03Column reorder that lifts the header

<main class="stage">
  <div class="rd is-demo" id="rd">
    <div class="rd__slot" aria-hidden="true"></div>
    <div class="rd__cols" id="rd-cols" role="grid" aria-label="Member table">
      <div class="rd__col" role="columnheader">
        <span class="rd__h"><span class="rd__grab" aria-hidden="true"><svg viewBox="0 0 256 256" width="1em" height="1em" fill="currentColor"><g><path d="M208 32v192a16 16 0 0 1-16 16H64a16 16 0 0 1-16-16V32a16 16 0 0 1 16-16h128a16 16 0 0 1 16 16" opacity=".2"/><path d="M104 60a12 12 0 1 1-12-12a12 12 0 0 1 12 12m60 12a12 12 0 1 0-12-12a12 12 0 0 0 12 12m-72 44a12 12 0 1 0 12 12a12 12 0 0 0-12-12m72 0a12 12 0 1 0 12 12a12 12 0 0 0-12-12m-72 68a12 12 0 1 0 12 12a12 12 0 0 0-12-12m72 0a12 12 0 1 0 12 12a12 12 0 0 0-12-12"/></g></svg></span>Name</span>
        <span class="rd__c">Sky</span><span class="rd__c">Gaon</span><span class="rd__c">Sunset</span>
      </div>
      <div class="rd__col" role="columnheader">
        <span class="rd__h"><span class="rd__grab" aria-hidden="true"><svg viewBox="0 0 256 256" width="1em" height="1em" fill="currentColor"><g><path d="M208 32v192a16 16 0 0 1-16 16H64a16 16 0 0 1-16-16V32a16 16 0 0 1 16-16h128a16 16 0 0 1 16 16" opacity=".2"/><path d="M104 60a12 12 0 1 1-12-12a12 12 0 0 1 12 12m60 12a12 12 0 1 0-12-12a12 12 0 0 0 12 12m-72 44a12 12 0 1 0 12 12a12 12 0 0 0-12-12m72 0a12 12 0 1 0 12 12a12 12 0 0 0-12-12m-72 68a12 12 0 1 0 12 12a12 12 0 0 0-12-12m72 0a12 12 0 1 0 12 12a12 12 0 0 0-12-12"/></g></svg></span>Tier</span>
        <span class="rd__c">Gold</span><span class="rd__c">Silver</span><span class="rd__c">Bronze</span>
      </div>
      <div class="rd__col" role="columnheader">
        <span class="rd__h"><span class="rd__grab" aria-hidden="true"><svg viewBox="0 0 256 256" width="1em" height="1em" fill="currentColor"><g><path d="M208 32v192a16 16 0 0 1-16 16H64a16 16 0 0 1-16-16V32a16 16 0 0 1 16-16h128a16 16 0 0 1 16 16" opacity=".2"/><path d="M104 60a12 12 0 1 1-12-12a12 12 0 0 1 12 12m60 12a12 12 0 1 0-12-12a12 12 0 0 0 12 12m-72 44a12 12 0 1 0 12 12a12 12 0 0 0-12-12m72 0a12 12 0 1 0 12 12a12 12 0 0 0-12-12m-72 68a12 12 0 1 0 12 12a12 12 0 0 0-12-12m72 0a12 12 0 1 0 12 12a12 12 0 0 0-12-12"/></g></svg></span>Points</span>
        <span class="rd__c">820</span><span class="rd__c">410</span><span class="rd__c">175</span>
      </div>
    </div>
  </div>
</main>

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

$duration: $dur-base;
$easing: $ease-spring;
$color: $subject-cream;

@include stage($stage-orange);

$row-h: 26px;
$col-w: 96px;
$panel: color.mix($subject-ink, $stage-orange, 84%);
$lifted: color.mix($subject-ink, $stage-orange, 66%);   // 집어 든 열은 바탕을 한 단계 밝혀 띄운다
$line: rgba(255, 247, 230, .16);

.rd {
  position: relative;
  box-sizing: border-box;
  padding: $sp-1;
  border-radius: $r-card;
  background: $panel;
  color: $color;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

