mWeight;
   }
 
   public @Nullable String getFontFamily() {

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

@@ -0,0 +1,22 @@
+/*
+ * 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.
+ */
+
+package com.facebook.react.views.text
+
+import com.facebook.react.common.ReactConstants.UNSET
+
+/** Interface for an entity providing effective text attributes of a text node/fragment */
+internal interface EffectiveTextAttributeProvider : BasicTextAttributeProvider {
+  val textTransform: TextTransform
+
+  val effectiveLetterSpacing: Float
+
+  /** @return The effective font size, or [UNSET] if not set */
+  val effectiveFontSize: Int
+
+  val effectiveLineHeight: Float
+}

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

@@ -0,0 +1,63 @@
+/*
+ * 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.
+ */
+
+package com.facebook.react.views.text
+
+import com.facebook.react.common.ReactConstants
+
+/**
+ * Implementation of [EffectiveTextAttributeProvider] that provides effective text attributes based
+ * on a [ReactBaseTextShadowNode] instance and its parent.
+ */
+internal class HierarchicTextAttributeProvider(
+    private val textShadowNode: ReactBaseTextShadowNode,
+    private val parentTextAttributes: TextAttributes?,
+    private val textAttributes: TextAttributes
+) : EffectiveTextAttributeProvider, BasicTextAttributeProvider by textShadowNode {
+  override val textTransform: TextTransform
+    get() = textAttributes.textTransform
+
+  override val effectiveLetterSpacing: Float
+    get() {
+      val letterSpacing = textAttributes.effectiveLetterSpacing
+
+      val isParentLetterSpacingDifferent =
+          parentTextAttributes == null ||
+              parentTextAttributes.effectiveLetterSpacing != letterSpacing
+
+      return if (!letterSpacing.isNaN() && isParentLetterSpacingDifferent) {
+        letterSpacing
+      } else {
+        Float.NaN
+      }
+    }
+
+  override val effectiveFontSize: Int
+    get() {
+      val fontSize = textAttributes.effectiveFontSize
+
+      return if (parentTextAttributes == null ||
+          parentTextAttributes.effectiveFontSize != fontSize) {
+        fontSize
+      } else {
+        ReactConstants.UNSET
+      }
+    }
+
+  override val effectiveLineHeight: Float
+    get() {
+      val lineHeight = textAttributes.effectiveLineHeight
+      val isParentLineHeightDifferent =
+          parentTextAttributes == null || parentTextAttributes.effectiveLineHeight != lineHeight
+
+      return if (!lineHeight.isNaN() && isParentLineHeightDifferent) {
+        lineHeight
+      } else {
+        Float.NaN
+      }
+    }
+}

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

@@ -21,7 +21,7 @@ import com.facebook.infer.annotation.Assertions;
 import com.facebook.react.bridge.ReadableArray;
 import com.facebook.react.bridge.ReadableMap;
 import com.facebook.react.common.ReactConstants;
-import com.facebook.react.common.assets.ReactFontManager;
+import com.facebook.react.config.ReactFeatureFlags;
 import com.facebook.react.uimanager.IllegalViewOperationException;
 import com.facebook.react.uimanager.LayoutShadowNode;
 import com.facebook.react.uimanager.NativeViewHierarchyOptimizer;
@@ -49,13 +49,13 @@ import java.util.Map;
  * <p>This also node calculates {@link Spannable} object based on subnodes of the same type, which
  * can be used in concrete classes to feed native views and compute layout.
  */
-public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
+public abstract class ReactBaseTextShadowNode extends LayoutShadowNode
+    implements BasicTextAttributeProvider {
 
   // Use a direction weak character so the placeholder doesn't change the direction of the previous
   // character.
   // https://en.wikipedia.org/wiki/Bi-directional_text#weak_characters
   private static final String INLINE_VIEW_PLACEHOLDER = "0";
-  public static final int UNSET = ReactFontManager.TypefaceStyle.UNSET;
 
   public static final String PROP_SHADOW_OFFSET = "textShadowOffset";
   public static final String PROP_SHADOW_OFFSET_WIDTH = "width";
@@ -77,6 +77,23 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
       boolean supportsInlineViews,
       @Nullable Map<Integer, ReactShadowNode> inlineViews,
       int start) {
+    if (ReactFeatureFlags.enableSpannableBuildingUnification) {
+      buildSpannedFromShadowNodeUnified(
+          textShadowNode, sb, ops, parentTextAttributes, supportsInlineViews, inlineViews, start);
+    } else {
+      buildSpannedFromShadowNodeDuplicated(
+          textShadowNode, sb, ops, parentTextAttributes, supportsInlineViews, inlineViews, start);
+    }
+  }
+
+  private static void buildSpannedFromShadowNodeDuplicated(
+      ReactBaseTextShadowNode textShadowNode,
+      SpannableStringBuilder sb,
+      List<SetSpanOperation> ops,
+      @Nullable TextAttributes parentTextAttributes,
+      boolean supportsInlineViews,
+      @Nullable Map<Integer, ReactShadowNode> inlineViews,
+      int start) {
 
     TextAttributes textAttributes;
     if (parentTextAttributes != null) {
@@ -93,7 +110,7 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
             TextTransform.apply(
                 ((ReactRawTextShadowNode) child).getText(), textAttributes.getTextTransform()));
       } else if (child instanceof ReactBaseTextShadowNode) {
-        buildSpannedFromShadowNode(
+        buildSpannedFromShadowNodeDuplicated(
             (ReactBaseTextShadowNode) child,
             sb,
             ops,
@@ -177,8 +194,8 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
           || parentTextAttributes.getEffectiveFontSize() != effectiveFontSize) {
         ops.add(new SetSpanOperation(start, end, new ReactAbsoluteSizeSpan(effectiveFontSize)));
       }
-      if (textShadowNode.mFontStyle != UNSET
-          || textShadowNode.mFontWeight != UNSET
+      if (textShadowNode.mFontStyle != ReactConstants.UNSET
+          || textShadowNode.mFontWeight != ReactConstants.UNSET
           || textShadowNode.mFontFamily != null) {
         ops.add(
             new SetSpanOperation(
@@ -221,6 +238,99 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
     }
   }
 
