02不確定ダッシュ切替 — 下位項目が一部だけ選択されると上位ボックスの表示値がダッシュ形状に変わる方式

<main class="stage">
<div class="cbi is-demo" id="cbi">
  <label class="cbi__row cbi__row--parent">
    <input type="checkbox" class="cbi__input" id="cbiParent">
    <span class="cbi__box" id="cbiParentBox" aria-hidden="true">
      <svg class="cbi__svg" viewBox="0 0 20 20" width="14" height="14">
        <path class="cbi__check" d="M4 10.5l3.5 3.5L16 5.5" fill="none" stroke="currentColor" stroke-width="2.6" stroke-linecap="round" stroke-linejoin="round"/>
        <line class="cbi__dash" x1="5" y1="10" x2="15" y2="10" stroke="currentColor" stroke-width="2.6" stroke-linecap="round"/>
      </svg>
    </span>
    <span class="cbi__text">通知を全選択</span>
  </label>
  <div class="cbi__children">
    <label class="cbi__row">
      <input type="checkbox" class="cbi__input" id="cbiChild0">
      <span class="cbi__box" id="cbiChildBox0" aria-hidden="true">
        <svg class="cbi__svg" viewBox="0 0 20 20" width="12" height="12">
          <path class="cbi__check" d="M4 10.5l3.5 3.5L16 5.5" fill="none" stroke="currentColor" stroke-width="2.6" stroke-linecap="round" stroke-linejoin="round"/>
        </svg>
      </span>
      <span class="cbi__text">メール通知</span>
    </label>
    <label class="cbi__row">
      <input type="checkbox" class="cbi__input" id="cbiChild1">
      <span class="cbi__box" id="cbiChildBox1" aria-hidden="true">
        <svg class="cbi__svg" viewBox="0 0 20 20" width="12" height="12">
          <path class="cbi__check" d="M4 10.5l3.5 3.5L16 5.5" fill="none" stroke="currentColor" stroke-width="2.6" stroke-linecap="round" stroke-linejoin="round"/>
        </svg>
      </span>
      <span class="cbi__text">SMS通知</span>
    </label>
    <label class="cbi__row">
      <input type="checkbox" class="cbi__input" id="cbiChild2">
      <span class="cbi__box" id="cbiChildBox2" aria-hidden="true">
        <svg class="cbi__svg" viewBox="0 0 20 20" width="12" height="12">
          <path class="cbi__check" d="M4 10.5l3.5 3.5L16 5.5" fill="none" stroke="currentColor" stroke-width="2.6" stroke-linecap="round" stroke-linejoin="round"/>
        </svg>
      </span>
      <span class="cbi__text">プッシュ通知</span>
    </label>
  </div>
</div>
</main>

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

// 계산 겹: index.html paintParent() 가 자식 선택 개수 ÷ 전체 개수로 선택 비율 값을 만들고,
// 그 값을 --cbi-alpha 로 사영해 부모 박스 배경의 실제 투명도를 만든다 — 체크·빈칸 두 상태만
// 있는 on/off 토글이 아니라 비율 값이 배경 진하기를 연속으로 결정한다.
@include stage($stage-yellow);

.cbi {
  display: grid;
  gap: $sp-3;
  width: 100%;
  max-width: 260px;
}

.cbi__row {
  display: flex;
  align-items: center;
  gap: $sp-3;
  cursor: pointer;
  user-select: none;
}

.cbi__row--parent {
  padding-bottom: $sp-2;
  border-bottom: 1px solid rgba($subject-ink, .18);
}

.cbi__children {
  display: grid;
  gap: $sp-2;
  padding-left: $sp-6;
}

.cbi__input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.cbi__box {
  --cbi-alpha: 0;
  flex: 0 0 auto;
  width: 22px;
  height: 22px;
  border-radius: $r-sm;
  border: 2px solid rgba($subject-ink, .4);
  background: rgba(#{red($subject-blue)}, #{green($subject-blue)}, #{blue($subject-blue)}, var(--cbi-alpha));
  color: $subject-cream;
  display: grid;
  place-items: center;
  box-sizing: border-box;
  transition: border-color $dur-quick $ease-out, background-color $dur-quick $ease-out;
}