// 놓을 자리 — 열이 비켜난 동안만 보이는 빈 홈
.rd__slot {
  position: absolute;
  left: 4px; top: 4px;
  width: $col-w;
  height: calc(100% - 8px);
  border: 2px dashed rgba(255, 247, 230, .42);
  border-radius: $r-sm;
  opacity: 0;
}

.rd__cols {
  position: relative;
  display: flex;
}
.rd__col {
  flex: 0 0 auto;
  width: $col-w;
  display: flex;
  flex-direction: column;
  border-radius: $r-sm;
  background: $panel;
  transition: transform $duration $easing;
}
.rd__col.is-lift {
  z-index: 2;
  background: $lifted;
  box-shadow: $shadow-raised;
  transition: none;
}

.rd__h {
  display: flex;
  align-items: center;
  gap: $sp-1;
  height: $row-h;
  padding: 0 $sp-2;
  border-bottom: 2px solid $line;
  font-size: 11px;
  line-height: $row-h;
  font-weight: 700;
  cursor: grab;
  touch-action: none;
  user-select: none;
}
.rd__col.is-lift .rd__h { cursor: grabbing; }
.rd__grab {
  display: inline-flex;
  width: 11px;
  height: 11px;
  opacity: .55;
}

.rd__c {
  height: $row-h;
  padding: 0 $sp-2;
  font-size: 12px;
  line-height: $row-h;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
}
.rd__c + .rd__c { border-top: 1px solid rgba(255, 247, 230, .09); }

// ── 자동 루프 (2s) ───────────────────────────────────
// 10% 에 셋째 열이 떠오르고(그림자 컷) 10~38% 에 왼쪽 끝으로 옮겨 간다. 나머지 두 열은
// 같은 구간에 한 칸씩 오른쪽으로 비킨다 — 세 열의 이동 거리를 하나의 열 폭으로 묶어 둔다.
// 58~84% 에 되돌아오고 84% 뒤에는 아무것도 움직이지 않는다(복귀는 90% 안).
.rd.is-demo .rd__col {
  animation-duration: $dur-loop;
  animation-timing-function: $easing;
  animation-iteration-count: infinite;
  animation-fill-mode: backwards;
}
.rd.is-demo .rd__col:nth-child(1),
.rd.is-demo .rd__col:nth-child(2) { animation-name: rd-aside; }
.rd.is-demo .rd__col:nth-child(3) { animation-name: rd-carry; }
.rd.is-demo .rd__col:nth-child(3) {
  z-index: 2;
}
.rd.is-demo .rd__slot {
  animation-name: rd-slot;
  animation-duration: $dur-loop;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}

@keyframes rd-aside {
  0%   { transform: translateX(0); }
  10%  { transform: translateX(0); }
  38%  { transform: translateX($col-w); }
  58%  { transform: translateX($col-w); }
  84%  { transform: translateX(0); }
  100% { transform: translateX(0); }
}
@keyframes rd-carry {
  0%   { transform: translateX(0) translateY(0); box-shadow: none; background: $panel; }
  10%  { transform: translateX(0) translateY(-16px); box-shadow: $shadow-raised; background: $lifted; }
  38%  { transform: translateX($col-w * -2) translateY(-16px); box-shadow: $shadow-raised; background: $lifted; }
  58%  { transform: translateX($col-w * -2) translateY(-16px); box-shadow: $shadow-raised; background: $lifted; }
  84%  { transform: translateX(0) translateY(0); box-shadow: none; background: $panel; }
  100% { transform: translateX(0) translateY(0); box-shadow: none; background: $panel; }
}
@keyframes rd-slot {
  0%   { opacity: 0; }
  10%  { opacity: 1; }
  58%  { opacity: 0; }
  100% { opacity: 0; }
}

// 320×200 — 세 열이 288px 이라 여백만 줄이고 열 폭은 그대로 둔다
@media (max-width: 340px) {
  .rd { padding: 0; }
  .rd__slot { left: 0; top: 0; height: 100%; }
  .rd__h, .rd__c { padding: 0 $sp-1; }
}