+  private static void buildSpannedFromShadowNodeUnified(
+      ReactBaseTextShadowNode textShadowNode,
+      SpannableStringBuilder sb,
+      List<SetSpanOperation> ops,
+      @Nullable TextAttributes parentTextAttributes,
+      boolean supportsInlineViews,
+      @Nullable Map<Integer, ReactShadowNode> inlineViews,
+      int start) {
+
+    TextAttributes textAttributes;
+    if (parentTextAttributes != null) {
+      textAttributes = parentTextAttributes.applyChild(textShadowNode.mTextAttributes);
+    } else {
+      textAttributes = textShadowNode.mTextAttributes;
+    }
+
+    final HierarchicTextAttributeProvider textAttributeProvider =
+        new HierarchicTextAttributeProvider(textShadowNode, parentTextAttributes, textAttributes);
+
+    for (int i = 0, length = textShadowNode.getChildCount(); i < length; i++) {
+      ReactShadowNode child = textShadowNode.getChildAt(i);
+
+      if (child instanceof ReactRawTextShadowNode) {
+        TextLayoutUtils.addText(
+            sb, ((ReactRawTextShadowNode) child).getText(), textAttributeProvider);
+      } else if (child instanceof ReactBaseTextShadowNode) {
+        buildSpannedFromShadowNodeUnified(
+            (ReactBaseTextShadowNode) child,
+            sb,
+            ops,
+            textAttributes,
+            supportsInlineViews,
+            inlineViews,
+            sb.length());
+      } else if (child instanceof ReactTextInlineImageShadowNode) {
+        addInlineImageSpan(ops, sb, (ReactTextInlineImageShadowNode) child);
+      } else if (supportsInlineViews) {
+        addInlineViewPlaceholderSpan(ops, sb, child);
+
+        inlineViews.put(child.getReactTag(), child);
+      } else {
+        throw new IllegalViewOperationException(
+            "Unexpected view type nested under a <Text> or <TextInput> node: " + child.getClass());
+      }
+      child.markUpdateSeen();
+    }
+    int end = sb.length();
+    if (end >= start) {
+      final int reactTag = textShadowNode.getReactTag();
+
+      TextLayoutUtils.addApplicableTextAttributeSpans(
+          ops, textAttributeProvider, reactTag, textShadowNode.getThemedContext(), start, end);
+    }
+  }
+
+  private static void addInlineImageSpan(
+      List<SetSpanOperation> ops, SpannableStringBuilder sb, ReactTextInlineImageShadowNode child) {
+    // We make the image take up 1 character in the span and put a corresponding character into
+    // the text so that the image doesn't run over any following text.
+    sb.append(INLINE_VIEW_PLACEHOLDER);
+    ops.add(
+        new SetSpanOperation(
+            sb.length() - INLINE_VIEW_PLACEHOLDER.length(),
+            sb.length(),
+            child.buildInlineImageSpan()));
+  }
+
+  private static void addInlineViewPlaceholderSpan(
+      List<SetSpanOperation> ops, SpannableStringBuilder sb, ReactShadowNode child) {
+    YogaValue widthValue = child.getStyleWidth();
+    YogaValue heightValue = child.getStyleHeight();
+
+    float width;
+    float height;
+    if (widthValue.unit != YogaUnit.POINT || heightValue.unit != YogaUnit.POINT) {
+      // If the measurement of the child isn't calculated, we calculate the layout for the
+      // view using Yoga
+      child.calculateLayout();
+      width = child.getLayoutWidth();
+      height = child.getLayoutHeight();
+    } else {
+      width = widthValue.value;
+      height = heightValue.value;
+    }
+
+    // We make the inline view take up 1 character in the span and put a corresponding character
+    // into the text so that
+    // the inline view doesn't run over any following text.
+    sb.append(INLINE_VIEW_PLACEHOLDER);
+
+    TextLayoutUtils.addInlineViewPlaceholderSpan(ops, sb, child.getReactTag(), width, height);
+  }
+
   // `nativeViewHierarchyOptimizer` can be `null` as long as `supportsInlineViews` is `false`.
   protected Spannable spannedFromShadowNode(
       ReactBaseTextShadowNode textShadowNode,
@@ -307,7 +417,7 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
   protected @Nullable AccessibilityRole mAccessibilityRole = null;
   protected @Nullable Role mRole = null;
 
-  protected int mNumberOfLines = UNSET;
+  protected int mNumberOfLines = ReactConstants.UNSET;
   protected int mTextAlign = Gravity.NO_GRAVITY;
   protected int mTextBreakStrategy = Layout.BREAK_STRATEGY_HIGH_QUALITY;
   protected int mHyphenationFrequency = Layout.HYPHENATION_FREQUENCY_NONE;
@@ -329,9 +439,9 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
    * mFontStyle can be {@link Typeface#NORMAL} or {@link Typeface#ITALIC}. mFontWeight can be {@link
    * Typeface#NORMAL} or {@link Typeface#BOLD}.
    */
-  protected int mFontStyle = UNSET;
+  protected int mFontStyle = ReactConstants.UNSET;
 
-  protected int mFontWeight = UNSET;
+  protected int mFontWeight = ReactConstants.UNSET;
   /**
    * NB: If a font family is used that does not have a style in a certain Android version (ie.
    * monospace bold pre Android 5.0), that style (ie. bold) will not be inherited by nested Text
@@ -384,9 +494,9 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
     return textAlign;
   }
 
-  @ReactProp(name = ViewProps.NUMBER_OF_LINES, defaultInt = UNSET)
+  @ReactProp(name = ViewProps.NUMBER_OF_LINES, defaultInt = ReactConstants.UNSET)
   public void setNumberOfLines(int numberOfLines) {
-    mNumberOfLines = numberOfLines == 0 ? UNSET : numberOfLines;
+    mNumberOfLines = numberOfLines == 0 ? ReactConstants.UNSET : numberOfLines;
     markUpdated();
   }
 
@@ -452,6 +562,11 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
     markUpdated();
   }
 
+  @Override
+  public int getColor() {
+    return mColor;
+  }
+
   @ReactProp(name = ViewProps.COLOR, customType = "Color")
   public void setColor(@Nullable Integer color) {
     mIsColorSet = (color != null);
@@ -461,6 +576,16 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
     markUpdated();
   }
 
+  @Override
+  public boolean isColorSet() {
+    return mIsColorSet;
+  }
+
+  @Override
+  public int getBackgroundColor() {
+    return mBackgroundColor;
+  }
+
   @ReactProp(name = ViewProps.BACKGROUND_COLOR, customType = "Color")
   public void setBackgroundColor(@Nullable Integer color) {
     // Background color needs to be handled here for virtual nodes so it can be incorporated into
@@ -476,6 +601,16 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
     }
   }
 
+  @Override
+  public boolean isBackgroundColorSet() {
+    return mIsBackgroundColorSet;
+  }
+
+  @Override
+  public @Nullable AccessibilityRole getAccessibilityRole() {
+    return mAccessibilityRole;
+  }
+
   @ReactProp(name = ViewProps.ACCESSIBILITY_ROLE)
   public void setAccessibilityRole(@Nullable String accessibilityRole) {
     if (isVirtual()) {
@@ -484,6 +619,11 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
     }
   }
 
+  @Override
+  public @Nullable Role getRole() {
+    return mRole;
+  }
+
   @ReactProp(name = ViewProps.ROLE)
   public void setRole(@Nullable String role) {
     if (isVirtual()) {
@@ -492,12 +632,22 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
     }
   }
 
+  @Override
+  public String getFontFamily() {
+    return mFontFamily;
+  }
+
   @ReactProp(name = ViewProps.FONT_FAMILY)
   public void setFontFamily(@Nullable String fontFamily) {
     mFontFamily = fontFamily;
     markUpdated();
   }
 
+  @Override
+  public int getFontWeight() {
+    return mFontWeight;
+  }
+
   @ReactProp(name = ViewProps.FONT_WEIGHT)
   public void setFontWeight(@Nullable String fontWeightString) {
     int fontWeight = ReactTypefaceUtils.parseFontWeight(fontWeightString);
@@ -517,6 +667,16 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
     }
   }
 
+  @Override
+  public String getFontFeatureSettings() {
+    return mFontFeatureSettings;
+  }
+
+  @Override
+  public int getFontStyle() {
+    return mFontStyle;
+  }
+
   @ReactProp(name = ViewProps.FONT_STYLE)
   public void setFontStyle(@Nullable String fontStyleString) {
     int fontStyle = ReactTypefaceUtils.parseFontStyle(fontStyleString);
@@ -547,6 +707,16 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
     markUpdated();
   }
 
+  @Override
+  public boolean isUnderlineTextDecorationSet() {
+    return mIsUnderlineTextDecorationSet;
+  }
+
+  @Override
+  public boolean isLineThroughTextDecorationSet() {
+    return mIsLineThroughTextDecorationSet;
+  }
+
   @ReactProp(name = ViewProps.TEXT_BREAK_STRATEGY)
   public void setTextBreakStrategy(@Nullable String textBreakStrategy) {
     if (textBreakStrategy == null || "highQuality".equals(textBreakStrategy)) {
@@ -584,6 +754,21 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
     markUpdated();
   }
 
+  @Override
+  public float getTextShadowOffsetDx() {
+    return mTextShadowOffsetDx;
+  }
+
+  @Override
+  public float getTextShadowOffsetDy() {
+    return mTextShadowOffsetDy;
+  }
+
+  @Override
+  public float getTextShadowRadius() {
+    return mTextShadowRadius;
+  }
+
   @ReactProp(name = PROP_SHADOW_RADIUS, defaultInt = 1)
   public void setTextShadowRadius(float textShadowRadius) {
     if (textShadowRadius != mTextShadowRadius) {
@@ -592,6 +777,11 @@ public abstract class ReactBaseTextShadowNode extends LayoutShadowNode {
     }
   }
 
