04드래그 핸들 순서 변경

<main class="stage">
  <ul class="drag-list is-demo" aria-label="처리 순서">
    <li class="drag-row">
      <button class="drag-row__handle" type="button" aria-label="드래그하거나 화살표 키로 순서 변경">⠿</button>
      <span class="drag-row__label">결제 확인</span>
    </li>
    <li class="drag-row">
      <button class="drag-row__handle" type="button" aria-label="드래그하거나 화살표 키로 순서 변경">⠿</button>
      <span class="drag-row__label">배송 준비</span>
    </li>
    <li class="drag-row">
      <button class="drag-row__handle" type="button" aria-label="드래그하거나 화살표 키로 순서 변경">⠿</button>
      <span class="drag-row__label">리뷰 요청</span>
    </li>
  </ul>
</main>

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

$duration: $dur-quick;                                 // 드래그 중 스냅 시간
$easing: $ease-out;
$color: $subject-blue;                                 // 핸들 색

@include stage($stage-paper);

.drag-list {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
  width: min(240px, 78vw);
  display: flex;
  flex-direction: column;
  gap: $sp-2;
}

.drag-row {
  display: flex;
  align-items: center;
  gap: $sp-2;
  padding: $sp-3;
  border-radius: $r-control;
  background: $subject-cream;
  box-shadow: $shadow-press;
  transition: transform $duration $easing;
  &.is-dragging { transition: none; z-index: 2; box-shadow: $shadow-raised; }
}

.drag-row__handle {
  flex: 0 0 auto;
  width: 28px;
  height: 28px;
  border: 0;
  border-radius: $r-sm;
  background: $color;
  color: $stage-paper;
  font-size: 14px;
  line-height: 1;
  cursor: grab;
  touch-action: none;
}
.drag-row__handle:focus-visible { outline: 2px solid $stage-ink; outline-offset: 2px; }

.drag-row__label { font-weight: 700; font-size: 13px; color: $stage-ink; font-family: inherit; }

.drag-list.is-demo .drag-row:nth-child(1) { animation: drag-a $dur-loop $easing infinite; }
.drag-list.is-demo .drag-row:nth-child(2) { animation: drag-b $dur-loop $easing infinite; }

@keyframes drag-a {
  0%, 10%   { transform: translateY(0); }
  45%, 65%  { transform: translateY(60px); }
  95%, 100% { transform: translateY(0); }
}
@keyframes drag-b {
  0%, 10%   { transform: translateY(0); }
  45%, 65%  { transform: translateY(-60px); }
  95%, 100% { transform: translateY(0); }
}

@media (prefers-reduced-motion: reduce) {
  .drag-row { transition: none; }
  .drag-list.is-demo .drag-row:nth-child(1),
  .drag-list.is-demo .drag-row:nth-child(2) { animation: none; }
}

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);
}

.drag-list {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
  width: min(240px, 78vw);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.drag-row {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px;
  border-radius: 12px;
  background: #fff7e6;
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
  transition: transform 220ms ease-out;
}
.drag-row.is-dragging {
  transition: none;
  z-index: 2;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
}

.drag-row__handle {
  flex: 0 0 auto;
  width: 28px;
  height: 28px;
  border: 0;
  border-radius: 8px;
  background: #2f6df6;
  color: #ffffff;
  font-size: 14px;
  line-height: 1;
  cursor: grab;
  touch-action: none;
}

.drag-row__handle:focus-visible {
  outline: 2px solid #17141a;
  outline-offset: 2px;
}

.drag-row__label {
  font-weight: 700;
  font-size: 13px;
  color: #17141a;
  font-family: inherit;
}

.drag-list.is-demo .drag-row:nth-child(1) {
  animation: drag-a 2s ease-out infinite;
}

.drag-list.is-demo .drag-row:nth-child(2) {
  animation: drag-b 2s ease-out infinite;
}

@keyframes drag-a {
  0%, 10% {
    transform: translateY(0);
  }
  45%, 65% {
    transform: translateY(60px);
  }
  95%, 100% {
    transform: translateY(0);
  }
}
@keyframes drag-b {
  0%, 10% {
    transform: translateY(0);
  }
  45%, 65% {
    transform: translateY(-60px);
  }
  95%, 100% {
    transform: translateY(0);
  }
}
@media (prefers-reduced-motion: reduce) {
  .drag-row {
    transition: none;
  }
  .drag-list.is-demo .drag-row:nth-child(1),
  .drag-list.is-demo .drag-row:nth-child(2) {
    animation: none;
  }
}

