react-native-tvos: A JavaScript repository from henninghall

react-native-tvos

Going forward, Apple TV support for React Native will be maintained here and in the corresponding react-native-tvos NPM package, and not in the core repo. This is a full fork of the main repository, with only the changes needed to support Apple TV.

Releases of react-native-tvos will be based on a public release of react-native; e.g. the 0.63.1-0 release of this package will be derived from the 0.63.1 release of react-native. All releases of this repo will follow the 0.xx.x-y format, where x digits are from a specific RN core release, and y represents the additional versioning from this repo.

Releases will be published on npmjs.org and you may find the latest release version here: https://www.npmjs.com/package/react-native-tvos?activeTab=versions or use the tag @latest

You will find the relevant tvOS support and maintenance within the branches marked tvos-v0.xx.x;

To build your project for Apple TV, you should change your package.json imports to import react-native as follows, so that this package is used instead of the core react-native package.

"react-native": "npm:react-native-tvos@latest",

You cannot use this package and the core react-native package simultaneously in a project.

Typescript

Due to the nature of the typing resolution, the current solution to include types is to:

install @types/react-native as a dev dependency
put import 'react-native/tvos-types.d' in any of your .ts files (root suggested)

General support for Apple TV

TV devices support has been implemented with the intention of making existing React Native applications "just work" on Apple TV, with few or no changes needed in the JavaScript code for the applications.

The RNTester app supports Apple TV. In this repo, RNTester/Podfile and RNTester/RNTesterPods.xcodeproj have been modified to work for tvOS. Run pod install, then open RNTesterPods.xcworkspace and build.

Pitfall

Make sure you do not globally install react-native or react-native-tvos. You should only install react-native-cli to use the commands below. If you have done this the wrong way, you may get error messages like:

ld: library not found for -lPods-TestApp-tvOS

You should also install yarn globally, as it should be used instead of npm for working in React Native projects.

Build changes

Native layer: React Native Xcode projects all now have Apple TV build targets, with names ending in the string '-tvOS'.
react-native init: Creating a new project that uses this package is done using the react-native CLI. New projects created this way will automatically have properly configured Apple TV targets created in their XCode projects.

To use this NPM package in a new project, you can reference it as in the following example using the older react-native-cli package:

# Make sure you have the CLI installed globally (this only needs to be done once on your system)
npm install -g react-native-cli
# Init an app called 'TestApp', note that you must not be in a node module (directory with node_modules sub-directory) for this to work
react-native init TestApp --version=react-native@npm:react-native-tvos@latest
# Now start the app in the tvOS Simulator - this will only work on a macOS machine
cd TestApp && react-native run-ios  --simulator "Apple TV" --scheme "TestApp-tvOS"

If you are using the newer @react-native-community/cli package, the syntax is slightly different:

# Make sure you have the CLI installed globally (this only needs to be done once on your system)
npm install -g @react-native-community/cli
# Init an app called 'TestApp', note that you must not be in a node module (directory with node_modules sub-directory) for this to work
react-native init TestApp --template=react-native-tvos@latest
# Now start the app in the tvOS Simulator - this will only work on a macOS machine
cd TestApp && react-native run-ios  --simulator "Apple TV" --scheme "TestApp-tvOS"

JavaScript layer: Support for Apple TV has been added to Platform.ios.js. You can check whether code is running on AppleTV by doing

var Platform = require('Platform');
var running_on_tv = Platform.isTV;

// If you want to be more specific and only detect devices running tvOS
// (but no Android TV devices) you can use:
var running_on_apple_tv = Platform.isTVOS;

Code changes

General support for tvOS: Apple TV specific changes in native code are all wrapped by the TARGET_OS_TV define. These include changes to suppress APIs that are not supported on tvOS (e.g. web views, sliders, switches, status bar, etc.), and changes to support user input from the TV remote or keyboard.
Common codebase: Since tvOS and iOS share most Objective-C and JavaScript code in common, most documentation for iOS applies equally to tvOS.
Access to touchable controls: When running on Apple TV, the native view class is RCTTVView, which has additional methods to make use of the tvOS focus engine. The Touchable mixin has code added to detect focus changes and use existing methods to style the components properly and initiate the proper actions when the view is selected using the TV remote, so TouchableWithoutFeedback, TouchableHighlight and TouchableOpacity will "just work". In particular:
- onFocus will be executed when the touchable view goes into focus
- onBlur will be executed when the touchable view goes out of focus
- onPress will be executed when the touchable view is actually selected by pressing the "select" button on the TV remote.
TV remote/keyboard input: A native class, RCTTVRemoteHandler, sets up gesture recognizers for TV remote events. When TV remote events occur, this class fires notifications that are picked up by RCTTVNavigationEventEmitter (a subclass of RCTEventEmitter), that fires a JS event. This event will be picked up by instances of the TVEventHandler JavaScript object. Application code that needs to implement custom handling of TV remote events can create an instance of TVEventHandler and listen for these events. In 0.63.1-1, we have added useTVEventHandler, which wraps useEffect to make this more convenient and simpler for use with functional components.

