07Button That Dims and Locks Out Clicks While Loading

<main class="stage">
<div class="scene is-demo" id="scene">
  <button class="btn" id="btn" type="button">
    <span class="btnFilm" id="film" aria-hidden="true"></span>
    <span class="btnLockWrap" id="lockWrap" aria-hidden="true">
      <svg viewBox="0 0 256 256" width="14" height="14">
        <g fill="currentColor"><path d="M208 88H48a8 8 0 0 0-8 8v112a8 8 0 0 0 8 8h160a8 8 0 0 0 8-8V96a8 8 0 0 0-8-8m-80 72a20 20 0 1 1 20-20a20 20 0 0 1-20 20" opacity=".2"/><path d="M208 80h-32V56a48 48 0 0 0-96 0v24H48a16 16 0 0 0-16 16v112a16 16 0 0 0 16 16h160a16 16 0 0 0 16-16V96a16 16 0 0 0-16-16M96 56a32 32 0 0 1 64 0v24H96Zm112 152H48V96h160zm-80-96a28 28 0 0 0-8 54.83V184a8 8 0 0 0 16 0v-17.17a28 28 0 0 0-8-54.83m0 40a12 12 0 1 1 12-12a12 12 0 0 1-12 12"/></g>
      </svg>
    </span>
    <span class="btnLabel" id="label">Confirm</span>
  </button>
  <span class="visuallyHidden" id="status" role="status" aria-live="polite"></span>
</div>
</main>

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

// 변수 3개
$duration: $dur-loop;
$easing: $ease-out;
$color: $subject-blue-deep;

// 계산 겹: index.html 의 pulseLoop() 가 남은 시간이 줄수록 진동수를 끌어올리며 phase 를
// 프레임 델타로 직접 적분해 막의 opacity 를 매 프레임 계산한다.
@include stage($stage-orange);

.scene {
  display: grid;
  place-items: center;
}

.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: $sp-2;
  height: 44px;
  padding: 0 $sp-5;
  border: none;
  border-radius: $r-control;
  background: $color;
  color: $subject-cream;
  font-weight: 600;
  font-size: 14px;
  line-height: 1;
  box-shadow: $shadow-press;
  cursor: pointer;
  overflow: hidden;

  &:focus-visible { outline: 2px solid $subject-cream; outline-offset: 3px; }
  &:disabled { cursor: default; }
}

.btnFilm {
  position: absolute;
  inset: 0;
  background: $subject-ink;
  opacity: 0;
}

.btnLockWrap {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  opacity: 0;
}

.btnLockWrap svg { color: $subject-cream; }

.btnLabel {
  position: relative;
  z-index: 1;
  white-space: nowrap;
}

.visuallyHidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

@media (max-width: 340px) {
  .btn { height: 40px; padding: 0 $sp-4; font-size: 13px; }
}

@media (prefers-reduced-motion: reduce) {
  // 실사용 경로 적용 — index.html 의 runReduced() 가 진동수 계산 없이 고정 opacity 로 즉시 바뀐다.
  // scss 만: 남은 트랜지션을 전부 끈다.
  * { transition: none !important; }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ff4d1f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.scene {
  display: grid;
  place-items: center;
}

.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 44px;
  padding: 0 20px;
  border: none;
  border-radius: 12px;
  background: #0a4fe8;
  color: #fff7e6;
  font-weight: 600;
  font-size: 14px;
  line-height: 1;
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
  cursor: pointer;
  overflow: hidden;
}
.btn:focus-visible {
  outline: 2px solid #fff7e6;
  outline-offset: 3px;
}
.btn:disabled {
  cursor: default;
}

.btnFilm {
  position: absolute;
  inset: 0;
  background: #17141a;
  opacity: 0;
}

.btnLockWrap {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  opacity: 0;
}

.btnLockWrap svg {
  color: #fff7e6;
}

.btnLabel {
  position: relative;
  z-index: 1;
  white-space: nowrap;
}

.visuallyHidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

@media (max-width: 340px) {
  .btn {
    height: 40px;
    padding: 0 16px;
    font-size: 13px;
  }
}
@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
  }
}

(function () {
  var COOLDOWN_MS = 1300;
  var FADE_MS = 160;
  var GAP_MS = 480;
  var START_DELAY_MS = 200;
  var BASE_HZ = 0.6;
  var MAX_HZ = 2.4;

  var scene = document.getElementById('scene');
  var btn = document.getElementById('btn');
  var film = document.getElementById('film');
  var lockWrap = document.getElementById('lockWrap');
  var status = document.getElementById('status');
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

  var gen = 0;
  var timers = [];
  var rafId = 0;

  function human() {
    if (scene.classList.contains('is-demo')) {
      scene.classList.remove('is-demo');
      timers.forEach(function (t) { clearTimeout(t); });
      timers = [];
    }
  }