.cbi__row--parent .cbi__box {
  width: 24px;
  height: 24px;
}

.cbi__check, .cbi__dash {
  opacity: 0;
  transition: opacity $dur-quick $ease-out;
}

.cbi__box--on {
  border-color: $subject-blue;
  .cbi__check { opacity: 1; }
}

.cbi__box--mixed {
  border-color: $subject-blue;
  .cbi__dash { opacity: 1; }
}

.cbi__input:focus-visible + .cbi__box {
  outline: 2px solid $subject-blue-light;
  outline-offset: 2px;
}

.cbi__text {
  color: $subject-ink;
  font-size: 13px;
  font-weight: 600;
}

.cbi__row--parent .cbi__text {
  font-size: 14px;
  font-weight: 700;
}

@media (max-width: 340px) {
  .cbi__children { padding-left: $sp-4; }
  .cbi__text { font-size: 12px; }
}

@media (prefers-reduced-motion: reduce) {
  .cbi__box, .cbi__check, .cbi__dash { transition: none; }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffd23f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.cbi {
  display: grid;
  gap: 12px;
  width: 100%;
  max-width: 260px;
}

.cbi__row {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  user-select: none;
}

.cbi__row--parent {
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(23, 20, 26, 0.18);
}

.cbi__children {
  display: grid;
  gap: 8px;
  padding-left: 24px;
}

.cbi__input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.cbi__box {
  --cbi-alpha: 0;
  flex: 0 0 auto;
  width: 22px;
  height: 22px;
  border-radius: 8px;
  border: 2px solid rgba(23, 20, 26, 0.4);
  background: rgba(47, 109, 246, var(--cbi-alpha));
  color: #fff7e6;
  display: grid;
  place-items: center;
  box-sizing: border-box;
  transition: border-color 220ms ease-out, background-color 220ms ease-out;
}

.cbi__row--parent .cbi__box {
  width: 24px;
  height: 24px;
}

.cbi__check, .cbi__dash {
  opacity: 0;
  transition: opacity 220ms ease-out;
}

.cbi__box--on {
  border-color: #2f6df6;
}
.cbi__box--on .cbi__check {
  opacity: 1;
}

.cbi__box--mixed {
  border-color: #2f6df6;
}
.cbi__box--mixed .cbi__dash {
  opacity: 1;
}

.cbi__input:focus-visible + .cbi__box {
  outline: 2px solid #5b8cf8;
  outline-offset: 2px;
}

.cbi__text {
  color: #17141a;
  font-size: 13px;
  font-weight: 600;
}

.cbi__row--parent .cbi__text {
  font-size: 14px;
  font-weight: 700;
}

@media (max-width: 340px) {
  .cbi__children {
    padding-left: 16px;
  }
  .cbi__text {
    font-size: 12px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .cbi__box, .cbi__check, .cbi__dash {
    transition: none;
  }
}

(function () {
  var MIX_ALPHA = .22; // 계산 겹 상수: 자식이 0개 선택됐을 때도 남기는 최소 배경 알파
  var CYCLE_MS = 520; // 자동 루프가 자식 하나씩 상태를 바꾸는 간격
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

  var root = document.getElementById('cbi');
  var parent = document.getElementById('cbiParent');
  var parentBox = document.getElementById('cbiParentBox');
  var children = [
    document.getElementById('cbiChild0'),
    document.getElementById('cbiChild1'),
    document.getElementById('cbiChild2')
  ];
  var childBoxes = [
    document.getElementById('cbiChildBox0'),
    document.getElementById('cbiChildBox1'),
    document.getElementById('cbiChildBox2')
  ];

  var isDemo = true;

