the claude code sourcemaps leaked march 31
1import { useCallback, useContext, useLayoutEffect, useRef } from 'react'
2import CursorDeclarationContext from '../components/CursorDeclarationContext.js'
3import type { DOMElement } from '../dom.js'
4
5/**
6 * Declares where the terminal cursor should be parked after each frame.
7 *
8 * Terminal emulators render IME preedit text at the physical cursor
9 * position, and screen readers / screen magnifiers track the native
10 * cursor — so parking it at the text input's caret makes CJK input
11 * appear inline and lets accessibility tools follow the input.
12 *
13 * Returns a ref callback to attach to the Box that contains the input.
14 * The declared (line, column) is interpreted relative to that Box's
15 * nodeCache rect (populated by renderNodeToOutput).
16 *
17 * Timing: Both ref attach and useLayoutEffect fire in React's layout
18 * phase — after resetAfterCommit calls scheduleRender. scheduleRender
19 * defers onRender via queueMicrotask, so onRender runs AFTER layout
20 * effects commit and reads the fresh declaration on the first frame
21 * (no one-keystroke lag). Test env uses onImmediateRender (synchronous,
22 * no microtask), so tests compensate by calling ink.onRender()
23 * explicitly after render.
24 */
25export function useDeclaredCursor({
26 line,
27 column,
28 active,
29}: {
30 line: number
31 column: number
32 active: boolean
33}): (element: DOMElement | null) => void {
34 const setCursorDeclaration = useContext(CursorDeclarationContext)
35 const nodeRef = useRef<DOMElement | null>(null)
36
37 const setNode = useCallback((node: DOMElement | null) => {
38 nodeRef.current = node
39 }, [])
40
41 // When active, set unconditionally. When inactive, clear conditionally
42 // (only if the currently-declared node is ours). The node-identity check
43 // handles two hazards:
44 // 1. A memo()ized active instance elsewhere (e.g. the search input in
45 // a memo'd Footer) doesn't re-render this commit — an inactive
46 // instance re-rendering here must not clobber it.
47 // 2. Sibling handoff (menu focus moving between list items) — when
48 // focus moves opposite to sibling order, the newly-inactive item's
49 // effect runs AFTER the newly-active item's set. Without the node
50 // check it would clobber.
51 // No dep array: must re-declare every commit so the active instance
52 // re-claims the declaration after another instance's unmount-cleanup or
53 // sibling handoff nulls it.
54 useLayoutEffect(() => {
55 const node = nodeRef.current
56 if (active && node) {
57 setCursorDeclaration({ relativeX: column, relativeY: line, node })
58 } else {
59 setCursorDeclaration(null, node)
60 }
61 })
62
63 // Clear on unmount (conditionally — another instance may own by then).
64 // Separate effect with empty deps so cleanup only fires once — not on
65 // every line/column change, which would transiently null between commits.
66 useLayoutEffect(() => {
67 return () => {
68 setCursorDeclaration(null, nodeRef.current)
69 }
70 }, [setCursorDeclaration])
71
72 return setNode
73}