lvchenyang / react-native-tab-view

A cross-platform Tab View component for React Native

React Native Tab View

A cross-platform Tab View component for React Native.

• Run the example app to see it in action.
• Checkout the example/ folder for source code.

Features

• Smooth animations and gestures
• Scrollable tabs
• Supports both top and bottom tab bars
• Follows Material Design spec
• Highly customizable
• Fully typed with Flow

Demo

Installation

Open a Terminal in the project root and run:

yarn add react-native-tab-view

If you are using Expo, you are done. Otherwise, continue to the next step.

Install and link react-native-gesture-handler and react-native-reanimated. To install and link them, run:

yarn add react-native-reanimated react-native-gesture-handler
react-native link react-native-reanimated
react-native link react-native-gesture-handler

IMPORTANT: There are additional steps required for react-native-gesture-handler on Android after running react-native link react-native-gesture-handler. Check the this guide to complete the installation.

Quick Start

import * as React from 'react';
import { View, StyleSheet, Dimensions } from 'react-native';
import { TabView, SceneMap } from 'react-native-tab-view';

const FirstRoute = () => (
  <View style={[styles.scene, { backgroundColor: '#ff4081' }]} />
);
const SecondRoute = () => (
  <View style={[styles.scene, { backgroundColor: '#673ab7' }]} />
);

export default class TabViewExample extends React.Component {
  state = {
    index: 0,
    routes: [
      { key: 'first', title: 'First' },
      { key: 'second', title: 'Second' },
    ],
  };

  render() {
    return (
      <TabView
        navigationState={this.state}
        renderScene={SceneMap({
          first: FirstRoute,
          second: SecondRoute,
        })}
        onIndexChange={index => this.setState({ index })}
        initialLayout={{ width: Dimensions.get('window').width }}
      />
    );
  }
}

const styles = StyleSheet.create({
  scene: {
    flex: 1,
  },
});

Try this example on Snack

More examples on Snack

• Custom Tab Bar
• Lazy Load

Integration with React Navigation

React Navigation integration can be achieved by the react-navigation-tabs package. Note that while it's easier to use, it is not as flexible as using the library directly.

API reference

The package exports a TabView component which is the one you'd use to render the tab view, and a TabBar component which is the default tab bar implementation.

TabView

Container component responsible for rendering and managing tabs. Follows material design styles by default.

Basic usage look like this:

<TabView
  navigationState={this.state}
  onIndexChange={index => this.setState({ index })}
  renderScene={SceneMap({
    first: FirstRoute,
    second: SecondRoute,
  })}
/>

Props

navigationState (required)

State for the tab view. The state should contain the following properties:

• index: a number representing the index of the active route in the routes array
• routes: an array containing a list of route objects used for rendering the tabs

Each route object should contain the following properties:

• key: a unique key to identify the route (required)
• title: title for the route to display in the tab bar
• icon: icon for the route to display in the tab bar
• accessibilityLabel: accessibility label for the tab button
• testID: test id for the tab button

Example:

{
  index: 1,
  routes: [
    { key: 'music', title: 'Music' },
    { key: 'albums', title: 'Albums' },
    { key: 'recents', title: 'Recents' },
    { key: 'purchased', title: 'Purchased' },
  ]
}

TabView is a controlled component, which means the index needs to be updated via the onIndexChange callback.

onIndexChange (required)

Callback which is called on tab change, receives the index of the new tab as argument. The navigation state needs to be updated when it's called, otherwise the change is dropped.

renderScene (required)

Callback which returns a react element to render as the page for the tab. Receives an object containing the route as the argument:

renderScene = ({ route, jumpTo }) => {
  switch (route.key) {
    case 'music':
      return <MusicRoute jumpTo={jumpTo} />;
    case 'albums':
      return <AlbumsRoute jumpTo={jumpTo} />;
  }
};

You need to make sure that your individual routes implement a shouldComponentUpdate to improve the performance. To make it easier to specify the components, you can use the SceneMap helper.

SceneMap takes an object with the mapping of route.key to React components and returns a function to use with renderScene prop.

import { SceneMap } from 'react-native-tab-view';

...

renderScene = SceneMap({
  music: MusicRoute,
  albums: AlbumsRoute,
});

Specifying the components this way is easier and takes care of implementing a shouldComponentUpdate method.

