Accept object font variation settings

Summary:
Allow `fontVariationSettings` to accept either the existing CSS-compatible
string or an object keyed by four-character OpenType axis tags. Normalize the
object at the shared style boundary so Text and TextInput retain the existing
native string representation on every platform.

Object serialization is deterministic, supports fractional finite values, and
preserves the current unset versus explicit-clear behavior.

Changelog:
[General][Added] - Add object syntax for `fontVariationSettings`

Differential Revision: D115640672

Author: evankatz14

packages/react-native/Libraries/Components/TextInput/AndroidTextInputNativeComponent.js

@@ -24,7 +24,10 @@ import type {TextInputNativeCommands} from './TextInputNativeCommands';
 
 import * as NativeComponentRegistry from '../../NativeComponent/NativeComponentRegistry';
 import codegenNativeCommands from '../../Utilities/codegenNativeCommands';
-import {colorAttribute} from '../View/ReactNativeStyleAttributes';
+import {
+  colorAttribute,
+  fontVariationSettingsAttribute,
+} from '../View/ReactNativeStyleAttributes';
 
 export type KeyboardType =
   // Cross Platform
@@ -715,7 +718,7 @@ export const __INTERNAL_VIEW_CONFIG: PartialViewConfig = {
     includeFontPadding: true,
     fontWeight: true,
     fontFamily: true,
-    fontVariationSettings: true,
+    fontVariationSettings: fontVariationSettingsAttribute,
     allowFontScaling: true,
     onSelectionChange: true,
     mostRecentEventCount: true,

packages/react-native/Libraries/Components/TextInput/RCTTextInputViewConfig.js

@@ -11,7 +11,10 @@
 import type {PartialViewConfig} from '../../Renderer/shims/ReactNativeTypes';
 
 import {ConditionallyIgnoredEventHandlers} from '../../NativeComponent/ViewConfigIgnore';
-import {colorAttribute} from '../View/ReactNativeStyleAttributes';
+import {
+  colorAttribute,
+  fontVariationSettingsAttribute,
+} from '../View/ReactNativeStyleAttributes';
 
 type PartialViewConfigWithoutName = Omit<PartialViewConfig, 'uiViewClassName'>;
 
@@ -102,6 +105,7 @@ const RCTTextInputViewConfig: PartialViewConfigWithoutName = {
     },
     allowFontScaling: true,
     fontStyle: true,
+    fontVariationSettings: fontVariationSettingsAttribute,
     textTransform: true,
     textAlign: true,
     fontFamily: true,

packages/react-native/Libraries/Components/TextInput/__tests__/RCTTextInputViewConfig-itest.js

@@ -0,0 +1,56 @@
+/**
+ * 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.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+import {__INTERNAL_VIEW_CONFIG as AndroidTextInputViewConfig} from '../AndroidTextInputNativeComponent';
+import RCTTextInputViewConfig from '../RCTTextInputViewConfig';
+import nullthrows from 'nullthrows';
+
+const {
+  create,
+} = require('../../../ReactNative/ReactFabricPublicInstance/ReactNativeAttributePayload');
+
+const androidValidAttributes = nullthrows(
+  AndroidTextInputViewConfig.validAttributes,
+);
+const appleValidAttributes = nullthrows(RCTTextInputViewConfig.validAttributes);
+
+describe('Android TextInput view config', () => {
+  it('serializes object font variation settings', () => {
+    expect(
+      create(
+        {fontVariationSettings: {wght: 552.5, opsz: 17.25}},
+        androidValidAttributes,
+      ),
+    ).toEqual({fontVariationSettings: "'opsz' 17.25, 'wght' 552.5"});
+  });
+
+  it('serializes an empty object as an explicit clear', () => {
+    expect(create({fontVariationSettings: {}}, androidValidAttributes)).toEqual(
+      {fontVariationSettings: ''},
+    );
+  });
+});
+
+describe('Apple TextInput view config', () => {
+  it('serializes object font variation settings', () => {
+    expect(
+      create(
+        {fontVariationSettings: {wght: 552.5, opsz: 17.25}},
+        appleValidAttributes,
+      ),
+    ).toEqual({fontVariationSettings: "'opsz' 17.25, 'wght' 552.5"});
+  });
+
+  it('serializes an empty object as an explicit clear', () => {
+    expect(create({fontVariationSettings: {}}, appleValidAttributes)).toEqual({
+      fontVariationSettings: '',
+    });
+  });
+});