  function human() {
    if (isDemo) { root.classList.remove('is-demo'); isDemo = false; }
  }

  function paintChildren() {
    children.forEach(function (c, i) { childBoxes[i].classList.toggle('cbi__box--on', c.checked); });
  }

  function paintParent() {
    paintChildren();
    var checkedCount = children.filter(function (c) { return c.checked; }).length;
    var ratio = checkedCount / children.length; // 계산 겹: 선택 비율 값
    var all = ratio === 1, none = ratio === 0;
    parent.checked = all;
    parent.indeterminate = !all && !none;
    parentBox.classList.toggle('cbi__box--on', all);
    parentBox.classList.toggle('cbi__box--mixed', !all && !none);
    // 계산 겹: 선택 비율을 배경 알파로 직접 사영한다(MIX_ALPHA 를 바닥으로 두고 남은 폭을 ratio 만큼 채움)
    var alpha = none ? 0 : (MIX_ALPHA + (1 - MIX_ALPHA) * ratio);
    parentBox.style.setProperty('--cbi-alpha', alpha.toFixed(3));
  }

  function setChild(idx, val) {
    children[idx].checked = val;
    paintParent();
  }

  children.forEach(function (c) {
    c.addEventListener('change', function () { human(); paintParent(); });
  });

  parent.addEventListener('change', function () {
    human();
    var next = parent.checked;
    children.forEach(function (c) { c.checked = next; });
    paintParent();
  });

  // 자동 루프: 자식을 하나씩 켜서 없음 → 부분 → 전체를 보여주고, 다시 하나씩 끈다
  var SEQ = [
    [false, false, false], [true, false, false], [true, true, false], [true, true, true],
    [true, true, false], [true, false, false], [false, false, false]
  ];
  var si = 0;
  var autoTimer = null;

  function autoTick() {
    var state = SEQ[si];
    children.forEach(function (c, i) { c.checked = state[i]; });
    paintParent();
    si = (si + 1) % SEQ.length;
  }

  if (!reduce) { autoTimer = setInterval(autoTick, CYCLE_MS); autoTick(); }
  else { autoTick(); }
})();

// IndeterminateDash — vanilla 판(run/368/demo/02-custom-checkbox-indeterminate-dash/index.html) 의 React 포트.
// 자식 선택 비율(ratio)을 계산해 네이티브 indeterminate 값과 배경 알파(--cbi-alpha)를 함께 만든다.
import { useEffect, useRef } from "react";
import styles from "./IndeterminateDash.module.scss";

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

const CHILDREN = [
  { id: "child0", label: "이메일 알림" },
  { id: "child1", label: "문자 알림" },
  { id: "child2", label: "푸시 알림" },
];

export default function IndeterminateDash() {
  const rootRef = useRef(null) as unknown as Box<HTMLDivElement>;
  const parentRef = useRef(null) as unknown as Box<HTMLInputElement>;
  const parentBoxRef = useRef(null) as unknown as Box<HTMLSpanElement>;
  const childRefs = useRef([null, null, null]) as unknown as Box<(HTMLInputElement | null)[]>;
  const childBoxRefs = useRef([null, null, null]) as unknown as Box<(HTMLSpanElement | null)[]>;
  const timerRef = useRef(0) as unknown as Box<number>;

  useEffect(() => {
    const MIX_ALPHA = 0.22; // 계산 겹 상수: 자식이 0개 선택됐을 때도 남기는 최소 배경 알파
    const CYCLE_MS = 520; // 자동 루프가 자식 하나씩 상태를 바꾸는 간격
    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;

    const root = rootRef.current;
    const parent = parentRef.current;
    const parentBox = parentBoxRef.current;
    const children = childRefs.current;
    const childBoxes = childBoxRefs.current;
    if (!root || !parent || !parentBox) return;

    let isDemo = true;

    function human() {
      if (isDemo) { root!.classList.remove(styles.isDemo); isDemo = false; }
    }

