BottomNavigation.js

/* @flow */
/* eslint-disable react/no-multi-comp */

import * as React from 'react';
import {
  View,
  Animated,
  TouchableWithoutFeedback,
  StyleSheet,
  Platform,
  Keyboard,
} from 'react-native';
import type { ViewStyleProp } from 'react-native/Libraries/StyleSheet/StyleSheet';
import { polyfill } from 'react-lifecycles-compat';
import SafeAreaView from 'react-native-safe-area-view';
import color from 'color';
import Icon from './Icon';
import Surface from './Surface';
import Badge from './Badge';
import TouchableRipple from './TouchableRipple';
import Text from './Typography/Text';
import { black, white } from '../styles/colors';
import { withTheme } from '../core/theming';
import type { Theme } from '../types';
import type { IconSource } from './Icon';

const AnimatedText = Animated.createAnimatedComponent(Text);

type Route = $Shape<{
  key: string,
  title: string,
  icon: IconSource,
  badge: string | number | boolean,
  color: string,
  accessibilityLabel: string,
  testID: string,
}>;

type NavigationState<T: Route> = {
  index: number,
  routes: Array<T>,
};

type Props<T> = {
  /**
   * Whether the shifting style is used, the active tab appears wider and the inactive tabs won't have a label.
   * By default, this is `true` when you have more than 3 tabs.
   */
  shifting?: boolean,
  /**
   * Whether to show labels in tabs. When `false`, only icons will be displayed.
   */
  labeled?: boolean,
  /**
   * State for the bottom navigation. The state should contain the following properties:
   *
   * - `index`: a number reprsenting 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 of the route to use as the tab label
   * - `icon`: icon to use as the tab icon, can be a string, an image source or a react component
   * - `color`: color to use as background color for shifting bottom navigation
   * - `badge`: badge to show on the tab icon, can be `true` to show a dot, `string` or `number` to show text.
   * - `accessibilityLabel`: accessibility label for the tab button
   * - `testID`: test id for the tab button
   *
   * Example:
   *
   * ```js
   * {
   *   index: 1,
   *   routes: [
   *     { key: 'music', title: 'Music', icon: 'queue-music', color: '#3F51B5' },
   *     { key: 'albums', title: 'Albums', icon: 'album', color: '#009688' },
   *     { key: 'recents', title: 'Recents', icon: 'history', color: '#795548' },
   *     { key: 'purchased', title: 'Purchased', icon: 'shopping-cart', color: '#607D8B' },
   *   ]
   * }
   * ```
   *
   * `BottomNavigation` is a controlled component, which means the `index` needs to be updated via the `onIndexChange` callback.
   */
  navigationState: NavigationState<T>,
  /**
   * 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.
   */
  onIndexChange: (index: number) => mixed,
  /**
   * Callback which returns a react element to render as the page for the tab. Receives an object containing the route as the argument:
   *
   * ```js
   * renderScene = ({ route, jumpTo }) => {
   *   switch (route.key) {
   *     case 'music':
   *       return <MusicRoute jumpTo={jumpTo} />;
   *     case 'albums':
   *       return <AlbumsRoute jumpTo={jumpTo} />;
   *   }
   * }
   * ```
   *
   * Pages are lazily rendered, which means that a page will be rendered the first time you navigate to it.
   * After initial render, all the pages stay rendered to preserve their state.
   *
   * 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:
   *
   * ```js
   * renderScene = BottomNavigation.SceneMap({
   *   music: MusicRoute,
   *   albums: AlbumsRoute,
   * });
   * ```
   *
   * Specifying the components this way is easier and takes care of implementing a `shouldComponentUpdate` method.
   * Each component will receive the current route and a `jumpTo` method as it's props.
   * The `jumpTo` method can be used to navigate to other tabs programmatically:
   *
   * ```js
   * this.props.jumpTo('albums')
   * ```
   */
  renderScene: (props: {
    route: T,
    jumpTo: (key: string) => mixed,
  }) => ?React.Node,
  /**
   * Callback which returns a React Element to be used as tab icon.
   */
  renderIcon?: (props: {
    route: T,
    focused: boolean,
    color: string,
  }) => React.Node,
  /**
   * Callback which React Element to be used as tab label.
   */
  renderLabel?: (props: {
    route: T,
    focused: boolean,
    color: string,
  }) => React.Node,
  /**
   * Get label text for the tab, uses `route.title` by default. Use `renderLabel` to replace label component.
   */
  getLabelText?: (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.
   */
  getAccessibilityLabel?: (props: { route: T }) => ?string,
  /**
   * Get the id to locate this tab button in tests, uses `route.testID` by default.
   */
  getTestID?: (props: { route: T }) => ?string,
  /**
   * Get badge for the tab, uses `route.badge` by default.
   */
  getBadge?: (props: { route: T }) => boolean | number | string,
  /**
  /**
   * Get color for the tab, uses `route.color` by default.
   */
  getColor?: (props: { route: T }) => string,
  /**
   * Function to execute on tab press. It receives the route for the pressed tab, useful for things like scroll to top.
   */
  onTabPress?: (props: { route: T }) => mixed,
  /**
   * Custom color for icon and label in the active tab.
   */
  activeColor?: string,
  /**
   * Custom color for icon and label in the inactive tab.
   */
  inactiveColor?: string,
  /**
   * Whether the bottom navigation bar is hidden when keyboard is shown.
   * On Android, this works best when [`windowSoftInputMode`](https://developer.android.com/guide/topics/manifest/activity-element#wsoft) is set to `adjustResize`.
   */
  keyboardHidesNavigationBar?: boolean,
  /**
   * Style for the bottom navigation bar.
   * You can set a bottom padding here if you have a translucent navigation bar on Android:
   *
   * ```js
   * barStyle={{ paddingBottom: 48 }}
   * ```
   */
  barStyle?: ViewStyleProp,
  style?: ViewStyleProp,
  /**
   * @optional
   */
  theme: Theme,
};

