sweep.js

A JavaScript library for smoother color transitions. Project page lives here.

Status: archived

This project is no longer maintained. CSS now has built-in support for setting color-interpolation-method. Transitioning through the oklch color space is a superior alternative to using this library.

About

sweep.js is a small JavaScript library (5kb zipped) that enables proper color transitions through the HSL and HSLuv spaces. Ordinary CSS transitions or existing frameworks convert HSL colors to RGB before transitioning. sweep.js addresses this by letting you transition through the color spectrum.

I've written an in-depth post about the need for HSL transitions here.

Install

bower install -S sweep

...or just download it from here.

Sweep's dependencies are bundled; all you have to do is include the script.

<script src="path/to/sweep.js"></script>

Sweep is wrapped with UMD, so it'll also work as a module in your system of choice.

Usage

Using sweep.js to transition an element's color is easy. Whenever you want to trigger an HSL sweep, call:

sweep(targets, properties, fromColor, toColor[, options])

• targets - element or array of elements that you wish to animate
• properties - CSS properties that you wish to animate on those targets (string or array of strings)
• fromColor - initial color before the transition
• toColor - final color after the transition
• options (optional) - an object that can set the following:
  • callback - function to be called once the animation finishes
  • direction - clockwise (1) or counterclockwise (-1)
  • duration - time (in ms) to complete the animation
  • space - 'HSL', 'HSLuv', or 'RGB'

Examples

Trigger a full color cycle on click:

//click

var ex1 = document.querySelector('#ex1');
ex1.addEventListener('click', function() {
  sweep(ex1, 'backgroundColor', '#a8f', '#a8f', {direction: -1, duration: 2000});
}, false);

Animate from purple to green on hover:

//hover

var ex2 = document.querySelector('#ex2');

ex2.addEventListener('mouseenter', function() {
  sweep(ex2, 'backgroundColor', getStyle(ex2, 'background-color'), '#0fa');
}, false);

ex2.addEventListener('mouseleave', function() {
  sweep(ex2, 'backgroundColor', getStyle(ex2, 'background-color'), '#a8f');
}, false);

Licensed under MIT. Created by rileyjshaw.