packages/react-native/Libraries/Components/View/ReactNativeStyleAttributes.js

@@ -20,6 +20,7 @@ import processBoxShadow from '../../StyleSheet/processBoxShadow';
 import processColor from '../../StyleSheet/processColor';
 import processFilter from '../../StyleSheet/processFilter';
 import processFontVariant from '../../StyleSheet/processFontVariant';
+import processFontVariationSettings from '../../StyleSheet/processFontVariationSettings';
 import processTransform from '../../StyleSheet/processTransform';
 import processTransformOrigin from '../../StyleSheet/processTransformOrigin';
 import sizesDiffer from '../../Utilities/differ/sizesDiffer';
@@ -71,6 +72,10 @@ export const fontVariantAttribute: AnyAttributeType = nativeCSSParsing
   ? true
   : {process: processFontVariant};
 
+export const fontVariationSettingsAttribute: AnyAttributeType = {
+  process: processFontVariationSettings,
+};
+
 export const aspectRatioAttribute: AnyAttributeType = nativeCSSParsing
   ? true
   : {process: processAspectRatio};
@@ -258,7 +263,7 @@ const ReactNativeStyleAttributes: {[string]: AnyAttributeType, ...} = {
   fontSize: true,
   fontStyle: true,
   fontVariant: fontVariantAttribute,
-  fontVariationSettings: true,
+  fontVariationSettings: fontVariationSettingsAttribute,
   fontWeight: true,
   includeFontPadding: true,
   letterSpacing: true,

packages/react-native/Libraries/StyleSheet/StyleSheetTypes.js

@@ -999,6 +999,9 @@ export type ____FontVariant_Internal =
 export type ____FontVariantArray_Internal =
   ReadonlyArray<____FontVariant_Internal>;
 
+export type ____FontVariationSettings_Internal =
+  string | Readonly<{[axis: string]: number}>;
+
 type ____TextStyle_InternalBase = Readonly<{
   color?: ____ColorValue_Internal,
   fontFamily?: string,
@@ -1012,11 +1015,12 @@ type ____TextStyle_InternalBase = Readonly<{
   fontWeight?: ____FontWeight_Internal,
   fontVariant?: ____FontVariantArray_Internal | string,
   /**
-   * Specifies OpenType font variation axis values using CSS syntax. An empty
-   * string resets inherited variation settings. On Android, this requires API
-   * level 26 or later.
+   * Specifies OpenType font variation axis values using CSS syntax or an
+   * object keyed by four-character axis tags. An empty string or object resets
+   * inherited variation settings. On Android, this requires API level 26 or
+   * later.
    */
-  fontVariationSettings?: string,
+  fontVariationSettings?: ____FontVariationSettings_Internal,
   textShadowOffset?: Readonly<{
     width: number,
     height: number,

packages/react-native/Libraries/StyleSheet/__tests__/processFontVariationSettings-itest.js