type State = {
  /**
   * Visibility of the navigation bar, visible state is 1 and invisible is 0.
   */
  visible: Animated.Value,
  /**
   * Active state of individual tab items, active state is 1 and inactve state is 0.
   */
  tabs: Animated.Value[],
  /**
   * The top offset for each tab item to position it offscreen.
   * Placing items offscreen helps to save memory usage for inactive screens with removeClippedSubviews.
   * We use animated values for this to prevent unnecesary re-renders.
   */
  offsets: Animated.Value[],
  /**
   * Index of the currently active tab. Used for setting the background color.
   * Use don't use the color as an animated value directly, because `setValue` seems to be buggy with colors.
   */
  index: Animated.Value,
  /**
   * Animation for the background color ripple, used to determine it's scale and opacity.
   */
  ripple: Animated.Value,
  /**
   * Layout of the navigation bar. The width is used to determine the size and position of the ripple.
   */
  layout: { height: number, width: number, measured: boolean },
  /**
   * Currently active index. Used only for getDerivedStateFromProps.
   */
  current: number,
  /**
   * Previously active index. Used to determine the position of the ripple.
   */
  previous: number,
  /**
   * List of loaded tabs, tabs will be loaded when navigated to.
   */
  loaded: number[],
  /**
   * Trak whether the keyboard is visible to show and hide the navigation bar.
   */
  keyboard: boolean,
};

const MIN_RIPPLE_SCALE = 0.001; // Minimum scale is not 0 due to bug with animation
const MIN_TAB_WIDTH = 96;
const MAX_TAB_WIDTH = 168;
const BAR_HEIGHT = 56;
const FAR_FAR_AWAY = 9999;

const Touchable = TouchableRipple.supported
  ? TouchableRipple
  : ({ style, children, borderless, centered, rippleColor, ...rest }) => (
      <TouchableWithoutFeedback {...rest}>
        <View style={style}>{children}</View>
      </TouchableWithoutFeedback>
    );

class SceneComponent extends React.PureComponent<*> {
  render() {
    const { component, ...rest } = this.props;
    return React.createElement(component, rest);
  }
}