+  @Override
+  public int getTextShadowColor() {
+    return mTextShadowColor;
+  }
+
   @ReactProp(name = PROP_SHADOW_COLOR, defaultInt = DEFAULT_TEXT_SHADOW_COLOR, customType = "Color")
   public void setTextShadowColor(int textShadowColor) {
     if (textShadowColor != mTextShadowColor) {

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

@@ -23,6 +23,7 @@ import com.facebook.react.bridge.ReactNoCrashSoftException;
 import com.facebook.react.bridge.ReactSoftExceptionLogger;
 import com.facebook.react.bridge.WritableArray;
 import com.facebook.react.bridge.WritableMap;
+import com.facebook.react.common.ReactConstants;
 import com.facebook.react.uimanager.NativeViewHierarchyOptimizer;
 import com.facebook.react.uimanager.PixelUtil;
 import com.facebook.react.uimanager.ReactShadowNode;
@@ -80,7 +81,7 @@ public class ReactTextShadowNode extends ReactBaseTextShadowNode {
             int minimumFontSize =
                 (int) Math.max(mMinimumFontScale * initialFontSize, PixelUtil.toPixelFromDIP(4));
             while (currentFontSize > minimumFontSize
-                && (mNumberOfLines != UNSET && layout.getLineCount() > mNumberOfLines
+                && (mNumberOfLines != ReactConstants.UNSET && layout.getLineCount() > mNumberOfLines
                     || heightMode != YogaMeasureMode.UNDEFINED && layout.getHeight() > height)) {
               // TODO: We could probably use a smarter algorithm here. This will require 0(n)
               // measurements
@@ -122,7 +123,7 @@ public class ReactTextShadowNode extends ReactBaseTextShadowNode {
           }
 
           final int lineCount =
-              mNumberOfLines == UNSET
+              mNumberOfLines == ReactConstants.UNSET
                   ? layout.getLineCount()
                   : Math.min(mNumberOfLines, layout.getLineCount());
 
@@ -327,7 +328,7 @@ public class ReactTextShadowNode extends ReactBaseTextShadowNode {
       ReactTextUpdate reactTextUpdate =
           new ReactTextUpdate(
               mPreparedSpannableText,
-              UNSET,
+              ReactConstants.UNSET,
               mContainsImages,
               getPadding(Spacing.START),
               getPadding(Spacing.TOP),

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

@@ -7,10 +7,9 @@
 
 package com.facebook.react.views.text;
 
-import static com.facebook.react.views.text.TextAttributeProps.UNSET;
-
 import android.text.Layout;
 import android.text.Spannable;
+import com.facebook.react.common.ReactConstants;
 
 /**
  * Class that contains the data needed for a text update. Used by both <Text/> and <TextInput/>
@@ -67,10 +66,10 @@ public class ReactTextUpdate {
         text,
         jsEventCounter,
         containsImages,
-        UNSET,
-        UNSET,
-        UNSET,
-        UNSET,
+        ReactConstants.UNSET,
+        ReactConstants.UNSET,
+        ReactConstants.UNSET,
+        ReactConstants.UNSET,
         textAlign,
         textBreakStrategy,
         justificationMode);

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

@@ -7,8 +7,6 @@
 
 package com.facebook.react.views.text;
 
-import static com.facebook.react.views.text.TextAttributeProps.UNSET;
-
 import android.content.Context;
 import android.graphics.drawable.Drawable;
 import android.os.Build;
@@ -376,10 +374,10 @@ public class ReactTextView extends AppCompatTextView implements ReactCompoundVie
     // In Fabric padding is set by the update of Layout Metrics and not as part of the "setText"
     // operation
     // TODO T56559197: remove this condition when we migrate 100% to Fabric
-    if (paddingLeft != UNSET
-        && paddingTop != UNSET
-        && paddingRight != UNSET
-        && paddingBottom != UNSET) {
+    if (paddingLeft != ReactConstants.UNSET
+        && paddingTop != ReactConstants.UNSET
+        && paddingRight != ReactConstants.UNSET
+        && paddingBottom != ReactConstants.UNSET) {
 
       setPadding(
           (int) Math.floor(paddingLeft),

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

@@ -13,6 +13,7 @@ import android.text.TextUtils;
 import androidx.annotation.Nullable;
 import com.facebook.infer.annotation.Nullsafe;
 import com.facebook.react.bridge.ReadableArray;
+import com.facebook.react.common.ReactConstants;
 import com.facebook.react.common.assets.ReactFontManager;
 import java.util.ArrayList;
 import java.util.List;
@@ -45,7 +46,7 @@ public class ReactTypefaceUtils {
           return 900;
       }
     }
-    return ReactFontManager.TypefaceStyle.UNSET;
+    return ReactConstants.UNSET;
   }
 
   public static int parseFontStyle(@Nullable String fontStyleString) {
@@ -57,7 +58,7 @@ public class ReactTypefaceUtils {
         return Typeface.NORMAL;
       }
     }
-    return ReactFontManager.TypefaceStyle.UNSET;
+    return ReactConstants.UNSET;
   }
 
   public static @Nullable String parseFontVariant(@Nullable ReadableArray fontVariantArray) {

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

@@ -12,7 +12,7 @@ import android.text.SpannableStringBuilder;
 import android.text.Spanned;
 import com.facebook.common.logging.FLog;
 
-class SetSpanOperation {
+public class SetSpanOperation {
   private static final String TAG = "SetSpanOperation";
   static final int SPAN_MAX_PRIORITY = Spanned.SPAN_PRIORITY >> Spanned.SPAN_PRIORITY_SHIFT;
 

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

@@ -12,6 +12,7 @@ import android.text.Layout;
 import android.text.TextUtils;
 import android.util.LayoutDirection;
 import android.view.Gravity;
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.facebook.common.logging.FLog;
 import com.facebook.react.bridge.ReadableArray;
@@ -30,7 +31,7 @@ import java.util.List;
 // TODO: T63643819 refactor naming of TextAttributeProps to make explicit that this represents
 // TextAttributes and not TextProps. As part of this refactor extract methods that don't belong to
 // TextAttributeProps (e.g. TextAlign)
-public class TextAttributeProps {
+public class TextAttributeProps implements EffectiveTextAttributeProvider {
 
   // constants for Text Attributes serialization
   public static final short TA_KEY_FOREGROUND_COLOR = 0;
@@ -61,8 +62,6 @@ public class TextAttributeProps {
   public static final short TA_KEY_ROLE = 26;
   public static final short TA_KEY_TEXT_TRANSFORM = 27;
 
-  public static final int UNSET = -1;
-
   private static final String PROP_SHADOW_OFFSET = "textShadowOffset";
   private static final String PROP_SHADOW_OFFSET_WIDTH = "width";
   private static final String PROP_SHADOW_OFFSET_HEIGHT = "height";
@@ -84,17 +83,17 @@ public class TextAttributeProps {
   protected boolean mIsBackgroundColorSet = false;
   protected int mBackgroundColor;
 
-  protected int mNumberOfLines = UNSET;
-  protected int mFontSize = UNSET;
-  protected float mFontSizeInput = UNSET;
-  protected float mLineHeightInput = UNSET;
+  protected int mNumberOfLines = ReactConstants.UNSET;
+  protected int mFontSize = ReactConstants.UNSET;
+  protected float mFontSizeInput = ReactConstants.UNSET;
+  protected float mLineHeightInput = ReactConstants.UNSET;
   protected float mLetterSpacingInput = Float.NaN;
   protected int mTextAlign = Gravity.NO_GRAVITY;
 
-  // `UNSET` is -1 and is the same as `LayoutDirection.UNDEFINED` but the symbol isn't available.
-  protected int mLayoutDirection = UNSET;
+  // `ReactConstants.UNSET` is -1, same as `LayoutDirection.UNDEFINED` (which is a hidden symbol)
+  protected int mLayoutDirection = ReactConstants.UNSET;
 
