fix(android): keep ReactTextView line breaking advance-based on Android 15+ so the last line is not clipped

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

@@ -24,6 +24,7 @@
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.TextView;
 import androidx.annotation.Nullable;
 import androidx.appcompat.widget.AppCompatTextView;
 import androidx.core.view.AccessibilityDelegateCompat;
@@ -46,10 +47,12 @@
 import com.facebook.react.uimanager.style.BorderStyle;
 import com.facebook.react.uimanager.style.LogicalEdge;
 import com.facebook.react.uimanager.style.Overflow;
+import com.facebook.react.util.AndroidVersion;
 import com.facebook.react.views.text.internal.span.CanvasEffectSpan;
 import com.facebook.react.views.text.internal.span.ReactFragmentIndexSpan;
 import com.facebook.react.views.text.internal.span.ReactTagSpan;
 import com.facebook.yoga.YogaMeasureMode;
+import java.lang.reflect.Method;
 
 @Nullsafe(Nullsafe.Mode.LOCAL)
 public class ReactTextView extends AppCompatTextView implements ReactCompoundView {
@@ -60,6 +63,10 @@ public class ReactTextView extends AppCompatTextView implements ReactCompoundVie
   // https://github.com/aosp-mirror/platform_frameworks_base/blob/master/core/java/android/widget/TextView.java#L854
   private static final int DEFAULT_GRAVITY = Gravity.TOP | Gravity.START;
 
+  // TextView.setUseBoundsForWidth (API 35+). Looked up reflectively because some internal targets
+  // compile against an SDK older than 35 (see AndroidVersion).
+  private static final @Nullable Method SET_USE_BOUNDS_FOR_WIDTH = resolveSetUseBoundsForWidth();
+
   private int mNumberOfLines;
   private @Nullable TextUtils.TruncateAt mEllipsizeLocation;
   private boolean mAdjustsFontSizeToFit;
@@ -76,9 +83,42 @@ public class ReactTextView extends AppCompatTextView implements ReactCompoundVie
 
   public ReactTextView(Context context) {
     super(context);
+    matchLineBreakingToMeasurement();
     initView();
   }
 
+  private static @Nullable Method resolveSetUseBoundsForWidth() {
+    if (Build.VERSION.SDK_INT < AndroidVersion.VERSION_CODE_VANILLA_ICE_CREAM) {
+      return null;
+    }
+    try {
+      return TextView.class.getMethod("setUseBoundsForWidth", boolean.class);
+    } catch (NoSuchMethodException e) {
+      return null;
+    }
+  }
+
+  /**
+   * Keeps this view's line breaking on the same basis as TextLayoutManager's measurement.
+   *
+   * <p>On Android 15+ a TextView in an app targeting API 35+ breaks lines on glyph bounds
+   * (TextView#USE_BOUNDS_FOR_WIDTH), while TextLayoutManager measures with a StaticLayout that
+   * breaks on glyph advances. For a font whose ink overhangs its advance, a line that fit at
+   * measure time can wrap at draw time; the extra line lands outside the measured height and is
+   * never seen. Drawing with advance-based breaking makes the painted line count match the
+   * measured one.
+   */
+  private void matchLineBreakingToMeasurement() {
+    if (SET_USE_BOUNDS_FOR_WIDTH == null) {
+      return;
+    }
+    try {
+      SET_USE_BOUNDS_FOR_WIDTH.invoke(this, false);
+    } catch (ReflectiveOperationException e) {
+      FLog.w(ReactConstants.TAG, "Could not disable useBoundsForWidth on ReactTextView", e);
+    }
+  }
+
   /**
    * Set all default values here as opposed to in the constructor or field defaults. It is important
    * that these properties are set during the constructor, but also on-demand whenever an existing
@@ -151,6 +191,7 @@ private void initView() {
     }
 
     setHyphenationFrequency(Layout.HYPHENATION_FREQUENCY_NONE);
+    matchLineBreakingToMeasurement();
     updateView(); // call after changing ellipsizeLocation in particular
   }
 

packages/react-native/ReactAndroid/src/test/java/com/facebook/react/views/text/ReactTextViewTest.kt

