Mouser.js ·

Mouser.js is a Javascript helper for mouse move animations. Import the function, pass a list of listeners, and they will recieve a vector with the current mouse position ranging from 0 to 1 relative to the reference, and the global position (gx and gy). {x: 0.23, y: 0.7, gx: 235, gy: 367}

• Zero-Dependencies: With a size of ~18kb (unpacked).
• Minimal: Mouser.js just registers the listeners and pass the vector to them. What you do with those values is totally up to you.
• Use Anywhere: Mouser.js doesn't make assumptions about your technology stack, so you can use mouser.js wherever you want.

Installation

Mouser.js has been designed for minimal and efficient usage. To avoid memory leaking and ensure efficiency, Mouser.js works as a singleton. It will only return a new object, only if the params field is used, otherwise it will return the same instance. Users are in charge of clearing the events with the removeEventListeners method. (See example below).

You can use Mouser.js as a <script> tag from a CDN (TO-DO), or as a mouser.js package on npm:

npm install --save mouser.js

import mouser from 'mouser.js'

// your code

Examples

Here is the first example to get you started:

import mouser from 'mouser.js'

const domElement = document.querySelector('#id')

mouser({
  reference: domElement, // optional, defaults to window
  listeners: [console.log]
})

This example will print the vector {x: number, y: number, gx: number, gy: number} to the console whenever the effect is triggered. You'll notice that we used a simple console.log method, but you can pass to the listener any synchronous function...

Using it with React

import React, { useState } from 'react';
import mouser from 'mouser.js';

function Example() {
  const [v, setV] = useState({x: 0, y: 0}); // you can pass any rest state

  useEffect(() => {
    mouser({
      listeners: [setV]
    });
    return () => mouser.removeEventListeners(); // clear all registered events
  }, [setV]);

  return (
    <div>
      <p>x: {v.x} - y: {v.y}</p>
      <p>global x: {v.gx} - global y: {v.gy}</p>
    </div>
  );
}

API

Params

Optional object the you can pass when calling the mouser.js function

import mouser from 'mouser.js';

const helper = mouser({
    // element from which the range values will be applied
    reference: Document | Window | HTMLElement // defaults to window

    // array of functions that accepts the x,y vector
    listeners: ((v: {x: number, y: number}) => void)[] // defaults to []

    // rate to apply the update of the returned vector
    refreshRate: number // defaults to 0

    // value that will be returned ONCE when mouse is out the reference
    restState: { x: number, y: number } // defaults to {x: 0, y: 0}
})

Methods

import mouser from 'mouser.js';

const helper = mouser();

// replaces the current reference
helper.addReference(el: Document | Window | HTMLElement);

// sets the reference to the default (window)
helper.removeReference();

// adds a listener to the current array of listeners
helper.addListener(listener: (v: {x: number, y: number}) => void);

// IMPORTANT clears all event listeners to avoid memory leaks
helper.removeEventListeners();

Rest State Behaviour

While you can provide a rest state to the values relative to the reference, the global values, when effect is not active it will maintain the last recorded position.

NOTE: as we are still in alpha, the restState parameter behaviour might change in the feature

Showcase

Articles

• Adding a custom cursor to your Next.js Website

PRs welcome!

Contributing

The main purpose of this repository is to continue evolving Mouser.js, making it faster and easier to use. Development of Mouser.js happens in the open on GitHub, and I am are grateful to the community for contributing bugfixes and improvements. Read below to learn how you can take part in improving Mouser.js.

Contributing Guide

Just send a PR or report an issue and I will be happy to review.

Good First Issues

To help you get your feet wet and get you familiar with our contribution process, we have a list of good first issues that contain bugs which have a relatively limited scope. This is a great place to get started.

License

Mouser.js is MIT licensed.

Note

This project has been heavily inspired by the Webflow approach to mouse move animations.