09Dual-list transfer picker

<main class="stage">
  <div class="tf is-demo">
    <div class="tf__col">
      <div class="tf__h">Available</div>
      <ul class="tf__list" id="avail" role="listbox" aria-label="Available items" aria-multiselectable="true"></ul>
    </div>
    <div class="tf__mid">
      <button type="button" class="tf__btn" id="toRight" aria-label="Move to selected">→</button>
      <button type="button" class="tf__btn" id="toLeft" aria-label="Move to available">←</button>
    </div>
    <div class="tf__col">
      <div class="tf__h">Selected</div>
      <ul class="tf__list" id="chosen" role="listbox" aria-label="Selected items" aria-multiselectable="true"></ul>
    </div>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────
$duration: $dur-base;
$easing: $ease-pop;
$color: $subject-blue;

@include stage($stage-ink);

.tf { display: flex; align-items: center; gap: $sp-2; color: $subject-cream; }
.tf__col { width: 96px; }
.tf__h { font-size: 11px; font-weight: 700; color: rgba($subject-cream, .5); margin-bottom: $sp-1; }
.tf__list {
  list-style: none; margin: 0; padding: $sp-1; height: 128px; overflow: auto;
  border: 1px solid rgba($subject-cream, .16); border-radius: $r-sm; background: rgba($subject-cream, .04);
}
.tf__item {
  padding: $sp-1 $sp-2; border-radius: $r-xs; font-size: 12px; cursor: pointer;
  transition: background-color $duration $easing, transform $duration $easing;
}
.tf__item.is-sel { background: rgba($color, .35); transform: translateX(2px); }
.tf__item:focus-visible { outline: 2px solid $color; outline-offset: -2px; }
.tf__mid { display: flex; flex-direction: column; gap: $sp-2; }
.tf__btn {
  appearance: none; border: 1px solid rgba($subject-cream, .2); background: rgba($subject-cream, .06);
  color: $subject-cream; width: 28px; height: 28px; border-radius: 50%; cursor: pointer; font-size: 13px;
  transition: transform $duration $easing, background-color $duration $easing;
}
.tf__btn:active { transform: scale(.88); }

@media (prefers-reduced-motion: reduce) {
  .tf__item, .tf__btn { transition: none; }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.tf {
  display: flex;
  align-items: center;
  gap: 8px;
  color: #fff7e6;
}

.tf__col {
  width: 96px;
}

.tf__h {
  font-size: 11px;
  font-weight: 700;
  color: rgba(255, 247, 230, 0.5);
  margin-bottom: 4px;
}

.tf__list {
  list-style: none;
  margin: 0;
  padding: 4px;
  height: 128px;
  overflow: auto;
  border: 1px solid rgba(255, 247, 230, 0.16);
  border-radius: 8px;
  background: rgba(255, 247, 230, 0.04);
}

.tf__item {
  padding: 4px 8px;
  border-radius: 4px;
  font-size: 12px;
  cursor: pointer;
  transition: background-color 300ms cubic-bezier(0.2, 1.4, 0.4, 1), transform 300ms cubic-bezier(0.2, 1.4, 0.4, 1);
}

.tf__item.is-sel {
  background: rgba(47, 109, 246, 0.35);
  transform: translateX(2px);
}

.tf__item:focus-visible {
  outline: 2px solid #2f6df6;
  outline-offset: -2px;
}

.tf__mid {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.tf__btn {
  appearance: none;
  border: 1px solid rgba(255, 247, 230, 0.2);
  background: rgba(255, 247, 230, 0.06);
  color: #fff7e6;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  cursor: pointer;
  font-size: 13px;
  transition: transform 300ms cubic-bezier(0.2, 1.4, 0.4, 1), background-color 300ms cubic-bezier(0.2, 1.4, 0.4, 1);
}

.tf__btn:active {
  transform: scale(0.88);
}

@media (prefers-reduced-motion: reduce) {
  .tf__item, .tf__btn {
    transition: none;
  }
}