Each scene receives the following props:

• route: the current route rendered by the component
• jumpTo: method to jump to other tabs, takes a route.key as it's argument

The jumpTo method can be used to navigate to other tabs programmatically:

this.props.jumpTo('albums');

All the scenes rendered with SceneMap are optimized using React.PureComponent and don't re-render when parent's props or states change. If you need more control over how your scenes update (e.g. - triggering a re-render even if the navigationState didn't change), use renderScene directly instead of using SceneMap.

IMPORTANT: Do not pass inline functions to SceneMap, for example, don't do the following:

SceneMap({
  first: () => <FirstRoute foo={this.props.foo} />,
  second: SecondRoute,
});

Always define your components elsewhere in the top level of the file. If you pass inline functions, it'll re-create the component every render, which will cause the entire route to unmount and remount every change. It's very bad for performance and will also cause any local state to be lost.

renderTabBar

Callback which returns a custom React Element to use as the tab bar:

import { TabBar } from 'react-native-tab-view';

...

renderTabBar = props => <TabBar {...props} />;

If this is not specified, the default tab bar is rendered. You pass this props to customize the default tab bar, provide your own tab bar, or disable the tab bar completely.

renderTabBar = () => null;

tabBarPosition

Position of the tab bar in the tab view. Possible values are 'top' and 'bottom'. Defaults to 'top'.

lazy

Boolean indicating whether to lazily render the scenes. By default all scenes are rendered to provide a smoother swipe experience. But you might want to defer the rendering of unfocused scenes until the user sees them. To enable lazy rendering, set lazy to true.

When you enable lazy, the unfocused screens will usually take some time to render when they come into focus. You can use the renderLazyPlaceholder prop to customize what the user sees during this short period.

renderLazyPlaceholder

Callback which returns a custom React Element to render for routes that haven't been rendered yet. Receives an object containing the route as the argument. The lazy prop also needs to be enabled.

This view is usually only shown for a split second. Keep it lightweight.

By default, this renders null.

removeClippedSubviews

Boolean indicating whether to remove invisible views (such as unfocused screens) from the native view hierarchy to improve memory usage. Defaults to false.

Note: Don't enable this on iOS where this is buggy and views don't re-appear.

keyboardDismissMode

String indicating whether the keyboard gets dismissed in response to a drag gesture. Possible values are:

• 'on-drag' (default): the keyboard is dismissed when a drag begins.
• 'none': drags do not dismiss the keyboard.

swipeEnabled

Boolean indicating whether to enable swipe gestures. Swipe gestures are enabled by default. Passing false will disable swipe gestures, but the user can still switch tabs by pressing the tab bar.

swipeDistanceThreshold

Minimum swipe distance which triggers a tab switch. By default, this is automatically determined based on the screen width.

swipeVelocityThreshold

Minimum swipe velocity which triggers a tab switch. Defaults to 1200.

onSwipeStart

Callback which is called when the swipe gesture starts, i.e. the user touches the screen and moves it.

onSwipeEnd

Callback which is called when the swipe gesture ends, i.e. the user lifts their finger from the screen after the swipe gesture.

initialLayout

Object containing the initial height and width of the screens. Passing this will improve the initial rendering performance. For most apps, this is a good default:

{ width: Dimensions.get('window').width }}

sceneContainerStyle

Style to apply to the view wrapping each screen. You can pass this to override some default styles such as overflow clipping:

style

Style to apply to the tab view container.

TabBar

Material design themed tab bar. To customize the tab bar, you'd need to use the renderTabBar prop of TabView to render the TabBar and pass additional props.

For example, to customize the indicator color and the tab bar background color, you can pass indicatorStyle and style props to the TabBar respectively:

renderTabBar={props =>
  <TabBar
    {...props}
    indicatorStyle={{ backgroundColor: 'white' }}
    style={{ backgroundColor: 'pink' }}
  />
}

Props

getLabelText

Function which takes an object with the current route and returns the label text for the tab. Uses route.title by default.

getLabelText={({ route }) => route.title}

getAccessible

Function which takes an object with the current route and returns a boolean to indicate whether to mark a tab as accessible. Defaults to true.

getAccessibilityLabel

Function which takes an object with the current route and returns a accessibility label for the tab button. Uses route.accessibilityLabel by default if specified, otherwise uses the route title.

