01Parallel multi-file progress values — each file's progress value updates independently within a list while several downloads run at once

<main class="stage">
<div class="dmf is-demo" id="dmf">
  <div class="dmf__row" data-i="0">
    <div class="dmf__head"><span class="dmf__name">File 1</span><span class="dmf__pct" id="dmfPct0">0%</span></div>
    <div class="dmf__track"><div class="dmf__fill" id="dmfFill0"></div></div>
  </div>
  <div class="dmf__row" data-i="1">
    <div class="dmf__head"><span class="dmf__name">File 2</span><span class="dmf__pct" id="dmfPct1">0%</span></div>
    <div class="dmf__track"><div class="dmf__fill" id="dmfFill1"></div></div>
  </div>
  <div class="dmf__row" data-i="2">
    <div class="dmf__head"><span class="dmf__name">File 3</span><span class="dmf__pct" id="dmfPct2">0%</span></div>
    <div class="dmf__track"><div class="dmf__fill" id="dmfFill2"></div></div>
  </div>
  <div class="dmf__row dmf__row--total">
    <div class="dmf__head"><span class="dmf__name">Total</span><span class="dmf__pct" id="dmfPctT">0%</span></div>
    <div class="dmf__track"><div class="dmf__fill dmf__fill--total" id="dmfFillT"></div></div>
  </div>
  <button class="dmf__btn" id="dmfBtn" type="button">Pause</button>
</div>
</main>

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

// 계산 겹: 전체 바 = 파일별 바이트 합 ÷ 크기 합(용량 가중 평균) — index.html 참조
@include stage($stage-ink);

.dmf {
  width: 100%;
  max-width: 240px;
  display: grid;
  gap: $sp-2;
}

.dmf__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  font: 600 12px/1.2 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: $subject-cream;
  margin-bottom: $sp-1;
}

.dmf__pct { font-variant-numeric: tabular-nums; color: rgba($subject-cream, .72); }

.dmf__track {
  width: 100%;
  height: $sp-2;
  border-radius: $r-pill;
  background: rgba($subject-cream, .16);
  overflow: hidden;
}

.dmf__fill {
  height: 100%;
  width: 100%;
  transform-origin: left center;
  transform: scaleX(0);
  border-radius: $r-pill;
  background: $subject-blue-light;
  transition: transform $dur-instant linear;
}

.dmf__row--total { margin-top: $sp-1; }
.dmf__row--total .dmf__fill--total { background: $subject-lilac; }
.dmf--done .dmf__row--total .dmf__fill--total { background: $subject-mint; }

.dmf__btn {
  margin-top: $sp-2;
  width: 100%;
  border: 0;
  border-radius: $r-control;
  padding: $sp-2 $sp-4;
  background: $subject-cream;
  color: $stage-ink;
  font: 700 12px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  cursor: pointer;
  transition: transform $dur-instant $ease-out;

  &:active { transform: scale(.96); }
}

@media (max-width: 340px) {
  .dmf { max-width: 200px; gap: $sp-1; }
  .dmf__row--total { margin-top: 0; }
  .dmf__btn { margin-top: $sp-1; padding: $sp-1 $sp-3; }
}

@media (prefers-reduced-motion: reduce) {
  .dmf__fill { transition: none; }
  .dmf__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);
}

.dmf {
  width: 100%;
  max-width: 240px;
  display: grid;
  gap: 8px;
}

.dmf__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  font: 600 12px/1.2 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: #fff7e6;
  margin-bottom: 4px;
}

.dmf__pct {
  font-variant-numeric: tabular-nums;
  color: rgba(255, 247, 230, 0.72);
}

.dmf__track {
  width: 100%;
  height: 8px;
  border-radius: 999px;
  background: rgba(255, 247, 230, 0.16);
  overflow: hidden;
}

.dmf__fill {
  height: 100%;
  width: 100%;
  transform-origin: left center;
  transform: scaleX(0);
  border-radius: 999px;
  background: #5b8cf8;
  transition: transform 140ms linear;
}