/**
 * Bottom navigation provides quick navigation between top-level views of an app with a bottom navigation bar.
 * It is primarily designed for use on mobile.
 *
 * For integration with React Navigation, you can use [react-navigation-material-bottom-tab-navigator](https://github.com/react-navigation/react-navigation-material-bottom-tab-navigator).
 *
 * <div class="screenshots">
 *   <img class="medium" src="screenshots/bottom-navigation.gif" />
 * </div>
 *
 * ## Usage
 * ```js
 * import * as React from 'react';
 * import { BottomNavigation, Text } from 'react-native-paper';
 *
 * const MusicRoute = () => <Text>Music</Text>;
 *
 * const AlbumsRoute = () => <Text>Albums</Text>;
 *
 * const RecentsRoute = () => <Text>Recents</Text>;
 *
 * export default class MyComponent extends React.Component {
 *   state = {
 *     index: 0,
 *     routes: [
 *       { key: 'music', title: 'Music', icon: 'queue-music' },
 *       { key: 'albums', title: 'Albums', icon: 'album' },
 *       { key: 'recents', title: 'Recents', icon: 'history' },
 *     ],
 *   };
 *
 *   _handleIndexChange = index => this.setState({ index });
 *
 *   _renderScene = BottomNavigation.SceneMap({
 *     music: MusicRoute,
 *     albums: AlbumsRoute,
 *     recents: RecentsRoute,
 *   });
 *
 *   render() {
 *     return (
 *       <BottomNavigation
 *         navigationState={this.state}
 *         onIndexChange={this._handleIndexChange}
 *         renderScene={this._renderScene}
 *       />
 *     );
 *   }
 * }
 * ```
 */
class BottomNavigation<T: *> extends React.Component<Props<T>, State> {
  /**
   * Function which takes a map of route keys to components.
   * Pure components are used to minmize re-rendering of the pages.
   * This drastically improves the animation performance.
   */
  static SceneMap(scenes: {
    [key: string]: React.ComponentType<{
      route: T,
      jumpTo: (key: string) => mixed,
    }>,
  }) {
    return ({ route, jumpTo }: *) => (
      <SceneComponent
        key={route.key}
        component={scenes[route.key]}
        route={route}
        jumpTo={jumpTo}
      />
    );
  }

  static defaultProps = {
    labeled: true,
    keyboardHidesNavigationBar: true,
  };

  static getDerivedStateFromProps(nextProps, prevState) {
    const { index, routes } = nextProps.navigationState;

    // Re-create animated values if routes have been added/removed
    // Preserve previous animated values if they exist, so we don't break animations
    const tabs = routes.map(
      // focused === 1, unfocused === 0
      (_, i) => prevState.tabs[i] || new Animated.Value(i === index ? 1 : 0)
    );
    const offsets = routes.map(
      // offscreen === 1, normal === 0
      (_, i) => prevState.offsets[i] || new Animated.Value(i === index ? 0 : 1)
    );

    const nextState = {
      tabs,
      offsets,
    };

    if (index !== prevState.current) {
      /* $FlowFixMe */
      Object.assign(nextState, {
        // Store the current index in state so that we can later check if the index has changed
        current: index,
        previous: prevState.current,
        // Set the current tab to be loaded if it was not loaded before
        loaded: prevState.loaded.includes(index)
          ? prevState.loaded
          : [...prevState.loaded, index],
      });
    }

    return nextState;
  }

  constructor(props) {
    super(props);

    const { index } = this.props.navigationState;