getAccessibilityLabel={({ route }) => route.accessibilityLabel}

testID

Function which takes an object with the current route and returns a test id for the tab button to locate this tab button in tests. Uses route.testID by default.

getTestID={({ route }) => route.testID}

getAccessibilityLabel: (props: { route: T }) => string; Get accessibility label for the tab button. This is read by the screen reader when the user taps the tab. Uses route.accessibilityLabel by default if specified, otherwise uses the route title.

getTestID: (props: { route: T }) => string | undefined; Get the id to locate this tab button in tests, uses route.testID by default.

renderIcon

Function which takes an object with the current route, focused status and color and returns a custom React Element to be used as a icon.

renderIcon={({ route, focused, color }) => (
  <Icon
    name={focused ? 'abums' : 'albums-outlined'}
    color={color}
  />
)}

renderLabel

Function which takes an object with the current route, focused status and color and returns a custom React Element to be used as a label.

renderLabel={({ route, focused, color }) => (
  <Text style={{ color, margin: 8 }}>
    {route.title}
  </Text>
)}

renderIndicator

Function which takes an object with the current route and returns a custom React Element to be used as a tab indicator.

renderBadge

Function which takes an object with the current route and returns a custom React Element to be used as a badge.

onTabPress

Function to execute on tab press. It receives the scene for the pressed tab, useful for things like scroll to top.

onTabLongPress

Function to execute on tab long press, use for things like showing a menu with more options

activeColor

Custom color for icon and label in the active tab.

inactiveColor

Custom color for icon and label in the inactive tab.

pressColor

Color for material ripple (Android >= 5.0 only).

pressOpacity

Opacity for pressed tab (iOS and Android < 5.0 only).

scrollEnabled

Boolean indicating whether to enable scrollable tabs.

bounces

Boolean indicating whether the tab bar bounces when scrolling.

tabStyle

Style to apply to the individual tab items in the tab bar.

indicatorStyle

Style to apply to the active indicator.

labelStyle

Style to apply to the tab item label.

contentContainerStyle

Style to apply to the inner container for tabs.

style

Style to apply to the tab bar container.

Optimization Tips

Avoid unnecessary re-renders

The renderScene function is called every time the index changes. If your renderScene function is expensive, it's good idea move each route to a separate component if they don't depend on the index, and apply shouldComponentUpdate in your route components to prevent unnecessary re-renders.

For example, instead of:

renderScene = ({ route }) => {
  switch (route.key) {
    case 'home':
      return (
        <View style={styles.page}>
          <Avatar />
          <NewsFeed />
        </View>
      );
    default:
      return null;
  }
};

Do the following:

renderScene = ({ route }) => {
  switch (route.key) {
    case 'home':
      return <HomeComponent />;
    default:
      return null;
  }
};

Where <HomeComponent /> is a PureComponent:

export default class HomeComponent extends React.PureComponent {
  render() {
    return (
      <View style={styles.page}>
        <Avatar />
        <NewsFeed />
      </View>
    );
  }
}

Avoid one frame delay

We need to measure the width of the container and hence need to wait before rendering some elements on the screen. If you know the initial width upfront, you can pass it in and we won't need to wait for measuring it. Most of the time, it's just the window width.

For example, pass the following initialLayout to TabView:

const initialLayout = {
  height: 0,
  width: Dimensions.get('window').width,
};

The tab view will still react to changes in the dimension and adjust accordingly to accommodate things like orientation change.

Optimize large number of routes

If you've a large number of routes, especially images, it can slow the animation down a lot. You can instead render a limited number of routes.

For example, do the following to render only 2 routes on each side:

renderScene = ({ route }) => {
  if (Math.abs(this.state.index - this.state.routes.indexOf(route)) > 2) {
    return <View />;
  }

  return <MySceneComponent route={route} />;
};

Avoid rendering TabView inside ScrollView

Nesting the TabView inside a vertical ScrollView will disable the optimizations in the FlatList components rendered inside the TabView. So avoid doing it if possible.

Contributing

While developing, you can run the example app to test your changes.

Make sure your code passes Flow and ESLint. Run the following to verify:

yarn flow
yarn lint

To fix formatting errors, run the following:

yarn lint -- --fix

Remember to add tests for your change if possible.