-  protected TextTransform mTextTransform = TextTransform.NONE;
+  @NonNull protected TextTransform mTextTransform = TextTransform.NONE;
 
   protected float mTextShadowOffsetDx = 0;
   protected float mTextShadowOffsetDy = 0;
@@ -108,8 +107,8 @@ public class TextAttributeProps {
   protected @Nullable AccessibilityRole mAccessibilityRole = null;
   protected @Nullable Role mRole = null;
 
-  protected int mFontStyle = UNSET;
-  protected int mFontWeight = UNSET;
+  protected int mFontStyle = ReactConstants.UNSET;
+  protected int mFontWeight = ReactConstants.UNSET;
   /**
    * NB: If a font family is used that does not have a style in a certain Android version (ie.
    * monospace bold pre Android 5.0), that style (ie. bold) will not be inherited by nested Text
@@ -233,11 +232,11 @@ public class TextAttributeProps {
 
   public static TextAttributeProps fromReadableMap(ReactStylesDiffMap props) {
     TextAttributeProps result = new TextAttributeProps();
-    result.setNumberOfLines(getIntProp(props, ViewProps.NUMBER_OF_LINES, UNSET));
-    result.setLineHeight(getFloatProp(props, ViewProps.LINE_HEIGHT, UNSET));
+    result.setNumberOfLines(getIntProp(props, ViewProps.NUMBER_OF_LINES, ReactConstants.UNSET));
+    result.setLineHeight(getFloatProp(props, ViewProps.LINE_HEIGHT, ReactConstants.UNSET));
     result.setLetterSpacing(getFloatProp(props, ViewProps.LETTER_SPACING, Float.NaN));
     result.setAllowFontScaling(getBooleanProp(props, ViewProps.ALLOW_FONT_SCALING, true));
-    result.setFontSize(getFloatProp(props, ViewProps.FONT_SIZE, UNSET));
+    result.setFontSize(getFloatProp(props, ViewProps.FONT_SIZE, ReactConstants.UNSET));
     result.setColor(props.hasKey(ViewProps.COLOR) ? props.getInt(ViewProps.COLOR, 0) : null);
     result.setColor(
         props.hasKey(ViewProps.FOREGROUND_COLOR)
@@ -343,6 +342,7 @@ public class TextAttributeProps {
 
   // Returns a line height which takes into account the requested line height
   // and the height of the inline images.
+  @Override
   public float getEffectiveLineHeight() {
     boolean useInlineViewHeight =
         !Float.isNaN(mLineHeight)
@@ -352,12 +352,12 @@ public class TextAttributeProps {
   }
 
   private void setNumberOfLines(int numberOfLines) {
-    mNumberOfLines = numberOfLines == 0 ? UNSET : numberOfLines;
+    mNumberOfLines = numberOfLines == 0 ? ReactConstants.UNSET : numberOfLines;
   }
 
   private void setLineHeight(float lineHeight) {
     mLineHeightInput = lineHeight;
-    if (lineHeight == UNSET) {
+    if (lineHeight == ReactConstants.UNSET) {
       mLineHeight = Float.NaN;
     } else {
       mLineHeight =
@@ -371,6 +371,12 @@ public class TextAttributeProps {
     mLetterSpacingInput = letterSpacing;
   }
 
+  @Override
+  @NonNull
+  public TextTransform getTextTransform() {
+    return mTextTransform;
+  }
+
   public float getLetterSpacing() {
     float letterSpacingPixels =
         mAllowFontScaling
@@ -386,6 +392,16 @@ public class TextAttributeProps {
     return letterSpacingPixels / mFontSize;
   }
 
+  @Override
+  public float getEffectiveLetterSpacing() {
+    return getLetterSpacing();
+  }
+
+  @Override
+  public int getEffectiveFontSize() {
+    return mFontSize;
+  }
+
   private void setAllowFontScaling(boolean allowFontScaling) {
     if (allowFontScaling != mAllowFontScaling) {
       mAllowFontScaling = allowFontScaling;
@@ -397,7 +413,7 @@ public class TextAttributeProps {
 
   private void setFontSize(float fontSize) {
     mFontSizeInput = fontSize;
-    if (fontSize != UNSET) {
+    if (fontSize != ReactConstants.UNSET) {
       fontSize =
           mAllowFontScaling
               ? (float) Math.ceil(PixelUtil.toPixelFromSP(fontSize))
@@ -406,6 +422,11 @@ public class TextAttributeProps {
     mFontSize = (int) fontSize;
   }
 
+  @Override
+  public int getColor() {
+    return mColor;
+  }
+
   private void setColor(@Nullable Integer color) {
     mIsColorSet = (color != null);
     if (mIsColorSet) {
@@ -413,6 +434,16 @@ public class TextAttributeProps {
     }
   }
 
+  @Override
+  public boolean isColorSet() {
+    return mIsColorSet;
+  }
+
+  @Override
+  public int getBackgroundColor() {
+    return mBackgroundColor;
+  }
+
   private void setBackgroundColor(Integer color) {
     // TODO: Don't apply background color to anchor TextView since it will be applied on the View
     // directly
@@ -424,6 +455,21 @@ public class TextAttributeProps {
     // }
   }
 
+  @Override
+  public boolean isBackgroundColorSet() {
+    return mIsBackgroundColorSet;
+  }
+
+  @Override
+  public int getFontStyle() {
+    return mFontStyle;
+  }
+
+  @Override
+  public String getFontFamily() {
+    return mFontFamily;
+  }
+
   private void setFontFamily(@Nullable String fontFamily) {
     mFontFamily = fontFamily;
   }
@@ -526,6 +572,16 @@ public class TextAttributeProps {
     mFontFeatureSettings = TextUtils.join(", ", features);
   }
 
+  @Override
+  public String getFontFeatureSettings() {
+    return mFontFeatureSettings;
+  }
+
+  @Override
+  public int getFontWeight() {
+    return mFontWeight;
+  }
+
   private void setFontWeight(@Nullable String fontWeightString) {
     mFontWeight = ReactTypefaceUtils.parseFontWeight(fontWeightString);
   }
@@ -552,6 +608,16 @@ public class TextAttributeProps {
     }
   }
 
+  @Override
+  public boolean isUnderlineTextDecorationSet() {
+    return mIsUnderlineTextDecorationSet;
+  }
+
+  @Override
+  public boolean isLineThroughTextDecorationSet() {
+    return mIsLineThroughTextDecorationSet;
+  }
+
   private void setTextShadowOffset(ReadableMap offsetMap) {
     mTextShadowOffsetDx = 0;
     mTextShadowOffsetDy = 0;
@@ -570,10 +636,20 @@ public class TextAttributeProps {
     }
   }
 
+  @Override
+  public float getTextShadowOffsetDx() {
+    return mTextShadowOffsetDx;
+  }
+
   private void setTextShadowOffsetDx(float dx) {
     mTextShadowOffsetDx = PixelUtil.toPixelFromDIP(dx);
   }
 
+  @Override
+  public float getTextShadowOffsetDy() {
+    return mTextShadowOffsetDy;
+  }
+
   private void setTextShadowOffsetDy(float dy) {
     mTextShadowOffsetDy = PixelUtil.toPixelFromDIP(dy);
   }
@@ -581,14 +657,14 @@ public class TextAttributeProps {
   public static int getLayoutDirection(@Nullable String layoutDirection) {
     int androidLayoutDirection;
     if (layoutDirection == null || "undefined".equals(layoutDirection)) {
-      androidLayoutDirection = UNSET;
+      androidLayoutDirection = ReactConstants.UNSET;
     } else if ("rtl".equals(layoutDirection)) {
       androidLayoutDirection = LayoutDirection.RTL;
     } else if ("ltr".equals(layoutDirection)) {
       androidLayoutDirection = LayoutDirection.LTR;
     } else {
       FLog.w(ReactConstants.TAG, "Invalid layoutDirection: " + layoutDirection);
-      androidLayoutDirection = UNSET;
+      androidLayoutDirection = ReactConstants.UNSET;
     }
     return androidLayoutDirection;
   }
@@ -597,12 +673,22 @@ public class TextAttributeProps {
     mLayoutDirection = getLayoutDirection(layoutDirection);
   }
 
