Measure text at the window's density on Android (#59087)

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlags.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<eb0bafceba60cb439a4be3d68b890725>>
+ * @generated SignedSource<<cfa7aa53731059247d858fd8fb6e914b>>
  */
 
 /**
@@ -564,6 +564,12 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun useTurboModuleInterop(): Boolean = accessor.useTurboModuleInterop()
 
+  /**
+   * Keeps the window density in the screen display metrics instead of the physical display density, so text is measured at the density the window renders at.
+   */
+  @JvmStatic
+  public fun useWindowDensityForDisplayMetricsAndroid(): Boolean = accessor.useWindowDensityForDisplayMetricsAndroid()
+
   /**
    * Outset the culling context frame with the provided ratio. The culling context frame size will be outset by width * ratio on the left and right, and height * ratio on the top and bottom.
    */

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxAccessor.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<0107593110db613063b6f4ceb50d8e58>>
+ * @generated SignedSource<<71d0554dc45df7d5365f81b7ec8c3d5b>>
  */
 
 /**
@@ -109,6 +109,7 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
   private var useSharedAnimatedBackendCache: Boolean? = null
   private var useTraitHiddenOnAndroidCache: Boolean? = null
   private var useTurboModuleInteropCache: Boolean? = null
+  private var useWindowDensityForDisplayMetricsAndroidCache: Boolean? = null
   private var viewCullingOutsetRatioCache: Double? = null
   private var viewTransitionEnabledCache: Boolean? = null
   private var viewTransitionUseHardwareBitmapAndroidCache: Boolean? = null
@@ -915,6 +916,15 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun useWindowDensityForDisplayMetricsAndroid(): Boolean {
+    var cached = useWindowDensityForDisplayMetricsAndroidCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.useWindowDensityForDisplayMetricsAndroid()
+      useWindowDensityForDisplayMetricsAndroidCache = cached
+    }
+    return cached
+  }
+
   override fun viewCullingOutsetRatio(): Double {
     var cached = viewCullingOutsetRatioCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxInterop.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<fa0374808e3cbe7122ca993780c0b627>>
+ * @generated SignedSource<<312cec99bd429d22e25f4e82d7fc4ee7>>
  */
 
 /**
@@ -206,6 +206,8 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun useTurboModuleInterop(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun useWindowDensityForDisplayMetricsAndroid(): Boolean
+
   @DoNotStrip @JvmStatic public external fun viewCullingOutsetRatio(): Double
 
   @DoNotStrip @JvmStatic public external fun viewTransitionEnabled(): Boolean

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsDefaults.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<768077a22c110aa98ab02bc96eec695b>>
+ * @generated SignedSource<<669f16e131d4a5ddc026ffecc6893575>>
  */
 
 /**
@@ -201,6 +201,8 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun useTurboModuleInterop(): Boolean = false
 
+  override fun useWindowDensityForDisplayMetricsAndroid(): Boolean = false
+
   override fun viewCullingOutsetRatio(): Double = 0.0
 
   override fun viewTransitionEnabled(): Boolean = false

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsLocalAccessor.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<86ebc7307e7ebe2023e909a868ed3117>>
+ * @generated SignedSource<<ee4c0f9c1e7c6af3b0d15948ebc519b3>>
  */
 
 /**
@@ -113,6 +113,7 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
   private var useSharedAnimatedBackendCache: Boolean? = null
   private var useTraitHiddenOnAndroidCache: Boolean? = null
   private var useTurboModuleInteropCache: Boolean? = null
+  private var useWindowDensityForDisplayMetricsAndroidCache: Boolean? = null
   private var viewCullingOutsetRatioCache: Double? = null
   private var viewTransitionEnabledCache: Boolean? = null
   private var viewTransitionUseHardwareBitmapAndroidCache: Boolean? = null
@@ -1008,6 +1009,16 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
     return cached
   }
 
+  override fun useWindowDensityForDisplayMetricsAndroid(): Boolean {
+    var cached = useWindowDensityForDisplayMetricsAndroidCache
+    if (cached == null) {
+      cached = currentProvider.useWindowDensityForDisplayMetricsAndroid()
+      accessedFeatureFlags.add("useWindowDensityForDisplayMetricsAndroid")
+      useWindowDensityForDisplayMetricsAndroidCache = cached
+    }
+    return cached
+  }
+
   override fun viewCullingOutsetRatio(): Double {
     var cached = viewCullingOutsetRatioCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<c83fba10dc6f7d596e3bcd9725c64e6e>>
+ * @generated SignedSource<<18267103ef4f3eb22f23a15b808528c2>>
  */
 
 /**
@@ -201,6 +201,8 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun useTurboModuleInterop(): Boolean
 
+  @DoNotStrip public fun useWindowDensityForDisplayMetricsAndroid(): Boolean
+
   @DoNotStrip public fun viewCullingOutsetRatio(): Double
 
