07칸이 대각선으로 채워지는 히트맵 로딩

<main class="stage">
<div class="ch is-demo" id="ch" role="img" aria-label="요일별 활동량 히트맵" aria-busy="true"></div>
<button type="button" class="ch__reload" id="chReload">히트맵 다시 불러오기</button>
</main>

@use "../../../../site/static/demo-tokens" as *;

// 변수 3개
$duration: $dur-loop;
$easing: $ease-out;
$color: $chart-4;

@include stage($stage-paper);

.ch {
  width: min(190px, 66vw);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: $sp-1;
}
.ch__cell { position: relative; aspect-ratio: 1; border-radius: $r-xs; overflow: hidden; }
.ch__sk {
  position: absolute; inset: 0; border-radius: inherit;
  background: rgba($subject-ink, .1);
  animation: chSkeleton $duration $easing infinite;
}
.ch__real {
  position: absolute; inset: 0; border-radius: inherit;
  opacity: 0; transform: scale(.9); transform-origin: center;
  animation: chReveal $duration $easing infinite;
}
.ch__real--b0 { background: $chart-1; }
.ch__real--b1 { background: $chart-2; }
.ch__real--b2 { background: $chart-3; }
.ch__real--b3 { background: $chart-4; }
.ch__reload {
  display: block; margin: $sp-3 auto 0; appearance: none; border: none; cursor: pointer;
  background: $subject-ink; color: $subject-cream; font-weight: 700; font-size: 12px;
  padding: $sp-1 $sp-3; border-radius: $r-pill;
}
.ch__reload:focus-visible { outline: 2px solid $subject-ink; outline-offset: 2px; }

@keyframes chSkeleton {
  0%   { opacity: 1; }
  10%  { opacity: 1; }
  22%  { opacity: 0; }
  100% { opacity: 0; }
}

@keyframes chReveal {
  0%   { opacity: 0; transform: scale(.9); }
  10%  { opacity: 0; transform: scale(.9); }
  26%  { opacity: 1; transform: scale(1); }
  92%  { opacity: 1; transform: scale(1); }
  100% { opacity: 0; transform: scale(.9); }
}

@media (max-width: 340px) {
  .ch { width: min(128px, 56vw); gap: $sp-1; }
  .ch__reload { margin-top: $sp-1; font-size: 10px; padding: 4px $sp-2; }
}

@media (prefers-reduced-motion: reduce) {
  // 실사용 경로 적용: 자동 루프를 멈추고 완성된 히트맵 칸만 보인다
  .ch__sk { animation: none; opacity: 0; }
  .ch__real { animation: none; opacity: 1; transform: scale(1); }
}

html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffffff;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.ch {
  width: min(190px, 66vw);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 4px;
}

.ch__cell {
  position: relative;
  aspect-ratio: 1;
  border-radius: 4px;
  overflow: hidden;
}

.ch__sk {
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: rgba(23, 20, 26, 0.1);
  animation: chSkeleton 2s ease-out infinite;
}

.ch__real {
  position: absolute;
  inset: 0;
  border-radius: inherit;
  opacity: 0;
  transform: scale(0.9);
  transform-origin: center;
  animation: chReveal 2s ease-out infinite;
}

.ch__real--b0 {
  background: #2f6df6;
}

.ch__real--b1 {
  background: #c2361a;
}

.ch__real--b2 {
  background: #2b9d74;
}

.ch__real--b3 {
  background: #8a5cd6;
}

.ch__reload {
  display: block;
  margin: 12px auto 0;
  appearance: none;
  border: none;
  cursor: pointer;
  background: #17141a;
  color: #fff7e6;
  font-weight: 700;
  font-size: 12px;
  padding: 4px 12px;
  border-radius: 999px;
}

.ch__reload:focus-visible {
  outline: 2px solid #17141a;
  outline-offset: 2px;
}