+  @Override
+  public float getTextShadowRadius() {
+    return mTextShadowRadius;
+  }
+
   private void setTextShadowRadius(float textShadowRadius) {
     if (textShadowRadius != mTextShadowRadius) {
       mTextShadowRadius = textShadowRadius;
     }
   }
 
+  @Override
+  public int getTextShadowColor() {
+    return mTextShadowColor;
+  }
+
   private void setTextShadowColor(int textShadowColor) {
     if (textShadowColor != mTextShadowColor) {
       mTextShadowColor = textShadowColor;
@@ -624,6 +710,11 @@ public class TextAttributeProps {
     }
   }
 
+  @Override
+  public AccessibilityRole getAccessibilityRole() {
+    return mAccessibilityRole;
+  }
+
   private void setAccessibilityRole(@Nullable String accessibilityRole) {
     if (accessibilityRole == null) {
       mAccessibilityRole = null;
@@ -632,6 +723,12 @@ public class TextAttributeProps {
     }
   }
 
+  @Nullable
+  @Override
+  public Role getRole() {
+    return mRole;
+  }
+
   private void setRole(@Nullable String role) {
     if (role == null) {
       mRole = null;

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

@@ -7,6 +7,7 @@
 
 package com.facebook.react.views.text;
 
+import androidx.annotation.NonNull;
 import com.facebook.common.logging.FLog;
 import com.facebook.react.common.ReactConstants;
 import com.facebook.react.uimanager.PixelUtil;
@@ -29,7 +30,8 @@ public class TextAttributes {
   private float mLetterSpacing = Float.NaN;
   private float mMaxFontSizeMultiplier = Float.NaN;
   private float mHeightOfTallestInlineViewOrImage = Float.NaN;
-  private TextTransform mTextTransform = TextTransform.UNSET;
+
+  @NonNull private TextTransform mTextTransform = TextTransform.UNSET;
 
   public TextAttributes() {}
 
@@ -118,7 +120,7 @@ public class TextAttributes {
     return mTextTransform;
   }
 
-  public void setTextTransform(TextTransform textTransform) {
+  public void setTextTransform(@NonNull TextTransform textTransform) {
     mTextTransform = textTransform;
   }
 

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

@@ -7,8 +7,6 @@
 
 package com.facebook.react.views.text;
 
-import static com.facebook.react.views.text.TextAttributeProps.UNSET;
-
 import android.content.Context;
 import android.graphics.Color;
 import android.os.Build;
@@ -31,12 +29,15 @@ import com.facebook.react.bridge.ReadableArray;
 import com.facebook.react.bridge.ReadableMap;
 import com.facebook.react.bridge.ReadableNativeMap;
 import com.facebook.react.bridge.WritableArray;
+import com.facebook.react.common.ReactConstants;
 import com.facebook.react.common.build.ReactBuildConfig;
+import com.facebook.react.config.ReactFeatureFlags;
 import com.facebook.react.uimanager.PixelUtil;
 import com.facebook.react.uimanager.ReactAccessibilityDelegate.AccessibilityRole;
 import com.facebook.react.uimanager.ReactAccessibilityDelegate.Role;
 import com.facebook.react.uimanager.ReactStylesDiffMap;
 import com.facebook.react.uimanager.ViewProps;
+import com.facebook.react.views.text.fragments.BridgeTextFragmentList;
 import com.facebook.yoga.YogaConstants;
 import com.facebook.yoga.YogaMeasureMode;
 import com.facebook.yoga.YogaMeasureOutput;
@@ -99,7 +100,19 @@ public class TextLayoutManager {
     sTagToSpannableCache.remove(reactTag);
   }
 
-  private static void buildSpannableFromFragment(
+  private static void buildSpannableFromFragments(
+      Context context,
+      ReadableArray fragments,
+      SpannableStringBuilder sb,
+      List<SetSpanOperation> ops) {
+    if (ReactFeatureFlags.enableSpannableBuildingUnification) {
+      buildSpannableFromFragmentsUnified(context, fragments, sb, ops);
+    } else {
+      buildSpannableFromFragmentsDuplicated(context, fragments, sb, ops);
+    }
+  }
+
+  private static void buildSpannableFromFragmentsDuplicated(
       Context context,
       ReadableArray fragments,
       SpannableStringBuilder sb,
@@ -152,8 +165,8 @@ public class TextLayoutManager {
         }
         ops.add(
             new SetSpanOperation(start, end, new ReactAbsoluteSizeSpan(textAttributes.mFontSize)));
-        if (textAttributes.mFontStyle != UNSET
-            || textAttributes.mFontWeight != UNSET
+        if (textAttributes.mFontStyle != ReactConstants.UNSET
+            || textAttributes.mFontWeight != ReactConstants.UNSET
             || textAttributes.mFontFamily != null) {
           ops.add(
               new SetSpanOperation(
@@ -197,6 +210,17 @@ public class TextLayoutManager {
     }
   }
 
+  private static void buildSpannableFromFragmentsUnified(
+      Context context,
+      ReadableArray fragments,
+      SpannableStringBuilder sb,
+      List<SetSpanOperation> ops) {
+
+    final BridgeTextFragmentList textFragmentList = new BridgeTextFragmentList(fragments);
+
+    TextLayoutUtils.buildSpannableFromTextFragmentList(context, textFragmentList, sb, ops);
+  }
+
   // public because both ReactTextViewManager and ReactTextInputManager need to use this
   public static Spannable getOrCreateSpannableForText(
       Context context,
@@ -219,7 +243,7 @@ public class TextLayoutManager {
     // a new spannable will be wiped out
     List<SetSpanOperation> ops = new ArrayList<>();
 
-    buildSpannableFromFragment(context, attributedString.getArray("fragments"), sb, ops);
+    buildSpannableFromFragments(context, attributedString.getArray("fragments"), sb, ops);
 
     // TODO T31905686: add support for inline Images
     // While setting the Spans on the final text, we also check whether any of them are images.
@@ -368,10 +392,10 @@ public class TextLayoutManager {
     int maximumNumberOfLines =
         paragraphAttributes.hasKey(MAXIMUM_NUMBER_OF_LINES_KEY)
             ? paragraphAttributes.getInt(MAXIMUM_NUMBER_OF_LINES_KEY)
-            : UNSET;
+            : ReactConstants.UNSET;
 
     int calculatedLineCount =
-        maximumNumberOfLines == UNSET || maximumNumberOfLines == 0
+        maximumNumberOfLines == ReactConstants.UNSET || maximumNumberOfLines == 0
             ? layout.getLineCount()
             : Math.min(maximumNumberOfLines, layout.getLineCount());
 

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

@@ -8,7 +8,6 @@
 package com.facebook.react.views.text;
 
 import static com.facebook.react.config.ReactFeatureFlags.enableTextSpannableCache;
-import static com.facebook.react.views.text.TextAttributeProps.UNSET;
 
 import android.content.Context;
 import android.graphics.Color;
@@ -29,12 +28,15 @@ import com.facebook.common.logging.FLog;
 import com.facebook.react.bridge.ReactNoCrashSoftException;
 import com.facebook.react.bridge.ReactSoftExceptionLogger;
 import com.facebook.react.bridge.WritableArray;
+import com.facebook.react.common.ReactConstants;
 import com.facebook.react.common.build.ReactBuildConfig;
 import com.facebook.react.common.mapbuffer.MapBuffer;
 import com.facebook.react.common.mapbuffer.ReadableMapBuffer;
+import com.facebook.react.config.ReactFeatureFlags;
 import com.facebook.react.uimanager.PixelUtil;
 import com.facebook.react.uimanager.ReactAccessibilityDelegate.AccessibilityRole;
 import com.facebook.react.uimanager.ReactAccessibilityDelegate.Role;
+import com.facebook.react.views.text.fragments.MapBufferTextFragmentList;
 import com.facebook.yoga.YogaConstants;
 import com.facebook.yoga.YogaMeasureMode;
 import com.facebook.yoga.YogaMeasureOutput;
@@ -123,7 +125,16 @@ public class TextLayoutManagerMapBuffer {
         == LayoutDirection.RTL;
   }
 