   @DoNotStrip public fun viewTransitionEnabled(): Boolean

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/DisplayMetricsHolder.kt

@@ -14,6 +14,7 @@ import android.util.DisplayMetrics
 import android.view.WindowManager
 import androidx.core.view.ViewCompat
 import androidx.core.view.WindowInsetsCompat
+import com.facebook.react.internal.featureflags.ReactNativeFeatureFlags
 import com.facebook.react.uimanager.PixelUtil.pxToDp
 
 /**
@@ -61,6 +62,13 @@ public object DisplayMetricsHolder {
       // Non-visual contexts (e.g. Application) may throw on API 30+.
       // Falls back to resource display metrics copied via setTo() above.
     }
+    if (
+        displayMetrics.densityDpi != screenDisplayMetrics.densityDpi &&
+            ReactNativeFeatureFlags.useWindowDensityForDisplayMetricsAndroid()
+    ) {
+      screenDisplayMetrics.density = displayMetrics.density
+      screenDisplayMetrics.densityDpi = displayMetrics.densityDpi
+    }
     // Preserve fontScale from the configuration because getRealMetrics() returns
     // physical display metrics without the system font scale setting.
     // This is needed for proper text scaling when fontScale < 1.0

packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.cpp

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<200266835197634d13de07182d80a2c1>>
+ * @generated SignedSource<<568d6e4175fb51e09bc3d4441ffa9741>>
  */
 
 /**
@@ -573,6 +573,12 @@ class ReactNativeFeatureFlagsJavaProvider
     return method(javaProvider_);
   }
 
+  bool useWindowDensityForDisplayMetricsAndroid() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("useWindowDensityForDisplayMetricsAndroid");
+    return method(javaProvider_);
+  }
+
   double viewCullingOutsetRatio() override {
     static const auto method =
         getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jdouble()>("viewCullingOutsetRatio");
@@ -1046,6 +1052,11 @@ bool JReactNativeFeatureFlagsCxxInterop::useTurboModuleInterop(
   return ReactNativeFeatureFlags::useTurboModuleInterop();
 }
 
+bool JReactNativeFeatureFlagsCxxInterop::useWindowDensityForDisplayMetricsAndroid(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::useWindowDensityForDisplayMetricsAndroid();
+}
+
 double JReactNativeFeatureFlagsCxxInterop::viewCullingOutsetRatio(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::viewCullingOutsetRatio();
@@ -1364,6 +1375,9 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "useTurboModuleInterop",
         JReactNativeFeatureFlagsCxxInterop::useTurboModuleInterop),
+      makeNativeMethod(
+        "useWindowDensityForDisplayMetricsAndroid",
+        JReactNativeFeatureFlagsCxxInterop::useWindowDensityForDisplayMetricsAndroid),
       makeNativeMethod(
         "viewCullingOutsetRatio",
         JReactNativeFeatureFlagsCxxInterop::viewCullingOutsetRatio),

packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<13aa248dae556b06b31c25a28e448460>>
+ * @generated SignedSource<<2e0f936c003aafc456ab3f960ca4b2f3>>
  */
 
 /**
@@ -297,6 +297,9 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool useTurboModuleInterop(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
+  static bool useWindowDensityForDisplayMetricsAndroid(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
   static double viewCullingOutsetRatio(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 

packages/react-native/ReactAndroid/src/test/java/com/facebook/react/uimanager/DisplayMetricsHolderTest.kt

@@ -17,6 +17,9 @@ import android.view.View
 import android.view.Window
 import android.view.WindowInsets
 import androidx.annotation.RequiresApi
+import com.facebook.react.internal.featureflags.ReactNativeFeatureFlags
+import com.facebook.react.internal.featureflags.ReactNativeFeatureFlagsDefaults
+import com.facebook.react.internal.featureflags.ReactNativeFeatureFlagsForTests
 import com.facebook.testutils.shadows.ShadowNativeLoader
 import com.facebook.testutils.shadows.ShadowNativeMap
 import com.facebook.testutils.shadows.ShadowReadableNativeMap
@@ -52,6 +55,7 @@ class DisplayMetricsHolderTest {
 
   @Before
   fun setUp() {
+    ReactNativeFeatureFlagsForTests.setUp()
     context = RuntimeEnvironment.getApplication()
     displayMetrics = context.resources.displayMetrics
     DisplayMetricsHolder.setScreenDisplayMetrics(null)
@@ -60,6 +64,7 @@ class DisplayMetricsHolderTest {
   @After
   fun tearDown() {
     DisplayMetricsHolder.setScreenDisplayMetrics(null)
+    ReactNativeFeatureFlags.dangerouslyReset()
   }
 
   @Test(expected = IllegalStateException::class)
@@ -142,6 +147,41 @@ class DisplayMetricsHolderTest {
     assertThat(screenMetrics.scaledDensity).isEqualTo(customScaledDensity)
   }
 