import { TVEventHandler, useTVEventHandler } from 'react-native';

// Functional component

const TVEventHandlerView: () => React.Node = () => {
  const [lastEventType, setLastEventType] = React.useState('');

  const myTVEventHandler = evt => {
    setLastEventType(evt.eventType);
  };

  useTVEventHandler(myTVEventHandler);

  return (
    <View>
      <TouchableOpacity onPress={() => {}}>
        <Text>
          This example enables an instance of TVEventHandler to show the last
          event detected from the Apple TV Siri remote or from a keyboard.
        </Text>
      </TouchableOpacity>
      <Text style={{color: 'blue'}}>{lastEventType}</Text>
    </View>
  );

};

// Class based component

class Game2048 extends React.Component {
  _tvEventHandler: any;

  _enableTVEventHandler() {
    this._tvEventHandler = new TVEventHandler();
    this._tvEventHandler.enable(this, function(cmp, evt) {
      if (evt && evt.eventType === 'right') {
        cmp.setState({board: cmp.state.board.move(2)});
      } else if(evt && evt.eventType === 'up') {
        cmp.setState({board: cmp.state.board.move(1)});
      } else if(evt && evt.eventType === 'left') {
        cmp.setState({board: cmp.state.board.move(0)});
      } else if(evt && evt.eventType === 'down') {
        cmp.setState({board: cmp.state.board.move(3)});
      } else if(evt && evt.eventType === 'playPause') {
        cmp.restartGame();
      }
    });
  }

  _disableTVEventHandler() {
    if (this._tvEventHandler) {
      this._tvEventHandler.disable();
      delete this._tvEventHandler;
    }
  }

  componentDidMount() {
    this._enableTVEventHandler();
  }

  componentWillUnmount() {
    this._disableTVEventHandler();
  }

Turbomodules: Working as of the 0.61.2-0 release.
Flipper: Working in the 0.62.2-x releases. Working in the 0.63.1-1 and later releases; however, tvOS requires the Flipper pods from 0.62.2-x. scripts/react_native_pods.rb contains macros for both versions. The new project template Podfile is correctly set up to provide the older Flipper for both iOS and tvOS targets.
LogBox: The new LogBox error/warning display (which replaced YellowBox in 0.63) is working as expected in tvOS, after a few adjustments to make the controls accessible to the focus engine.
Pressable: The new Pressable API for React Native 0.63 works with TV. Additional onFocus and onBlur props are provided to allow you to customize behavior when a Pressable enters or leaves focus. Similar to the pressed state that is true while a user is pressing the component on a touchscreen, the focused state will be true when it is focused on TV. PressableExample in RNTester has been modified appropriately.
Dev Menu support: On the simulator, cmd-D will bring up the developer menu, just like on iOS. To bring it up on a real Apple TV device, make a long press on the play/pause button on the remote. (Please do not shake the Apple TV device, that will not work :) )
TV remote animations: RCTTVView native code implements Apple-recommended parallax animations to help guide the eye as the user navigates through views. The animations can be disabled or adjusted with new optional view properties.
Back navigation with the TV remote menu button: The BackHandler component, originally written to support the Android back button, now also supports back navigation on the Apple TV using the menu button on the TV remote.
TVMenuControl: This module provides methods to enable and disable navigation using the menu key on the TV remote. This is required in order to fix an issue with Apple's guidelines for menu key navigation (see facebook/react-native#18930). The RNTester app uses this new module to implement correct menu key behavior.
TVFocusGuideView: This component provides support for Apple's UIFocusGuide API, to help ensure that focusable controls can be navigated to, even if they are not directly in line with other controls. An example is provided in RNTester that shows two different ways of using this component.
Next Focus Direction: the props nextFocus* on View should work as expected on iOS too (previously android only). One caveat is that if there is no focusable in the nextFocusable* direction next to the starting view, iOS doesn't check if we want to override the destination.
TVTextScrollView: On Apple TV, a ScrollView will not scroll unless there are focusable items inside it or above/below it. This component wraps ScrollView and uses tvOS-specific native code to allow scrolling using swipe gestures from the remote control.
Known issues:
- As of the 0.61.2-0 release, Fabric code does not compile or run. Issue is under investigation.
- There are known issues with the TabBarIOS component, due to changes that Apple made in UITabBar for tvOS 13.

henninghall/react-native-tvos