Popper is now Floating UI! For Popper v2, visit its dedicated branch.

Website

Floating UI is a low-level library for positioning "floating" elements like tooltips, popovers, dropdowns, menus and more while intelligently keeping them in view.

Challenges arise when positioning floating elements as they get taken out of the normal layout flow of a document, leading to issues with clipping and overflow, which is where this library can help!

• Tiny: 600-byte core with highly modular architecture for tree-shaking
• Low-level: Granular control over positioning behavior
• Pure: Predictable and side-effect free
• Extensible: Powerful middleware system
• Platform-agnostic: Runs on any JavaScript environment which provides measurement APIs, including the web and React Native

Installation

To use it on the web:

npm install @floating-ui/dom

yarn add @floating-ui/dom

Quick start

import {computePosition} from '@floating-ui/dom';

const referenceElement = document.querySelector('#button');
const floatingElement = document.querySelector('#tooltip');

function applyStyles({x = 0, y = 0, strategy = 'absolute'}) {
  Object.assign(floatingElement.style, {
    position: strategy,
    left: `${x}px`,
    top: `${y}px`,
  });
}

applyStyles();

computePosition(referenceElement, floatingElement, {
  placement: 'right',
}).then(applyStyles);

Visit the docs for detailed information.

React

• React DOM
• React Native (*experimental)

Components

Right now, Floating UI focuses on positioning floating elements, but a package that exposes higher-level primitives for building these elements more easily is in development.

Contributing

This project is a monorepo written in TypeScript using npm workspaces. The website is using Next.js SSG and Tailwind CSS for styling.

• Fork and clone the repo
• Install dependencies in root directory with npm install
• Build initial package dist files with npm run build

Testing grounds

npm run dev in the root will launch the @floating-ui/dom development visual tests at http://localhost:1234. The playground uses React to write each test route, bundled by Parcel. When making changes to packages/core or packages/dom, Parcel will hot reload the app and display the changes.

Each route has screenshots taken of the page by Playwright to ensure all the functionalities work as expected; this is an easy, reliable and high-level way of testing the code.

Below the main container are UI controls to turn on certain state and options. Every single combination of state is tested visually via the snapshots to cover as much as possible.

Website

npm -w website run dev in the root will launch the website at localhost:3000.

License

MIT