08Thanh chọn nhiều mục

<main class="stage">
  <div class="bulk-list is-demo">
    <label class="bulk-list__row bulk-list__row--all">
      <input type="checkbox" class="bulk-list__selectall">
      <span>Chọn tất cả</span>
    </label>
    <label class="bulk-list__row">
      <input type="checkbox" class="bulk-list__item">
      <span>Bao-cao-Q1-2026.pdf</span>
    </label>
    <label class="bulk-list__row">
      <input type="checkbox" class="bulk-list__item">
      <span>ban-thiet-ke-v3.fig</span>
    </label>
    <div class="bulk-list__toolbar">
      <span class="bulk-list__count"><span class="bulk-list__count-num">0</span> mục đã chọn</span>
      <button type="button">Di chuyển</button>
      <button type="button">Xóa</button>
    </div>
  </div>
</main>

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

$duration: $dur-base;                                  // 툴바가 올라오는 시간
$easing: $ease-spring;
$color: $subject-blue;                                 // 체크박스·툴바 강조 색

@include stage($stage-paper);

.bulk-list {
  position: relative;
  overflow: hidden;
  width: min(240px, 78vw);
  display: flex;
  flex-direction: column;
  gap: $sp-2;
  padding-bottom: $sp-10;
}

.bulk-list__row {
  display: flex;
  align-items: center;
  gap: $sp-2;
  padding: $sp-2 $sp-3;
  border-radius: $r-control;
  background: $subject-cream;
  font-size: 12px;
  color: $stage-ink;
  cursor: pointer;
}
.bulk-list__row--all { background: none; font-weight: 700; padding-left: $sp-3; }

.bulk-list input[type="checkbox"] {
  width: 16px;
  height: 16px;
  accent-color: $color;
}
.bulk-list input[type="checkbox"]:focus-visible { outline: 2px solid $color; outline-offset: 2px; }

.bulk-list__toolbar {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  align-items: center;
  gap: $sp-2;
  padding: $sp-2 $sp-3;
  border-radius: $r-control;
  background: $stage-ink;
  color: $stage-paper;
  transform: translateY(0);   // 정지 상태는 보이는 자리 — 반복 재생은 .is-demo 에서만
  transition: transform $duration $easing;
  button {
    margin-left: auto;
    border: 0;
    border-radius: $r-pill;
    padding: $sp-1 $sp-3;
    background: $color;
    color: $stage-paper;
    font-size: 11px;
    font-weight: 700;
    font-family: inherit;
    cursor: pointer;
    & + button { margin-left: $sp-1; background: $error; }
  }
}
.bulk-list__count { font-size: 11px; }

.bulk-list.has-selection .bulk-list__toolbar { transform: translateY(0); }
.bulk-list.is-demo .bulk-list__toolbar { animation: bulk-toolbar-loop $dur-loop $easing infinite; }

@keyframes bulk-toolbar-loop {
  0%, 15%   { transform: translateY(120%); }
  45%, 65%  { transform: translateY(0); }
  95%, 100% { transform: translateY(120%); }
}

@media (prefers-reduced-motion: reduce) {
  .bulk-list__toolbar { transition: none; }
  .bulk-list.is-demo .bulk-list__toolbar { animation: none; transform: translateY(0); }
}

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);
}

.bulk-list {
  position: relative;
  overflow: hidden;
  width: min(240px, 78vw);
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-bottom: 40px;
}

.bulk-list__row {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: 12px;
  background: #fff7e6;
  font-size: 12px;
  color: #17141a;
  cursor: pointer;
}

.bulk-list__row--all {
  background: none;
  font-weight: 700;
  padding-left: 12px;
}

.bulk-list input[type=checkbox] {
  width: 16px;
  height: 16px;
  accent-color: #2f6df6;
}

.bulk-list input[type=checkbox]:focus-visible {
  outline: 2px solid #2f6df6;
  outline-offset: 2px;
}