  function clamp01(v) { return Math.min(1, Math.max(0, v)); }

  // 계산 겹: 남은 시간(remaining)이 줄어들수록 진동수를 BASE_HZ→MAX_HZ 로 끌어올린다.
  // 진동수가 시간에 따라 바뀌므로 sin(2π·f·t) 를 그대로 쓸 수 없어 phase 를 프레임 델타로
  // 직접 적분한다(phase += 2π·f(now)·dt) — 막이 남은 시간이 줄수록 더 빨리 깜빡인다.
  function pulseLoop(myGen) {
    var last = null;
    var phase = 0;
    var loopStart = null;
    function step(now) {
      if (myGen !== gen) return;
      if (last === null) { last = now; loopStart = now; }
      var dt = now - last;
      last = now;
      var elapsed = now - loopStart;
      var remainingFrac = clamp01(1 - elapsed / COOLDOWN_MS);
      var freq = BASE_HZ + (MAX_HZ - BASE_HZ) * (1 - remainingFrac);
      phase += 2 * Math.PI * freq * (dt / 1000);
      var wave = (1 + Math.sin(phase)) / 2;
      film.style.opacity = String(.14 + .16 * wave);
      rafId = requestAnimationFrame(step);
    }
    rafId = requestAnimationFrame(step);
  }

  function fade(el, from, to, ms, myGen, onDone) {
    var start = null;
    function step(now) {
      if (myGen !== gen) return;
      if (start === null) start = now;
      var p = Math.min(1, (now - start) / ms);
      el.style.opacity = String(from + (to - from) * p);
      if (p < 1) requestAnimationFrame(step); else if (onDone) onDone();
    }
    requestAnimationFrame(step);
  }

  function runAnimated() {
    gen++;
    var myGen = gen;
    btn.disabled = true;
    btn.setAttribute('aria-busy', 'true');
    status.textContent = 'Please wait';
    fade(lockWrap, 0, 1, FADE_MS, myGen);
    film.style.opacity = '.14';
    pulseLoop(myGen);
    timers.push(setTimeout(function () {
      cancelAnimationFrame(rafId);
      fade(film, parseFloat(film.style.opacity || '0'), 0, FADE_MS, myGen);
      fade(lockWrap, 1, 0, FADE_MS, myGen, function () {
        btn.disabled = false;
        btn.removeAttribute('aria-busy');
        status.textContent = '';
      });
    }, COOLDOWN_MS));
  }

  function runReduced() {
    gen++;
    btn.disabled = true;
    btn.setAttribute('aria-busy', 'true');
    status.textContent = 'Please wait';
    film.style.opacity = '.2';
    lockWrap.style.opacity = '1';
    timers.push(setTimeout(function () {
      film.style.opacity = '0';
      lockWrap.style.opacity = '0';
      btn.disabled = false;
      btn.removeAttribute('aria-busy');
      status.textContent = '';
    }, COOLDOWN_MS));
  }

  btn.addEventListener('click', function () {
    if (btn.disabled) return;
    human();
    if (reduce) runReduced(); else runAnimated();
  });

  // reduce: 실사용 경로 적용 — runReduced() 는 진동수 계산 없이 고정 opacity 로 즉시 바뀐다.
  // 아래 자동 루프는 시연 게이트만 — reduce 에서는 돌지 않는다.
  function cycle() {
    if (!scene.classList.contains('is-demo')) return;
    runAnimated();
    timers.push(setTimeout(function () {
      timers.push(setTimeout(cycle, GAP_MS));
    }, COOLDOWN_MS + FADE_MS));
  }

  if (!reduce) {
    timers.push(setTimeout(cycle, START_DELAY_MS));
  }
})();

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

const COOLDOWN_MS = 1300;
const FADE_MS = 160;
const GAP_MS = 480;
const START_DELAY_MS = 200;
const BASE_HZ = 0.6;
const MAX_HZ = 2.4;

export default function ButtonLoadingDisabledDimLock() {
  const sceneRef = useRef<HTMLDivElement>(null);
  const btnRef = useRef<HTMLButtonElement>(null);
  const filmRef = useRef<HTMLSpanElement>(null);
  const lockWrapRef = useRef<HTMLSpanElement>(null);
  const statusRef = useRef<HTMLSpanElement>(null);

  useEffect(() => {
    const scene = sceneRef.current;
    const btn = btnRef.current;
    const film = filmRef.current;
    const lockWrap = lockWrapRef.current;
    const status = statusRef.current;
    if (!scene || !btn || !film || !lockWrap || !status) return undefined;
    const reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

    let gen = 0;
    let timers: number[] = [];
    let rafId = 0;

    function human() {
      if (scene!.classList.contains(styles['is-demo'])) {
        scene!.classList.remove(styles['is-demo']);
        timers.forEach((t) => window.clearTimeout(t));
        timers = [];
      }
    }