    function paintChildren() {
      children.forEach((c, i) => { childBoxes[i]?.classList.toggle(styles.boxOn, c ? c.checked : false); });
    }

    function paintParent() {
      paintChildren();
      const checkedCount = children.filter((c) => c?.checked).length;
      const ratio = checkedCount / children.length; // 계산 겹: 선택 비율 값
      const all = ratio === 1, none = ratio === 0;
      parent!.checked = all;
      parent!.indeterminate = !all && !none;
      parentBox!.classList.toggle(styles.boxOn, all);
      parentBox!.classList.toggle(styles.boxMixed, !all && !none);
      // 계산 겹: 선택 비율을 배경 알파로 직접 사영한다(MIX_ALPHA 를 바닥으로 두고 남은 폭을 ratio 만큼 채움)
      const alpha = none ? 0 : (MIX_ALPHA + (1 - MIX_ALPHA) * ratio);
      parentBox!.style.setProperty("--cbi-alpha", alpha.toFixed(3));
    }

    const childHandlers = children.map((c) => {
      const fn = () => { human(); paintParent(); };
      c?.addEventListener("change", fn);
      return fn;
    });

    function onParentChange() {
      human();
      const next = parent!.checked;
      children.forEach((c) => { if (c) c.checked = next; });
      paintParent();
    }
    parent.addEventListener("change", onParentChange);

    const SEQ = [
      [false, false, false], [true, false, false], [true, true, false], [true, true, true],
      [true, true, false], [true, false, false], [false, false, false],
    ];
    let si = 0;

    function autoTick() {
      const state = SEQ[si];
      children.forEach((c, i) => { if (c) c.checked = state[i]; });
      paintParent();
      si = (si + 1) % SEQ.length;
    }

    if (!reduce) { timerRef.current = window.setInterval(autoTick, CYCLE_MS); autoTick(); }
    else { autoTick(); }

    return () => {
      children.forEach((c, i) => c?.removeEventListener("change", childHandlers[i]));
      parent.removeEventListener("change", onParentChange);
      window.clearInterval(timerRef.current);
    };
  }, []);

  return (
    <main className={styles.stage}>
      <div className={styles.cbi + " " + styles.isDemo} ref={rootRef}>
        <label className={styles.cbiRow + " " + styles.cbiRowParent}>
          <input type="checkbox" className={styles.cbiInput} ref={parentRef} />
          <span className={styles.cbiBox} ref={parentBoxRef} aria-hidden="true">
            <svg className={styles.cbiSvg} viewBox="0 0 20 20" width={14} height={14}>
              <path className={styles.cbiCheck} d="M4 10.5l3.5 3.5L16 5.5" fill="none" stroke="currentColor" strokeWidth={2.6} strokeLinecap="round" strokeLinejoin="round" />
              <line className={styles.cbiDash} x1={5} y1={10} x2={15} y2={10} stroke="currentColor" strokeWidth={2.6} strokeLinecap="round" />
            </svg>
          </span>
          <span className={styles.cbiText}>알림 전체 선택</span>
        </label>
        <div className={styles.cbiChildren}>
          {CHILDREN.map((c, i) => (
            <label className={styles.cbiRow} key={c.id}>
              <input
                type="checkbox"
                className={styles.cbiInput}
                ref={(el: HTMLInputElement | null) => { childRefs.current[i] = el; }}
              />
              <span
                className={styles.cbiBox}
                ref={(el: HTMLSpanElement | null) => { childBoxRefs.current[i] = el; }}
                aria-hidden="true"
              >
                <svg className={styles.cbiSvg} viewBox="0 0 20 20" width={12} height={12}>
                  <path className={styles.cbiCheck} d="M4 10.5l3.5 3.5L16 5.5" fill="none" stroke="currentColor" strokeWidth={2.6} strokeLinecap="round" strokeLinejoin="round" />
                </svg>
              </span>
              <span className={styles.cbiText}>{c.label}</span>
            </label>
          ))}
        </div>
      </div>
    </main>
  );
}