konnostoc-primitive.tsx115 lines · main
| 1 | 'use client' |
| 2 | |
| 3 | import { mergeRefs, useAnchorObserver, useOnChange } from 'common' |
| 4 | import { createContext, forwardRef, useContext, useMemo, useRef } from 'react' |
| 5 | import type { AnchorHTMLAttributes, ReactNode, RefObject } from 'react' |
| 6 | import scrollIntoView from 'scroll-into-view-if-needed' |
| 7 | |
| 8 | import type { TableOfContents } from './server/get-toc' |
| 9 | |
| 10 | export const ActiveAnchorContext = createContext<string[]>([]) |
| 11 | |
| 12 | const ScrollContext = createContext<RefObject<HTMLElement | null>>({ |
| 13 | current: null, |
| 14 | }) |
| 15 | |
| 16 | /** |
| 17 | * The estimated active heading ID |
| 18 | */ |
| 19 | export function useActiveAnchor(): string | undefined { |
| 20 | return useContext(ActiveAnchorContext).at(-1) |
| 21 | } |
| 22 | |
| 23 | /** |
| 24 | * The id of visible anchors |
| 25 | */ |
| 26 | export function useActiveAnchors(): string[] { |
| 27 | return useContext(ActiveAnchorContext) |
| 28 | } |
| 29 | |
| 30 | export interface AnchorProviderProps { |
| 31 | toc: TableOfContents |
| 32 | /** |
| 33 | * Only accept one active item at most |
| 34 | * |
| 35 | * @defaultValue true |
| 36 | */ |
| 37 | single?: boolean |
| 38 | children?: ReactNode |
| 39 | } |
| 40 | |
| 41 | export interface ScrollProviderProps { |
| 42 | /** |
| 43 | * Scroll into the view of container when active |
| 44 | */ |
| 45 | containerRef: RefObject<HTMLElement | null> |
| 46 | |
| 47 | children?: ReactNode |
| 48 | } |
| 49 | |
| 50 | export function ScrollProvider({ |
| 51 | containerRef, |
| 52 | children, |
| 53 | }: ScrollProviderProps): React.ReactElement { |
| 54 | return <ScrollContext.Provider value={containerRef}>{children}</ScrollContext.Provider> |
| 55 | } |
| 56 | |
| 57 | export function AnchorProvider({ |
| 58 | toc, |
| 59 | single = true, |
| 60 | children, |
| 61 | }: AnchorProviderProps): React.ReactElement { |
| 62 | const headings = useMemo(() => { |
| 63 | return toc.map((item) => item.url.split('#')[1]) |
| 64 | }, [toc]) |
| 65 | |
| 66 | return ( |
| 67 | <ActiveAnchorContext.Provider value={useAnchorObserver(headings, single)}> |
| 68 | {children} |
| 69 | </ActiveAnchorContext.Provider> |
| 70 | ) |
| 71 | } |
| 72 | |
| 73 | export interface TOCItemProps extends Omit<AnchorHTMLAttributes<HTMLAnchorElement>, 'href'> { |
| 74 | href: string |
| 75 | |
| 76 | onActiveChange?: (v: boolean) => void |
| 77 | } |
| 78 | |
| 79 | export const TOCItem = forwardRef<HTMLAnchorElement, TOCItemProps>( |
| 80 | ({ onActiveChange, ...props }, ref) => { |
| 81 | const containerRef = useContext(ScrollContext) |
| 82 | |
| 83 | const anchors = useActiveAnchors() |
| 84 | const anchorRef = useRef<HTMLAnchorElement>(null) |
| 85 | const mergedRef = mergeRefs(anchorRef, ref) |
| 86 | |
| 87 | const isActive = anchors.includes(props.href.slice(1)) |
| 88 | |
| 89 | useOnChange(isActive, (v) => { |
| 90 | const element = anchorRef.current |
| 91 | |
| 92 | if (!element) return |
| 93 | |
| 94 | if (v && containerRef.current) { |
| 95 | scrollIntoView(element, { |
| 96 | behavior: 'smooth', |
| 97 | block: 'center', |
| 98 | inline: 'center', |
| 99 | scrollMode: 'always', |
| 100 | boundary: containerRef.current, |
| 101 | }) |
| 102 | } |
| 103 | |
| 104 | onActiveChange?.(v) |
| 105 | }) |
| 106 | |
| 107 | return ( |
| 108 | <a ref={mergedRef} data-active={isActive} {...props}> |
| 109 | {props.children} |
| 110 | </a> |
| 111 | ) |
| 112 | } |
| 113 | ) |
| 114 | |
| 115 | TOCItem.displayName = 'TOCItem' |