04Button That Shakes Briefly on Failure Then Reverts to Its Label

<main class="stage">
<div class="scene is-demo" id="scene">
  <button class="btn" id="btn" type="button">
    <span class="btnContent">
      <span class="btnLabel" id="label">Submit</span>
      <span class="btnRingWrap" id="ringWrap" aria-hidden="true">
        <svg viewBox="0 0 24 24" width="16" height="16" class="ringSvg">
          <circle id="ring" cx="12" cy="12" r="9" fill="none" stroke-width="2.5" stroke-linecap="round" stroke-dasharray="34 22"></circle>
        </svg>
      </span>
      <span class="btnXWrap" id="xWrap" aria-hidden="true">
        <svg viewBox="0 0 256 256" width="16" height="16">
          <g fill="currentColor"><path d="M216 56v144a16 16 0 0 1-16 16H56a16 16 0 0 1-16-16V56a16 16 0 0 1 16-16h144a16 16 0 0 1 16 16" opacity=".2"/><path d="M205.66 194.34a8 8 0 0 1-11.32 11.32L128 139.31l-66.34 66.35a8 8 0 0 1-11.32-11.32L116.69 128L50.34 61.66a8 8 0 0 1 11.32-11.32L128 116.69l66.34-66.35a8 8 0 0 1 11.32 11.32L139.31 128Z"/></g>
        </svg>
      </span>
    </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-quick;
$easing: $ease-out;
$color: $subject-blue-deep;

// 계산 겹: index.html 의 shake() 가 감쇠 사인파 x(t)=A·e^(-decay·t)·sin(2π·freq·t) 를
// 매 프레임 계산해 버튼 전체의 translateX 에 적용한다.
@include stage($stage-paper);

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

.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  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;
  will-change: transform;

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

.btnContent {
  position: relative;
  display: inline-block;
  min-width: 58px;
  height: 18px;
}

.btnLabel,
.btnRingWrap,
.btnXWrap {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  white-space: nowrap;
}

.btnRingWrap,
.btnXWrap { opacity: 0; }

.ringSvg circle {
  stroke: $subject-cream;
  transform-origin: 12px 12px;
}

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

.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 흔들림 트윈 없이 opacity 만 즉시 바꾼다.
  // 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: #ffffff;
  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;
  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;
  will-change: transform;
}
.btn:focus-visible {
  outline: 2px solid #0a4fe8;
  outline-offset: 3px;
}
.btn:disabled {
  cursor: default;
}

.btnContent {
  position: relative;
  display: inline-block;
  min-width: 58px;
  height: 18px;
}

.btnLabel,
.btnRingWrap,
.btnXWrap {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  white-space: nowrap;
}

.btnRingWrap,
.btnXWrap {
  opacity: 0;
}

.ringSvg circle {
  stroke: #fff7e6;
  transform-origin: 12px 12px;
}

.btnXWrap svg {
  color: #fff7e6;
}

.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 FADE_MS = 180;
  var SPIN_MS = 600;
  var ICON_SWAP_MS = 150;
  var SHAKE_MS = 520;
  var HOLD_MS = 300;
  var GAP_MS = 480;
  var START_DELAY_MS = 200;
  var DEG_PER_MS = 360 / 750;
  var SHAKE_AMPLITUDE_PX = 9;
  var SHAKE_DECAY_PER_S = 9;
  var SHAKE_FREQ_HZ = 8;

  var scene = document.getElementById('scene');
  var btn = document.getElementById('btn');
  var label = document.getElementById('label');
  var ringWrap = document.getElementById('ringWrap');
  var ring = document.getElementById('ring');
  var xWrap = document.getElementById('xWrap');
  var status = document.getElementById('status');
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

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

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

  function easeInOutQuad(p) { return p < .5 ? 2 * p * p : 1 - Math.pow(-2 * p + 2, 2) / 2; }

  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) * easeInOutQuad(p));
      if (p < 1) requestAnimationFrame(step); else if (onDone) onDone();
    }
    requestAnimationFrame(step);
  }

  function spinLoop(myGen) {
    var start = null;
    function step(now) {
      if (myGen !== gen) return;
      if (start === null) start = now;
      var angle = ((now - start) * DEG_PER_MS) % 360;
      ring.style.transform = 'rotate(' + angle.toFixed(1) + 'deg)';
      spinRafId = requestAnimationFrame(step);
    }
    spinRafId = requestAnimationFrame(step);
  }