+  @Test
+  fun initDisplayMetrics_withWindowDensityFlag_usesTheWindowDensity() {
+    overrideWindowDensityFlag(true)
+    setWindowDensityTo400Dpi()
+
+    DisplayMetricsHolder.initDisplayMetrics(context)
+
+    val screenMetrics = DisplayMetricsHolder.getScreenDisplayMetrics()
+    assertThat(screenMetrics.density).isEqualTo(2.5f)
+    assertThat(screenMetrics.densityDpi).isEqualTo(DisplayMetrics.DENSITY_400)
+    assertThat(PixelUtil.toDIPFromPixel(PixelUtil.toPixelFromSP(16f))).isEqualTo(16f)
+  }
+
+  @Test
+  fun initDisplayMetrics_withoutWindowDensityFlag_usesTheDisplayDensity() {
+    DisplayMetricsHolder.initDisplayMetrics(context)
+    val displayDensityDpi = DisplayMetricsHolder.getScreenDisplayMetrics().densityDpi
+    overrideWindowDensityFlag(false)
+    setWindowDensityTo400Dpi()
+
+    DisplayMetricsHolder.initDisplayMetrics(context)
+
+    assertThat(DisplayMetricsHolder.getScreenDisplayMetrics().densityDpi)
+        .isEqualTo(displayDensityDpi)
+        .isNotEqualTo(DisplayMetrics.DENSITY_400)
+  }
+
+  @Test
+  fun initDisplayMetrics_withMatchingDensities_doesNotReadFeatureFlags() {
+    DisplayMetricsHolder.initDisplayMetrics(context)
+    overrideWindowDensityFlag(true)
+
+    assertThat(ReactNativeFeatureFlags.useWindowDensityForDisplayMetricsAndroid()).isTrue()
+  }
+
   @Test
   fun initDisplayMetrics_doesNotCrashWithNonVisualContext() {
     val mockContext: Context = mock()
@@ -164,4 +204,19 @@ class DisplayMetricsHolderTest {
     // Metrics should still be set from resource display metrics
     assertThat(DisplayMetricsHolder.getScreenDisplayMetrics()).isNotNull()
   }
+
+  private fun overrideWindowDensityFlag(enabled: Boolean) {
+    ReactNativeFeatureFlags.override(
+        object : ReactNativeFeatureFlagsDefaults() {
+          override fun useWindowDensityForDisplayMetricsAndroid(): Boolean = enabled
+        },
+    )
+  }
+
+  private fun setWindowDensityTo400Dpi() {
+    val resourceMetrics = context.resources.displayMetrics
+    resourceMetrics.density = 2.5f
+    resourceMetrics.densityDpi = DisplayMetrics.DENSITY_400
+    resourceMetrics.scaledDensity = 2.5f
+  }
 }

packages/react-native/ReactAndroid/src/test/java/com/facebook/react/uimanager/PixelUtilTest.kt

@@ -14,6 +14,8 @@ import android.content.Context
 import android.content.res.Configuration
 import android.content.res.Resources
 import android.util.DisplayMetrics
+import com.facebook.react.internal.featureflags.ReactNativeFeatureFlags
+import com.facebook.react.internal.featureflags.ReactNativeFeatureFlagsForTests
 import com.facebook.testutils.shadows.ShadowNativeLoader
 import com.facebook.testutils.shadows.ShadowSoLoader
 import kotlin.math.abs
@@ -36,13 +38,15 @@ class PixelUtilTest {
 
   @Before
   fun setUp() {
+    ReactNativeFeatureFlagsForTests.setUp()
     context = RuntimeEnvironment.getApplication()
     DisplayMetricsHolder.setScreenDisplayMetrics(null)
   }
 
   @After
   fun tearDown() {
     DisplayMetricsHolder.setScreenDisplayMetrics(null)
+    ReactNativeFeatureFlags.dangerouslyReset()
   }
 
   @Test

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.cpp

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<fc4b67b43c846eac0085ed4a5528a170>>
+ * @generated SignedSource<<f90778065a9a5f48383dd9b4606bd862>>
  */
 
 /**
@@ -382,6 +382,10 @@ bool ReactNativeFeatureFlags::useTurboModuleInterop() {
   return getAccessor().useTurboModuleInterop();
 }
 
+bool ReactNativeFeatureFlags::useWindowDensityForDisplayMetricsAndroid() {
+  return getAccessor().useWindowDensityForDisplayMetricsAndroid();
+}
+
 double ReactNativeFeatureFlags::viewCullingOutsetRatio() {
   return getAccessor().viewCullingOutsetRatio();
 }

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<1a9a8a587b477b6aa0d3aa57e30272c2>>
+ * @generated SignedSource<<62dbb584d6aaf595314636a81346e3e5>>
  */
 
 /**
@@ -486,6 +486,11 @@ class ReactNativeFeatureFlags {
    */
   RN_EXPORT static bool useTurboModuleInterop();
 
+  /**
+   * Keeps the window density in the screen display metrics instead of the physical display density, so text is measured at the density the window renders at.
+   */
+  RN_EXPORT static bool useWindowDensityForDisplayMetricsAndroid();
+
   /**
    * Outset the culling context frame with the provided ratio. The culling context frame size will be outset by width * ratio on the left and right, and height * ratio on the top and bottom.
    */