@media (prefers-reduced-motion: reduce) {
  .rd.is-demo .rd__col,
  .rd.is-demo .rd__slot { animation: none !important; }
  .rd.is-demo .rd__col:nth-child(3) { box-shadow: $shadow-raised; }
  .rd__col { transition: none; }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ff4d1f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.rd {
  position: relative;
  box-sizing: border-box;
  padding: 4px;
  border-radius: 16px;
  background: rgb(23.5764705882%, 11.4196078431%, 10.5098039216%);
  color: #fff7e6;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

.rd__slot {
  position: absolute;
  left: 4px;
  top: 4px;
  width: 96px;
  height: calc(100% - 8px);
  border: 2px dashed rgba(255, 247, 230, 0.42);
  border-radius: 8px;
  opacity: 0;
}

.rd__cols {
  position: relative;
  display: flex;
}

.rd__col {
  flex: 0 0 auto;
  width: 96px;
  display: flex;
  flex-direction: column;
  border-radius: 8px;
  background: rgb(23.5764705882%, 11.4196078431%, 10.5098039216%);
  transition: transform 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.rd__col.is-lift {
  z-index: 2;
  background: rgb(39.9529411765%, 15.4431372549%, 10.862745098%);
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  transition: none;
}

.rd__h {
  display: flex;
  align-items: center;
  gap: 4px;
  height: 26px;
  padding: 0 8px;
  border-bottom: 2px solid rgba(255, 247, 230, 0.16);
  font-size: 11px;
  line-height: 26px;
  font-weight: 700;
  cursor: grab;
  touch-action: none;
  user-select: none;
}

.rd__col.is-lift .rd__h {
  cursor: grabbing;
}

.rd__grab {
  display: inline-flex;
  width: 11px;
  height: 11px;
  opacity: 0.55;
}

.rd__c {
  height: 26px;
  padding: 0 8px;
  font-size: 12px;
  line-height: 26px;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
}

.rd__c + .rd__c {
  border-top: 1px solid rgba(255, 247, 230, 0.09);
}

.rd.is-demo .rd__col {
  animation-duration: 2s;
  animation-timing-function: cubic-bezier(0.2, 0.8, 0.2, 1);
  animation-iteration-count: infinite;
  animation-fill-mode: backwards;
}

.rd.is-demo .rd__col:nth-child(1),
.rd.is-demo .rd__col:nth-child(2) {
  animation-name: rd-aside;
}

.rd.is-demo .rd__col:nth-child(3) {
  animation-name: rd-carry;
}

.rd.is-demo .rd__col:nth-child(3) {
  z-index: 2;
}

.rd.is-demo .rd__slot {
  animation-name: rd-slot;
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}

@keyframes rd-aside {
  0% {
    transform: translateX(0);
  }
  10% {
    transform: translateX(0);
  }
  38% {
    transform: translateX(96px);
  }
  58% {
    transform: translateX(96px);
  }
  84% {
    transform: translateX(0);
  }
  100% {
    transform: translateX(0);
  }
}
@keyframes rd-carry {
  0% {
    transform: translateX(0) translateY(0);
    box-shadow: none;
    background: rgb(23.5764705882%, 11.4196078431%, 10.5098039216%);
  }
  10% {
    transform: translateX(0) translateY(-16px);
    box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
    background: rgb(39.9529411765%, 15.4431372549%, 10.862745098%);
  }
  38% {
    transform: translateX(-192px) translateY(-16px);
    box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
    background: rgb(39.9529411765%, 15.4431372549%, 10.862745098%);
  }
  58% {
    transform: translateX(-192px) translateY(-16px);
    box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
    background: rgb(39.9529411765%, 15.4431372549%, 10.862745098%);
  }
  84% {
    transform: translateX(0) translateY(0);
    box-shadow: none;
    background: rgb(23.5764705882%, 11.4196078431%, 10.5098039216%);
  }
  100% {
    transform: translateX(0) translateY(0);
    box-shadow: none;
    background: rgb(23.5764705882%, 11.4196078431%, 10.5098039216%);
  }
}
@keyframes rd-slot {
  0% {
    opacity: 0;
  }
  10% {
    opacity: 1;
  }
  58% {
    opacity: 0;
  }
  100% {
    opacity: 0;
  }
}
@media (max-width: 340px) {
  .rd {
    padding: 0;
  }
  .rd__slot {
    left: 0;
    top: 0;
    height: 100%;
  }
  .rd__h, .rd__c {
    padding: 0 4px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .rd.is-demo .rd__col,
  .rd.is-demo .rd__slot {
    animation: none !important;
  }
  .rd.is-demo .rd__col:nth-child(3) {
    box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  }
  .rd__col {
    transition: none;
  }
}

