react-native-scrollable-tab-view

This is probably my favorite navigation pattern on Android, I wish it were more common on iOS! This is a very simple JavaScript-only implementation of it for React Native. For more information about how the animations behind this work, check out the Rebound section of the React Native Animation Guide

Add it to your project

1. Run npm install react-native-scrollable-tab-view --save
2. var ScrollableTabView = require('react-native-scrollable-tab-view');

Demo

Basic usage

var ScrollableTabView = require('react-native-scrollable-tab-view');

var App = React.createClass({
  render() {
    return (
      <ScrollableTabView>
        <ReactPage tabLabel="React" />
        <FlowPage tabLabel="Flow" />
        <JestPage tabLabel="Jest" />
      </ScrollableTabView>
    );
  }
}

Injecting a custom tab bar

Suppose we had a custom tab bar called CustomTabBar, we would inject it into our ScrollableTabView like this:

var ScrollableTabView = require('react-native-scrollable-tab-view');
var CustomTabBar = require('./CustomTabBar');

var App = React.createClass({
  render() {
    return (
      <ScrollableTabView renderTabBar={() => <CustomTabBar someProp={'here'} />}>
        <ReactPage tabLabel="React" />
        <FlowPage tabLabel="Flow" />
        <JestPage tabLabel="Jest" />
      </ScrollableTabView>
    );
  }
}

Below is the default tab bar, renamed to CustomTabBar, you can use this as a template for implementing your own.

var React = require('react-native');
var {
  StyleSheet,
  Text,
  View,
  TouchableOpacity,
} = React;

var deviceWidth = require('Dimensions').get('window').width;
var precomputeStyle = require('precomputeStyle');
var TAB_UNDERLINE_REF = 'TAB_UNDERLINE';

var styles = StyleSheet.create({
  tab: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
    paddingBottom: 10,
  },

  tabs: {
    height: 50,
    flexDirection: 'row',
    marginTop: 20,
    borderWidth: 1,
    borderTopWidth: 0,
    borderLeftWidth: 0,
    borderRightWidth: 0,
    borderBottomColor: '#ccc',
  },
});

var CustomTabBar = React.createClass({
  propTypes: {
    goToPage: React.PropTypes.func,
    activeTab: React.PropTypes.number,
    tabs: React.PropTypes.array
  },

  renderTabOption(name, page) {
    var isTabActive = this.props.activeTab === page;

    return (
      <TouchableOpacity key={name} onPress={() => this.props.goToPage(page)} style={[styles.tab]}>
        <Text style={{color: isTabActive ? 'navy' : 'black', fontWeight: isTabActive ? 'bold' : 'normal'}}>{name}</Text>
      </TouchableOpacity>
    );
  },

  setAnimationValue(value) {
    this.refs[TAB_UNDERLINE_REF].setNativeProps(precomputeStyle({
      left: (deviceWidth * value) / this.props.tabs.length
    }));
  },

  render() {
    var numberOfTabs = this.props.tabs.length;
    var tabUnderlineStyle = {
      position: 'absolute',
      width: deviceWidth / numberOfTabs,
      height: 4,
      backgroundColor: 'navy',
      bottom: 0,
    };

    return (
      <View style={styles.tabs}>
        {this.props.tabs.map((tab, i) => this.renderTabOption(tab, i))}
        <View style={tabUnderlineStyle} ref={TAB_UNDERLINE_REF} />
      </View>
    );
  },
});

module.exports = CustomTabBar;

Props

• renderTabBar (Function:ReactComponent) - should return a component to use as the tab bar. The component has goToPage, tabs, activeTab and ref added to the props, and should implement setAnimationValue to be able to animate itself along with the tab content.
• tabBarPosition (String) - if "top", the tab bar will render above the tabs. If "bottom", the tab bar will render below the tabs. Defaults to "top".
• onChangeTab (Function) - function to call when tab changes, should accept 1 argument which is an Object containing two keys: i: the index of the tab that is selected, ref: the ref of the tab that is selected
• edgeHitWidth (Integer) - region (in pixels) from the left & right edges of the screen that can trigger swipe. Default is 30, which is the same as the swipe-back gesture on iOS.
• hasTouch (Function) - returns true when ScrollableTabView starts being panned and false when it is released. Not triggered when locked (Bool) is true.
• locked (Bool) - dynamically disable scrolling between tabs.
• springTension (Integer) - a number between 1 and 100, controls the amount of tension on the spring that guides the scroll animation - see example.
• springFriction (Integer) - a number between 1 and 30, controls the amount of friction on the spring that guides the scroll animation - see example.
• clampSpring (Bool) - if true, the spring will not bounce at all - if false, it will oscillate around the target value before settling.
• initialPage (Integer) - the index of the initially selected tab, defaults to 0 === first tab.
• children (ReactComponents) - each top-level child component should have a tabLabel prop that can be used by the tab bar component to render out the labels. The default tab bar expects it to be a string, but you can use anything you want if you make a custom tab bar.

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MIT Licensed