react-native-swipeable-item

A horizontally swipeable flatlist row compatible with react-native-draggable-flatlist

Usage no npm install needed!

<script type="module">
  import reactNativeSwipeableItem from 'https://cdn.skypack.dev/react-native-swipeable-item';
</script>

README

React Native Swipeable Item

A swipeable component with underlay for React Native.
Fully native interactions powered by Reanimated and React Native Gesture Handler

Compatible with React Native Draggable Flatlist

Swipeable Item demo

Install

  1. Follow installation instructions for reanimated and react-native-gesture-handler
  2. npm install or yarn add react-native-swipeable-item
  3. import SwipeableItem from 'react-native-swipeable-item'

Props

NOTE: Naming is hard. When you swipe right, you reveal the item on the left. So what do you name these things? I have decided to name everything according to swipe direction. Therefore, a swipe left reveals the renderUnderlayLeft() component with width underlayWidthLeft. Not perfect but it works.

export type UnderlayParams<T> = {
  item: T;
  open: OpenPromiseFn;
  close: VoidPromiseFn;
  percentOpen: Animated.DerivedValue<number>;
  isGestureActive: Animated.DerivedValue<boolean>;
  direction: OpenDirection;
};

export type OverlayParams<T> = {
  item: T;
  openLeft: OpenPromiseFn;
  openRight: OpenPromiseFn;
  close: VoidPromiseFn;
  openDirection: OpenDirection;
  percentOpenLeft: Animated.DerivedValue<number>;
  percentOpenRight: Animated.DerivedValue<number>;
};

type RenderUnderlay<T> = (params: UnderlayParams<T>) => React.ReactNode;

type RenderOverlay<T> = (params: OverlayParams<T>) => React.ReactNode;

enum OpenDirection {
  LEFT = "left",
  RIGHT = "right",
  NONE = "none",
}
Name Type Description
renderUnderlayLeft RenderUnderlay Component to be rendered underneath row on left swipe.
renderUnderlayRight RenderUnderlay Component to be rendered underneath row on right swipe.
snapPointsLeft number[] Pixel values left-swipe snaps to (eg. [100, 300])
snapPointsRight number[] Pixel values right-swipe snaps to (eg. [100, 300])
renderOverlay RenderOverlay Component to be rendered on top. Use if you need access to programmatic open/close methods. May altenatively pass children to SwipeableItem.
onChange (params: { open: OpenDirection, snapPoint: number }) => void Called when row is opened or closed.
swipeEnabled boolean Enable/disable swipe. Defaults to true.
activationThreshold number Distance finger must travel before swipe engages. Defaults to 20.
swipeDamping number How much swipe velocity determines snap position. A smaller number means swipe velocity will have a larger effect and row will swipe open more easily. Defaults to 10.

Hooks

Name Type Description
useSwipeableItemParams () => OverlayParams<T> & { open: OpenPromiseFn, percentOpen: Animated.DerivedValue<number> } Utility hook that reutrns the same params as the render functions are called with. open() and percentOpen params reflect the context in which the hook is called (i.e. within an underlay or overlay component).
function MyUnderlayComponent() {
  // Underlay components "know" which direction to open, so we don't need to call `openLeft()` or `openRight()`, we can just call 'open()'
  // Underlay components also receive the `percentOpen` value of their own direction (`percentOpenLeft` or `percentOpenRight`)
  const swipeableItemParams = useSwipeableItemParams();
  return <TouchableOpacity onPress={swipeableItemParams.open} />;
}

function MyOverlayComponent() {
  // Overlay components get the same params, but have defaults filled in for `open()` and `percentOpen` params.
  const swipeableItemParams = useSwipeableItemParams();
  return <TouchableOpacity onPress={swipeableItemParams.openLeft} />;
}

Instance Methods

Name Type Description
open (OpenDirection.LEFT \| OpenDirection.RIGHT, snapIndex?: number) => Promise<void> Imperatively open left or right. Promise resolves once open.
close () => Promise<void> Close all. Promise resolves once closed.
// Imperative open example
const itemRef: SwipeableItem | null = null

...

<SwipeableItem ref={ref => itemRef = ref} />

...
if (itemRef) itemRef.open(OpenDirection.LEFT)

Notes

Gesture handlers can sometimes capture a gesture unintentionally. If you are using with react-native-draggable-flatlist and the list is periodically not scrolling, try adding a small activationDistance (see example below).