.bulk-list__toolbar {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: 12px;
  background: #17141a;
  color: #ffffff;
  transform: translateY(0);
  transition: transform 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
}
.bulk-list__toolbar button {
  margin-left: auto;
  border: 0;
  border-radius: 999px;
  padding: 4px 12px;
  background: #2f6df6;
  color: #ffffff;
  font-size: 11px;
  font-weight: 700;
  font-family: inherit;
  cursor: pointer;
}
.bulk-list__toolbar button + button {
  margin-left: 4px;
  background: #c2361a;
}

.bulk-list__count {
  font-size: 11px;
}

.bulk-list.has-selection .bulk-list__toolbar {
  transform: translateY(0);
}

.bulk-list.is-demo .bulk-list__toolbar {
  animation: bulk-toolbar-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes bulk-toolbar-loop {
  0%, 15% {
    transform: translateY(120%);
  }
  45%, 65% {
    transform: translateY(0);
  }
  95%, 100% {
    transform: translateY(120%);
  }
}
@media (prefers-reduced-motion: reduce) {
  .bulk-list__toolbar {
    transition: none;
  }
  .bulk-list.is-demo .bulk-list__toolbar {
    animation: none;
    transform: translateY(0);
  }
}

(function () {
  var list = document.querySelector('.bulk-list');
  var all = list.querySelector('.bulk-list__selectall');
  var items = Array.prototype.slice.call(list.querySelectorAll('.bulk-list__item'));
  var count = list.querySelector('.bulk-list__count-num');
  function sync() {
    var n = items.filter(function (c) { return c.checked; }).length;
    all.checked = n === items.length;
    all.indeterminate = n > 0 && n < items.length;
    list.classList.toggle('has-selection', n > 0);
    list.classList.remove('is-demo');
    count.textContent = String(n);
  }
  all.addEventListener('change', function () {
    items.forEach(function (c) { c.checked = all.checked; });
    sync();
  });
  items.forEach(function (c) { c.addEventListener('change', sync); });
})();

import { useEffect, useMemo, useRef, useState, type CSSProperties } from "react";
import styles from "./BulkSelectToolbar.module.scss";

export type BulkSelectToolbarProps = {
  files: string[];
  /** 툴바가 올라오는 시간 (기본 300ms) */
  duration?: number;
  easing?: string;
  /** 체크박스·툴바 강조 색 */
  color?: string;
};

type Vars = CSSProperties & { "--duration"?: string; "--easing"?: string; "--color"?: string };

export default function BulkSelectToolbar({
  files,
  duration = 300,
  easing = "cubic-bezier(.2, .8, .2, 1)",
  color = "#2f6df6",
}: BulkSelectToolbarProps) {
  const [checked, setChecked] = useState<boolean[]>(files.map(() => false));
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };
  const count = useMemo(() => checked.filter(Boolean).length, [checked]);
  const allChecked = count === files.length;
  const someChecked = count > 0 && !allChecked;
  const allRef = useRef<HTMLInputElement | null>(null);

  // .indeterminate 는 DOM 프로퍼티일 뿐 HTML 속성이 아니라서 JSX 에 그대로 못 준다 — ref 로 직접 써야 한다
  // (vanilla 판의 all.indeterminate = n > 0 && n < items.length 와 동일한 지점)
  useEffect(() => {
    if (allRef.current) allRef.current.indeterminate = someChecked;
  }, [someChecked]);

  const toggleOne = (i: number) => {
    const next = checked.slice();
    next[i] = !next[i];
    setChecked(next);
  };
  const toggleAll = () => setChecked(files.map(() => !allChecked));

  return (
    <div className={`${styles.list} ${count > 0 ? styles.hasSelection : ""}`} style={vars}>
      <label className={`${styles.row} ${styles.rowAll}`}>
        <input ref={allRef} type="checkbox" checked={allChecked} onChange={toggleAll} />
        <span>전체 선택</span>
      </label>
      {files.map((f, i) => (
        <label className={styles.row} key={f}>
          <input type="checkbox" checked={checked[i]} onChange={() => toggleOne(i)} />
          <span>{f}</span>
        </label>
      ))}
      <div className={styles.toolbar}>
        <span className={styles.count}>{count}개 선택됨</span>
        <button type="button">이동</button>
        <button type="button">삭제</button>
      </div>
    </div>
  );
}