(function () {
  var tf = document.querySelector('.tf');
  var availEl = document.getElementById('avail'), chosenEl = document.getElementById('chosen');
  var avail = ['CSS', 'JS', 'HTML', 'SCSS', 'React'], chosen = [];
  var selA = {}, selC = {};
  function row(name, sel, i) {
    var li = document.createElement('li');
    li.className = 'tf__item'; li.setAttribute('role', 'option'); li.textContent = name;
    li.tabIndex = i === 0 ? 0 : -1;
    li.setAttribute('aria-selected', sel[name] ? 'true' : 'false');
    li.classList.toggle('is-sel', !!sel[name]);
    return li;
  }
  function render() {
    availEl.innerHTML = ''; chosenEl.innerHTML = '';
    avail.forEach(function (n, i) { availEl.appendChild(bind(row(n, selA, i), n, selA, availEl)); });
    chosen.forEach(function (n, i) { chosenEl.appendChild(bind(row(n, selC, i), n, selC, chosenEl)); });
  }
  function bind(li, name, sel, list) {
    li.addEventListener('click', function () { stop(); sel[name] = !sel[name]; render(); });
    li.addEventListener('keydown', function (e) {
      stop();
      var items = Array.prototype.slice.call(list.children);
      var i = items.indexOf(li);
      if (e.key === 'ArrowDown' || e.key === 'ArrowUp') {
        e.preventDefault();
        var n = items[Math.max(0, Math.min(items.length - 1, i + (e.key === 'ArrowDown' ? 1 : -1)))];
        items.forEach(function (x) { x.tabIndex = -1; }); n.tabIndex = 0; n.focus({ preventScroll: true });
      } else if (e.key === ' ' || e.key === 'Enter') { e.preventDefault(); sel[name] = !sel[name]; render(); }
    });
    return li;
  }
  function move(from, to, sel) {
    var keep = [], moved = [];
    from.forEach(function (n) { (sel[n] ? moved : keep).push(n); });
    from.length = 0; Array.prototype.push.apply(from, keep);
    Array.prototype.push.apply(to, moved);
    Object.keys(sel).forEach(function (k) { delete sel[k]; });
    render();
  }
  document.getElementById('toRight').addEventListener('click', function () { stop(); move(avail, chosen, selA); });
  document.getElementById('toLeft').addEventListener('click', function () { stop(); move(chosen, avail, selC); });

  var t = setInterval(function () {
    if (avail.length) { selA[avail[0]] = true; move(avail, chosen, selA); }
    else { selC[chosen[0]] = true; move(chosen, avail, selC); }
  }, 380);
  function stop() { tf.classList.remove('is-demo'); clearInterval(t); }
  render();
}());

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

export type DualListTransferPickerProps = {
  items?: string[];
  duration?: number;
  easing?: string;
  color?: string;
};

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

export default function DualListTransferPicker({
  items = ["CSS", "JS", "HTML", "SCSS", "React"],
  duration = 220,
  easing = "cubic-bezier(.2,1.4,.4,1)",
  color = "#2f6df6",
}: DualListTransferPickerProps) {
  const [avail, setAvail] = useState(items);
  const [chosen, setChosen] = useState<string[]>([]);
  const [selA, setSelA] = useState<Record<string, boolean>>({});
  const [selC, setSelC] = useState<Record<string, boolean>>({});
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--c": color };

  function toggle(name: string, sel: Record<string, boolean>, setSel: (v: Record<string, boolean>) => void) {
    setSel({ ...sel, [name]: !sel[name] });
  }

  function move(from: string[], setFrom: (v: string[]) => void, to: string[], setTo: (v: string[]) => void,
    sel: Record<string, boolean>, setSel: (v: Record<string, boolean>) => void) {
    const moved = from.filter((n) => sel[n]);
    setFrom(from.filter((n) => !sel[n]));
    setTo([...to, ...moved]);
    setSel({});
  }

  function list(names: string[], sel: Record<string, boolean>, setSel: (v: Record<string, boolean>) => void, label: string) {
    return (
      <ul className={styles.list} role="listbox" aria-label={label} aria-multiselectable="true">
        {names.map((n, i) => (
          <li key={n} role="option" aria-selected={!!sel[n]} data-sel={!!sel[n]} className={styles.item}
            tabIndex={i === 0 ? 0 : -1}
            onClick={() => toggle(n, sel, setSel)}
            onKeyDown={(e: any) => { if (e.key === " " || e.key === "Enter") { e.preventDefault(); toggle(n, sel, setSel); } }}>
            {n}
          </li>
        ))}
      </ul>
    );
  }

  return (
    <div className={styles.tf} style={vars}>
      <div className={styles.col}>
        <div className={styles.h}>Available</div>
        {list(avail, selA, (v) => setSelA(v), "Available items")}
      </div>
      <div className={styles.mid}>
        <button type="button" className={styles.btn} aria-label="Move to selected"
          onClick={() => move(avail, setAvail, chosen, setChosen, selA, setSelA)}>→</button>
        <button type="button" className={styles.btn} aria-label="Move to available"
          onClick={() => move(chosen, setChosen, avail, setAvail, selC, setSelC)}>←</button>
      </div>
      <div className={styles.col}>
        <div className={styles.h}>Selected</div>
        {list(chosen, selC, (v) => setSelC(v), "Selected items")}
      </div>
    </div>
  );
}