// 실제 동작: 헤더를 잡으면 그 열이 통째로 떠오르고, 놓을 자리의 열들이 자리를 비켜 준다.
var rd = document.getElementById('rd');
var rdCols = document.getElementById('rd-cols');
var rdW = 96, rdFrom = 0, rdAt = 0, rdTo = 0, rdEl = null;
function rdList() { return [].slice.call(rdCols.children); }
function rdMove(e) {
  var dx = e.clientX - rdAt;
  rdEl.style.transform = 'translateX(' + dx + 'px)';
  rdTo = Math.max(0, Math.min(rdList().length - 1, rdFrom + Math.round(dx / rdW)));
  rdList().forEach(function (el, i) {
    if (el === rdEl) return;
    var shift = 0;
    if (rdTo > rdFrom && i > rdFrom && i <= rdTo) shift = -rdW;
    if (rdTo < rdFrom && i >= rdTo && i < rdFrom) shift = rdW;
    el.style.transform = 'translateX(' + shift + 'px)';
  });
}
function rdUp() {
  var list = rdList();
  list.forEach(function (el) { el.style.transition = 'none'; el.style.transform = ''; });
  var after = list[rdTo > rdFrom ? rdTo + 1 : rdTo];
  rdCols.insertBefore(rdEl, after || null);
  rd.classList.remove('is-drag');
  rdEl.classList.remove('is-lift');
  requestAnimationFrame(function () { list.forEach(function (el) { el.style.transition = ''; }); });
  window.removeEventListener('pointermove', rdMove);
  window.removeEventListener('pointerup', rdUp);
  rdEl = null;
}
rdList().forEach(function (col) {
  col.querySelector('.rd__h').addEventListener('pointerdown', function (e) {
    rd.classList.remove('is-demo');
    rd.classList.add('is-drag');
    rdEl = col; rdEl.classList.add('is-lift');
    rdW = col.getBoundingClientRect().width;
    rdFrom = rdList().indexOf(col); rdTo = rdFrom; rdAt = e.clientX;
    window.addEventListener('pointermove', rdMove);
    window.addEventListener('pointerup', rdUp);
  });
});

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

export type ReorderCol = { key: string; head: string; cells: string[] };

export type ColumnReorderDragProps = {
  columns?: ReorderCol[];
  tableLabel?: string;
  /** 자동 재생 루프 (갤러리용). 사람이 손대면 꺼진다 */
  demo?: boolean;
  duration?: number;
  easing?: string;
  color?: string;
};

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

const DEFAULT_COLS: ReorderCol[] = [
  { key: "name", head: "Name", cells: ["Sky", "Gaon", "Sunset"] },
  { key: "tier", head: "Tier", cells: ["Gold", "Silver", "Bronze"] },
  { key: "points", head: "Points", cells: ["820", "410", "175"] },
];

function Grab() {
  return (
    <svg viewBox="0 0 256 256" width="1em" height="1em" fill="currentColor">
      <g>
        <path d="M208 32v192a16 16 0 0 1-16 16H64a16 16 0 0 1-16-16V32a16 16 0 0 1 16-16h128a16 16 0 0 1 16 16" opacity=".2" />
        <path d="M104 60a12 12 0 1 1-12-12a12 12 0 0 1 12 12m60 12a12 12 0 1 0-12-12a12 12 0 0 0 12 12m-72 44a12 12 0 1 0 12 12a12 12 0 0 0-12-12m72 0a12 12 0 1 0 12 12a12 12 0 0 0-12-12m-72 68a12 12 0 1 0 12 12a12 12 0 0 0-12-12m72 0a12 12 0 1 0 12 12a12 12 0 0 0-12-12" />
      </g>
    </svg>
  );
}

