This is an enhanced version of 10clouds' fluid tab bar for React Native.

Changes:

• Added Expo compatibility by removing react-native-view-overflow and the need to link it.
• Added integrated vector icons via @expo/vector-icons so you don't have to supply your own icons.
• Tab bar now auto-selects first tab index on mount (this behavior is customizable).
• Tab bar background color is now fully customizable.
• Icon highlight color on select is now fully customizable.
• Icon font size and font family is now fully customizable.
• Deprecated the ability to provide image sources for icon images.
• Removed example project in favor of expanded usage documentation.

yarn add enhanced-fluid-bottom-navigation-bar

npm i enhanced-fluid-bottom-navigation-bar

This component requires just 2 props:

• onPress: a function that should handle rendering tabs.
• values: an array of objects that contains the title and icon properties for each tab.

<TabBar
  onPress={(tabIndex) => { this._handlePress(tabIndex) }}
  values={[
    {
      title: 'News',      // required
      icon: 'news',       // required
      iconSet: 'Entypo',  // required
      size: 32            // required (icon will be size x size)
    }
  ]}
/>

Look up valid icon names and their corresponding icon set at the @expo/vector-icons directory.

1. Define a custom component that renders TabBar with the values you want. React's tab navigator will pass navigation and onTabPress props to your component when hooked up; use these to implement the onPress callback to navigate to the appropriate route:

import TabBar from 'enhanced-fluid-bottom-navigation-bar';

class FluidTabBar extends Component {
  render() {
    return (
      <TabBar
        onPress={tabIndex => {
          let route = this.props.navigation.state.routes[tabIndex];
          this.props.onTabPress({route});
        }}
        values={[
          {
            title: 'Tab 1',
            icon: 'star',     
            iconSet: 'MaterialIcons',
            size: 32          
          }, {
            title: 'Tab 2',
            icon: 'check',     
            iconSet: 'AntDesign',
            size: 32          
          }
        ]}
      />
    );
  }
}

In this case, pressing a tab in FluidTabBar navigates to the route that shares the same array index.

2. Create a tab navigator and supply our custom component to tabBarComponent.

import {createBottomTabNavigator} from 'react-navigation-tabs';

const myTabNavigator = createBottomTabNavigator(
  {  // RouteConfigs
    Tab1: { screen: Tab1Screen },
    Tab2: { screen: Tab2Screen },
  },
  {
    initialRouteName: 'Tab1',
    tabBarComponent: FluidTabBar,
  }
);

3. Create an app container from your tab navigator and use it as your top-level component.

import {createAppContainer} from 'react-navigation';

const myAppContainer = createAppContainer(myTabNavigator)

Original Author: Patryk Mierzejewski

Modifications By: Victor Li

Available under the MIT license. See the LICENSE file for more info.