.dmf__row--total {
  margin-top: 4px;
}

.dmf__row--total .dmf__fill--total {
  background: #b9a0ff;
}

.dmf--done .dmf__row--total .dmf__fill--total {
  background: #4cd4a6;
}

.dmf__btn {
  margin-top: 8px;
  width: 100%;
  border: 0;
  border-radius: 12px;
  padding: 8px 16px;
  background: #fff7e6;
  color: #17141a;
  font: 700 12px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  cursor: pointer;
  transition: transform 140ms ease-out;
}
.dmf__btn:active {
  transform: scale(0.96);
}

@media (max-width: 340px) {
  .dmf {
    max-width: 200px;
    gap: 4px;
  }
  .dmf__row--total {
    margin-top: 0;
  }
  .dmf__btn {
    margin-top: 4px;
    padding: 4px 12px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .dmf__fill {
    transition: none;
  }
  .dmf__btn {
    transition: none;
  }
}

(function () {
  var root = document.getElementById('dmf');
  var btn = document.getElementById('dmfBtn');
  var fills = [document.getElementById('dmfFill0'), document.getElementById('dmfFill1'), document.getElementById('dmfFill2')];
  var pcts = [document.getElementById('dmfPct0'), document.getElementById('dmfPct1'), document.getElementById('dmfPct2')];
  var fillT = document.getElementById('dmfFillT');
  var pctT = document.getElementById('dmfPctT');

  // 시드 고정: 파일별 크기(KB, 가상)와 틱마다 더할 속도 배열(KB/틱). 실 fetch·File API 0
  var SIZES = [420, 980, 640];
  var SPEEDS = [
    [32, 40, 48, 52, 46, 38, 30, 44, 56, 60, 50, 36],
    [58, 64, 60, 52, 44, 38, 46, 54, 62, 58, 48, 40],
    [20, 26, 32, 38, 44, 40, 34, 28, 24, 30, 36, 42]
  ];
  var TICK_MS = 140;
  var HOLD_MS = 700;

  var done = [0, 0, 0];
  var tick = 0;
  var paused = false;
  var timer = null;

  // 계산 겹: Total In progress 값 = 파일별 다운로드 바이트 합 ÷ Total 크기 합(용량 가중 평균, 단순 3칸 평균 아님)
  function overall() {
    var d = done[0] + done[1] + done[2];
    var s = SIZES[0] + SIZES[1] + SIZES[2];
    return d / s;
  }

  function paint() {
    for (var i = 0; i < 3; i++) {
      var p = done[i] / SIZES[i];
      fills[i].style.transform = 'scaleX(' + p.toFixed(3) + ')';
      pcts[i].textContent = Math.round(p * 100) + '%';
    }
    var o = overall();
    fillT.style.transform = 'scaleX(' + o.toFixed(3) + ')';
    pctT.textContent = Math.round(o * 100) + '%';
    root.classList.toggle('dmf--done', o >= 1);
  }

  function step() {
    var allDone = true;
    for (var i = 0; i < 3; i++) {
      if (done[i] < SIZES[i]) {
        done[i] = Math.min(SIZES[i], done[i] + SPEEDS[i][tick % SPEEDS[i].length]);
        allDone = false;
      }
    }
    tick++;
    paint();
    if (allDone) {
      timer = setTimeout(function () { done = [0, 0, 0]; tick = 0; paint(); loop(); }, HOLD_MS);
    } else {
      loop();
    }
  }

  function loop() {
    if (paused) return;
    timer = setTimeout(step, TICK_MS);
  }

  paint();
  loop();

  btn.addEventListener('click', function () {
    root.classList.remove('is-demo');
    paused = !paused;
    btn.textContent = paused ? 'Resume' : 'Pause';
    if (!paused) loop();
    else if (timer) clearTimeout(timer);
  });
})();

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

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

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

  useEffect(() => {
    const root = rootRef.current;
    if (!root) return;
    const fills = [0, 1, 2].map((i) => root.querySelector(`.${styles["fill" + i]}`) as HTMLElement | null);
    const pcts = [0, 1, 2].map((i) => root.querySelector(`.${styles["pct" + i]}`) as HTMLElement | null);
    const fillT = root.querySelector(`.${styles.fillT}`) as HTMLElement | null;
    const pctT = root.querySelector(`.${styles.pctT}`) as HTMLElement | null;
    const btn = root.querySelector(`.${styles.btn}`) as HTMLElement | null;
    if (!fillT || !pctT || !btn) return;