@@ -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.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+import '@react-native/fantom/src/setUpDefaultReactNativeEnvironment';
+
+import processFontVariationSettings from '../processFontVariationSettings';
+
+describe('processFontVariationSettings', () => {
+  it('passes string settings through unchanged', () => {
+    expect(processFontVariationSettings("'wght' 550, 'opsz' 18")).toBe(
+      "'wght' 550, 'opsz' 18",
+    );
+  });
+
+  it('serializes object settings in deterministic axis order', () => {
+    expect(processFontVariationSettings({wght: 552.5, opsz: 17.25})).toBe(
+      "'opsz' 17.25, 'wght' 552.5",
+    );
+  });
+
+  it('serializes an empty object as an explicit clear', () => {
+    expect(processFontVariationSettings({})).toBe('');
+  });
+
+  it('supports printable four-character tags containing a single quote', () => {
+    expect(processFontVariationSettings({["a'b "]: 1})).toBe('"a\'b " 1');
+  });
+
+  it('preserves backslashes in printable four-character tags', () => {
+    expect(processFontVariationSettings({['a\\bc']: 1})).toBe("'a\\bc' 1");
+  });
+
+  it('rejects tags that cannot be delimited without escaping', () => {
+    expect(() => processFontVariationSettings({[`a'"b`]: 1})).toThrow(
+      'Font variation axis tags containing both quote characters must use the string form: "a\'\\"b"',
+    );
+  });
+
+  it('rejects invalid axis tags', () => {
+    expect(() => processFontVariationSettings({weight: 550})).toThrow(
+      'Font variation axis tags must be exactly four printable ASCII characters: "weight"',
+    );
+    expect(() => processFontVariationSettings({['a\nbc']: 1})).toThrow(
+      'Font variation axis tags must be exactly four printable ASCII characters: "a\\nbc"',
+    );
+  });
+
+  it('rejects non-finite axis values', () => {
+    expect(() => processFontVariationSettings({wght: NaN})).toThrow(
+      'Font variation axis values must be finite numbers: NaN',
+    );
+    expect(() => processFontVariationSettings({wght: Infinity})).toThrow(
+      'Font variation axis values must be finite numbers: Infinity',
+    );
+  });
+});

packages/react-native/Libraries/StyleSheet/processFontVariationSettings.js

@@ -0,0 +1,61 @@
+/**
+ * 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.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+'use strict';
+
+import type {____FontVariationSettings_Internal} from './StyleSheetTypes';
+
+function quoteAxis(axis: string): string {
+  if (
+    axis.length !== 4 ||
+    axis.split('').some(character => {
+      const code = character.charCodeAt(0);
+      return code < 0x20 || code > 0x7e;
+    })
+  ) {
+    throw new Error(
+      `Font variation axis tags must be exactly four printable ASCII characters: ${JSON.stringify(axis)}`,
+    );
+  }
+
+  if (!axis.includes("'")) {
+    return `'${axis}'`;
+  }
+  if (!axis.includes('"')) {
+    return `"${axis}"`;
+  }
+
+  throw new Error(
+    `Font variation axis tags containing both quote characters must use the string form: ${JSON.stringify(axis)}`,
+  );
+}
+
+function processFontVariationSettings(
+  settings: ____FontVariationSettings_Internal,
+): string {
+  if (typeof settings === 'string') {
+    return settings;
+  }
+
+  return Object.keys(settings)
+    .sort()
+    .map(axis => {
+      const value = settings[axis];
+      if (!Number.isFinite(value)) {
+        throw new Error(
+          `Font variation axis values must be finite numbers: ${String(value)}`,
+        );
+      }
+      return `${quoteAxis(axis)} ${String(value)}`;
+    })
+    .join(', ');
+}
+
+export default processFontVariationSettings;

packages/react-native/Libraries/Text/__tests__/Text-itest.js

@@ -52,6 +52,44 @@ describe('<Text>', () => {
       });
     });
 
+    describe('fontVariationSettings', () => {
+      it('serializes object settings', () => {
+        const root = Fantom.createRoot();
+
+        Fantom.runTask(() => {
+          root.render(
+            <Text style={{fontVariationSettings: {wght: 552.5, opsz: 17.25}}}>
+              {TEST_TEXT}
+            </Text>,
+          );
+        });
+
+        expect(
+          root.getRenderedOutput({props: ['fontVariationSettings']}).toJSX(),
+        ).toEqual(
+          <rn-paragraph fontVariationSettings="'opsz' 17.25, 'wght' 552.5">
+            {TEST_TEXT}
+          </rn-paragraph>,
+        );
+      });
+
+      it('serializes an empty object as an explicit clear', () => {
+        const root = Fantom.createRoot();
+
+        Fantom.runTask(() => {
+          root.render(
+            <Text style={{fontVariationSettings: {}}}>{TEST_TEXT}</Text>,
+          );
+        });
+
+        expect(
+          root.getRenderedOutput({props: ['fontVariationSettings']}).toJSX(),
+        ).toEqual(
+          <rn-paragraph fontVariationSettings="">{TEST_TEXT}</rn-paragraph>,
+        );
+      });
+    });
+
     describe('adjustsFontSizeToFit', () => {
       it(`can be set to "true"`, () => {
         const root = Fantom.createRoot();