vaneenige / uos

🐭 A tiny 250b scroll listener with progress.

Update On Scroll (uos)

Update On Scroll (uos) is a tiny library to provide the easiest way for updating values on scroll. Based on percentual or pixel based begin and end values, progress is returned trough a callback.

This utility can be useful for CSS animations, DOM changes, WebGL transitions or anything that can be updated based on a progress value.

Features:

• Small in size, no dependencies
• Percentage or pixel based values
• Optimized for multiple instances

Install

$ npm install --save uos

Usage

Import the library:

import updateOnScroll from 'uos';

Update an element based on pixels:

updateOnScroll(100, 500, progress => {
  // Progress between 100px and 500px
});

Update an element based on percentages:

updateOnScroll(0.2, 0.6, progress => {
  // Progress between 20% and 60%
});

Only a single scroll listener will be used regardless of how many instances are created. The callback of an instance will be called on every update.

License

MIT © Colin van Eenige