@@ -27,6 +27,7 @@ import org.junit.Test
 import org.junit.runner.RunWith
 import org.robolectric.RobolectricTestRunner
 import org.robolectric.RuntimeEnvironment
+import org.robolectric.annotation.Config
 
 @RunWith(RobolectricTestRunner::class)
 class ReactTextViewTest {
@@ -86,6 +87,28 @@ class ReactTextViewTest {
     assertThat(fontSizeWhenShort).isLessThan(fontSizeWhenTall)
   }
 
+  @Test
+  @Config(sdk = [35])
+  fun breaksLinesOnAdvancesLikeMeasurementOnApi35() {
+    // TextLayoutManager measures with an advance-based StaticLayout; on API 35+ a TextView in an
+    // app targeting 35+ defaults to bounds-based breaking, which can wrap one more line at draw
+    // than at measure and clip it. The view must opt out so both agree.
+    val view = ReactTextView(RuntimeEnvironment.getApplication())
+
+    assertThat(view.useBoundsForWidth).isFalse()
+  }
+
+  @Test
+  @Config(sdk = [35])
+  fun recyclingRestoresAdvanceBasedLineBreaking() {
+    val view = ReactTextView(RuntimeEnvironment.getApplication())
+    view.useBoundsForWidth = true
+
+    view.recycleView()
+
+    assertThat(view.useBoundsForWidth).isFalse()
+  }
+
   private fun layoutAndDraw(view: TestReactTextView, width: Int, height: Int) {
     view.measure(
         View.MeasureSpec.makeMeasureSpec(width, View.MeasureSpec.EXACTLY),

packages/rn-tester/js/examples/Text/TextExample.android.js

@@ -1442,6 +1442,51 @@ const examples = [
       );
     },
   },
+  {
+    title: 'Android 15+ glyph overhang (last line must not disappear)',
+    name: 'androidGlyphOverhangLineBreaking',
+    render(): React.Node {
+      // Android's generic `cursive` family (Dancing Script) has glyphs whose
+      // ink extends past their advance. In a shrink-wrapping container the view
+      // is measured on advances; if the drawn TextView breaks lines on bounds
+      // instead, the trailing colored "f" wraps to a line outside the measured
+      // height and is never painted. Every row must show its green "f".
+      const rows = [
+        'Enjoy your',
+        'Enjoy your coffee',
+        'Enjoy your coffee, my',
+        'Enjoy your morning coffee, my friend',
+      ];
+      return (
+        <View>
+          {rows.map(text => (
+            <View key={text} style={{flexDirection: 'row', gap: 8}}>
+              <View style={styles.overhangBubble}>
+                <Text
+                  allowFontScaling={false}
+                  style={{fontFamily: 'cursive', fontSize: 18, lineHeight: 27}}>
+                  {text}
+                  <Text style={{color: 'green'}}> f</Text>
+                </Text>
+              </View>
+              <View style={styles.overhangBubble}>
+                <Text
+                  allowFontScaling={false}
+                  style={{fontSize: 18, lineHeight: 27}}>
+                  {text}
+                  <Text style={{color: 'green'}}> f</Text>
+                </Text>
+              </View>
+            </View>
+          ))}
+          <RNTesterText style={{marginTop: 8}}>
+            Left: cursive (overhangs). Right: default font (control). A missing
+            green f on the left is the bug.
+          </RNTesterText>
+        </View>
+      );
+    },
+  },
   {
     title: 'Text metrics legend',
     name: 'textMetricLegend',
@@ -1846,6 +1891,15 @@ const examples = [
 ];
 
 const styles = StyleSheet.create({
+  overhangBubble: {
+    alignSelf: 'flex-start',
+    maxWidth: '48%',
+    borderWidth: 1,
+    borderColor: '#ccc',
+    borderRadius: 8,
+    padding: 8,
+    marginBottom: 8,
+  },
   backgroundColorText: {
     left: 5,
     backgroundColor: 'rgba(100, 100, 100, 0.3)',