04Bottom sheet snap

<main class="stage is-demo">
  <div class="page" id="page">
    <button class="trigger" type="button" aria-haspopup="dialog" aria-controls="sheet4">Open list</button>
  </div>
  <div class="overlay"></div>
  <div class="sheet" id="sheet4" role="dialog" aria-modal="true" aria-labelledby="t4" data-snap="half">
    <button class="sheet__handle" type="button" aria-label="Toggle sheet size (peek, half, full)"></button>
    <h2 id="t4">12 places nearby</h2>
    <p>Each tap on the handle cycles peek → half → full.</p>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-base;       // 300ms — 스냅마다 딱 멈추는 시간
$easing: $ease-out;         // 관성 없이 멈춘다(스프링 아님)
$color: $subject-ink;       // 손잡이·강조색

// ── 데모 무대 ───────────────────────────────────────────
@include stage($stage-paper);

.stage { position: relative; }
.page { display: grid; place-items: center; }

.trigger {
  border: 0; border-radius: $r-pill;
  padding: $sp-3 $sp-6;
  font-weight: 600;
  font-size: clamp(13px, 4vmin, 16px);
  line-height: 1;
  font-family: inherit;
  color: $stage-paper; background: $color;
  cursor: pointer; -webkit-tap-highlight-color: transparent;
}

.overlay {
  position: fixed; inset: 0;
  background: rgba($stage-ink, .45);
  opacity: 0; pointer-events: none;
  transition: opacity $duration $easing;
}

// 세 스냅 값은 시트 자기 높이 기준 %(transform 만 사용)
.sheet {
  position: fixed; left: 50%; bottom: 0; top: auto;
  transform: translate(-50%, 100%);
  width: min(94vw, 300px);
  box-sizing: border-box;
  padding: $sp-2 $sp-4 $sp-6;
  border-radius: $r-card $r-card 0 0;
  background: $subject-cream; color: $stage-ink;
  box-shadow: $shadow-raised;
  pointer-events: none;
  transition: transform $duration $easing;

  h2 { margin: $sp-2 0 $sp-1; font-size: clamp(13px, 4.2vmin, 17px); }
  p  { margin: 0; font-size: clamp(10px, 3.2vmin, 13px); color: rgba($stage-ink, .7); }
}

.sheet__handle {
  display: block;
  width: 36px; height: $sp-1; margin: 0 auto;
  border: 0; border-radius: $r-pill; background: rgba($stage-ink, .28);
  cursor: pointer;
}

.stage.is-open .overlay { opacity: 1; pointer-events: auto; }
.stage.is-open .sheet   { pointer-events: auto; }
.stage.is-open .sheet[data-snap="peek"] { transform: translate(-50%, 78%); }
.stage.is-open .sheet[data-snap="half"] { transform: translate(-50%, 40%); }
.stage.is-open .sheet[data-snap="full"] { transform: translate(-50%, 0); }

// 데모 루프: 닫힘 → peek → half → full → peek 순으로 2초 안에 한 바퀴
.stage.is-demo .overlay { animation: overlay-loop $dur-loop ease-in-out infinite; }
.stage.is-demo .sheet   { animation: sheet-loop $dur-loop $easing infinite; }

@keyframes overlay-loop {
  0%, 100% { opacity: 0; }
  10%, 90% { opacity: 1; }
  95%      { opacity: 0; }
}
@keyframes sheet-loop {
  0%   { transform: translate(-50%, 100%); }
  10%  { transform: translate(-50%, 78%); }
  40%  { transform: translate(-50%, 40%); }
  70%  { transform: translate(-50%, 0); }
  90%  { transform: translate(-50%, 78%); }
  100% { transform: translate(-50%, 100%); }
}

@media (prefers-reduced-motion: reduce) {
  .stage.is-demo .overlay, .stage.is-demo .sheet { animation: none; }
  .overlay, .sheet { transition-duration: 1ms; }
}

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);
}

.stage {
  position: relative;
}

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

.trigger {
  border: 0;
  border-radius: 999px;
  padding: 12px 24px;
  font-weight: 600;
  font-size: clamp(13px, 4vmin, 16px);
  line-height: 1;
  font-family: inherit;
  color: #ffffff;
  background: #17141a;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(23, 20, 26, 0.45);
  opacity: 0;
  pointer-events: none;
  transition: opacity 300ms ease-out;
}

.sheet {
  position: fixed;
  left: 50%;
  bottom: 0;
  top: auto;
  transform: translate(-50%, 100%);
  width: min(94vw, 300px);
  box-sizing: border-box;
  padding: 8px 16px 24px;
  border-radius: 16px 16px 0 0;
  background: #fff7e6;
  color: #17141a;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  pointer-events: none;
  transition: transform 300ms ease-out;
}
.sheet h2 {
  margin: 8px 0 4px;
  font-size: clamp(13px, 4.2vmin, 17px);
}
.sheet p {
  margin: 0;
  font-size: clamp(10px, 3.2vmin, 13px);
  color: rgba(23, 20, 26, 0.7);
}

