AccessibilityInfo.announceForAccessibility (#24746)

Summary:
AccessibilityInfo.announceForAccessibility is currently only available on iOS. I've added the Android specific implementation, updated RNTester, and the documentation.

[Android] [Added] - Added AccessibilityInfo.announceForAccessibility for Android
[General] [Added] - RNTester example for AccessibilityInfo.announceForAccessibility
Pull Request resolved: https://github.com/facebook/react-native/pull/24746

Differential Revision: D15258054

Pulled By: cpojer

fbshipit-source-id: 3e057a5c32b28e30ea2ee74a18854b012cd2dbfd

Libraries/Components/AccessibilityInfo/AccessibilityInfo.android.js

@@ -135,6 +135,15 @@ const AccessibilityInfo = {
       UIManager.AccessibilityEventTypes.typeViewFocused,
     );
   },
+
+  /**
+   * Post a string to be announced by the screen reader.
+   *
+   * See http://facebook.github.io/react-native/docs/accessibilityinfo.html#announceforaccessibility
+   */
+  announceForAccessibility: function(announcement: string): void {
+    RCTAccessibilityInfo.announceForAccessibility(announcement);
+  },
 };
 
 module.exports = AccessibilityInfo;

Libraries/Components/AccessibilityInfo/AccessibilityInfo.ios.js

@@ -210,8 +210,6 @@ const AccessibilityInfo = {
   /**
    * Post a string to be announced by the screen reader.
    *
-   * @platform ios
-   *
    * See http://facebook.github.io/react-native/docs/accessibilityinfo.html#announceforaccessibility
    */
   announceForAccessibility: function(announcement: string): void {

RNTester/js/AccessibilityExample.js

@@ -452,6 +452,22 @@ class ScreenReaderStatusExample extends React.Component<{}> {
   }
 }
 
+class AnnounceForAccessibility extends React.Component<{}> {
+  _handleOnPress = () =>
+    AccessibilityInfo.announceForAccessibility('Announcement Test');
+
+  render() {
+    return (
+      <View>
+        <Button
+          onPress={this._handleOnPress}
+          title="Announce for Accessibility"
+        />
+      </View>
+    );
+  }
+}
+
 exports.title = 'Accessibility';
 exports.description = 'Examples of using Accessibility APIs.';
 exports.examples = [
@@ -473,4 +489,10 @@ exports.examples = [
       return <ScreenReaderStatusExample />;
     },
   },
+  {
+    title: 'Check if the screen reader announces',
+    render(): React.Element<typeof AnnounceForAccessibility> {
+      return <AnnounceForAccessibility />;
+    },
+  },
 ];

ReactAndroid/src/main/java/com/facebook/react/modules/accessibilityinfo/AccessibilityInfoModule.java

@@ -16,6 +16,7 @@ import android.os.Build;
 import android.os.Handler;
 import android.os.Looper;
 import android.provider.Settings;
+import android.view.accessibility.AccessibilityEvent;
 import android.view.accessibility.AccessibilityManager;
 
 import com.facebook.react.bridge.Callback;
@@ -170,4 +171,18 @@ public class AccessibilityInfoModule extends ReactContextBaseJavaModule
     @Override
     public void onHostDestroy() {
     }
+
+    @ReactMethod
+    public void announceForAccessibility(String message) {
+        if (mAccessibilityManager == null || !mAccessibilityManager.isEnabled()) {
+            return;
+        }
+
+        AccessibilityEvent event = AccessibilityEvent.obtain(AccessibilityEvent.TYPE_ANNOUNCEMENT);
+        event.getText().add(message);
+        event.setClassName(AccessibilityInfoModule.class.getName());
+        event.setPackageName(getReactApplicationContext().getPackageName());
+
+        mAccessibilityManager.sendAccessibilityEvent(event);
+    }
 }