    this.state = {
      visible: new Animated.Value(1),
      tabs: [],
      offsets: [],
      index: new Animated.Value(index),
      ripple: new Animated.Value(MIN_RIPPLE_SCALE),
      touch: new Animated.Value(MIN_RIPPLE_SCALE),
      layout: { height: 0, width: 0, measured: false },
      current: index,
      previous: 0,
      loaded: [index],
      keyboard: false,
    };
  }

  componentDidMount() {
    // Workaround for native animated bug in react-native@^0.57
    // Context: https://github.com/callstack/react-native-paper/pull/637
    this._animateToCurrentIndex();

    if (Platform.OS === 'ios') {
      Keyboard.addListener('keyboardWillShow', this._handleKeyboardShow);
      Keyboard.addListener('keyboardWillHide', this._handleKeyboardHide);
    } else {
      Keyboard.addListener('keyboardDidShow', this._handleKeyboardShow);
      Keyboard.addListener('keyboardDidHide', this._handleKeyboardHide);
    }
  }

  componentDidUpdate(prevProps) {
    if (prevProps.navigationState.index === this.props.navigationState.index) {
      return;
    }

    // Reset offsets of previous and current tabs before animation
    this.state.offsets.forEach((offset, i) => {
      if (
        i === this.props.navigationState.index ||
        i === prevProps.navigationState.index
      ) {
        offset.setValue(0);
      }
    });

    this._animateToCurrentIndex();
  }

  componentWillUnmount() {
    if (Platform.OS === 'ios') {
      Keyboard.removeListener('keyboardWillShow', this._handleKeyboardShow);
      Keyboard.removeListener('keyboardWillHide', this._handleKeyboardHide);
    } else {
      Keyboard.removeListener('keyboardDidShow', this._handleKeyboardShow);
      Keyboard.removeListener('keyboardDidHide', this._handleKeyboardHide);
    }
  }

  _handleKeyboardShow = () =>
    this.setState({ keyboard: true }, () =>
      Animated.timing(this.state.visible, {
        toValue: 0,
        duration: 150,
        useNativeDriver: true,
      }).start()
    );

  _handleKeyboardHide = () =>
    Animated.timing(this.state.visible, {
      toValue: 1,
      duration: 100,
      useNativeDriver: true,
    }).start(() => {
      this.setState({ keyboard: false });
    });

  _animateToCurrentIndex = () => {
    const shifting = this._isShifting();
    const { routes, index } = this.props.navigationState;

    // Reset the ripple to avoid glitch if it's currently animating
    this.state.ripple.setValue(MIN_RIPPLE_SCALE);

    Animated.parallel([
      Animated.timing(this.state.ripple, {
        toValue: 1,
        duration: shifting ? 400 : 0,
        useNativeDriver: true,
      }),
      ...routes.map((_, i) =>
        Animated.timing(this.state.tabs[i], {
          toValue: i === index ? 1 : 0,
          duration: shifting ? 150 : 75,
          useNativeDriver: true,
        })
      ),
    ]).start(({ finished }) => {
      // Workaround a bug in native animations where this is reset after first animation
      this.state.tabs.map((tab, i) => tab.setValue(i === index ? 1 : 0));

      // Update the index to change bar's bacground color and then hide the ripple
      this.state.index.setValue(index);
      this.state.ripple.setValue(MIN_RIPPLE_SCALE);

      if (finished) {
        // Position all inactive screens offscreen to save memory usage
        // Only do it when animation has finished to avoid glitches mid-transition if switching fast
        this.state.offsets.forEach((offset, i) => {
          if (i === index) {
            offset.setValue(0);
          } else {
            offset.setValue(1);
          }
        });
      }
    });
  };

  _handleLayout = e => {
    const { layout } = this.state;
    const { height, width } = e.nativeEvent.layout;

    if (height === layout.height && width === layout.width) {
      return;
    }

    this.setState({
      layout: {
        height,
        width,
        measured: true,
      },
    });
  };

  _handleTabPress = (index: number) => {
    const { navigationState, onTabPress, onIndexChange } = this.props;

    if (onTabPress) {
      onTabPress({
        route: navigationState.routes[index],
      });
    }

    if (index !== navigationState.index) {
      onIndexChange(index);
    }
  };

