Add a pseudo flow declaration for AccessibilityInfo

Summary: Changelog: [Internal] - Create a type declaration for AccsesibilityInfo for clearer signal when our public API types change

Reviewed By: yungsters

Differential Revision: D38712552

fbshipit-source-id: cc7c727d41fb03ca714cb05fd10dc32038374fd0

Libraries/Components/AccessibilityInfo/AccessibilityInfo.flow.js

@@ -0,0 +1,198 @@
+/**
+ * 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 type {HostComponent} from '../../Renderer/shims/ReactNativeTypes';
+import type {EventSubscription} from '../../vendor/emitter/EventEmitter';
+import type {ElementRef} from 'react';
+
+// Events that are only supported on Android.
+type AccessibilityEventDefinitionsAndroid = {
+  accessibilityServiceChanged: [boolean],
+};
+
+// Events that are only supported on iOS.
+type AccessibilityEventDefinitionsIOS = {
+  announcementFinished: [{announcement: string, success: boolean}],
+  boldTextChanged: [boolean],
+  grayscaleChanged: [boolean],
+  invertColorsChanged: [boolean],
+  reduceTransparencyChanged: [boolean],
+};
+
+type AccessibilityEventDefinitions = {
+  ...AccessibilityEventDefinitionsAndroid,
+  ...AccessibilityEventDefinitionsIOS,
+  change: [boolean], // screenReaderChanged
+  reduceMotionChanged: [boolean],
+  screenReaderChanged: [boolean],
+};
+
+type AccessibilityEventTypes = 'click' | 'focus';
+/**
+ * Sometimes it's useful to know whether or not the device has a screen reader
+ * that is currently active. The `AccessibilityInfo` API is designed for this
+ * purpose. You can use it to query the current state of the screen reader as
+ * well as to register to be notified when the state of the screen reader
+ * changes.
+ *
+ * See https://reactnative.dev/docs/accessibilityinfo
+ */
+export interface AccessibilityInfo {
+  /**
+   * Query whether bold text is currently enabled.
+   *
+   * Returns a promise which resolves to a boolean.
+   * The result is `true` when bold text is enabled and `false` otherwise.
+   *
+   * See https://reactnative.dev/docs/accessibilityinfo#isBoldTextEnabled
+   */
+  isBoldTextEnabled: () => Promise<boolean>;
+
+  /**
+   * Query whether grayscale is currently enabled.
+   *
+   * Returns a promise which resolves to a boolean.
+   * The result is `true` when grayscale is enabled and `false` otherwise.
+   *
+   * See https://reactnative.dev/docs/accessibilityinfo#isGrayscaleEnabled
+   */
+  isGrayscaleEnabled: () => Promise<boolean>;
+
+  /**
+   * Query whether inverted colors are currently enabled.
+   *
+   * Returns a promise which resolves to a boolean.
+   * The result is `true` when invert color is enabled and `false` otherwise.
+   *
+   * See https://reactnative.dev/docs/accessibilityinfo#isInvertColorsEnabled
+   */
+  isInvertColorsEnabled: () => Promise<boolean>;
+
+  /**
+   * Query whether reduced motion is currently enabled.
+   *
+   * Returns a promise which resolves to a boolean.
+   * The result is `true` when a reduce motion is enabled and `false` otherwise.
+   *
+   * See https://reactnative.dev/docs/accessibilityinfo#isReduceMotionEnabled
+   */
+  isReduceMotionEnabled: () => Promise<boolean>;
+
+  /**
+   * Query whether reduced transparency is currently enabled.
+   *
+   * Returns a promise which resolves to a boolean.
+   * The result is `true` when a reduce transparency is enabled and `false` otherwise.
+   *
+   * See https://reactnative.dev/docs/accessibilityinfo#isReduceTransparencyEnabled
+   */
+  isReduceTransparencyEnabled: () => Promise<boolean>;
+
+  /**
+   * Query whether a screen reader is currently enabled.
+   *
+   * Returns a promise which resolves to a boolean.
+   * The result is `true` when a screen reader is enabled and `false` otherwise.
+   *
+   * See https://reactnative.dev/docs/accessibilityinfo#isScreenReaderEnabled
+   */
+  isScreenReaderEnabled: () => Promise<boolean>;
+
+  /**
+   * Query whether Accessibility Service is currently enabled.
+   *
+   * Returns a promise which resolves to a boolean.
+   * The result is `true` when any service is enabled and `false` otherwise.
+   *
+   * @platform android
+   *
+   * See https://reactnative.dev/docs/accessibilityinfo/#isaccessibilityserviceenabled-android
+   */
+  isAccessibilityServiceEnabled: () => Promise<boolean>;
+
+  /**
+   * Add an event handler. Supported events:
+   *
+   * - `reduceMotionChanged`: Fires when the state of the reduce motion toggle changes.
+   *   The argument to the event handler is a boolean. The boolean is `true` when a reduce
+   *   motion is enabled (or when "Transition Animation Scale" in "Developer options" is
+   *   "Animation off") and `false` otherwise.
+   * - `screenReaderChanged`: Fires when the state of the screen reader changes. The argument
+   *   to the event handler is a boolean. The boolean is `true` when a screen
+   *   reader is enabled and `false` otherwise.
+   *
+   * These events are only supported on iOS:
+   *
+   * - `boldTextChanged`: iOS-only event. Fires when the state of the bold text toggle changes.
+   *   The argument to the event handler is a boolean. The boolean is `true` when a bold text
+   *   is enabled and `false` otherwise.
+   * - `grayscaleChanged`: iOS-only event. Fires when the state of the gray scale toggle changes.
+   *   The argument to the event handler is a boolean. The boolean is `true` when a gray scale
+   *   is enabled and `false` otherwise.
+   * - `invertColorsChanged`: iOS-only event. Fires when the state of the invert colors toggle
+   *   changes. The argument to the event handler is a boolean. The boolean is `true` when a invert
+   *   colors is enabled and `false` otherwise.
+   * - `reduceTransparencyChanged`: iOS-only event. Fires when the state of the reduce transparency
+   *   toggle changes.  The argument to the event handler is a boolean. The boolean is `true`
+   *   when a reduce transparency is enabled and `false` otherwise.
+   * - `announcementFinished`: iOS-only event. Fires when the screen reader has
+   *   finished making an announcement. The argument to the event handler is a
+   *   dictionary with these keys:
+   *     - `announcement`: The string announced by the screen reader.
+   *     - `success`: A boolean indicating whether the announcement was
+   *       successfully made.
+   *
+   * See https://reactnative.dev/docs/accessibilityinfo#addeventlistener
+   */
+  addEventListener<K: $Keys<AccessibilityEventDefinitions>>(
+    eventName: K,
+    handler: (...$ElementType<AccessibilityEventDefinitions, K>) => void,
+  ): EventSubscription;
+
+  /**
+   * Set accessibility focus to a React component.
+   *
+   * See https://reactnative.dev/docs/accessibilityinfo#setaccessibilityfocus
+   */
+  setAccessibilityFocus: (reactTag: number) => void;
+
+  /**
+   * Send a named accessibility event to a HostComponent.
+   */
+  sendAccessibilityEvent: (
+    handle: ElementRef<HostComponent<mixed>>,
+    eventType: AccessibilityEventTypes,
+  ) => void;
+
+  /**
+   * Post a string to be announced by the screen reader.
+   *
+   * See https://reactnative.dev/docs/accessibilityinfo#announceforaccessibility
+   */
+  announceForAccessibility: (announcement: string) => void;
+
+  /**
+   * Post a string to be announced by the screen reader.
+   * - `announcement`: The string announced by the screen reader.
+   * - `options`: An object that configures the reading options.
+   *   - `queue`: The announcement will be queued behind existing announcements. iOS only.
+   */
+  announceForAccessibilityWithOptions: (
+    announcement: string,
+    options: {queue?: boolean},
+  ) => void;
+
+  /**
+   * Get the recommended timeout for changes to the UI needed by this user.
+   *
+   * See https://reactnative.dev/docs/accessibilityinfo#getrecommendedtimeoutmillis
+   */
+  getRecommendedTimeoutMillis: (originalTimeout: number) => Promise<number>;
+}

