wp-calypso/packages/components/src/tabs/index.tsx

/**
 * Forked from `@wordpress/components`
 * - Removed Tabs.Context from Storybook sub-components.
 * - Converted styles from Emotion to (S)CSS modules.
 * - Added `density` prop to `Tabs.TabList`, with new `compact` variant.
 */

import * as Ariakit from '@ariakit/react';
import { isRTL } from '@wordpress/i18n';
import { useEffect, useMemo, useId } from 'react';
import { TabsContext } from './context';
import { Tab } from './tab';
import { TabList } from './tablist';
import { TabPanel } from './tabpanel';
import type { TabsProps } from './types';

function externalToInternalTabId( externalId: string | undefined | null, instanceId: string ) {
	return externalId && `${ instanceId }-${ externalId }`;
}

function internalToExternalTabId( internalId: string | undefined | null, instanceId: string ) {
	return typeof internalId === 'string' ? internalId.replace( `${ instanceId }-`, '' ) : internalId;
}

/**
 * Tabs is a collection of React components that combine to render
 * an [ARIA-compliant tabs pattern](https://www.w3.org/WAI/ARIA/apg/patterns/tabs/).
 *
 * Tabs organizes content across different screens, data sets, and interactions.
 * It has two sections: a list of tabs, and the view to show when a tab is chosen.
 *
 * `Tabs` itself is a wrapper component and context provider.
 * It is responsible for managing the state of the tabs, and rendering one instance
 * of the `Tabs.TabList` component and one or more instances of the `Tab.TabPanel`
 * component.
 */
export const Tabs = Object.assign(
	function Tabs( {
		selectOnMove = true,
		defaultTabId,
		orientation = 'horizontal',
		onSelect,
		children,
		selectedTabId,
		activeTabId,
		defaultActiveTabId,
		onActiveTabIdChange,
	}: TabsProps ) {
		const instanceId = useId();
		const store = Ariakit.useTabStore( {
			selectOnMove,
			orientation,
			defaultSelectedId: externalToInternalTabId( defaultTabId, instanceId ),
			setSelectedId: ( newSelectedId ) => {
				onSelect?.( internalToExternalTabId( newSelectedId, instanceId ) );
			},
			selectedId: externalToInternalTabId( selectedTabId, instanceId ),
			defaultActiveId: externalToInternalTabId( defaultActiveTabId, instanceId ),
			setActiveId: ( newActiveId ) => {
				onActiveTabIdChange?.( internalToExternalTabId( newActiveId, instanceId ) );
			},
			activeId: externalToInternalTabId( activeTabId, instanceId ),
			rtl: isRTL(),
		} );

		const { items, activeId } = Ariakit.useStoreState( store );
		const { setActiveId } = store;

		useEffect( () => {
			requestAnimationFrame( () => {
				const focusedElement = items?.[ 0 ]?.element?.ownerDocument.activeElement;

				if ( ! focusedElement || ! items.some( ( item ) => focusedElement === item.element ) ) {
					return; // Return early if no tabs are focused.
				}

				// If, after ariakit re-computes the active tab, that tab doesn't match
				// the currently focused tab, then we force an update to ariakit to avoid
				// any mismatches, especially when navigating to previous/next tab with
				// arrow keys.
				if ( activeId !== focusedElement.id ) {
					setActiveId( focusedElement.id );
				}
			} );
		}, [ activeId, items, setActiveId ] );

		const contextValue = useMemo(
			() => ( {
				store,
				instanceId,
			} ),
			[ store, instanceId ]
		);

		return <TabsContext.Provider value={ contextValue }>{ children }</TabsContext.Provider>;
	},
	{
		/**
		 * Renders a single tab.
		 *
		 * The currently active tab receives default styling that can be
		 * overridden with CSS targeting `[aria-selected="true"]`.
		 */
		Tab: Object.assign( Tab, {
			displayName: 'Tabs.Tab',
		} ),
		/**
		 * A wrapper component for the `Tab` components.
		 *
		 * It is responsible for rendering the list of tabs.
		 */
		TabList: Object.assign( TabList, {
			displayName: 'Tabs.TabList',
		} ),
		/**
		 * Renders the content to display for a single tab once that tab is selected.
		 */
		TabPanel: Object.assign( TabPanel, {
			displayName: 'Tabs.TabPanel',
		} ),
		Context: Object.assign( TabsContext, {
			displayName: 'Tabs.Context',
		} ),
	}
);