  // 계산 겹: 감쇠 사인파 x(t) = A · e^(-decay·t) · sin(2π·freq·t) 를 매 프레임 계산해
  // 버튼 전체의 translateX 에 적용한다 — 고정 키프레임이 아니라 물리량으로 흔든다.
  function shake(myGen, ms, onDone) {
    var start = null;
    function step(now) {
      if (myGen !== gen) return;
      if (start === null) start = now;
      var elapsed = now - start;
      var tSec = elapsed / 1000;
      var x = SHAKE_AMPLITUDE_PX * Math.exp(-SHAKE_DECAY_PER_S * tSec) * Math.sin(2 * Math.PI * SHAKE_FREQ_HZ * tSec);
      btn.style.transform = 'translateX(' + x.toFixed(2) + 'px)';
      if (elapsed < ms) requestAnimationFrame(step);
      else { btn.style.transform = 'translateX(0px)'; if (onDone) onDone(); }
    }
    requestAnimationFrame(step);
  }

  function runAnimated() {
    gen++;
    var myGen = gen;
    btn.disabled = true;
    btn.setAttribute('aria-busy', 'true');
    status.textContent = 'Submitting';
    fade(label, 1, 0, FADE_MS, myGen);
    fade(ringWrap, 0, 1, FADE_MS, myGen, function () { spinLoop(myGen); });
    timers.push(setTimeout(function () {
      cancelAnimationFrame(spinRafId);
      status.textContent = 'Submission failed';
      fade(ringWrap, 1, 0, ICON_SWAP_MS, myGen);
      fade(xWrap, 0, 1, ICON_SWAP_MS, myGen);
      shake(myGen, SHAKE_MS, function () {
        timers.push(setTimeout(function () {
          fade(xWrap, 1, 0, FADE_MS, myGen);
          fade(label, 0, 1, FADE_MS, myGen, function () {
            btn.disabled = false;
            btn.removeAttribute('aria-busy');
            status.textContent = '';
          });
        }, HOLD_MS));
      });
    }, SPIN_MS));
  }

  function runReduced() {
    gen++;
    btn.disabled = true;
    btn.setAttribute('aria-busy', 'true');
    status.textContent = 'Submitting';
    label.style.opacity = '0';
    ringWrap.style.opacity = '1';
    timers.push(setTimeout(function () {
      status.textContent = 'Submission failed';
      ringWrap.style.opacity = '0';
      xWrap.style.opacity = '1';
      timers.push(setTimeout(function () {
        xWrap.style.opacity = '0';
        label.style.opacity = '1';
        btn.disabled = false;
        btn.removeAttribute('aria-busy');
        status.textContent = '';
      }, HOLD_MS));
    }, SPIN_MS));
  }

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

  // reduce: 실사용 경로 적용 — runReduced() 는 회전·흔들림 트윈 없이 opacity 만 즉시 바꾼다.
  // 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));
    }, SPIN_MS + SHAKE_MS + HOLD_MS + FADE_MS));
  }

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

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

const FADE_MS = 180;
const SPIN_MS = 600;
const ICON_SWAP_MS = 150;
const SHAKE_MS = 520;
const HOLD_MS = 300;
const GAP_MS = 480;
const START_DELAY_MS = 200;
const DEG_PER_MS = 360 / 750;
const SHAKE_AMPLITUDE_PX = 9;
const SHAKE_DECAY_PER_S = 9;
const SHAKE_FREQ_HZ = 8;

export default function ButtonLoadingErrorShakeRevert() {
  const sceneRef = useRef<HTMLDivElement>(null);
  const btnRef = useRef<HTMLButtonElement>(null);
  const labelRef = useRef<HTMLSpanElement>(null);
  const ringWrapRef = useRef<HTMLSpanElement>(null);
  const ringRef = useRef<SVGCircleElement>(null);
  const xWrapRef = useRef<HTMLSpanElement>(null);
  const statusRef = useRef<HTMLSpanElement>(null);

  useEffect(() => {
    const scene = sceneRef.current;
    const btn = btnRef.current;
    const label = labelRef.current;
    const ringWrap = ringWrapRef.current;
    const ring = ringRef.current;
    const xWrap = xWrapRef.current;
    const status = statusRef.current;
    if (!scene || !btn || !label || !ringWrap || !ring || !xWrap || !status) return undefined;
    const reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

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

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

    function easeInOutQuad(p: number) { return p < .5 ? 2 * p * p : 1 - Math.pow(-2 * p + 2, 2) / 2; }

    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) * easeInOutQuad(p));
        if (p < 1) requestAnimationFrame(step); else if (onDone) onDone();
      }
      requestAnimationFrame(step);
    }

    function spinLoop(myGen: number) {
      let start: number | null = null;
      function step(now: number) {
        if (myGen !== gen) return;
        if (start === null) start = now;
        const angle = ((now - start) * DEG_PER_MS) % 360;
        ring!.style.transform = 'rotate(' + angle.toFixed(1) + 'deg)';
        spinRafId = requestAnimationFrame(step);
      }
      spinRafId = requestAnimationFrame(step);
    }

