npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

@ref/react-dnd-scrollzone

v1.0.2

Published

A cross browser solution to scrolling during drag and drop.

Downloads

3

Readme

frontend-collective-react-dnd-scrollzone

Forked from https://github.com/azuqua/react-dnd-scrollzone with support for react-dnd@7.

Cross browser compatible scrolling containers for drag and drop interactions.

Basic Example

import React, { Component } from 'react';
import { DragDropContextProvider } from 'react-dnd';
import HTML5Backend from 'react-dnd-html5-backend';
import withScrolling from 'react-dnd-scrollzone';
import DragItem from './DragItem';
import './App.css';

const ScrollingComponent = withScrolling('div');

const ITEMS = [1,2,3,4,5,6,7,8,9,10];

export default class App extends Component {
  render() {
    return (
      <DragDropContextProvider backend={HTML5Backend}>
        <ScrollingComponent className="App">
          {ITEMS.map(n => (
            <DragItem key={n} label={`Item ${n}`} />
          ))}
        </ScrollingComponent>
      </DragDropContextProvider>
    );
  }
}

Note: You should replace the original div you would like to make scrollable with the ScrollingComponent.

Easing Example

import React, { Component } from 'react';
import { DragDropContextProvider } from 'react-dnd';
import HTML5Backend from 'react-dnd-html5-backend';
import withScrolling, { createHorizontalStrength, createVerticalStrength } from 'react-dnd-scrollzone';
import DragItem from './DragItem';
import './App.css';


const ScrollZone = withScrolling('ul');
const linearHorizontalStrength = createHorizontalStrength(150);
const linearVerticalStrength = createVerticalStrength(150);
const ITEMS = [1,2,3,4,5,6,7,8,9,10];

// this easing function is from https://gist.github.com/gre/1650294 and
// expects/returns a number between [0, 1], however strength functions
// expects/returns a value between [-1, 1]
function ease(val) {
  const t = (val + 1) / 2; // [-1, 1] -> [0, 1]
  const easedT = t<.5 ? 2*t*t : -1+(4-2*t)*t;
  return easedT * 2 - 1; // [0, 1] -> [-1, 1]
}

function hStrength(box, point) {
  return ease(linearHorizontalStrength(box, point));
}

function vStrength(box, point) {
  return ease(linearVerticalStrength(box, point));
}

export default App(props) {
  return (
    <DragDropContextProvider backend={HTML5Backend}>
      <ScrollingComponent
        className="App"
        verticalStrength={vStrength}
        horizontalStrength={hStrength} >

        {ITEMS.map(n => (
          <DragItem key={n} label={`Item ${n}`} />
        ))}
      </ScrollingComponent>
    </DragDropContextProvider>
  );
}

Note: You should replace the original div you would like to make scrollable with the ScrollingComponent.

Virtualized Example

Since react-dnd-scrollzone utilizes the Higher Order Components (HOC) pattern, drag and drop scrolling behaviour can easily be added to existing components. For example to speedup huge lists by using react-virtualized for a windowed view where only the visible rows are rendered:

import React from 'react';
import { DragDropContextProvider } from 'react-dnd';
import HTML5Backend from 'react-dnd-html5-backend';
import withScrolling from 'react-dnd-scrollzone';
import { List } from 'react-virtualized';
import DragItem from './DragItem';
import './App.css';

const ScrollingVirtualList = withScrolling(List);

// creates array with 1000 entries
const ITEMS = Array.from(Array(1000)).map((e,i)=> `Item ${i}`);


export default App(props) {
  return (
    <DragDropContextProvider backend={HTML5Backend}>
      <ScrollingVirtualList
        className="App"
        height={600}
        width={800}
        rowCount={ITEMS.length}
        rowHeight={34}
        rowRenderer={
          ({ key, index, style }) => (
            <DragItem
              key={key}
              style={style}
              label={ITEMS[index]}
            />
          )
        }
       />
    </DragDropContextProvider>
  );
}

API

withScrolling

A React higher order component with the following properties:

const ScrollZone = withScrolling(String|Component);

<ScrollZone
  strengthMultiplier={Number}
  horizontalStrength={Function}
  verticalStrength={Function}
  onScrollChange={Function} >

  {children}
</Scrollzone>

Apply the withScrolling function to any html-identifier ("div", "ul" etc) or react component to add drag and drop scrolling behaviour.

  • horizontalStrength a function that returns the strength of the horizontal scroll direction
  • verticalStrength - a function that returns the strength of the vertical scroll direction
  • strengthMultiplier - strength multiplier, play around with this (default 30)
  • onScrollChange - a function that is called when scrollLeft or scrollTop of the component are changed. Called with those two arguments in that order.

The strength functions are both called with two arguments. An object representing the rectangle occupied by the Scrollzone, and an object representing the coordinates of mouse.

They should return a value between -1 and 1.

  • Negative values scroll up or left.
  • Positive values scroll down or right.
  • 0 stops all scrolling.

createVerticalStrength(buffer) and createHorizontalStrength(buffer)

These allow you to create linearly scaling strength functions with a sensitivity different than the default value of 150px.

Example
import withScrolling, { createVerticalStrength, createHorizontalStrength } from 'react-dnd-scrollzone';

const Scrollzone = withScrolling('ul');
const vStrength = createVerticalStrength(500);
const hStrength = createHorizontalStrength(300);

// zone will scroll when the cursor drags within
// 500px of the top/bottom and 300px of the left/right
const zone = (
  <Scrollzone verticalStrength={vStrength} horizontalStrength={hStrength}>

  </Scrollzone>
);