function moveItem(list: ReorderCol[], from: number, to: number): ReorderCol[] {
  const next = list.slice();
  const it = next.splice(from, 1)[0];
  next.splice(to, 0, it);
  return next;
}

export default function ColumnReorderDrag({
  columns = DEFAULT_COLS,
  tableLabel = "Member table",
  demo = true,
  duration = 300,
  easing = "cubic-bezier(.2,.8,.2,1)",
  color = "#fff7e6",
}: ColumnReorderDragProps) {
  const [cols, setCols] = useState<ReorderCol[]>(columns);
  const [lift, setLift] = useState(-1);
  const [target, setTarget] = useState(-1);
  const [dx, setDx] = useState(0);
  // 놓는 순간 한 프레임만 전환을 끈다 — 바닐라의 transition:none → rAF 복구와 같은 뜻
  const [settle, setSettle] = useState(false);
  const [live, setLive] = useState(demo);

  // ambient useRef 는 항상 T | null 을 돌려준다 — 지역 별칭으로 한 번만 좁혀 쓴다
  const dragRef = useRef<{ from: number; to: number; at: number; w: number }>({ from: 0, to: 0, at: 0, w: 96 });
  const drag = dragRef.current || { from: 0, to: 0, at: 0, w: 96 };
  const elsRef = useRef<(HTMLElement | null)[]>([]);
  const els: (HTMLElement | null)[] = elsRef.current || [];

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

  useEffect(() => {
    if (lift < 0) return;
    function move(e: PtrEvt) {
      const d = e.clientX - drag.at;
      setDx(d);
      const t = Math.max(0, Math.min(cols.length - 1, drag.from + Math.round(d / drag.w)));
      drag.to = t;
      setTarget(t);
    }
    function up() {
      setSettle(true);
      setCols(moveItem(cols, drag.from, drag.to));
      setLift(-1);
      setTarget(-1);
      setDx(0);
    }
    window.addEventListener("pointermove", move);
    window.addEventListener("pointerup", up);
    return () => {
      window.removeEventListener("pointermove", move);
      window.removeEventListener("pointerup", up);
    };
  }, [lift, cols]);

  useEffect(() => {
    if (!settle) return;
    const id = requestAnimationFrame(() => setSettle(false));
    return () => cancelAnimationFrame(id);
  }, [settle]);

  function onGrab(i: number, e: PtrEvt) {
    setLive(false);
    const el = els[i];
    drag.w = el ? el.getBoundingClientRect().width : 96;
    drag.from = i;
    drag.to = i;
    drag.at = e.clientX;
    setLift(i);
    setTarget(i);
    setDx(0);
  }

  function styleOf(i: number): CSSProperties | undefined {
    if (settle) return { transition: "none" };
    if (lift < 0) return undefined;
    if (i === lift) return { transform: `translateX(${dx}px)` };
    let shift = 0;
    if (target > lift && i > lift && i <= target) shift = -drag.w;
    if (target < lift && i >= target && i < lift) shift = drag.w;
    return { transform: `translateX(${shift}px)` };
  }

  return (
    <div className={`${styles.root} ${live ? styles.isDemo : ""}`} style={vars}>
      <div className={styles.slot} aria-hidden="true" />
      <div className={styles.cols} role="grid" aria-label={tableLabel}>
        {cols.map((col, i) => (
          <div
            key={col.key}
            className={`${styles.col} ${lift === i ? styles.isLift : ""}`}
            style={styleOf(i)}
            role="columnheader"
            ref={(el: HTMLElement | null) => { els[i] = el; }}
          >
            <span className={styles.h} onPointerDown={(e: PtrEvt) => onGrab(i, e)}>
              <span className={styles.grab} aria-hidden="true"><Grab /></span>
              {col.head}
            </span>
            {col.cells.map((v) => (
              <span className={styles.c} key={v}>{v}</span>
            ))}
          </div>
        ))}
      </div>
    </div>
  );
}