Paged Parallax Swiper with Effects
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Latest commit dc84840 Oct 5, 2018

README.md

React Native Parallax Swiper

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Configurable parallax swiper based on an iOS pattern.

Features

  • Flexible. Pass your own Animated.Value and use that value for both ParallaxSwiper and your own UI.
  • Performant. Leverages useNativeDriver for 60FPS and no latency.
  • Cross-platform. Implement your parallax on both iOS and Android.
  • Progress Bar. Horizontal or vertical progress bar.

Twitter Moments Demo
Vevo Demo
Lightbox Demo

Examples

React Native Parallax Swiper Expo QR code

Check out the GIF examples above via Expo. Or 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

  • Create Expo demos
  • Create examples
  • Expose current index
  • Support scrollToIndex
  • Fix Android
  • Expose Animated.Value for animation outside of ParallaxSwiper
  • Add drag effects e.g. zoom, blur, darken
  • Expose rest of ScrollView props
  • Use FlatList instead of ScrollView

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.

Copyright

Copyright (c) 2017 Zachary Gibson Licensed under the MIT license.