LeafyGreen Provider

LeafyGreen Provider is a package made to provide, and make it easy to consume page-wide, interaction-related state within components, such as whether a user is navigating with a keyboard or mouse. This lets us make improvements to the user experience that would be cumbersome, or impossible to make without access to a global state.

Components should always gracefully degrade when the provider is not an ancestor. Please implement these APIs with that in mind.

Installation

Yarn

yarn add @leafygreen-ui/leafygreen-provider

NPM

npm install @leafygreen-ui/leafygreen-provider

LeafyGreenProvider

This is the context provider for LeafyGreen Provider, and should be added as high in the document tree as possible.

Example

Input

import LeafyGreenProvider from '@leafygreen-ui/leafygreen-provider';

<LeafyGreenProvider>
  <div>My Children</div>
</LeafyGreenProvider>;

Output

<div>My Children</div>

Properties

Prop	Type	Description	Default
children	node	Children passed to LeafyGreenProvider will be unmodified, aside from having access to its state.
baseFontSize	14, 16	Describes the font-size that the application is using. <Body/> and <InlineCode /> components use this value to determine the font-size and line-height applied to their content	14

useUsingKeyboardContext

Returns:

{
  usingKeyboard: boolean | undefined,
  setUsingKeyboard: boolean => void,
}

This hook allows you to directly read, and set the state of whether a user is interacting with the keyboard. The primary use-case for this is to set usingKeyboard to true when manually setting focus on an element.

Example

import { useUsingKeyboardContext } from '@leafygreen-ui/leafygreen-provider';

const { usingKeyboard, setUsingKeyboard } = useUsingKeyboardContext();
const inputRef = useRef(null);

function autoFocus() {
  inputRef.current?.focus();

  if (!usingKeyboard) {
    setUsingKeyboard(true);
  }
}

<input type={text} ref={inputRef} />;

useBaseFontSize

Returns:

`number`;

This hook allows you to read the base font-size of an application, based on the number returned from the hook.

Example

import { useBaseFontSize } from '@leafygreen-ui/leafygreen-provider';

function InlineCode({ children, className }: InlineCodeProps) {
  const size = useBaseFontSize();
  const body = size === 16 ? typeScale2 : typeScale1;

  return (
    <code className={cx(sharedStyles, code, body, className)}>{children}</code>
  );
}