@keyframes chSkeleton {
  0% {
    opacity: 1;
  }
  10% {
    opacity: 1;
  }
  22% {
    opacity: 0;
  }
  100% {
    opacity: 0;
  }
}
@keyframes chReveal {
  0% {
    opacity: 0;
    transform: scale(0.9);
  }
  10% {
    opacity: 0;
    transform: scale(0.9);
  }
  26% {
    opacity: 1;
    transform: scale(1);
  }
  92% {
    opacity: 1;
    transform: scale(1);
  }
  100% {
    opacity: 0;
    transform: scale(0.9);
  }
}
@media (max-width: 340px) {
  .ch {
    width: min(128px, 56vw);
    gap: 4px;
  }
  .ch__reload {
    margin-top: 4px;
    font-size: 10px;
    padding: 4px 8px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .ch__sk {
    animation: none;
    opacity: 0;
  }
  .ch__real {
    animation: none;
    opacity: 1;
    transform: scale(1);
  }
}

(function () {
  var COLS = 4;
  var ROWS = 4;
  var WAVE_SPEED = 6; // 칸 단위 / 초 — 값이 클수록 파동이 격자를 빨리 훑는다
  var VALUES = [
    12, 38, 61, 90,
    27, 55, 82, 34,
    70, 20, 46, 65,
    88, 63, 18, 41
  ];
  var grid = document.getElementById('ch');
  var reload = document.getElementById('chReload');
  var cells = [];

  function bucket(v) { return Math.min(3, Math.floor(v / 25)); }

  // 계산 겹: 오른쪽 위 모서리를 파원으로 두고 유클리드 거리를 파동 속도로 나눠 지연을 구한다
  function waveDelayMs(row, col) {
    var dx = (COLS - 1 - col);
    var dy = row;
    var distance = Math.sqrt(dx * dx + dy * dy);
    return Math.round((distance / WAVE_SPEED) * 1000);
  }

  for (var r = 0; r < ROWS; r += 1) {
    for (var c = 0; c < COLS; c += 1) {
      var idx = r * COLS + c;
      var cell = document.createElement('div');
      cell.className = 'ch__cell';
      cell.setAttribute('data-row', String(r));
      cell.setAttribute('data-col', String(c));
      var sk = document.createElement('div');
      sk.className = 'ch__sk';
      var real = document.createElement('div');
      real.className = 'ch__real ch__real--b' + bucket(VALUES[idx]);
      cell.appendChild(sk);
      cell.appendChild(real);
      grid.appendChild(cell);
      cells.push(cell);
      var delay = waveDelayMs(r, c);
      sk.style.animationDelay = delay + 'ms';
      real.style.animationDelay = delay + 'ms';
    }
  }

  function human() {
    grid.classList.remove('is-demo');
    grid.setAttribute('aria-busy', 'true');
    var maxDelay = 0;
    cells.forEach(function (cell) {
      var sk = cell.querySelector('.ch__sk');
      var real = cell.querySelector('.ch__real');
      sk.getAnimations().forEach(function (a) { a.cancel(); });
      real.getAnimations().forEach(function (a) { a.cancel(); });
      sk.style.animation = 'none';
      real.style.animation = 'none';
      sk.style.opacity = '1';
      real.style.opacity = '0';
      real.style.transform = 'scale(.9)';
      var row = Number(cell.getAttribute('data-row'));
      var col = Number(cell.getAttribute('data-col'));
      var delay = waveDelayMs(row, col);
      if (delay > maxDelay) { maxDelay = delay; }
      window.setTimeout(function () {
        sk.style.transition = 'opacity 200ms ease-out';
        real.style.transition = 'opacity 200ms ease-out, transform 200ms ease-out';
        sk.style.opacity = '0';
        real.style.opacity = '1';
        real.style.transform = 'scale(1)';
      }, 200 + delay);
    });
    window.setTimeout(function () { grid.setAttribute('aria-busy', 'false'); }, 200 + maxDelay + 260);
  }

  reload.addEventListener('click', human);
  reload.addEventListener('keydown', function (e) {
    if (e.key === 'Enter' || e.key === ' ') { e.preventDefault(); human(); }
  });
}());

import { useEffect, useRef } from 'react';
import styles from './ChartLoadingHeatmapDiagonalReveal.module.scss';

const COLS = 4;
const ROWS = 4;
const WAVE_SPEED = 6; // 칸 단위 / 초 — 값이 클수록 파동이 격자를 빨리 훑는다
const VALUES = [
  12, 38, 61, 90,
  27, 55, 82, 34,
  70, 20, 46, 65,
  88, 63, 18, 41
];

