Minimalistic but perfect custom scrollbar plugin

README.md

perfect-scrollbar

Minimalistic but perfect custom scrollbar plugin

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To read documentation for versions < 1.0, please visit v0.8.1.

Why perfect-scrollbar?

perfect-scrollbar is minimalistic but perfect (for me, and maybe for most developers) scrollbar plugin.

  • No change on design layout
  • No manipulation on DOM tree
  • Use plain scrollTop and scrollLeft
  • Scrollbar style is fully customizable
  • Efficient update on layout change

I hope you love it!

Demo

It's on the GitHub Pages.

Table of Contents

Install

npm

The best way to install and use perfect-scrollbar is with npm. It's registered as perfect-scrollbar.

$ npm install perfect-scrollbar

Manual download

You can manually download perfect-scrollbar from Releases.

From sources

If you want to use the development version of the plugin, build from source manually. The development version may be unstable.

$ git clone https://github.com/utatti/perfect-scrollbar.git
$ cd perfect-scrollbar
$ npm install
$ npm run build

JSFiddle

You can fork the following JSFiddles for testing and experimenting purposes:

Unofficial sources

Sources not mentioned above are not maintained officially. If there are issues of the following sources, please ask and resolve in each repository.

Before using perfect-scrollbar

The following requirements should meet.

  • the container must have a position style.
  • the container must be a normal container element.

The following requirements are included in the basic CSS, but please keep in mind when you'd like to change the CSS files.

  • the container must have an overflow: hidden css style.
  • the scrollbar's position must be absolute.
  • the scrollbar-x must have bottom or top, and the scrollbar-y must have right or left.

Finally, scroll hooking is generally considered as a bad practice, and perfect-scrollbar should be used carefully. Unless custom scroll is really needed, using browser-native scroll is always recommended.

Caveats

perfect-scrollbar emulates some scrolls, but not all of the kinds. It also does not work in some situations. You can find these cases in Caveats. Basically, items listed in the caveats are hacky to implement and may not be implemented in the future. If the features are really needed, please consider using browser-native scroll.

How to use

First of all, please check if the container element meets the requirements and the main CSS is imported.

<style>
  #container {
    position: relative;
    width: 600px;
    height: 400px;
  }
</style>
<link rel="stylesheet" href="css/perfect-scrollbar.css">

Import via ES modules:

import PerfectScrollbar from 'perfect-scrollbar';

Or in browser:

<script src="dist/perfect-scrollbar.js"></script>

To initialise:

const container = document.querySelector('#container');
const ps = new PerfectScrollbar(container);

// or just with selector string
const ps = new PerfectScrollbar('#container');

It can be initialised with options.

const ps = new PerfectScrollbar('#container', {
  wheelSpeed: 2,
  wheelPropagation: true,
  minScrollbarLength: 20
});

If the size of your container or content changes, call update.

ps.update();

If you want to destroy the scrollbar, use destroy.

ps.destroy();
ps = null; // to make sure garbages are collected

If you want to scroll to somewhere, just update scrollTop.

const container = document.querySelector('#container');
container.scrollTop = 0;

You can also get information about how to use the plugin from code in examples/.

Options

handlers {String[]}

It is a list of handlers to scroll the element.

Default: ['click-rail', 'drag-thumb', 'keyboard', 'wheel', 'touch']

wheelSpeed {Number}

The scroll speed applied to mousewheel event.

Default: 1

wheelPropagation {Boolean}

If this option is true, when the scroll reaches the end of the side, mousewheel event will be propagated to parent element.

Default: false

swipeEasing {Boolean}

If this option is true, swipe scrolling will be eased.

Default: true

minScrollbarLength {Number?}

When set to an integer value, the thumb part of the scrollbar will not shrink below that number of pixels.

Default: null

maxScrollbarLength {Number?}

When set to an integer value, the thumb part of the scrollbar will not expand over that number of pixels.

Default: null

scrollingThreshold {Number}

This sets threashold for ps--scrolling-x and ps--scrolling-y classes to remain. In the default CSS, they make scrollbars shown regardless of hover state. The unit is millisecond.

Default: 1000

useBothWheelAxes {Boolean}

When set to true, and only one (vertical or horizontal) scrollbar is visible then both vertical and horizontal scrolling will affect the scrollbar.

Default: false

suppressScrollX {Boolean}

When set to true, the scroll bar in X axis will not be available, regardless of the content width.

Default: false

suppressScrollY {Boolean}

When set to true, the scroll bar in Y axis will not be available, regardless of the content height.

Default: false

scrollXMarginOffset {Number}

The number of pixels the content width can surpass the container width without enabling the X axis scroll bar. Allows some "wiggle room" or "offset break", so that X axis scroll bar is not enabled just because of a few pixels.

Default: 0

scrollYMarginOffset {Number}

The number of pixels the content height can surpass the container height without enabling the Y axis scroll bar. Allows some "wiggle room" or "offset break", so that Y axis scroll bar is not enabled just because of a few pixels.

Default: 0

Events

perfect-scrollbar dispatches custom events.

container.addEventListener('ps-scroll-x', () => ...);

ps-scroll-y

This event fires when the y-axis is scrolled in either direction.

ps-scroll-x

This event fires when the x-axis is scrolled in either direction.

ps-scroll-up

This event fires when scrolling upwards.

ps-scroll-down

This event fires when scrolling downwards.

ps-scroll-left

This event fires when scrolling to the left.

ps-scroll-right

This event fires when scrolling to the right.

ps-y-reach-start

This event fires when scrolling reaches the start of the y-axis.

ps-y-reach-end

This event fires when scrolling reaches the end of the y-axis (useful for infinite scroll).

ps-x-reach-start

This event fires when scrolling reaches the start of the x-axis.

ps-x-reach-end

This event fires when scrolling reaches the end of the x-axis.

You can also watch the reach state via the reach property.

const ps = new PerfectScrollbar(...);

console.log(ps.reach.x); // => 'start' or 'end' or null
console.log(ps.reach.y); // => 'start' or 'end' or null

Helpdesk

If you have any idea to improve this project or any problem using this, please feel free to upload an issue.

For common problems, there is a FAQ wiki page. Please check the page before uploading an issue.

Also, the project is not actively maintained. No maintainer is paid, and most of us are busy on our professional or personal works. Please understand that it may take a while for an issue to be resolved. Uploading a PR would be the fastest way to fix an issue.

IE Support

The plugin is developed to work in modern MS browsers including Edge and IE11, but may have some issues in IE11 mainly because of IE rendering bug concerning sync update on scroll properties. The problem is mentioned in Caveats too.

IE<11 is not supported, and patches to fix problems in IE<=10 will not be accepted. When old IEs should be supported, please fork the project and make modification locally.

License

MIT