    function clamp01(v: number) { return Math.min(1, Math.max(0, v)); }

    // 계산 겹: 남은 시간(remaining)이 줄어들수록 진동수를 BASE_HZ→MAX_HZ 로 끌어올린다.
    // 진동수가 시간에 따라 바뀌므로 sin(2π·f·t) 를 그대로 쓸 수 없어 phase 를 프레임 델타로
    // 직접 적분한다(phase += 2π·f(now)·dt) — 막이 남은 시간이 줄수록 더 빨리 깜빡인다.
    function pulseLoop(myGen: number) {
      let last: number | null = null;
      let phase = 0;
      let loopStart: number | null = null;
      function step(now: number) {
        if (myGen !== gen) return;
        if (last === null) { last = now; loopStart = now; }
        const dt = now - last;
        last = now;
        const elapsed = now - loopStart!;
        const remainingFrac = clamp01(1 - elapsed / COOLDOWN_MS);
        const freq = BASE_HZ + (MAX_HZ - BASE_HZ) * (1 - remainingFrac);
        phase += 2 * Math.PI * freq * (dt / 1000);
        const wave = (1 + Math.sin(phase)) / 2;
        film!.style.opacity = String(.14 + .16 * wave);
        rafId = requestAnimationFrame(step);
      }
      rafId = requestAnimationFrame(step);
    }

    function fade(el: HTMLElement, from: number, to: number, ms: number, myGen: number, onDone?: () => void) {
      let start: number | null = null;
      function step(now: number) {
        if (myGen !== gen) return;
        if (start === null) start = now;
        const p = Math.min(1, (now - start) / ms);
        el.style.opacity = String(from + (to - from) * p);
        if (p < 1) requestAnimationFrame(step); else if (onDone) onDone();
      }
      requestAnimationFrame(step);
    }

    function runAnimated() {
      gen++;
      const myGen = gen;
      btn!.disabled = true;
      btn!.setAttribute('aria-busy', 'true');
      status!.textContent = '잠시 기다리는 중';
      fade(lockWrap!, 0, 1, FADE_MS, myGen);
      film!.style.opacity = '.14';
      pulseLoop(myGen);
      timers.push(window.setTimeout(() => {
        cancelAnimationFrame(rafId);
        fade(film!, parseFloat(film!.style.opacity || '0'), 0, FADE_MS, myGen);
        fade(lockWrap!, 1, 0, FADE_MS, myGen, () => {
          btn!.disabled = false;
          btn!.removeAttribute('aria-busy');
          status!.textContent = '';
        });
      }, COOLDOWN_MS));
    }

    function runReduced() {
      gen++;
      btn!.disabled = true;
      btn!.setAttribute('aria-busy', 'true');
      status!.textContent = '잠시 기다리는 중';
      film!.style.opacity = '.2';
      lockWrap!.style.opacity = '1';
      timers.push(window.setTimeout(() => {
        film!.style.opacity = '0';
        lockWrap!.style.opacity = '0';
        btn!.disabled = false;
        btn!.removeAttribute('aria-busy');
        status!.textContent = '';
      }, COOLDOWN_MS));
    }

    function onClick() {
      if (btn!.disabled) return;
      human();
      if (reduce) runReduced(); else runAnimated();
    }
    btn.addEventListener('click', onClick);

    // reduce: 실사용 경로 적용 — runReduced() 는 진동수 계산 없이 고정 opacity 로 즉시 바뀐다.
    // 아래 자동 루프는 시연 게이트만 — reduce 에서는 돌지 않는다.
    function cycle() {
      if (!scene!.classList.contains(styles['is-demo'])) return;
      runAnimated();
      timers.push(window.setTimeout(() => {
        timers.push(window.setTimeout(cycle, GAP_MS));
      }, COOLDOWN_MS + FADE_MS));
    }

    if (!reduce) {
      timers.push(window.setTimeout(cycle, START_DELAY_MS));
    }

    return () => {
      btn.removeEventListener('click', onClick);
      timers.forEach((t) => window.clearTimeout(t));
      cancelAnimationFrame(rafId);
    };
  }, []);

  return (
    <main className={styles.stage}>
      <div className={styles.scene + ' ' + styles['is-demo']} ref={sceneRef}>
        <button className={styles.btn} ref={btnRef} type="button">
          <span className={styles.btnFilm} ref={filmRef} aria-hidden="true" />
          <span className={styles.btnLockWrap} ref={lockWrapRef} aria-hidden="true">
            <svg viewBox="0 0 256 256" width="14" height="14">
              <g fill="currentColor">
                <path d="M208 88H48a8 8 0 0 0-8 8v112a8 8 0 0 0 8 8h160a8 8 0 0 0 8-8V96a8 8 0 0 0-8-8m-80 72a20 20 0 1 1 20-20a20 20 0 0 1-20 20" opacity=".2" />
                <path d="M208 80h-32V56a48 48 0 0 0-96 0v24H48a16 16 0 0 0-16 16v112a16 16 0 0 0 16 16h160a16 16 0 0 0 16-16V96a16 16 0 0 0-16-16M96 56a32 32 0 0 1 64 0v24H96Zm112 152H48V96h160zm-80-96a28 28 0 0 0-8 54.83V184a8 8 0 0 0 16 0v-17.17a28 28 0 0 0-8-54.83m0 40a12 12 0 1 1 12-12a12 12 0 0 1-12 12" />
              </g>
            </svg>
          </span>
          <span className={styles.btnLabel}>Confirm</span>
        </button>
        <span className={styles.visuallyHidden} ref={statusRef} role="status" aria-live="polite" />
      </div>
    </main>
  );
}