  _jumpTo = (key: string) => {
    const index = this.props.navigationState.routes.findIndex(
      route => route.key === key
    );

    this.props.onIndexChange(index);
  };

  _isShifting = () =>
    typeof this.props.shifting === 'boolean'
      ? this.props.shifting
      : this.props.navigationState.routes.length > 3;

  render() {
    const {
      navigationState,
      renderScene,
      renderIcon,
      renderLabel,
      getLabelText = ({ route }: Object) => route.title,
      getBadge = ({ route }: Object) => route.badge,
      getColor = ({ route }: Object) => route.color,
      getAccessibilityLabel = ({ route }: Object) => route.accessibilityLabel,
      getTestID = ({ route }: Object) => route.testID,
      activeColor,
      inactiveColor,
      keyboardHidesNavigationBar,
      barStyle,
      labeled,
      style,
      theme,
    } = this.props;

    const { layout, loaded } = this.state;
    const { routes } = navigationState;
    const { colors } = theme;

    const shifting = this._isShifting();

    const { backgroundColor: approxBackgroundColor = colors.primary } =
      StyleSheet.flatten(barStyle) || {};

    const backgroundColor = shifting
      ? this.state.index.interpolate({
          inputRange: routes.map((_, i) => i),
          outputRange: routes.map(
            route => getColor({ route }) || approxBackgroundColor
          ),
        })
      : approxBackgroundColor;

    const isDark = !color(approxBackgroundColor).light();

    const textColor = isDark ? white : black;
    const activeTintColor =
      typeof activeColor !== 'undefined' ? activeColor : textColor;
    const inactiveTintColor =
      typeof inactiveColor !== 'undefined'
        ? inactiveColor
        : color(textColor)
            .alpha(0.5)
            .rgb()
            .string();

    const touchColor = color(activeColor)
      .alpha(0.12)
      .rgb()
      .string();

    const maxTabWidth = routes.length > 3 ? MIN_TAB_WIDTH : MAX_TAB_WIDTH;
    const tabWidth = Math.min(
      // Account for horizontal padding around the items
      (layout.width * 4) / routes.length,
      maxTabWidth
    );

    return (
      <View
        style={[styles.container, style]}
        pointerEvents={layout.measured ? 'auto' : 'none'}
      >
        <View style={[styles.content, { backgroundColor: colors.background }]}>
          {routes.map((route, index) => {
            if (!loaded.includes(index)) {
              // Don't render a screen if we've never navigated to it
              return null;
            }

            const opacity = this.state.tabs[index];
            const top = this.state.offsets[index].interpolate({
              inputRange: [0, 1],
              outputRange: [0, FAR_FAR_AWAY],
            });

            const focused = navigationState.index === index;