    // 시드 고정: 파일별 크기(KB, 가상)와 틱마다 더할 속도 배열(KB/틱). 실 fetch·File API 0
    const SIZES = [420, 980, 640];
    const SPEEDS = [
      [32, 40, 48, 52, 46, 38, 30, 44, 56, 60, 50, 36],
      [58, 64, 60, 52, 44, 38, 46, 54, 62, 58, 48, 40],
      [20, 26, 32, 38, 44, 40, 34, 28, 24, 30, 36, 42],
    ];
    const TICK_MS = 140;
    const HOLD_MS = 700;

    let done = [0, 0, 0];
    let tick = 0;
    let paused = false;
    let timer = 0;
    let stopped = false;

    // 계산 겹: 전체 진행 값 = 파일별 다운로드 바이트 합 ÷ 전체 크기 합(용량 가중 평균, 단순 3칸 평균 아님)
    function overall() {
      const d = done[0] + done[1] + done[2];
      const s = SIZES[0] + SIZES[1] + SIZES[2];
      return d / s;
    }

    function paint() {
      for (let i = 0; i < 3; i++) {
        const p = done[i] / SIZES[i];
        const fillEl = fills[i];
        const pctEl = pcts[i];
        if (fillEl) fillEl.style.transform = "scaleX(" + p.toFixed(3) + ")";
        if (pctEl) pctEl.textContent = Math.round(p * 100) + "%";
      }
      const o = overall();
      fillT!.style.transform = "scaleX(" + o.toFixed(3) + ")";
      pctT!.textContent = Math.round(o * 100) + "%";
      root!.classList.toggle(styles["dmf--done"], o >= 1);
    }

    function step() {
      if (stopped) return;
      let allDone = true;
      for (let i = 0; i < 3; i++) {
        if (done[i] < SIZES[i]) {
          done[i] = Math.min(SIZES[i], done[i] + SPEEDS[i][tick % SPEEDS[i].length]);
          allDone = false;
        }
      }
      tick++;
      paint();
      if (allDone) {
        timer = window.setTimeout(() => { done = [0, 0, 0]; tick = 0; paint(); loop(); }, HOLD_MS);
      } else {
        loop();
      }
    }

    function loop() {
      if (paused || stopped) return;
      timer = window.setTimeout(step, TICK_MS);
    }

    paint();
    loop();

    function onClick() {
      root!.classList.remove(styles["is-demo"]);
      paused = !paused;
      btn!.textContent = paused ? "재개" : "일시정지";
      if (!paused) loop();
      else window.clearTimeout(timer);
    }
    btn.addEventListener("click", onClick);

    return () => {
      stopped = true;
      window.clearTimeout(timer);
      btn.removeEventListener("click", onClick);
    };
  }, []);

  return (
    <div ref={rootRef} className={`${styles.stage} ${styles.dmf} ${styles["is-demo"]}`}>
      <div className={styles.row}>
        <div className={styles.head}><span className={styles.name}>파일 1</span><span className={`${styles.pct} ${styles.pct0}`}>0%</span></div>
        <div className={styles.track}><div className={`${styles.fill} ${styles.fill0}`} /></div>
      </div>
      <div className={styles.row}>
        <div className={styles.head}><span className={styles.name}>파일 2</span><span className={`${styles.pct} ${styles.pct1}`}>0%</span></div>
        <div className={styles.track}><div className={`${styles.fill} ${styles.fill1}`} /></div>
      </div>
      <div className={styles.row}>
        <div className={styles.head}><span className={styles.name}>파일 3</span><span className={`${styles.pct} ${styles.pct2}`}>0%</span></div>
        <div className={styles.track}><div className={`${styles.fill} ${styles.fill2}`} /></div>
      </div>
      <div className={`${styles.row} ${styles["row--total"]}`}>
        <div className={styles.head}><span className={styles.name}>전체</span><span className={`${styles.pct} ${styles.pctT}`}>0%</span></div>
        <div className={styles.track}><div className={`${styles.fill} ${styles["fill--total"]} ${styles.fillT}`} /></div>
      </div>
      <button className={styles.btn} type="button">일시정지</button>
    </div>
  );
}