.sheet__handle {
  display: block;
  width: 36px;
  height: 4px;
  margin: 0 auto;
  border: 0;
  border-radius: 999px;
  background: rgba(23, 20, 26, 0.28);
  cursor: pointer;
}

.stage.is-open .overlay {
  opacity: 1;
  pointer-events: auto;
}

.stage.is-open .sheet {
  pointer-events: auto;
}

.stage.is-open .sheet[data-snap=peek] {
  transform: translate(-50%, 78%);
}

.stage.is-open .sheet[data-snap=half] {
  transform: translate(-50%, 40%);
}

.stage.is-open .sheet[data-snap=full] {
  transform: translate(-50%, 0);
}

.stage.is-demo .overlay {
  animation: overlay-loop 2s ease-in-out infinite;
}

.stage.is-demo .sheet {
  animation: sheet-loop 2s ease-out infinite;
}

@keyframes overlay-loop {
  0%, 100% {
    opacity: 0;
  }
  10%, 90% {
    opacity: 1;
  }
  95% {
    opacity: 0;
  }
}
@keyframes sheet-loop {
  0% {
    transform: translate(-50%, 100%);
  }
  10% {
    transform: translate(-50%, 78%);
  }
  40% {
    transform: translate(-50%, 40%);
  }
  70% {
    transform: translate(-50%, 0);
  }
  90% {
    transform: translate(-50%, 78%);
  }
  100% {
    transform: translate(-50%, 100%);
  }
}
@media (prefers-reduced-motion: reduce) {
  .stage.is-demo .overlay, .stage.is-demo .sheet {
    animation: none;
  }
  .overlay, .sheet {
    transition-duration: 1ms;
  }
}

// 손잡이를 누를 때마다 data-snap 을 세 값 사이로 순환시킨다. CSS 는 그 값에 맞는 translateY 로만 반응.
(function () {
  var stage = document.querySelector('.stage');
  var page = document.getElementById('page');
  var trigger = document.querySelector('.trigger');
  var overlay = document.querySelector('.overlay');
  var sheet = document.querySelector('.sheet');
  var handle = document.querySelector('.sheet__handle');
  var steps = ['peek', 'half', 'full'];
  function open() {
    stage.classList.remove('is-demo'); stage.classList.add('is-open');
    page.setAttribute('inert', ''); page.setAttribute('aria-hidden', 'true');
    handle.focus({ preventScroll: true });
  }
  function shut() {
    stage.classList.remove('is-open'); sheet.dataset.snap = 'half';
    page.removeAttribute('inert'); page.removeAttribute('aria-hidden');
    trigger.focus({ preventScroll: true });
  }
  handle.addEventListener('click', function () {
    var i = steps.indexOf(sheet.dataset.snap);
    sheet.dataset.snap = steps[(i + 1) % steps.length];
  });
  trigger.addEventListener('click', open);
  overlay.addEventListener('click', shut);
  document.addEventListener('keydown', function (e) {
    if (stage.classList.contains('is-open') && e.key === 'Escape') shut();
  });
})();

import { useState } from "react";
import type { CSSProperties } from "react";
import styles from "./BottomSheetSnap.module.scss";

export type SnapStep = "closed" | "peek" | "half" | "full";

export type BottomSheetSnapProps = {
  duration?: number;
  easing?: string;
  color?: string;
};

const STEPS: SnapStep[] = ["peek", "half", "full"];

export default function BottomSheetSnap({
  duration = 300,
  easing = "ease-out",
  color = "#17141a",
}: BottomSheetSnapProps) {
  const [snap, setSnap] = useState<SnapStep>("closed");
  const open = snap !== "closed";

  function cycle() {
    const i = STEPS.indexOf(snap === "closed" ? "peek" : snap);
    setSnap(STEPS[(i + 1) % STEPS.length]);
  }

  const vars: CSSProperties = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  return (
    <div className={styles.stage} style={vars}>
      <button className={styles.trigger} type="button" onClick={() => setSnap("half")}>목록 열기</button>
      <div className={styles.overlay} data-open={open} onClick={() => setSnap("closed")} />
      <div className={styles.sheet} data-snap={snap} role="dialog" aria-modal="true" aria-label="주변 장소 12곳">
        <button
          className={styles.handle}
          type="button"
          aria-label="시트 크기 전환(peek·half·full)"
          onClick={cycle}
        />
        <h2>주변 장소 12곳</h2>
        <p>손잡이를 누를 때마다 peek → half → full 순으로 바뀐다.</p>
      </div>
    </div>
  );
}