    // 계산 겹: 감쇠 사인파 x(t) = A · e^(-decay·t) · sin(2π·freq·t) 를 매 프레임 계산해
    // 버튼 전체의 translateX 에 적용한다 — 고정 키프레임이 아니라 물리량으로 흔든다.
    function shake(myGen: number, ms: number, onDone?: () => void) {
      let start: number | null = null;
      function step(now: number) {
        if (myGen !== gen) return;
        if (start === null) start = now;
        const elapsed = now - start;
        const tSec = elapsed / 1000;
        const x = SHAKE_AMPLITUDE_PX * Math.exp(-SHAKE_DECAY_PER_S * tSec) * Math.sin(2 * Math.PI * SHAKE_FREQ_HZ * tSec);
        btn!.style.transform = 'translateX(' + x.toFixed(2) + 'px)';
        if (elapsed < ms) requestAnimationFrame(step);
        else { btn!.style.transform = 'translateX(0px)'; if (onDone) onDone(); }
      }
      requestAnimationFrame(step);
    }

    function runAnimated() {
      gen++;
      const myGen = gen;
      btn!.disabled = true;
      btn!.setAttribute('aria-busy', 'true');
      status!.textContent = '제출하는 중';
      fade(label!, 1, 0, FADE_MS, myGen);
      fade(ringWrap!, 0, 1, FADE_MS, myGen, () => { spinLoop(myGen); });
      timers.push(window.setTimeout(() => {
        cancelAnimationFrame(spinRafId);
        status!.textContent = '제출 실패';
        fade(ringWrap!, 1, 0, ICON_SWAP_MS, myGen);
        fade(xWrap!, 0, 1, ICON_SWAP_MS, myGen);
        shake(myGen, SHAKE_MS, () => {
          timers.push(window.setTimeout(() => {
            fade(xWrap!, 1, 0, FADE_MS, myGen);
            fade(label!, 0, 1, FADE_MS, myGen, () => {
              btn!.disabled = false;
              btn!.removeAttribute('aria-busy');
              status!.textContent = '';
            });
          }, HOLD_MS));
        });
      }, SPIN_MS));
    }

    function runReduced() {
      gen++;
      btn!.disabled = true;
      btn!.setAttribute('aria-busy', 'true');
      status!.textContent = '제출하는 중';
      label!.style.opacity = '0';
      ringWrap!.style.opacity = '1';
      timers.push(window.setTimeout(() => {
        status!.textContent = '제출 실패';
        ringWrap!.style.opacity = '0';
        xWrap!.style.opacity = '1';
        timers.push(window.setTimeout(() => {
          xWrap!.style.opacity = '0';
          label!.style.opacity = '1';
          btn!.disabled = false;
          btn!.removeAttribute('aria-busy');
          status!.textContent = '';
        }, HOLD_MS));
      }, SPIN_MS));
    }

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

    // reduce: 실사용 경로 적용 — runReduced() 는 회전·흔들림 트윈 없이 opacity 만 즉시 바꾼다.
    // 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));
      }, SPIN_MS + SHAKE_MS + HOLD_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(spinRafId);
    };
  }, []);

  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.btnContent}>
            <span className={styles.btnLabel} ref={labelRef}>Submit</span>
            <span className={styles.btnRingWrap} ref={ringWrapRef} aria-hidden="true">
              <svg viewBox="0 0 24 24" width="16" height="16" className={styles.ringSvg}>
                <circle ref={ringRef} cx="12" cy="12" r="9" fill="none" strokeWidth="2.5" strokeLinecap="round" strokeDasharray="34 22" />
              </svg>
            </span>
            <span className={styles.btnXWrap} ref={xWrapRef} aria-hidden="true">
              <svg viewBox="0 0 256 256" width="16" height="16">
                <g fill="currentColor">
                  <path d="M216 56v144a16 16 0 0 1-16 16H56a16 16 0 0 1-16-16V56a16 16 0 0 1 16-16h144a16 16 0 0 1 16 16" opacity=".2" />
                  <path d="M205.66 194.34a8 8 0 0 1-11.32 11.32L128 139.31l-66.34 66.35a8 8 0 0 1-11.32-11.32L116.69 128L50.34 61.66a8 8 0 0 1 11.32-11.32L128 116.69l66.34-66.35a8 8 0 0 1 11.32 11.32L139.31 128Z" />
                </g>
              </svg>
            </span>
          </span>
        </button>
        <span className={styles.visuallyHidden} ref={statusRef} role="status" aria-live="polite" />
      </div>
    </main>
  );
}