README.md

Pager RN

This library is a port of react-native-pager using the latest Reanimated / React Native Gesture Handler APIs

Install

yarn add pager-rn

Required Peer Dependencies:

yarn add react-native-reanimated react-native-gesture-handler

Note: These versions were used to develop this package:

{
  "react-native-gesture-handler": "^2.8.0",
  "react-native-reanimated": "^2.12.0"
}

Basic Example

import * as React from "react";
import { View, Text } from "react-native";
import { GestureHandlerRootView } from "react-native-gesture-handler";

import { Pager } from "pager-rn";

export default function App() {
  return (
    <GestureHandlerRootView style={{ flex: 1 }}>
      <Pager.Root style={{ padding: 24 }}>
        <Pager.Container style={{ padding: 24, borderWidth: 1 }}>
          <Pager.Page>
            <MyPage>1</MyPage>
          </Pager.Page>
          <Pager.Page>
            <MyPage>2</MyPage>
          </Pager.Page>
          <Pager.Page>
            <MyPage>3</MyPage>
          </Pager.Page>
        </Pager.Container>
      </Pager.Root>
    </GestureHandlerRootView>
  );
}

function MyPage({ children }) {
  return (
    <View
      style={{
        flex: 1,
        justifyContent: "center",
        alignItems: "center",
        borderWidth: 1,
        backgroundColor: "white",
      }}
    >
      <Text>{children}</Text>
    </View>
  );
}

Components

<Pager.Root />

Establishes the pan-able area for the pager.

<Pager.Container />

Where the Pages are rendered.

<Pager.Page />

Namespace for an individual Page

Props

import * as React from "react";
import { View } from "react-native";
import { GestureHandlerRootView } from "react-native-gesture-handler";
import { useSharedValue } from "react-native-reanimated";

import { Pager } from "pager-rn";

export default function App() {
  // Control the current activeIndex with state:
  let [activeIndex, setActiveIndex] = React.useState(0);

  // Access the animatedIndex to synchronize your own animations
  let myAnimatedIndex = useSharedValue(0);

  // Apply styles to the area around the pager
  let rootStyles = { padding: 24 };

  // Apply styles to the pager
  let containerStyles = { padding: 24, borderWidth: 1, overflow: "hidden" };

  // Orient pages vertically:
  let orientation = "vertical"; // or "horizontal"

  // Loop the slides infinitely - defaults to false
  let circular = false;

  // Restrict the number of pages rendered at any given time:
  // E.g: This will render the 5 pages left and right of the activeIndex
  let pageOffset = 5;

  return (
    <GestureHandlerRootView style={{ flex: 1 }}>
      <Pager.Root
        activeIndex={activeIndex}
        onChange={setActiveIndex}
        animatedIndex={myAnimatedIndex}
        style={rootStyles}
        orientation={orientation}
        circular={circular}
        maxPages={maxPages}
      >
        <Pager.Container style={containerStyles}>
          <Pager.Page>
            <MyPage>1</MyPage>
          </Pager.Page>
          <Pager.Page>
            <MyPage>2</MyPage>
          </Pager.Page>
          <Pager.Page>
            <MyPage>3</MyPage>
          </Pager.Page>
        </Pager.Container>
      </Pager.Root>
    </GestureHandlerRootView>
  );
}

Interpolations

import * as React from "react";
import { View } from "react-native";
import { GestureHandlerRootView } from "react-native-gesture-handler";
import { useSharedValue } from "react-native-reanimated";

import { Pager, Interpolation } from "pager-rn";

// Interpolations apply styles to a page based on its relative position
let interpolation: Interpolation = {
  transforms: {
    // Apply 0.2 scale to pages left of (or below) the active page
    scale: [0.2, 1],
    // Rotate pages around the active page by 45 degrees
    rotate: ["45deg", "0deg", "45deg"],
  },

  // Ensure sibling pages appear behind the active page
  zIndex: [0, 1, 0],

  // Interpolations are configurable:
  opacity: {
    // The input refers to the position relative to the active page
    // e.g [left, active, right]
    input: [-1, 0, 1],
    // The output is the applied style value
    // e.g [opacity: 0, opacity: 1, opacity: 0.6]
    output: [0, 1, 0.6],
    // Extrapolate is applied to values outside the bounds of input/output
    extrapolate: "clamp",
  },
};

export default function App() {
  return (
    <GestureHandlerRootView style={{ flex: 1 }}>
      <Pager.Root interpolation={interpolation}>
        <Pager.Container>
          <Pager.Page>
            <MyPage>1</MyPage>
          </Pager.Page>
          <Pager.Page>
            <MyPage>2</MyPage>
          </Pager.Page>
          <Pager.Page>
            <MyPage>3</MyPage>
          </Pager.Page>
        </Pager.Container>
      </Pager.Root>
    </GestureHandlerRootView>
  );
}

You can do lots of cool stuff with interpolations - for example, the video at the top of this README uses the following interopolation prop:

let interpolation: Interpolation = {
  transforms: {
    scale: [0.95, 1, 0.95],
    translateY: [0, 0, 0, 10, -15],
    translateX: [0, 0, -325],
    rotate: ["-20deg", "-20deg", "0deg", "-7.5deg", "5deg"],
  },
  zIndex: [1, 1, 0],
  opacity: [0, 0, 1, 1, 1, 1, 0],
  extrapolate: "extend",
};

Interpolations can be applied at a page level via the useInterpolation() hook:

Note - zIndex will not work with this hook!

import * as React from "react";
import Animated from "react-native-reanimated";
import { useInterpolation } from "pager-rn";

function MyPage({ bg = "white", children }) {
  let interpolatedStyle = useInterpolation({
    transforms: {
      scale: [0.2, 1],
      rotate: ["45deg", "0deg", "45deg"],
    },

    opacity: [0, 1, 0.5],
  });

  return (
    <Animated.View
      style={[
        {
          flex: 1,
          justifyContent: "center",
          alignItems: "center",
          backgroundColor: bg,
        },
        interpolatedStyle,
      ]}
    >
      <Animated.Text>{children}</Animated.Text>
    </Animated.View>
  );
}