npm package: @gsoftware/react-native-appearance
Description: Polyfill for `Appearance` API which will be available in `react-native@0.62`.
Author: Brent Vatne
Latest version: 0.3.5

# react-native-appearance

Access operating system appearance information on iOS, Android, and web. Currently supports detecting preferred color scheme (light/dark).

> ⚠️ [Appearance](https://reactnative.dev/docs/appearance) in React Native core is recommended unless you have a good reason to use the library (eg: you're on an older React Native version.) This project is archived now that it will not be needed going forward.

## Installation

Installation instructions vary depending on whether you're using a managed Expo project or a bare React Native project.

### Managed Expo project

This library is supported in Expo SDK 35+ (SDK 35 includes iOS support, SDK 36 and higher includes support for all platforms).

```sh
expo install react-native-appearance
```

Then, in **app.json**, include `"userInterfaceStyle"` to listen to the device's appearance settings:

```js
{
  "expo": {
    /*
        Supported user interface styles. If left blank, "light" will be used. Use "automatic" if you would like to support either "light" or "dark" depending on device settings.
      */
    "userInterfaceStyle": "automatic" | "light" | "dark"
  }
}
```

> Android support and web support are available on SDK36+.

### Bare React Native project

```sh
yarn add react-native-appearance
```

## Linking

> If you are not using AndroidX on your project already (this is the default on React Native 0.60+, but not on lower versions) you will want to use the `jetifier` npm package. Install the package with `yarn add -D jetifier` and then under `scripts` add `"postinstall": "jetify -r"`. Next run `yarn jetify`.

After installing the package you need to link the native parts of the library for the platforms you are using. The easiest way to link the library is using the CLI tool by running this command from the root of your project:

```sh
react-native link react-native-appearance
```

If you can't or don't want to use the CLI tool, you can also manually link the library using the instructions below (click on the arrow to show them):

<details>
<summary>Manually link the library on iOS</summary>

Either follow the [instructions in the React Native documentation](https://facebook.github.io/react-native/docs/linking-libraries-ios#manual-linking) to manually link the framework or link using [Cocoapods](https://cocoapods.org) by adding this to your `Podfile`:

```ruby
pod 'react-native-appearance', :path => '../node_modules/react-native-appearance'
```

</details>

<details>
<summary>Manually link the library on Android</summary>

1. Open up `android/app/src/main/java/[...]/MainApplication.java`

- Add `import io.expo.appearance.RNCAppearancePackage;` to the imports at the top of the file
- Add `new RNCAppearancePackage()` to the list returned by the `getPackages()` method

2. Append the following lines to `android/settings.gradle`:

```
include ':react-native-appearance'
project(':react-native-appearance').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-appearance/android')

```

3. Insert the following lines inside the dependencies block in `android/app/build.gradle`:

```
implementation project(':react-native-appearance')
```

</details>

## Configuration

<details>
<summary>iOS configuration</summary>

In Expo managed projects, add `ios.userInterfaceStyle` to your `app.json`:

```json
{
  "expo": {
    "ios": {
      "userInterfaceStyle": "automatic"
    }
  }
}
```

For bare React Native apps, run `npx pod-install`. You can configure supported styles with the [UIUserInterfaceStyle](https://developer.apple.com/documentation/bundleresources/information_property_list/uiuserinterfacestyle) key in your app `Info.plist`.

</details>

<details>
<summary>Android configuration</summary>

Add the `uiMode` flag in `AndroidManifest.xml`:

```xml
<activity
...
android:configChanges="keyboard|keyboardHidden|orientation|screenSize|uiMode">
```

Implement the `onConfigurationChanged` method in `MainActivity.java`:

```java
import android.content.Intent; // <--- import
import android.content.res.Configuration; // <--- import

public class MainActivity extends ReactActivity {
  ......

  // copy these lines
  @Override
  public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    Intent intent = new Intent("onConfigurationChanged");
    intent.putExtra("newConfig", newConfig);
    sendBroadcast(intent);
  }

  ......
}
```

</details>

## Usage

First, you need to wrap your app in the `AppearanceProvider`. At the root of your app, do the following:

```js
import { AppearanceProvider } from 'react-native-appearance';

export default () => (
  <AppearanceProvider>
    <App />
  </AppearanceProvider>
);
```

Now you can use `Appearance` and `useColorScheme` anywhere in your app.

```js
import { Appearance, useColorScheme } from 'react-native-appearance';

/**
 * Get the current color scheme
 */
Appearance.getColorScheme();

/**
 * Subscribe to color scheme changes with a hook
 */
function MyComponent() {
  const colorScheme = useColorScheme();
  if (colorScheme === 'dark') {
    // render some dark thing
  } else {
    // render some light thing
  }
}

/**
 * Subscribe to color scheme without a hook
 */
const subscription = Appearance.addChangeListener(({ colorScheme }) => {
  // do something with color scheme
});

// Remove the subscription at some point
subscription.remove();
```

## Attribution

This was mostly written by Facebook for inclusion in React Native core.