A React Native Component That Lets You Drag and Drop Dynamic Items of a FlatList

react-native-draggable-dynamic-flatlist

A react native component that lets you drag and drop dynamic items of a FlatList. Inspired by react-native-draggable-flatlist

Install

1. npm install react-native-draggable-dynamic-flatlist or yarn add react-native-draggable-dynamic-flatlist
2. import DraggableFlatList from 'react-native-draggable-dynamic-flatlist'

Api

Props

All props are spread onto underlying FlatList

Name	Type	Description
data	Array	Items to be rendered.
horizontal	Boolean	Orientation of list.
renderItem	Function	({ item, index, move, moveEnd, isActive }) => <Component />. Call move when the row should become active (in an onPress, onLongPress, etc). Call moveEnd when the gesture is complete (in onPressOut).
keyExtractor	Function	(item, index) => string
scrollPercent	Number	Sets where scrolling begins. A value of 5 will scroll up if the finger is in the top 5% of the FlatList container and scroll down in the bottom 5%.
scaleSelectionFactor	Number	Sets the scale factor of the selected item.
onMoveEnd	Function	({ data, to, from, row }) => void Returns updated ordering of data
onMoveBegin	Function	(index) => void Called when row becomes active.
spacerStyle	View.style	Style of the spacer when an item is moved (ghost view)
removeClippedSubviews	Boolean	Improve scroll performance for large lists. May have bugs (missing content) in some circumstances (Default false)

Example

import React, { Component } from 'react'
import { View, TouchableOpacity, Text } from 'react-native'
import DraggableFlatList from 'react-native-draggable-dynamic-flatlist'

class Example extends Component {

  state = {
    data: [...Array(20)].map((d, index) => ({
      key: `item-${index}`,
      label: index,
      backgroundColor: `rgb(${Math.floor(Math.random() * 255)}, ${index * 5}, ${132})`,
    }))
  }

  renderItem = ({ item, index, move, moveEnd, isActive }) => {
    return (
      <TouchableOpacity
        style={{ 
          height: 100, 
          backgroundColor: isActive ? 'blue' : item.backgroundColor,
          alignItems: 'center', 
          justifyContent: 'center' 
        }}
        onLongPress={move}
        onPressOut={moveEnd}>
        <Text style={{ 
          fontWeight: 'bold', 
          color: 'white',
          fontSize: 32,
        }}>{item.label}</Text>
      </TouchableOpacity>
    )
  }

  render() {
    return (
      <View style={{ flex: 1 }}>
        <DraggableFlatList
          data={this.state.data}
          renderItem={this.renderItem}
          keyExtractor={(item, index) => `draggable-item-${item.key}`}
          scrollPercent={5}
          onMoveEnd={({ data }) => this.setState({ data })}
        />
      </View>
    )
  }
}

export default Example

Main differences with react-native-draggable-flatlist

react-native-draggable-flatlist is good but it doesn’t work when item’s sizes are changing. The positions (x and y) are not calculated properly. It’s using measure functions which doesn’t work perfectly on react-native, lot of unsolvable bugs (especially on android). Also, the measure function doesn’t work when the item is hidden on a flatlist (out of the screen), so if you have big items, it doesn’t work really well. The whole measuring system has been refactored by calculating all the positions manually. This library is using the onLayout property on each item and scrollview which makes it more stable with dynamic content. onLayout works perfectly on react-native and there is no more problem with dynamic content.

Download Details:

Author: thomasrovayaz

Source Code: https://github.com/thomasrovayaz/react-native-draggable-dynamic-flatlist

#react #react-native #mobile-apps