const BUCKET_CLASS = [styles.chRealB0, styles.chRealB1, styles.chRealB2, styles.chRealB3];

function bucket(v: number) { return Math.min(3, Math.floor(v / 25)); }

export default function ChartLoadingHeatmapDiagonalReveal() {
  const gridRef = useRef<HTMLDivElement>(null);
  const reloadRef = useRef<HTMLButtonElement>(null);
  const skRefs = useRef<HTMLDivElement[]>([]);
  const realRefs = useRef<HTMLDivElement[]>([]);

  const cells: { row: number; col: number; v: number }[] = [];
  for (let r = 0; r < ROWS; r += 1) {
    for (let c = 0; c < COLS; c += 1) { cells.push({ row: r, col: c, v: VALUES[r * COLS + c] }); }
  }

  useEffect(() => {
    const grid = gridRef.current;
    const reload = reloadRef.current;
    if (!grid || !reload) return undefined;
    const sks = skRefs.current!;
    const reals = realRefs.current!;
    if (!sks || !reals) return undefined;

    // 계산 겹: 오른쪽 위 모서리를 파원으로 두고 유클리드 거리를 파동 속도로 나눠 지연을 구한다
    function waveDelayMs(row: number, col: number) {
      const dx = COLS - 1 - col;
      const dy = row;
      const distance = Math.sqrt(dx * dx + dy * dy);
      return Math.round((distance / WAVE_SPEED) * 1000);
    }

    cells.forEach((cell, i) => {
      const delay = waveDelayMs(cell.row, cell.col);
      sks[i].style.animationDelay = delay + 'ms';
      reals[i].style.animationDelay = delay + 'ms';
    });

    const timers: number[] = [];
    function human() {
      grid!.classList.remove(styles['is-demo']);
      grid!.setAttribute('aria-busy', 'true');
      let maxDelay = 0;
      cells.forEach((cell, i) => {
        const sk = sks[i];
        const real = reals[i];
        sk.getAnimations().forEach((a) => a.cancel());
        real.getAnimations().forEach((a) => a.cancel());
        sk.style.animation = 'none';
        real.style.animation = 'none';
        sk.style.opacity = '1';
        real.style.opacity = '0';
        real.style.transform = 'scale(.9)';
        const delay = waveDelayMs(cell.row, cell.col);
        if (delay > maxDelay) { maxDelay = delay; }
        timers.push(window.setTimeout(() => {
          sk.style.transition = 'opacity 200ms ease-out';
          real.style.transition = 'opacity 200ms ease-out, transform 200ms ease-out';
          sk.style.opacity = '0';
          real.style.opacity = '1';
          real.style.transform = 'scale(1)';
        }, 200 + delay));
      });
      timers.push(window.setTimeout(() => { grid!.setAttribute('aria-busy', 'false'); }, 200 + maxDelay + 260));
    }

    function onClick() { human(); }
    function onKey(e: KeyboardEvent) { if (e.key === 'Enter' || e.key === ' ') { e.preventDefault(); human(); } }
    reload.addEventListener('click', onClick);
    reload.addEventListener('keydown', onKey);

    return () => {
      reload.removeEventListener('click', onClick);
      reload.removeEventListener('keydown', onKey);
      timers.forEach((id) => window.clearTimeout(id));
    };
  }, []);

  return (
    <main className={styles.stage}>
      <div className={styles.ch + ' ' + styles['is-demo']} ref={gridRef} role="img" aria-label="요일별 활동량 히트맵" aria-busy="true">
        {cells.map((cell, i) => (
          <div className={styles.chCell} data-row={cell.row} data-col={cell.col} key={i}>
            <div className={styles.chSk} ref={(el: HTMLDivElement | null) => { if (el) skRefs.current![i] = el; }} />
            <div
              className={styles.chReal + ' ' + BUCKET_CLASS[bucket(cell.v)]}
              ref={(el: HTMLDivElement | null) => { if (el) realRefs.current![i] = el; }}
            />
          </div>
        ))}
      </div>
      <button type="button" className={styles.chReload} ref={reloadRef}>히트맵 다시 불러오기</button>
    </main>
  );
}