03Selection-value highlight toggle — when a row's selection value turns on, its highlight-color value deepens, and it returns to the original value when off

<main class="stage">
<table class="tsh is-demo" id="tsh">
  <tbody>
    <tr class="tsh__row" id="tshRow0"><td class="tsh__cell">Item A</td><td class="tsh__cell tsh__cell--num">14</td></tr>
    <tr class="tsh__row" id="tshRow1"><td class="tsh__cell">Item B</td><td class="tsh__cell tsh__cell--num">27</td></tr>
    <tr class="tsh__row" id="tshRow2"><td class="tsh__cell">Item C</td><td class="tsh__cell tsh__cell--num">9</td></tr>
    <tr class="tsh__row" id="tshRow3"><td class="tsh__cell">Item D</td><td class="tsh__cell tsh__cell--num">31</td></tr>
  </tbody>
</table>
</main>

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

// 계산 겹: 선택 값 → 목표(0/1), 실제 강조 값은 스프링 방정식(k=.26·d=.62)을 매 프레임 적분해
// 1을 살짝 넘겼다 되돌아오는 오버슛으로 색을 섞는다 — index.html tick() 참조. reduce 시 k=d=1(오버슛 없음)
@include stage($stage-ink);

.tsh {
  width: 100%;
  max-width: 240px;
  border-collapse: collapse;
  font: 400 12px/1.3 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: $subject-cream;
}

.tsh__row {
  cursor: pointer;
}

.tsh__row:not(:first-child) .tsh__cell {
  border-top: 1px solid rgba(255, 247, 230, .14);
}

.tsh__cell {
  padding: $sp-2 $sp-3;
  box-sizing: border-box;
}

.tsh__cell--num {
  text-align: right;
  font-variant-numeric: tabular-nums;
}

@media (max-width: 340px) {
  .tsh { max-width: 200px; font-size: 11px; }
  .tsh__cell { padding: $sp-1 $sp-2; }
}

@media (prefers-reduced-motion: reduce) {
  .tsh__row { 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);
}

.tsh {
  width: 100%;
  max-width: 240px;
  border-collapse: collapse;
  font: 400 12px/1.3 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: #fff7e6;
}

.tsh__row {
  cursor: pointer;
}

.tsh__row:not(:first-child) .tsh__cell {
  border-top: 1px solid rgba(255, 247, 230, 0.14);
}

.tsh__cell {
  padding: 8px 12px;
  box-sizing: border-box;
}

.tsh__cell--num {
  text-align: right;
  font-variant-numeric: tabular-nums;
}

@media (max-width: 340px) {
  .tsh {
    max-width: 200px;
    font-size: 11px;
  }
  .tsh__cell {
    padding: 4px 8px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .tsh__row {
    transition: none;
  }
}

(function () {
  var root = document.getElementById('tsh');
  var rows = [0, 1, 2, 3].map(function (i) { return document.getElementById('tshRow' + i); });

  // 상수: 스프링 강성(k) · 감쇠(d) · 프레임당 시간 스텝 · 자동 루프 간격
  var REDUCE = !!(window.matchMedia && window.matchMedia('(prefers-reduced-motion: reduce)').matches);
  var K = REDUCE ? 1 : 0.26;
  var D = REDUCE ? 1 : 0.62;
  var DT = 1;
  var AUTO_SELECT_MS = 550;

  var selected = [false, false, false, false];
  var pos = [0, 0, 0, 0];   // 강조 진행 값(0~1+overshoot)
  var vel = [0, 0, 0, 0];

  function baseColor() { return [35, 31, 40]; }   // tick-panel
  function hiColor() { return [10, 79, 232]; }     // subject-blue-deep

  // 계산 겹: 목표(0 또는 1)로 스프링 방정식(가속도 = -k*(pos-target) - d*vel)을 매 프레임 적분해
  // 값이 1을 살짝 넘겼다 되돌아오는 오버슛을 만든다(단순 트윈이 아니다)
  function tick() {
    for (var i = 0; i < 4; i++) {
      var target = selected[i] ? 1 : 0;
      var acc = -K * (pos[i] - target) - D * vel[i];
      vel[i] += acc * DT;
      pos[i] += vel[i] * DT;
      var clampedForColor = Math.max(0, Math.min(1, pos[i]));
      var over = Math.max(0, pos[i] - 1);
      var b = baseColor(), h = hiColor();
      var r = b[0] + (h[0] - b[0]) * clampedForColor;
      var g = b[1] + (h[1] - b[1]) * clampedForColor;
      var bl = b[2] + (h[2] - b[2]) * clampedForColor;
      rows[i].style.background = 'rgb(' + r.toFixed(0) + ',' + g.toFixed(0) + ',' + bl.toFixed(0) + ')';
      rows[i].style.boxShadow = over > 0.001 ? ('inset 0 0 0 ' + (over * 6).toFixed(1) + 'px rgba(255,255,255,' + Math.min(0.6, over).toFixed(2) + ')') : 'none';
    }
    requestAnimationFrame(tick);
  }
  requestAnimationFrame(tick);

  function select(i) {
    selected[i] = !selected[i];
  }

  rows.forEach(function (el, i) {
    el.addEventListener('click', function () {
      root.classList.remove('is-demo');
      select(i);
    });
  });