            return (
              <Animated.View
                key={route.key}
                pointerEvents={focused ? 'auto' : 'none'}
                accessibilityElementsHidden={!focused}
                importantForAccessibility={
                  focused ? 'auto' : 'no-hide-descendants'
                }
                style={[StyleSheet.absoluteFill, { opacity }]}
                collapsable={false}
                removeClippedSubviews={
                  // On iOS, set removeClippedSubviews to true only when not focused
                  // This is an workaround for a bug where the clipped view never re-appears
                  Platform.OS === 'ios' ? navigationState.index !== index : true
                }
              >
                <Animated.View style={[styles.content, { top }]}>
                  {renderScene({
                    route,
                    jumpTo: this._jumpTo,
                  })}
                </Animated.View>
              </Animated.View>
            );
          })}
        </View>
        <Surface
          style={[
            styles.bar,
            keyboardHidesNavigationBar
              ? {
                  // When the keyboard is shown, slide down the navigation bar
                  transform: [
                    {
                      translateY: this.state.visible.interpolate({
                        inputRange: [0, 1],
                        outputRange: [this.state.layout.height, 0],
                      }),
                    },
                  ],
                  // Absolutely position the navigation bar so that the content is below it
                  // This is needed to avoid gap at bottom when the navigation bar is hidden
                  position: this.state.keyboard ? 'absolute' : null,
                }
              : null,
            barStyle,
          ]}
          pointerEvents={
            keyboardHidesNavigationBar && this.state.keyboard ? 'none' : 'auto'
          }
          onLayout={this._handleLayout}
        >
          <Animated.View style={[styles.barContent, { backgroundColor }]}>
            <SafeAreaView
              forceInset={{ top: 'never', bottom: 'always' }}
              style={[styles.items, { maxWidth: maxTabWidth * routes.length }]}
            >
              {shifting ? (
                <Animated.View
                  pointerEvents="none"
                  style={[
                    styles.ripple,
                    {
                      // Since we have a single ripple, we have to reposition it so that it appears to expand from active tab.
                      // We need to move it from the top to center of the navigation bar and from the left to the active tab.
                      top: BAR_HEIGHT / 2 - layout.width / 8,
                      left:
                        navigationState.index * tabWidth +
                        tabWidth / 2 -
                        layout.width / 8,
                      height: layout.width / 4,
                      width: layout.width / 4,
                      borderRadius: layout.width / 2,
                      backgroundColor: getColor({
                        route: routes[navigationState.index],
                      }),
                      transform: [
                        {
                          // Scale to twice the size  to ensure it covers the whole navigation bar
                          scale: this.state.ripple.interpolate({
                            inputRange: [0, 1],
                            outputRange: [0, 8],
                          }),
                        },
                      ],
                      opacity: this.state.ripple.interpolate({
                        inputRange: [0, MIN_RIPPLE_SCALE, 0.3, 1],
                        outputRange: [0, 0, 1, 1],
                      }),
                    },
                  ]}
                />
              ) : null}
              {routes.map((route, index) => {
                const focused = navigationState.index === index;
                const active = this.state.tabs[index];

                // Scale the label up
                const scale =
                  labeled && shifting
                    ? active.interpolate({
                        inputRange: [0, 1],
                        outputRange: [0.5, 1],
                      })
                    : 1;

                // Move down the icon to account for no-label in shifting and smaller label in non-shifting.
                const translateY = labeled
                  ? shifting
                    ? active.interpolate({
                        inputRange: [0, 1],
                        outputRange: [7, 0],
                      })
                    : 0
                  : 7;

                // We render the active icon and label on top of inactive ones and cross-fade them on change.
                // This trick gives the illusion that we are animating between active and inactive colors.
                // This is to ensure that we can use native driver, as colors cannot be animated with native driver.
                const activeOpacity = active;
                const inactiveOpacity = active.interpolate({
                  inputRange: [0, 1],
                  outputRange: [1, 0],
                });

                const badge = getBadge({ route });