-  private static void buildSpannableFromFragment(
+  private static void buildSpannableFromFragments(
+      Context context, MapBuffer fragments, SpannableStringBuilder sb, List<SetSpanOperation> ops) {
+    if (ReactFeatureFlags.enableSpannableBuildingUnification) {
+      buildSpannableFromFragmentsUnified(context, fragments, sb, ops);
+    } else {
+      buildSpannableFromFragmentsDuplicated(context, fragments, sb, ops);
+    }
+  }
+
+  private static void buildSpannableFromFragmentsDuplicated(
       Context context, MapBuffer fragments, SpannableStringBuilder sb, List<SetSpanOperation> ops) {
 
     for (int i = 0, length = fragments.getCount(); i < length; i++) {
@@ -172,8 +183,8 @@ public class TextLayoutManagerMapBuffer {
         }
         ops.add(
             new SetSpanOperation(start, end, new ReactAbsoluteSizeSpan(textAttributes.mFontSize)));
-        if (textAttributes.mFontStyle != UNSET
-            || textAttributes.mFontWeight != UNSET
+        if (textAttributes.mFontStyle != ReactConstants.UNSET
+            || textAttributes.mFontWeight != ReactConstants.UNSET
             || textAttributes.mFontFamily != null) {
           ops.add(
               new SetSpanOperation(
@@ -217,6 +228,14 @@ public class TextLayoutManagerMapBuffer {
     }
   }
 
+  private static void buildSpannableFromFragmentsUnified(
+      Context context, MapBuffer fragments, SpannableStringBuilder sb, List<SetSpanOperation> ops) {
+
+    final MapBufferTextFragmentList textFragmentList = new MapBufferTextFragmentList(fragments);
+
+    TextLayoutUtils.buildSpannableFromTextFragmentList(context, textFragmentList, sb, ops);
+  }
+
   // public because both ReactTextViewManager and ReactTextInputManager need to use this
   public static Spannable getOrCreateSpannableForText(
       Context context,
@@ -260,7 +279,7 @@ public class TextLayoutManagerMapBuffer {
     // a new spannable will be wiped out
     List<SetSpanOperation> ops = new ArrayList<>();
 
-    buildSpannableFromFragment(context, attributedString.getMapBuffer(AS_KEY_FRAGMENTS), sb, ops);
+    buildSpannableFromFragments(context, attributedString.getMapBuffer(AS_KEY_FRAGMENTS), sb, ops);
 
     // TODO T31905686: add support for inline Images
     // While setting the Spans on the final text, we also check whether any of them are images.
@@ -390,10 +409,10 @@ public class TextLayoutManagerMapBuffer {
     int maximumNumberOfLines =
         paragraphAttributes.contains(PA_KEY_MAX_NUMBER_OF_LINES)
             ? paragraphAttributes.getInt(PA_KEY_MAX_NUMBER_OF_LINES)
-            : UNSET;
+            : ReactConstants.UNSET;
 
     int calculatedLineCount =
-        maximumNumberOfLines == UNSET || maximumNumberOfLines == 0
+        maximumNumberOfLines == ReactConstants.UNSET || maximumNumberOfLines == 0
             ? layout.getLineCount()
             : Math.min(maximumNumberOfLines, layout.getLineCount());
 