  // 자동 루프: 선택 값을 순서대로 켜고 끈다
  var autoI = 0;
  var autoSeq = [0, 1, 2, 3, 0, 1, 2, 3];
  function autoStep() {
    if (root.classList.contains('is-demo')) {
      select(autoSeq[autoI % autoSeq.length]);
    }
    autoI++;
    setTimeout(autoStep, AUTO_SELECT_MS);
  }
  setTimeout(autoStep, AUTO_SELECT_MS);
})();

import { useEffect, useRef } from "react";
import styles from "./TableRowSelectHighlight.module.scss";

type Box<T> = { current: T };

export default function TableRowSelectHighlight() {
  const rootRef = useRef(null) as unknown as Box<HTMLTableElement | null>;

  useEffect(() => {
    const root = rootRef.current;
    if (!root) return;
    const rows = [0, 1, 2, 3].map((i) => root.querySelector(`.${styles["row" + i]}`) as HTMLElement | null);
    if (rows.some((el) => !el)) return;

    // 상수: 스프링 강성(k) · 감쇠(d) · 프레임당 시간 스텝 · 자동 루프 간격
    const REDUCE = !!(window.matchMedia && window.matchMedia("(prefers-reduced-motion: reduce)").matches);
    const K = REDUCE ? 1 : 0.26;
    const D = REDUCE ? 1 : 0.62;
    const DT = 1;
    const AUTO_SELECT_MS = 550;

    const selected = [false, false, false, false];
    const pos = [0, 0, 0, 0];
    const vel = [0, 0, 0, 0];
    let stopped = false;
    let rafId = 0;
    let autoTimer = 0;

    function baseColor() { return [35, 31, 40]; }
    function hiColor() { return [10, 79, 232]; }

    function tick() {
      if (stopped) return;
      for (let i = 0; i < 4; i++) {
        const target = selected[i] ? 1 : 0;
        const acc = -K * (pos[i] - target) - D * vel[i];
        vel[i] += acc * DT;
        pos[i] += vel[i] * DT;
        const clampedForColor = Math.max(0, Math.min(1, pos[i]));
        const over = Math.max(0, pos[i] - 1);
        const b = baseColor(), h = hiColor();
        const r = b[0] + (h[0] - b[0]) * clampedForColor;
        const g = b[1] + (h[1] - b[1]) * clampedForColor;
        const bl = b[2] + (h[2] - b[2]) * clampedForColor;
        rows[i]!.style.background = "rgb(" + r.toFixed(0) + "," + g.toFixed(0) + "," + bl.toFixed(0) + ")";
        rows[i]!.style.boxShadow = over > 0.001 ? ("inset 0 0 0 " + (over * 6).toFixed(1) + "px rgba(255,255,255," + Math.min(0.6, over).toFixed(2) + ")") : "none";
      }
      rafId = requestAnimationFrame(tick);
    }
    rafId = requestAnimationFrame(tick);

    function select(i: number) {
      selected[i] = !selected[i];
    }

    const cleanups: Array<() => void> = [];
    rows.forEach((el, i) => {
      function onClick() {
        root!.classList.remove(styles["is-demo"]);
        select(i);
      }
      el!.addEventListener("click", onClick);
      cleanups.push(() => el!.removeEventListener("click", onClick));
    });

    let autoI = 0;
    const autoSeq = [0, 1, 2, 3, 0, 1, 2, 3];
    function autoStep() {
      if (stopped) return;
      if (root!.classList.contains(styles["is-demo"])) {
        select(autoSeq[autoI % autoSeq.length]);
      }
      autoI++;
      autoTimer = window.setTimeout(autoStep, AUTO_SELECT_MS);
    }
    autoTimer = window.setTimeout(autoStep, AUTO_SELECT_MS);

    return () => {
      stopped = true;
      cancelAnimationFrame(rafId);
      window.clearTimeout(autoTimer);
      cleanups.forEach((fn) => fn());
    };
  }, []);

  return (
    <table ref={rootRef} className={`${styles.stage} ${styles.tsh} ${styles["is-demo"]}`}>
      <tbody>
        <tr className={`${styles.row} ${styles.row0}`}><td className={styles.cell}>항목 A</td><td className={`${styles.cell} ${styles.cellNum}`}>14</td></tr>
        <tr className={`${styles.row} ${styles.row1}`}><td className={styles.cell}>항목 B</td><td className={`${styles.cell} ${styles.cellNum}`}>27</td></tr>
        <tr className={`${styles.row} ${styles.row2}`}><td className={styles.cell}>항목 C</td><td className={`${styles.cell} ${styles.cellNum}`}>9</td></tr>
        <tr className={`${styles.row} ${styles.row3}`}><td className={styles.cell}>항목 D</td><td className={`${styles.cell} ${styles.cellNum}`}>31</td></tr>
      </tbody>
    </table>
  );
}