Example

https://snack.expo.io/@computerjazz/swipeable-draggable-list

import React, { useState, useRef, useCallback } from "react";
import {
  Text,
  View,
  StyleSheet,
  FlatList,
  LayoutAnimation,
  TouchableOpacity,
  Platform,
  UIManager,
} from "react-native";
import Animated, { useAnimatedStyle } from "react-native-reanimated";
import SwipeableItem, {
  useSwipeableItemParams,
} from "react-native-swipeable-item";
import DraggableFlatList, {
  RenderItemParams,
  ScaleDecorator,
} from "react-native-draggable-flatlist";
const { multiply, sub } = Animated;

if (Platform.OS === "android") {
  UIManager.setLayoutAnimationEnabledExperimental &&
    UIManager.setLayoutAnimationEnabledExperimental(true);
}
const OVERSWIPE_DIST = 20;
const NUM_ITEMS = 20;

function getColor(i: number) {
  const multiplier = 255 / (NUM_ITEMS - 1);
  const colorVal = i * multiplier;
  return `rgb(${colorVal}, ${Math.abs(128 - colorVal)}, ${255 - colorVal})`;
}

type Item = {
  key: string;
  text: string;
  backgroundColor: string;
  height: number;
};

const initialData: Item[] = [...Array(NUM_ITEMS)].fill(0).map((d, index) => {
  const backgroundColor = getColor(index);
  return {
    text: `row ${index}d`,
    key: `key-${backgroundColor}`,
    backgroundColor,
    height: 100,
  };
});

function App() {
  const [data, setData] = useState(initialData);
  const itemRefs = useRef(new Map());

  const renderItem = useCallback((params: RenderItemParams<Item>) => {
    return <RowItem {...params} itemRefs={itemRefs} />;
  }, []);

  return (
    <View style={styles.container}>
      <DraggableFlatList
        keyExtractor={(item) => item.key}
        data={data}
        renderItem={renderItem}
        onDragEnd={({ data }) => setData(data)}
        activationDistance={20}
      />
    </View>
  );
}

export default App;

type RowItemProps = {
  item: Item;
  drag: () => void;
  itemRefs: React.MutableRefObject<Map<any, any>>;
};

function RowItem({ item, itemRefs, drag }: RowItemProps) {
  return (
    <ScaleDecorator>
      <SwipeableItem
        key={item.key}
        item={item}
        ref={(ref) => {
          if (ref && !itemRefs.current.get(item.key)) {
            itemRefs.current.set(item.key, ref);
          }
        }}
        onChange={({ open }) => {
          if (open) {
            // Close all other open items
            [...itemRefs.current.entries()].forEach(([key, ref]) => {
              if (key !== item.key && ref) ref.close();
            });
          }
        }}
        overSwipe={OVERSWIPE_DIST}
        renderUnderlayLeft={() => <UnderlayLeft drag={drag} />}
        renderUnderlayRight={() => <UnderlayRight />}
        snapPointsLeft={[50, 150, 175]}
        snapPointsRight={[175]}
      >
        <View
          style={[
            styles.row,
            { backgroundColor: item.backgroundColor, height: item.height },
          ]}
        >
          <TouchableOpacity onPressIn={drag}>
            <Text style={styles.text}>{item.text}</Text>
          </TouchableOpacity>
        </View>
      </SwipeableItem>
    </ScaleDecorator>
  );
}

const UnderlayLeft = ({ drag }: { drag: () => void }) => {
  const { item, percentOpen } = useSwipeableItemParams<Item>();
  const animStyle = useAnimatedStyle(
    () => ({
      opacity: percentOpen.value,
    }),
    [percentOpen]
  );

  return (
    <Animated.View
      style={[styles.row, styles.underlayLeft, animStyle]} // Fade in on open
    >
      <TouchableOpacity onPressIn={drag}>
        <Text style={styles.text}>{`[drag]`}</Text>
      </TouchableOpacity>
    </Animated.View>
  );
};

function UnderlayRight() {
  const { close } = useSwipeableItemParams<Item>();
  return (
    <Animated.View style={[styles.row, styles.underlayRight]}>
      <TouchableOpacity onPressOut={close}>
        <Text style={styles.text}>CLOSE</Text>
      </TouchableOpacity>
    </Animated.View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
  },
  row: {
    flexDirection: "row",
    flex: 1,
    alignItems: "center",
    justifyContent: "center",
    padding: 15,
  },
  text: {
    fontWeight: "bold",
    color: "white",
    fontSize: 32,
  },
  underlayRight: {
    flex: 1,
    backgroundColor: "teal",
    justifyContent: "flex-start",
  },
  underlayLeft: {
    flex: 1,
    backgroundColor: "tomato",
    justifyContent: "flex-end",
  },
});