                return (
                  <Touchable
                    key={route.key}
                    borderless
                    centered
                    rippleColor={touchColor}
                    onPress={() => this._handleTabPress(index)}
                    testID={getTestID({ route })}
                    accessibilityLabel={getAccessibilityLabel({ route })}
                    accessibilityTraits={
                      focused ? ['button', 'selected'] : 'button'
                    }
                    accessibilityComponentType="button"
                    accessibilityRole="button"
                    accessibilityStates={['selected']}
                    style={styles.item}
                  >
                    <View pointerEvents="none">
                      <Animated.View
                        style={[
                          styles.iconContainer,
                          { transform: [{ translateY }] },
                        ]}
                      >
                        <Animated.View
                          style={[
                            styles.iconWrapper,
                            { opacity: activeOpacity },
                          ]}
                        >
                          {renderIcon ? (
                            renderIcon({
                              route,
                              focused: true,
                              color: activeTintColor,
                            })
                          ) : (
                            <Icon
                              source={(route: Object).icon}
                              color={activeTintColor}
                              size={24}
                            />
                          )}
                        </Animated.View>
                        <Animated.View
                          style={[
                            styles.iconWrapper,
                            { opacity: inactiveOpacity },
                          ]}
                        >
                          {renderIcon ? (
                            renderIcon({
                              route,
                              focused: false,
                              color: inactiveTintColor,
                            })
                          ) : (
                            <Icon
                              source={(route: Object).icon}
                              color={inactiveTintColor}
                              size={24}
                            />
                          )}
                        </Animated.View>
                        <View
                          style={[
                            styles.badgeContainer,
                            {
                              right:
                                (badge != null && typeof badge !== 'boolean'
                                  ? String(badge).length * -2
                                  : 0) - 2,
                            },
                          ]}
                        >
                          {typeof badge === 'boolean' ? (
                            <Badge visible={badge} size={8} />
                          ) : (
                            <Badge visible={badge != null} size={16}>
                              {badge}
                            </Badge>
                          )}
                        </View>
                      </Animated.View>
                      {labeled ? (
                        <Animated.View
                          style={[
                            styles.labelContainer,
                            { transform: [{ scale }] },
                          ]}
                        >
                          <Animated.View
                            style={[
                              styles.labelWrapper,
                              { opacity: activeOpacity },
                            ]}
                          >
                            {renderLabel ? (
                              renderLabel({
                                route,
                                focused: true,
                                color: activeTintColor,
                              })
                            ) : (
                              <AnimatedText
                                style={[
                                  styles.label,
                                  { color: activeTintColor },
                                ]}
                              >
                                {getLabelText({ route })}
                              </AnimatedText>
                            )}
                          </Animated.View>
                          {shifting ? null : (
                            <Animated.View
                              style={[
                                styles.labelWrapper,
                                { opacity: inactiveOpacity },
                              ]}
                            >
                              {renderLabel ? (
                                renderLabel({
                                  route,
                                  focused: false,
                                  color: inactiveTintColor,
                                })
                              ) : (
                                <AnimatedText
                                  style={[
                                    styles.label,
                                    { color: inactiveTintColor },
                                  ]}
                                >
                                  {getLabelText({ route })}
                                </AnimatedText>
                              )}
                            </Animated.View>
                          )}
                        </Animated.View>
                      ) : (
                        <View style={styles.labelContainer} />
                      )}
                    </View>
                  </Touchable>
                );
              })}
            </SafeAreaView>
          </Animated.View>
        </Surface>
      </View>
    );
  }
}

polyfill(BottomNavigation);

export default withTheme(BottomNavigation);

const styles = StyleSheet.create({
  container: {
    flex: 1,
    overflow: 'hidden',
  },
  content: {
    flex: 1,
  },
  bar: {
    left: 0,
    right: 0,
    bottom: 0,
    elevation: 8,
  },
  barContent: {
    alignItems: 'center',
    overflow: 'hidden',
  },
  items: {
    flexDirection: 'row',
    width: '100%',
  },
  item: {
    flex: 1,
    // Top padding is 6 and bottom padding is 10
    // The extra 4dp bottom padding is offset by label's height
    paddingVertical: 6,
  },
  ripple: {
    position: 'absolute',
  },
  iconContainer: {
    height: 24,
    width: 24,
    marginTop: 2,
    marginHorizontal: 12,
    alignSelf: 'center',
  },
  iconWrapper: {
    ...StyleSheet.absoluteFillObject,
    alignItems: 'center',
  },
  labelContainer: {
    height: 16,
    paddingBottom: 2,
  },
  labelWrapper: {
    ...StyleSheet.absoluteFillObject,
  },
  label: {
    fontSize: 12,
    textAlign: 'center',
    backgroundColor: 'transparent',
    ...((Platform.OS === 'web'
      ? {
          whiteSpace: 'nowrap',
        }
      : null): any),
  },
  badgeContainer: {
    position: 'absolute',
    left: 0,
    top: -2,
  },
});