React Native Parallax Swiper

Configurable parallax swiper based on an iOS pattern.

Features

Flexible. Share one Animated.Value between ParallaxSwiper and your own UI.
Performant. Runs on the native thread for 60FPS with no latency.
Cross-platform. Works on both iOS and Android.
Progress Bar. Horizontal or vertical progress bar.

Examples

Clone this repo and:

$ cd examples/ParallaxSwiperExample
$ npm install
$ react-native link
$ react-native run-ios

Installation

$ npm install react-native-parallax-swiper --save

Usage

import React from "react";
import {
  Animated,
  Text,
  View,
  Image,
  StyleSheet,
  Dimensions
} from "react-native";

import {
  ParallaxSwiper,
  ParallaxSwiperPage
} from "react-native-parallax-swiper";

const { width, height } = Dimensions.get("window");

export default class App extends React.Component {
  myCustomAnimatedValue = new Animated.Value(0);

  getPageTransformStyle = index => ({
    transform: [
      {
        scale: this.myCustomAnimatedValue.interpolate({
          inputRange: [
            (index - 1) * (width + 8), // Add 8 for dividerWidth
            index * (width + 8),
            (index + 1) * (width + 8)
          ],
          outputRange: [0, 1, 0],
          extrapolate: "clamp"
        })
      },
      {
        rotate: this.myCustomAnimatedValue.interpolate({
          inputRange: [
            (index - 1) * (width + 8),
            index * (width + 8),
            (index + 1) * (width + 8)
          ],
          outputRange: ["180deg", "0deg", "-180deg"],
          extrapolate: "clamp"
        })
      }
    ]
  });

  render() {
    return (
      <ParallaxSwiper
        speed={0.5}
        animatedValue={this.myCustomAnimatedValue}
        dividerWidth={8}
        dividerColor="black"
        backgroundColor="black"
        onMomentumScrollEnd={activePageIndex => console.log(activePageIndex)}
        showProgressBar={true}
        progressBarBackgroundColor="rgba(0,0,0,0.25)"
        progressBarValueBackgroundColor="white"
      >
        <ParallaxSwiperPage
          BackgroundComponent={
            <Image
              style={styles.backgroundImage}
              source={{ uri: "https://goo.gl/wtHtxG" }}
            />
          }
          ForegroundComponent={
            <View style={styles.foregroundTextContainer}>
              <Animated.Text
                style={[styles.foregroundText, this.getPageTransformStyle(0)]}
              >
                Page 1
              </Animated.Text>
            </View>
          }
        />
        <ParallaxSwiperPage
          BackgroundComponent={
            <Image
              style={styles.backgroundImage}
              source={{ uri: "https://goo.gl/gt4rWa" }}
            />
          }
          ForegroundComponent={
            <View style={styles.foregroundTextContainer}>
              <Animated.Text
                style={[styles.foregroundText, this.getPageTransformStyle(1)]}
              >
                Page 2
              </Animated.Text>
            </View>
          }
        />
        <ParallaxSwiperPage
          BackgroundComponent={
            <Image
              style={styles.backgroundImage}
              source={{ uri: "https://goo.gl/KAaVXt" }}
            />
          }
          ForegroundComponent={
            <View style={styles.foregroundTextContainer}>
              <Animated.Text
                style={[styles.foregroundText, this.getPageTransformStyle(2)]}
              >
                Page 3
              </Animated.Text>
            </View>
          }
        />
      </ParallaxSwiper>
    );
  }
}

const styles = StyleSheet.create({
  backgroundImage: {
    width,
    height
  },
  foregroundTextContainer: {
    flex: 1,
    alignItems: "center",
    justifyContent: "center",
    backgroundColor: "transparent"
  },
  foregroundText: {
    fontSize: 34,
    fontWeight: "700",
    letterSpacing: 0.41,
    color: "white"
  }
});

ParallaxSwiper Props

Prop	Type	Default	Description
`speed`	Number	`0.25`	This number determines how fast `BackgroundComponent` moves. Set to 0 for no movement at all, set to 1 and background will move as fast as the scroll.
`dividerWidth`	Number	`8`	The width of the divider between each page. (horizontal only)
`dividerColor`	String	`black`	Color of divider.
`backgroundColor`	String	`black`	ParallaxSwiper’s background color.
`scrollToIndex`	Number	0	Scroll to page with a smooth animation. Note: You need to use state if you want to change index any other time than when component is rendered.
`onMomentumScrollEnd`	Function	`N/A`	Fired when ScrollView stops scrolling and is passed the current page index.
`animatedValue`	Number (Animated.Value)	`0`	Optionally pass a new instance of Animated.Value to access the animated value outside of ParallaxSwiper.
`vertical`	Boolean	`false`	When true, ParallaxSwiper’s children are arranged vertically in a column instead of horizontally in a row. For now only iOS supports this.
`showsHorizontalScrollIndicator`	Boolean	`false`	When true, shows a horizontal scroll indicator. The default value is false.
`showsVerticalScrollIndicator`	Boolean	`false`	When true, shows a vertical scroll indicator. The default value is false.
`children`	React component (ParallaxSwiperPage)	`N/A`	Each top-level ParallaxSwiperPage child.
`showProgressBar`	Boolean	false	When true, a progress bar will render on bottom for horizontal and left on vertical.
`progressBarThickness`	Number	4	Thickness translates to height for horizontal and width for vertical progress bar.
`progressBarBackgroundColor`	String	`rgba(255,255,255,0.25)`	Background color of progress bar background.
`progressBarValueBackgroundColor`	String	`white`	Background color of progress bar value background.

ParallaxSwiperPage Props

Prop	Type	Default	Description
`BackgroundComponent`	React element	`N/A`	This component will render in the background of the page and will be animated based on scroll.
`ForegroundComponent`	React element	`N/A`	This component will render in the foreground of the page.

TODO

Why another parallax component? 😒

This component is inspired by an iOS pattern that no react-native-parallax-whatever previously delivered. It emulates this pattern by using the ScrollView component which has features like velocity, paging, and platform specific easing curves; It also has optional dividers to split up each page. You can see this pattern in apps like iOS Camera Roll, Twitter Moments, Kylie Jenner’s app, Vevo’s app, and more.

Contributors

_{Chris LeBlanc} [💻]

Questions or suggestions?

Hit me up on Twitter, or create an issue.

zachgibson/react-native-parallax-swiper

zachgibson

Reviews

Repository Details