eps1lon/popper-core

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

Floating UI is a low-level library for creating "floating" elements like tooltips, popovers, dropdowns, menus, and more.

The library provides two key functionalities:

Positioning primitives: Ensure your floating element is positioned optimally in the viewport for the user (placement, overflow prevention/clipping detection, and more).
Interaction primitives: Add accessible interactions that power floating elements (event listeners, dismissing, ARIA attributes, focus trapping, list navigation, and more).

The positioning engine features a tiny 600-byte core with strong tree-shaking support, is extensible through custom middleware, and can support any platform.

Install

Choose the package that suits you.

Vanilla DOM positioning engine

Use with vanilla JavaScript or a non-React framework (view tutorial).

npm install @floating-ui/dom

React DOM positioning engine

Use with React DOM (view docs).

npm install @floating-ui/react-dom

React DOM interactions and positioning engine

Primitive hooks and components, in addition to the positioning engine, to use with React DOM (view docs).

npm install @floating-ui/react-dom-interactions

React Native positioning engine

Use with React Native (view docs).

npm install @floating-ui/react-native

Canvas or other platforms

Learn about creating a Platform.

npm install @floating-ui/core

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.

Development and production builds

Floating UI is published with default, development, and production builds, using Node's support for export conditions.

"default": uses process.env.NODE_ENV, in which your bundler handles the env variable, dead code elimination, and minification
"production": minified with no debug logging
"development": unminified with debug logging

If you're using a bundler like webpack, Vite, or Parcel, this is handled for you automatically.

If this is not handled, you must opt into one of the builds in tools that support export conditions. This is done differently for each tool.

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.

Credits

The floating shapes in the banner image are made by the amazing artists @artstar3d, @killnicole and @liiiiiiii on Figma — check out their work!

License

MIT

eps1lon / popper-core