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An API to get and set screen brightness.

On Android, there is a global system-wide brightness setting, and each app has its own brightness setting that can optionally override the global setting. It is possible to set either of these values with this API. On iOS, the system brightness setting cannot be changed programmatically; instead, any changes to the screen brightness will persist until the device is locked or powered off.

Installation

If you are installing this in an existing React Native app, make sure to install expo in your project.

Configuration

<uses-permission android:name="android.permission.WRITE_SETTINGS" />

Usage

import { useEffect } from 'react';
import { StyleSheet, View, Text } from 'react-native';
import * as Brightness from 'expo-brightness';

export default function App() {
  useEffect(() => {
    (async () => {
      const { status } = await Brightness.requestPermissionsAsync();
      if (status === 'granted') {
        Brightness.setSystemBrightnessAsync(1);
      }
    })();
  }, []);

  return (
    <View style={styles.container}>
      <Text>Brightness Module Example</Text>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#fff',
    alignItems: 'center',
    justifyContent: 'center',
  },
});

API

import * as Brightness from 'expo-brightness';

No API data file found, sorry!

Error codes

ERR_BRIGHTNESS

An error occurred when getting or setting the app brightness.

ERR_BRIGHTNESS_MODE

An error occurred when getting or setting the system brightness mode. See the nativeError property of the thrown error for more information.

ERR_BRIGHTNESS_PERMISSIONS_DENIED

An attempt to set the system brightness was made without the proper permissions from the user. The user did not grant SYSTEM_BRIGHTNESS permissions.

ERR_BRIGHTNESS_SYSTEM

An error occurred when getting or setting the system brightness.

ERR_INVALID_ARGUMENT

An invalid argument was passed. Only BrightnessMode.MANUAL or BrightnessMode.AUTOMATIC are allowed.

Permissions

Android

You must add the following permissions to your app.json inside the expo.android.permissions array.

iOS

No permissions required.