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

@@ -0,0 +1,280 @@
+/*
+ * 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.
+ */
+
+package com.facebook.react.views.text
+
+import android.content.Context
+import android.graphics.Color
+import android.text.*
+import android.view.View
+import com.facebook.react.common.ReactConstants
+import com.facebook.react.uimanager.PixelUtil
+import com.facebook.react.uimanager.ReactAccessibilityDelegate
+import com.facebook.react.views.text.fragments.TextFragmentList
+
+/** Utility methods for building [Spannable]s */
+internal object TextLayoutUtils {
+  private const val INLINE_VIEW_PLACEHOLDER = "0"
+
+  @JvmStatic
+  fun buildSpannableFromTextFragmentList(
+      context: Context,
+      textFragmentList: TextFragmentList,
+      sb: SpannableStringBuilder,
+      ops: MutableList<SetSpanOperation>,
+  ) {
+
+    for (i in 0 until textFragmentList.count) {
+      val fragment = textFragmentList.getFragment(i)
+      val start = sb.length
+
+      // ReactRawText
+      val textAttributes = fragment.textAttributeProps
+
+      addText(sb, fragment.string, textAttributes)
+
+      val end = sb.length
+      val reactTag = if (fragment.hasReactTag()) fragment.reactTag else View.NO_ID
+      if (fragment.hasIsAttachment() && fragment.isAttachment) {
+        val width = PixelUtil.toPixelFromSP(fragment.width)
+        val height = PixelUtil.toPixelFromSP(fragment.height)
+
+        addInlineViewPlaceholderSpan(ops, sb, reactTag, width, height)
+      } else if (end >= start) {
+        addApplicableTextAttributeSpans(ops, textAttributes, reactTag, context, start, end)
+      }
+    }
+  }
+
+  @JvmStatic
+  fun addText(
+      sb: SpannableStringBuilder,
+      text: String?,
+      textAttributeProvider: EffectiveTextAttributeProvider
+  ) {
+    sb.append(TextTransform.apply(text, textAttributeProvider.textTransform))
+  }
+
+  @JvmStatic
+  fun addInlineViewPlaceholderSpan(
+      ops: MutableList<SetSpanOperation>,
+      sb: SpannableStringBuilder,
+      reactTag: Int,
+      width: Float,
+      height: Float
+  ) {
+    ops.add(
+        SetSpanOperation(
+            sb.length - INLINE_VIEW_PLACEHOLDER.length,
+            sb.length,
+            TextInlineViewPlaceholderSpan(reactTag, width.toInt(), height.toInt())))
+  }
+
+  @JvmStatic
+  fun addApplicableTextAttributeSpans(
+      ops: MutableList<SetSpanOperation>,
+      textAttributeProvider: EffectiveTextAttributeProvider,
+      reactTag: Int,
+      context: Context,
+      start: Int,
+      end: Int
+  ) {
+    addColorSpanIfApplicable(ops, textAttributeProvider, start, end)
+
+    addBackgroundColorSpanIfApplicable(ops, textAttributeProvider, start, end)
+
+    addLinkSpanIfApplicable(ops, textAttributeProvider, reactTag, start, end)
+
+    addLetterSpacingSpanIfApplicable(ops, textAttributeProvider, start, end)
+
+    addFontSizeSpanIfApplicable(ops, textAttributeProvider, start, end)
+
+    addCustomStyleSpanIfApplicable(ops, textAttributeProvider, context, start, end)
+
+    addUnderlineSpanIfApplicable(ops, textAttributeProvider, start, end)
+
+    addStrikethroughSpanIfApplicable(ops, textAttributeProvider, start, end)
+
+    addShadowStyleSpanIfApplicable(ops, textAttributeProvider, start, end)
+
+    addLineHeightSpanIfApplicable(ops, textAttributeProvider, start, end)
+
+    addReactTagSpan(ops, start, end, reactTag)
+  }
+
+  @JvmStatic
+  private fun addLinkSpanIfApplicable(
+      ops: MutableList<SetSpanOperation>,
+      textAttributeProvider: EffectiveTextAttributeProvider,
+      reactTag: Int,
+      start: Int,
+      end: Int
+  ) {
+    val roleIsLink =
+        textAttributeProvider.role?.let { it == ReactAccessibilityDelegate.Role.LINK }
+            ?: (textAttributeProvider.accessibilityRole ==
+                ReactAccessibilityDelegate.AccessibilityRole.LINK)
+    if (roleIsLink) {
+      ops.add(SetSpanOperation(start, end, ReactClickableSpan(reactTag)))
+    }
+  }
+
+  @JvmStatic
+  private fun addColorSpanIfApplicable(
+      ops: MutableList<SetSpanOperation>,
+      textAttributeProvider: EffectiveTextAttributeProvider,
+      start: Int,
+      end: Int
+  ) {
+    if (textAttributeProvider.isColorSet) {
+      ops.add(SetSpanOperation(start, end, ReactForegroundColorSpan(textAttributeProvider.color)))
+    }
+  }
+
+  @JvmStatic
+  private fun addBackgroundColorSpanIfApplicable(
+      ops: MutableList<SetSpanOperation>,
+      textAttributeProvider: EffectiveTextAttributeProvider,
+      start: Int,
+      end: Int
+  ) {
+    if (textAttributeProvider.isBackgroundColorSet) {
+      ops.add(
+          SetSpanOperation(
+              start, end, ReactBackgroundColorSpan(textAttributeProvider.backgroundColor)))
+    }
+  }
+
+  @JvmStatic
+  private fun addLetterSpacingSpanIfApplicable(
+      ops: MutableList<SetSpanOperation>,
+      textAttributeProvider: EffectiveTextAttributeProvider,
+      start: Int,
+      end: Int
+  ) {
+    val effectiveLetterSpacing = textAttributeProvider.effectiveLetterSpacing
+
+    if (!effectiveLetterSpacing.isNaN()) {
+      ops.add(SetSpanOperation(start, end, CustomLetterSpacingSpan(effectiveLetterSpacing)))
+    }
+  }
+
+  @JvmStatic
+  private fun addFontSizeSpanIfApplicable(
+      ops: MutableList<SetSpanOperation>,
+      textAttributeProvider: EffectiveTextAttributeProvider,
+      start: Int,
+      end: Int
+  ) {
+    val effectiveFontSize = textAttributeProvider.effectiveFontSize
+
+    if (effectiveFontSize != ReactConstants.UNSET) {
+      ops.add(SetSpanOperation(start, end, ReactAbsoluteSizeSpan(effectiveFontSize)))
+    }
+  }
+
+  @JvmStatic
+  private fun addCustomStyleSpanIfApplicable(
+      ops: MutableList<SetSpanOperation>,
+      textAttributeProvider: EffectiveTextAttributeProvider,
+      context: Context,
+      start: Int,
+      end: Int
+  ) {
+    val fontStyle = textAttributeProvider.fontStyle
+    val fontWeight = textAttributeProvider.fontWeight
+    val fontFamily = textAttributeProvider.fontFamily
+
+    if (fontStyle != ReactConstants.UNSET ||
+        fontWeight != ReactConstants.UNSET ||
+        fontFamily != null) {
+      ops.add(
+          SetSpanOperation(
+              start,
+              end,
+              CustomStyleSpan(
+                  fontStyle,
+                  fontWeight,
+                  textAttributeProvider.fontFeatureSettings,
+                  fontFamily,
+                  context.assets)))
+    }
+  }
+
+  @JvmStatic
+  private fun addUnderlineSpanIfApplicable(
+      ops: MutableList<SetSpanOperation>,
+      textAttributeProvider: EffectiveTextAttributeProvider,
+      start: Int,
+      end: Int
+  ) {
+    if (textAttributeProvider.isUnderlineTextDecorationSet) {
+      ops.add(SetSpanOperation(start, end, ReactUnderlineSpan()))
+    }
+  }
+
+  @JvmStatic
+  private fun addStrikethroughSpanIfApplicable(
+      ops: MutableList<SetSpanOperation>,
+      textAttributeProvider: EffectiveTextAttributeProvider,
+      start: Int,
+      end: Int
+  ) {
+    if (textAttributeProvider.isLineThroughTextDecorationSet) {
+      ops.add(SetSpanOperation(start, end, ReactStrikethroughSpan()))
+    }
+  }
+
+  @JvmStatic
+  private fun addShadowStyleSpanIfApplicable(
+      ops: MutableList<SetSpanOperation>,
+      textAttributeProvider: EffectiveTextAttributeProvider,
+      start: Int,
+      end: Int
+  ) {
+    val hasTextShadowOffset =
+        textAttributeProvider.textShadowOffsetDx != 0f ||
+            textAttributeProvider.textShadowOffsetDy != 0f
+    val hasTextShadowRadius = textAttributeProvider.textShadowRadius != 0f
+    val hasTextShadowColorAlpha = Color.alpha(textAttributeProvider.textShadowColor) != 0
+
+    if ((hasTextShadowOffset || hasTextShadowRadius) && hasTextShadowColorAlpha) {
+      ops.add(
+          SetSpanOperation(
+              start,
+              end,
+              ShadowStyleSpan(
+                  textAttributeProvider.textShadowOffsetDx,
+                  textAttributeProvider.textShadowOffsetDy,
+                  textAttributeProvider.textShadowRadius,
+                  textAttributeProvider.textShadowColor)))
+    }
+  }
+
+  @JvmStatic
+  private fun addLineHeightSpanIfApplicable(
+      ops: MutableList<SetSpanOperation>,
+      textAttributeProvider: EffectiveTextAttributeProvider,
+      start: Int,
+      end: Int
+  ) {
+    val effectiveLineHeight = textAttributeProvider.effectiveLineHeight
+    if (!effectiveLineHeight.isNaN()) {
+      ops.add(SetSpanOperation(start, end, CustomLineHeightSpan(effectiveLineHeight)))
+    }
+  }
+
+  @JvmStatic
+  private fun addReactTagSpan(
+      ops: MutableList<SetSpanOperation>,
+      start: Int,
+      end: Int,
+      reactTag: Int
+  ) {
+    ops.add(SetSpanOperation(start, end, ReactTagSpan(reactTag)))
+  }
+}

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

@@ -7,6 +7,7 @@
 
 package com.facebook.react.views.text;
 
+import androidx.annotation.Nullable;
 import java.text.BreakIterator;
 
 /** Types of text transforms for CustomTextTransformSpan */
@@ -17,7 +18,7 @@ public enum TextTransform {
   CAPITALIZE,
   UNSET;
 
-  public static String apply(String text, TextTransform textTransform) {
+  public static String apply(@Nullable String text, TextTransform textTransform) {
     if (text == null) {
       return null;
     }

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

@@ -0,0 +1,39 @@
+/*
+ * 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.
+ */
+
+package com.facebook.react.views.text.fragments
+
+import com.facebook.react.bridge.ReadableMap
+import com.facebook.react.uimanager.ReactStylesDiffMap
+import com.facebook.react.uimanager.ViewProps
+import com.facebook.react.views.text.TextAttributeProps
+
+/** A [TextFragment] implementation backed by a a [ReadableMap] */
+internal class BridgeTextFragment(private val fragment: ReadableMap) : TextFragment {
+  override val textAttributeProps: TextAttributeProps
+    get() =
+        TextAttributeProps.fromReadableMap(ReactStylesDiffMap(fragment.getMap("textAttributes")))
+
+  override val string: String?
+    get() = fragment.getString("string")
+
+  override fun hasReactTag(): Boolean = fragment.hasKey("reactTag")
+
+  override val reactTag: Int
+    get() = fragment.getInt("reactTag")
+
+  override fun hasIsAttachment(): Boolean = fragment.hasKey(ViewProps.IS_ATTACHMENT)
+
+  override val isAttachment: Boolean
+    get() = fragment.getBoolean(ViewProps.IS_ATTACHMENT)
+
+  override val width: Double
+    get() = fragment.getDouble(ViewProps.WIDTH)
+
+  override val height: Double
+    get() = fragment.getDouble(ViewProps.HEIGHT)
+}

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

@@ -0,0 +1,18 @@
+/*
+ * 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.
+ */
+
+package com.facebook.react.views.text.fragments
+
+import com.facebook.react.bridge.ReadableArray
+
+/** A list of [TextFragment]s backed by a [ReadableArray] */
+internal class BridgeTextFragmentList(private val fragments: ReadableArray) : TextFragmentList {
+  override fun getFragment(index: Int): TextFragment = BridgeTextFragment(fragments.getMap(index))
+
+  override val count: Int
+    get() = fragments.size()
+}

