compute-scroll-into-view

What is compute-scroll-into-view?

The compute-scroll-into-view npm package is a utility that calculates the scroll position necessary to make an element visible within its container. This is useful for smoothly scrolling items into view, especially in custom scrolling interfaces where the default browser behavior does not suffice.

What are compute-scroll-into-view's main functionalities?

Compute scroll position

This feature calculates the necessary scroll positions to bring an element into view within its container. The function returns an array of actions that can be applied to achieve the desired scroll effect. Each action specifies the element to scroll and the new top and left scroll positions.

import computeScrollIntoView from 'compute-scroll-into-view';
const element = document.getElementById('targetElement');
const actions = computeScrollIntoView(element, {
  scrollMode: 'if-needed',
  block: 'nearest',
  inline: 'nearest'
});
actions.forEach(({ el, top, left }) => {
  el.scrollTop = top;
  el.scrollLeft = left;
});

Other packages similar to compute-scroll-into-view

scroll-into-view-if-needed

This package also calculates and performs scrolling to bring an element into view if it's not already visible. It is similar to compute-scroll-into-view but also provides the functionality to automatically perform the scroll, whereas compute-scroll-into-view only computes the necessary scroll positions.

smooth-scroll-into-view-if-needed

An extension of scroll-into-view-if-needed, this package adds smooth scrolling effects. It compares to compute-scroll-into-view by providing both the computation and the smooth scrolling execution, offering a more integrated solution for developers looking for out-of-the-box smooth scrolling.

README

Lower level API that is used by the ponyfill scroll-into-view-if-needed to compute where (if needed) elements should scroll based on options defined in the spec. Use this if you want the smallest possible bundlesize and is ok with implementing the actual scrolling yourself.

Install

yarn add compute-scroll-into-view

The UMD build is also available on unpkg:

<script src="https://unpkg.com/compute-scroll-into-view/umd/compute-scroll-into-view.min.js"></script>

You can find the library on window.computeScrollIntoView.

Usage

// es6 import
import computeScrollIntoView from 'compute-scroll-into-view'
// or es5
const computeScrollIntoView = require('compute-scroll-into-view')

const node = document.getElementById('hero')

// same behavior as Element.scrollIntoView({block: "nearest", inline: "nearest"})
// see: https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollIntoView
const actions = computeScrollIntoView(node, {
  scrollMode: 'if-needed',
  block: 'nearest',
  inline: 'nearest',
})

// same behavior as Element.scrollIntoViewIfNeeded(true)
// see: https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollIntoViewIfNeeded
const actions = computeScrollIntoView(node, { scrollMode: 'if-needed' block: 'center', inline: 'center' })

// Then perform the scrolling, use scroll-into-view-if-needed if you don't want to implement this part
actions.forEach(({ el, top, left }) => {
  el.scrollTop = top
  el.scrollLeft = left
})