07Drag-and-drop file dropzone

<main class="stage">
  <div class="drop is-demo" id="drop">
    <label class="drop__zone" for="file-input" id="zone">
      <span class="drop__icon" aria-hidden="true">⬆</span>
      <span class="drop__text">Drag a file here or click to browse</span>
      <input class="drop__input" type="file" id="file-input">
    </label>
    <p class="drop__file" id="filename" aria-live="polite"></p>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-quick;    // 테두리·배경 전환 시간
$easing: $ease-out;
$color: $subject-blue;    // 드래그 중 강조 색

// ── 데모 무대 ──────────────────────────────────────────
@include stage($stage-orange);

.drop {
  box-sizing: border-box;
  width: min(280px, 86vw);
}

.drop__zone {
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: $sp-2;
  width: 100%;
  border: 2px dashed rgba(255, 255, 255, .7);
  border-radius: $r-card;
  padding: $sp-8 $sp-4;
  cursor: pointer;
  background: rgba(255, 255, 255, .12);
  transition: border-color $duration $easing, background $duration $easing, transform $duration $easing;

  &.is-over {
    border-color: $color;
    background: rgba(255, 255, 255, .28);
    transform: scale(1.02);
  }

  &:focus-within { outline: 2px solid $color; outline-offset: 3px; }
}

.drop__icon {
  font-size: 22px;
  line-height: 1;
  color: $stage-ink;
}

.drop__text {
  font-weight: 600;
  font-size: 13px;
  line-height: 1.4;
  text-align: center;
  font-family: inherit;
  color: $stage-ink;
}

.drop__input {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}

.drop__file {
  margin: $sp-2 0 0;
  min-height: 16px;
  font-weight: 600;
  font-size: 12px;
  font-family: inherit;
  color: $stage-ink;
  border-radius: $r-xs;
  display: inline-block;

  &:not(:empty) { background: $subject-cream; padding: $sp-1 $sp-2; }
}

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

.drop {
  box-sizing: border-box;
  width: min(280px, 86vw);
}

.drop__zone {
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  width: 100%;
  border: 2px dashed rgba(255, 255, 255, 0.7);
  border-radius: 16px;
  padding: 32px 16px;
  cursor: pointer;
  background: rgba(255, 255, 255, 0.12);
  transition: border-color 220ms ease-out, background 220ms ease-out, transform 220ms ease-out;
}
.drop__zone.is-over {
  border-color: #2f6df6;
  background: rgba(255, 255, 255, 0.28);
  transform: scale(1.02);
}
.drop__zone:focus-within {
  outline: 2px solid #2f6df6;
  outline-offset: 3px;
}

.drop__icon {
  font-size: 22px;
  line-height: 1;
  color: #17141a;
}

.drop__text {
  font-weight: 600;
  font-size: 13px;
  line-height: 1.4;
  text-align: center;
  font-family: inherit;
  color: #17141a;
}

.drop__input {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.drop__file {
  margin: 8px 0 0;
  min-height: 16px;
  font-weight: 600;
  font-size: 12px;
  font-family: inherit;
  color: #17141a;
  border-radius: 4px;
  display: inline-block;
}
.drop__file:not(:empty) {
  background: #fff7e6;
  padding: 4px 8px;
}

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

(function () {
  var wrap = document.getElementById('drop');
  var zone = document.getElementById('zone');
  var input = document.getElementById('file-input');
  var filename = document.getElementById('filename');

  ['dragenter', 'dragover'].forEach(function (ev) {
    zone.addEventListener(ev, function (e) { e.preventDefault(); stopDemo(); zone.classList.add('is-over'); });
  });
  ['dragleave', 'dragend'].forEach(function (ev) {
    zone.addEventListener(ev, function () { zone.classList.remove('is-over'); });
  });
  zone.addEventListener('drop', function (e) {
    e.preventDefault(); stopDemo();
    zone.classList.remove('is-over');
    var f = e.dataTransfer && e.dataTransfer.files[0];
    if (f) show(f.name);
  });
  input.addEventListener('change', function () {
    stopDemo();
    if (input.files[0]) show(input.files[0].name);
  });
  input.addEventListener('pointerdown', stopDemo);

  function show(name) { filename.textContent = 'Selected: ' + name; }

  function stopDemo() {
    if (!wrap.classList.contains('is-demo')) return;
    wrap.classList.remove('is-demo');
    clearInterval(timer);
    zone.classList.remove('is-over');
    filename.textContent = '';
  }

  var phase = 0;
  var timer = setInterval(function () {
    phase = (phase + 1) % 6;
    if (phase === 1) { zone.classList.add('is-over'); filename.textContent = ''; }
    else if (phase === 3) { zone.classList.remove('is-over'); show('design-draft.png'); }
    else if (phase === 5) { filename.textContent = ''; }
  }, 320);
})();

import { useRef, useState } from "react";
import styles from "./FileDropzone.module.scss";

export type FileDropzoneProps = {
  text?: string;
  onFile?: (file: File) => void;
};

export default function FileDropzone({
  text = "여기로 파일을 끌어다 놓거나 클릭하세요",
  onFile,
}: FileDropzoneProps) {
  const [over, setOver] = useState(false);
  const [name, setName] = useState("");
  const inputRef = useRef<HTMLInputElement | null>(null);

  const handleFile = (f?: File) => {
    if (!f) return;
    setName(f.name);
    onFile?.(f);
  };

  return (
    <div className={styles.drop}>
      <label
        className={over ? `${styles.zone} ${styles.over}` : styles.zone}
        onDragEnter={(e: any) => { e.preventDefault(); setOver(true); }}
        onDragOver={(e: any) => { e.preventDefault(); setOver(true); }}
        onDragLeave={() => setOver(false)}
        onDrop={(e: any) => {
          e.preventDefault();
          setOver(false);
          handleFile(e.dataTransfer?.files?.[0]);
        }}
      >
        <span className={styles.icon} aria-hidden="true">⬆</span>
        <span className={styles.text}>{text}</span>
        <input
          ref={inputRef}
          className={styles.input}
          type="file"
          onChange={(e: any) => handleFile(e.target.files?.[0])}
        />
      </label>
      <p className={styles.file} aria-live="polite">{name ? `선택됨: ${name}` : ""}</p>
    </div>
  );
}