64:I[314491,["/_next/static/immutable/chunks/3arlv5bvukoo2.js","/_next/static/immutable/chunks/39v64hmfyo-sr.js","/_next/static/immutable/chunks/2nvof3-29tvc3.js","/_next/static/immutable/chunks/3tjobt77z_9dj.js","/_next/static/immutable/chunks/04j_o97cgxn2x.js","/_next/static/immutable/chunks/3upr08c9vtj8w.js","/_next/static/immutable/chunks/1ww0328si-u8x.js","/_next/static/immutable/chunks/11mfl5ymqld9-.js","/_next/static/immutable/chunks/2xxcqy6ppds3l.js","/_next/static/immutable/chunks/1bpgyrs5qflhu.js","/_next/static/immutable/chunks/0-6vu2ul1h6ld.js","/_next/static/immutable/chunks/43_s7jweyypoh.js","/_next/static/immutable/chunks/0p6vao205o1jc.js","/_next/static/immutable/chunks/1_kyvgkyokw92.js","/_next/static/immutable/chunks/1lo-zn37dolb5.js","/_next/static/immutable/chunks/1v8k6yxw1rg0u.js"],"FilesView"] 65:T1b90,"use client"; // ShutterTelegraphBoard — an ambient multi-stage status board modelled on the // Admiralty six-shutter telegraph (Murray's telegraph, England 1795-1816): a // 2x3 board of louvred shutters, each independently flipped edge-on (nearly // invisible, background shows through) or face-on (a solid opaque square), // read hilltop to hilltop through a telescope. Each of the 63 open/closed // combinations encoded a number or codebook phrase. // // Pure DOM/CSS, no canvas. Each shutter is a small stack of two divs: a // fixed 1px --foreground-at-25%-opacity frame (the shutter's edge, visible // once the panel in front of it rotates out of the way) and an opaque // --foreground panel driven purely by `transform: perspective(...) // rotateY(deg)` between 0deg (face-on/closed) and 90deg (edge-on/open) — the // perspective projection itself is what visually collapses the panel to a // near-invisible sliver, no opacity fade involved. Every 2s a new symbol // (one of 8 fixed 6-bit patterns) is applied; the six shutters that need to // flip each get a 60ms-staggered transitionDelay in reading order // (left-to-right, top-to-bottom) so a symbol change reads as a wave // crossing the board rather than a simultaneous snap, each individual flip // taking 320ms ease-in-out. Colours are plain `var(--foreground)` in inline // styles — pure DOM with no per-pixel colour math, so (as with the shipped // flag-hoist-run) there is nothing for getComputedStyle/MutationObserver to // do that the CSS cascade doesn't already do for free on a theme switch. import { useEffect, useRef, useState } from "react"; const COLS = 2; const ROWS = 3; const CELL_COUNT = COLS * ROWS; const FLIP_MS = 320; const STAGGER_MS = 60; const DWELL_MS = 1700; const SYMBOL_INTERVAL_MS = DWELL_MS + (CELL_COUNT - 1) * STAGGER_MS; // ~2000ms const PERSPECTIVE_PX = 600; // 8 fixed 6-bit symbols, reading order (row-major, top-to-bottom, // left-to-right within a row): true = open (edge-on), false = closed // (face-on). Index 4 is an exact checkerboard — 3 open / 3 closed, the // maximum structural contrast in the set — reserved as the reduced-motion // freeze frame. The set deliberately also contains the degenerate // all-closed (0) and all-open (5) symbols elsewhere in the loop, which is // exactly why those two are never chosen as the static frame. const SYMBOLS: readonly boolean[][] = [ [false, false, false, false, false, false], [true, true, false, false, true, false], [false, true, true, false, true, true], [true, false, true, true, false, false], [true, false, false, true, true, false], // checkerboard — reduced-motion frame [true, true, true, true, true, true], [false, true, false, true, false, true], [true, false, true, false, true, false], ]; const STATIC_SYMBOL_INDEX = 4; const START_SYMBOL_INDEX = 2; // a mixed, non-degenerate t0 export interface ShutterTelegraphBoardProps { /** accessible label for the ambient board */ label?: string; /** extra classes merged onto the rendered root element */ className?: string; } export function ShutterTelegraphBoard({ label = "Signal board", className = "", }: ShutterTelegraphBoardProps) { const rootRef = useRef(null); const gridRef = useRef(null); const [cellSize, setCellSize] = useState(0); const [reduced, setReduced] = useState(false); // matches SSR's default (reduced motion is unknown server-side); flipped // to STATIC_SYMBOL_INDEX synchronously in the reduced-motion effect below // before any timer would otherwise fire, so no flash of the wrong symbol. const [symbolIndex, setSymbolIndex] = useState(START_SYMBOL_INDEX); // -- reduced motion: pin to the checkerboard symbol, never advance. ---- useEffect(() => { const isReduced = window.matchMedia("(prefers-reduced-motion: reduce)").matches; setReduced(isReduced); if (isReduced) setSymbolIndex(STATIC_SYMBOL_INDEX); }, []); // -- geometry: square shutters sized from the container's smaller // dimension, so the board reads at card scale on any card. ------------- useEffect(() => { const root = rootRef.current; if (!root) return; const ro = new ResizeObserver((entries) => { const rect = entries[0]?.contentRect; if (!rect) return; const minDim = Math.min(rect.width, rect.height); setCellSize(minDim / 4); }); ro.observe(root); return () => ro.disconnect(); }, []); // -- the loop: a new symbol every SYMBOL_INTERVAL_MS, unbounded, 8-symbol // repeat (~16s per full cycle). Paused while off-screen, skipped // entirely under reduced motion. ---------------------------------------- useEffect(() => { if (reduced) return; const root = rootRef.current; if (!root) return; let id = 0; const start = () => { if (id) return; id = window.setInterval(() => { setSymbolIndex((i) => (i + 1) % SYMBOLS.length); }, SYMBOL_INTERVAL_MS); }; const stop = () => { if (!id) return; window.clearInterval(id); id = 0; }; const io = new IntersectionObserver((entries) => { if (entries[0]?.isIntersecting) start(); else stop(); }); io.observe(root); return () => { stop(); io.disconnect(); }; }, [reduced]); const gap = cellSize * 0.14; const pattern = SYMBOLS[symbolIndex] ?? SYMBOLS[0]!; return (

0 ? "visible" : "hidden", }} > {pattern.map((open, i) => (

))}

); } 63:["$","div",null,{"className":"mt-3 flex min-h-0 min-w-0 flex-1 flex-col gap-3","children":[null,["$","$L64",null,{"files":[{"path":"registry/core/shutter-telegraph-board/component.tsx","content":"$65","type":"registry:ui","target":"components/ui/shutter-telegraph-board.tsx"}],"className":"h-[70svh] min-h-80"}]]}]