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

@@ -0,0 +1,42 @@
+/*
+ * 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.
+ */
+
+package com.facebook.react.views.text.fragments
+
+import com.facebook.react.common.mapbuffer.MapBuffer
+import com.facebook.react.views.text.TextAttributeProps
+import com.facebook.react.views.text.TextLayoutManagerMapBuffer.FR_KEY_HEIGHT
+import com.facebook.react.views.text.TextLayoutManagerMapBuffer.FR_KEY_IS_ATTACHMENT
+import com.facebook.react.views.text.TextLayoutManagerMapBuffer.FR_KEY_REACT_TAG
+import com.facebook.react.views.text.TextLayoutManagerMapBuffer.FR_KEY_STRING
+import com.facebook.react.views.text.TextLayoutManagerMapBuffer.FR_KEY_TEXT_ATTRIBUTES
+import com.facebook.react.views.text.TextLayoutManagerMapBuffer.FR_KEY_WIDTH
+
+/** A [TextFragment] implementation backed by a [MapBuffer] */
+internal class MapBufferTextFragment(private val fragment: MapBuffer) : TextFragment {
+  override val textAttributeProps: TextAttributeProps
+    get() = TextAttributeProps.fromMapBuffer(fragment.getMapBuffer(FR_KEY_TEXT_ATTRIBUTES.toInt()))
+
+  override val string: String
+    get() = fragment.getString(FR_KEY_STRING.toInt())
+
+  override fun hasReactTag(): Boolean = fragment.contains(FR_KEY_REACT_TAG.toInt())
+
+  override val reactTag: Int
+    get() = fragment.getInt(FR_KEY_REACT_TAG.toInt())
+
+  override fun hasIsAttachment(): Boolean = fragment.contains(FR_KEY_IS_ATTACHMENT.toInt())
+
+  override val isAttachment: Boolean
+    get() = fragment.getBoolean(FR_KEY_IS_ATTACHMENT.toInt())
+
+  override val width: Double
+    get() = fragment.getDouble(FR_KEY_WIDTH.toInt())
+
+  override val height: Double
+    get() = fragment.getDouble(FR_KEY_HEIGHT.toInt())
+}

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

@@ -0,0 +1,19 @@
+/*
+ * 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.
+ */
+
+package com.facebook.react.views.text.fragments
+
+import com.facebook.react.common.mapbuffer.MapBuffer
+
+/** A list of [TextFragment]s backed by a [MapBuffer] */
+internal class MapBufferTextFragmentList(private val fragments: MapBuffer) : TextFragmentList {
+  override fun getFragment(index: Int): TextFragment =
+      MapBufferTextFragment(fragments.getMapBuffer(index))
+
+  override val count: Int
+    get() = fragments.count
+}

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

@@ -0,0 +1,29 @@
+/*
+ * 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.
+ */
+
+package com.facebook.react.views.text.fragments
+
+import com.facebook.react.views.text.TextAttributeProps
+
+/** Interface for a text fragment */
+internal interface TextFragment {
+  val textAttributeProps: TextAttributeProps
+
+  val string: String?
+
+  fun hasReactTag(): Boolean
+
+  val reactTag: Int
+
+  fun hasIsAttachment(): Boolean
+
+  val isAttachment: Boolean
+
+  val width: Double
+
+  val height: Double
+}

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

@@ -0,0 +1,15 @@
+/*
+ * 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.
+ */
+
+package com.facebook.react.views.text.fragments
+
+/** Interface for a list of [TextFragment]s */
+internal interface TextFragmentList {
+  fun getFragment(index: Int): TextFragment
+
+  val count: Int
+}

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactEditText.java

@@ -46,6 +46,7 @@ import com.facebook.common.logging.FLog;
 import com.facebook.infer.annotation.Assertions;
 import com.facebook.react.bridge.ReactContext;
 import com.facebook.react.bridge.ReactSoftExceptionLogger;
+import com.facebook.react.common.ReactConstants;
 import com.facebook.react.common.build.ReactBuildConfig;
 import com.facebook.react.uimanager.ReactAccessibilityDelegate;
 import com.facebook.react.uimanager.StateWrapper;
@@ -96,8 +97,6 @@ public class ReactEditText extends AppCompatEditText {
   /** A count of events sent to JS or C++. */
   protected int mNativeEventCount;
 
-  private static final int UNSET = -1;
-
   private @Nullable ArrayList<TextWatcher> mListeners;
   private @Nullable TextWatcherDelegator mTextWatcherDelegator;
   private int mStagedInputType;
@@ -114,8 +113,8 @@ public class ReactEditText extends AppCompatEditText {
   private TextAttributes mTextAttributes;
   private boolean mTypefaceDirty = false;
   private @Nullable String mFontFamily = null;
-  private int mFontWeight = UNSET;
-  private int mFontStyle = UNSET;
+  private int mFontWeight = ReactConstants.UNSET;
+  private int mFontStyle = ReactConstants.UNSET;
   private boolean mAutoFocus = false;
   private boolean mDidAttachToWindow = false;
   private @Nullable String mPlaceholder = null;
@@ -379,7 +378,7 @@ public class ReactEditText extends AppCompatEditText {
       return;
     }
 
-    if (start != UNSET && end != UNSET) {
+    if (start != ReactConstants.UNSET && end != ReactConstants.UNSET) {
       // clamp selection values for safety
       start = clampToTextLength(start);
       end = clampToTextLength(end);
@@ -588,8 +587,8 @@ public class ReactEditText extends AppCompatEditText {
 
     // Match behavior of CustomStyleSpan and enable SUBPIXEL_TEXT_FLAG when setting anything
     // nonstandard
-    if (mFontStyle != UNSET
-        || mFontWeight != UNSET
+    if (mFontStyle != ReactConstants.UNSET
+        || mFontWeight != ReactConstants.UNSET
         || mFontFamily != null
         || getFontFeatureSettings() != null) {
       setPaintFlags(getPaintFlags() | Paint.SUBPIXEL_TEXT_FLAG);
@@ -819,8 +818,8 @@ public class ReactEditText extends AppCompatEditText {
           new CustomLetterSpacingSpan(effectiveLetterSpacing), 0, workingText.length(), spanFlags);
     }
 
-    if (mFontStyle != UNSET
-        || mFontWeight != UNSET
+    if (mFontStyle != ReactConstants.UNSET
+        || mFontWeight != ReactConstants.UNSET
         || mFontFamily != null
         || getFontFeatureSettings() != null) {
       workingText.setSpan(

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactTextInputShadowNode.java

@@ -36,7 +36,7 @@ import com.facebook.yoga.YogaNode;
 public class ReactTextInputShadowNode extends ReactBaseTextShadowNode
     implements YogaMeasureFunction {
 
-  private int mMostRecentEventCount = UNSET;
+  private int mMostRecentEventCount = ReactConstants.UNSET;
   private @Nullable EditText mInternalEditText;
   private @Nullable ReactTextInputLocalData mLocalData;
 
@@ -108,7 +108,7 @@ public class ReactTextInputShadowNode extends ReactBaseTextShadowNode
     } else {
       editText.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTextAttributes.getEffectiveFontSize());
 
-      if (mNumberOfLines != UNSET) {
+      if (mNumberOfLines != ReactConstants.UNSET) {
         editText.setLines(mNumberOfLines);
       }
 
@@ -191,7 +191,7 @@ public class ReactTextInputShadowNode extends ReactBaseTextShadowNode
   public void onCollectExtraUpdates(UIViewOperationQueue uiViewOperationQueue) {
     super.onCollectExtraUpdates(uiViewOperationQueue);
 
-    if (mMostRecentEventCount != UNSET) {
+    if (mMostRecentEventCount != ReactConstants.UNSET) {
       ReactTextUpdate reactTextUpdate =
           new ReactTextUpdate(
               spannedFromShadowNode(