Libraries/Components/AccessibilityInfo/AccessibilityInfo.js

@@ -17,6 +17,7 @@ import NativeAccessibilityInfoAndroid from './NativeAccessibilityInfo';
 import NativeAccessibilityManagerIOS from './NativeAccessibilityManager';
 import legacySendAccessibilityEvent from './legacySendAccessibilityEvent';
 import type {ElementRef} from 'react';
+import type {AccessibilityInfo as AccessibilityInfoType} from './AccessibilityInfo.flow';
 
 // Events that are only supported on Android.
 type AccessibilityEventDefinitionsAndroid = {
@@ -73,7 +74,7 @@ const EventNames: Map<
  *
  * See https://reactnative.dev/docs/accessibilityinfo
  */
-const AccessibilityInfo = {
+const AccessibilityInfo: AccessibilityInfoType = {
   /**
    * Query whether bold text is currently enabled.
    *
@@ -295,6 +296,7 @@ const AccessibilityInfo = {
    */
   addEventListener<K: $Keys<AccessibilityEventDefinitions>>(
     eventName: K,
+    // $FlowIssue[incompatible-type] - Flow bug with unions and generics (T128099423)
     handler: (...$ElementType<AccessibilityEventDefinitions, K>) => void,
   ): EventSubscription {
     const deviceEventName = EventNames.get(eventName);