(function () {
  var list = document.querySelector('.drag-list');
  Array.prototype.forEach.call(list.children, function (row) {
    var handle = row.querySelector('.drag-row__handle');
    var startY = 0, dy = 0, dragging = false;
    handle.addEventListener('pointerdown', function (e) {
      list.classList.remove('is-demo');
      dragging = true; startY = e.clientY; row.classList.add('is-dragging');
      handle.setPointerCapture(e.pointerId);
    });
    handle.addEventListener('pointermove', function (e) {
      if (!dragging) return;
      dy = e.clientY - startY;
      row.style.transform = 'translateY(' + dy + 'px)';
    });
    function end() {
      if (!dragging) return;
      dragging = false; row.classList.remove('is-dragging');
      var target = dy > 30 ? row.nextElementSibling : dy < -30 ? row.previousElementSibling : null;
      row.style.transform = '';
      if (target) list.insertBefore(dy > 0 ? target : row, dy > 0 ? row : target);
      dy = 0;
    }
    handle.addEventListener('pointerup', end);
    handle.addEventListener('pointercancel', end);
    handle.addEventListener('keydown', function (e) {
      list.classList.remove('is-demo');
      var sib = e.key === 'ArrowDown' ? row.nextElementSibling : e.key === 'ArrowUp' ? row.previousElementSibling : null;
      if (!sib) return;
      e.preventDefault();
      if (e.key === 'ArrowDown') list.insertBefore(sib, row); else list.insertBefore(row, sib);
      handle.focus({ preventScroll: true });
    });
  });
})();

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

export type DragHandleReorderProps = {
  items: string[];
  /** 드래그 스냅 시간 (기본 220ms) */
  duration?: number;
  easing?: string;
  /** 핸들 색 */
  color?: string;
};

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

export default function DragHandleReorder({
  items,
  duration = 220,
  easing = "ease-out",
  color = "#2f6df6",
}: DragHandleReorderProps) {
  const [rows, setRows] = useState(items);
  const [dragIndex, setDragIndex] = useState<number | null>(null);
  const [dy, setDy] = useState(0);
  const startY = useRef(0);
  const handles = useRef<{ [label: string]: HTMLButtonElement | null }>({});
  const refocusLabel = useRef<string | null>(null);
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  // 키보드로 순서를 바꾼 뒤에도 같은 핸들에 포커스가 남아 있어야 연속으로 화살표 키를 누를 수 있다
  // (vanilla 판의 handle.focus({ preventScroll: true }) 와 같은 목적 — react 는 key 재조정으로도
  // 대개 포커스가 유지되지만, 여기서는 명시적으로 한 번 더 확인해 다른 리렌더에 흔들리지 않게 한다)
  useEffect(() => {
    const label = refocusLabel.current;
    if (label) { handles.current![label]?.focus({ preventScroll: true }); refocusLabel.current = null; }
  }, [rows]);

  const swap = (i: number, j: number, keyboardLabel?: string) => {
    if (j < 0 || j >= rows.length) return;
    const next = rows.slice();
    const t = next[i]; next[i] = next[j]; next[j] = t;
    if (keyboardLabel) refocusLabel.current = keyboardLabel;
    setRows(next);
  };
  const down = (i: number) => (e: PointerEvent<HTMLButtonElement>) => {
    setDragIndex(i); startY.current = e.clientY;
    e.currentTarget.setPointerCapture(e.pointerId);
  };
  const move = (e: PointerEvent<HTMLButtonElement>) => {
    if (dragIndex === null) return;
    setDy(e.clientY - (startY.current ?? 0));
  };
  const up = () => {
    if (dragIndex === null) return;
    if (dy > 30) swap(dragIndex, dragIndex + 1);
    else if (dy < -30) swap(dragIndex, dragIndex - 1);
    setDragIndex(null); setDy(0);
  };
  const key = (i: number, label: string) => (e: any) => {
    if (e.key === "ArrowDown") { e.preventDefault(); swap(i, i + 1, label); }
    else if (e.key === "ArrowUp") { e.preventDefault(); swap(i, i - 1, label); }
  };

  return (
    <ul className={styles.list} style={vars}>
      {rows.map((label, i) => (
        <li
          key={label}
          className={styles.row}
          style={dragIndex === i ? { transform: `translateY(${dy}px)`, transition: "none" } : undefined}
        >
          <button
            ref={(el: HTMLButtonElement | null) => { handles.current![label] = el; }}
            className={styles.handle}
            type="button"
            aria-label="드래그하거나 화살표 키로 순서 변경"
            onPointerDown={down(i)}
            onPointerMove={move}
            onPointerUp={up}
            onPointerCancel={up}
            onKeyDown={key(i, label)}
          >⠿</button>
          <span className={styles.label}>{label}</span>
        </li>
      ))}
    </ul>
  );
}