拖拽排序

<div class="motion-demo motion-demo--drag-to-reorder" data-motion="drag-to-reorder" aria-label="拖拽排序 示例">
  <div><ul class="motion-list" role="listbox" aria-label="按住并拖动排序；键盘用户按空格键拾取，再用上下方向键移动。" data-reorder-list><li class="motion-list-item" role="option" tabindex="0" aria-grabbed="false" data-reorder-item data-pickup-label="已拾取项目，使用上下方向键移动，空格键放下" data-drop-label="项目已移动" data-move-label="项目位置" data-cancel-label="操作已取消">拖动项目 A</li><li class="motion-list-item" role="option" tabindex="0" aria-grabbed="false" data-reorder-item data-pickup-label="已拾取项目，使用上下方向键移动，空格键放下" data-drop-label="项目已移动" data-move-label="项目位置" data-cancel-label="操作已取消">拖动项目 B</li><li class="motion-list-item" role="option" tabindex="0" aria-grabbed="false" data-reorder-item data-pickup-label="已拾取项目，使用上下方向键移动，空格键放下" data-drop-label="项目已移动" data-move-label="项目位置" data-cancel-label="操作已取消">拖动项目 C</li></ul><span class="motion-status" data-motion-status role="status" aria-live="assertive"></span></div>
</div>

.motion-demo.motion-demo--drag-to-reorder {
  box-sizing: border-box;
  position: relative;
  display: grid;
  place-items: center;
  width: min(100%, 34rem);
  min-height: 15rem;
  padding: 2rem;
  overflow: hidden;
  color: #18181b;
  background: #fafafa;
  border: 1px solid #e4e4e7;
  border-radius: 16px;
  isolation: isolate;
}

.motion-demo.motion-demo--drag-to-reorder *, .motion-demo.motion-demo--drag-to-reorder *::before, .motion-demo.motion-demo--drag-to-reorder *::after {
  box-sizing: border-box;
}

.motion-demo.motion-demo--drag-to-reorder .motion-surface {
  position: relative;
  display: grid;
  gap: 0.65rem;
  width: min(100%, 18rem);
  padding: 1.25rem;
  background: #ffffff;
  border: 1px solid #e4e4e7;
  border-radius: 16px;
  box-shadow: none;
}

.motion-demo.motion-demo--drag-to-reorder .motion-surface strong { font-weight: 500; }

.motion-demo.motion-demo--drag-to-reorder .motion-line {
  display: block;
  width: 100%;
  height: 0.5rem;
  background: #e4e4e7;
  border-radius: 999px;
}

.motion-demo.motion-demo--drag-to-reorder .motion-line:last-child { width: 62%; }

.motion-demo.motion-demo--drag-to-reorder .motion-button {
  position: relative;
  min-height: 2.75rem;
  padding: 0.75rem 1.1rem;
  color: white;
  font: inherit;
  font-weight: 700;
  background: #18181b;
  border: 0;
  border-radius: 999px;
  cursor: pointer;
}

.motion-demo.motion-demo--drag-to-reorder .motion-button:focus-visible { outline: 3px solid rgb(37 99 235 / 32%); outline-offset: 3px; }

.motion-demo.motion-demo--drag-to-reorder .motion-action-row {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 0.85rem;
}

.motion-demo.motion-demo--drag-to-reorder .motion-replay-scene {
  width: min(100%, 22rem);
  display: grid;
  place-items: center;
}

.motion-demo.motion-demo--drag-to-reorder .motion-pausable-scene {
  width: min(100%, 22rem);
  display: grid;
  place-items: center;
}

.motion-demo.motion-demo--drag-to-reorder button.motion-surface {
  color: inherit;
  font: inherit;
  text-align: start;
  cursor: pointer;
}

.motion-demo.motion-demo--drag-to-reorder .motion-replay-button,
.motion-demo.motion-demo--drag-to-reorder .motion-undo-button,
.motion-demo.motion-demo--drag-to-reorder .motion-dismiss-button,
.motion-demo.motion-demo--drag-to-reorder .motion-pause-button {
  min-height: 2.75rem;
  padding: 0.65rem 0.9rem;
  color: #18181b;
  font: 650 0.78rem/1 ui-sans-serif, system-ui, sans-serif;
  background: #ffffff;
  border: 1px solid #d4d4d8;
  border-radius: 8px;
  cursor: pointer;
}

.motion-demo.motion-demo--drag-to-reorder .motion-replay-button:focus-visible,
.motion-demo.motion-demo--drag-to-reorder .motion-undo-button:focus-visible,
.motion-demo.motion-demo--drag-to-reorder .motion-dismiss-button:focus-visible,
.motion-demo.motion-demo--drag-to-reorder .motion-pause-button:focus-visible,
.motion-demo.motion-demo--drag-to-reorder [data-reorder-item]:focus-visible,
.motion-demo.motion-demo--drag-to-reorder [data-swipe-target]:focus-visible {
  outline: 3px solid rgb(37 99 235 / 32%);
  outline-offset: 3px;
}

.motion-demo.motion-demo--drag-to-reorder .motion-status {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.motion-demo.motion-demo--drag-to-reorder .motion-ripple-ink {
  position: absolute;
  width: 12px;
  height: 12px;
  pointer-events: none;
  background: rgb(255 255 255 / 72%);
  border-radius: 50%;
  transform: translate(-50%, -50%) scale(0.95);
  opacity: 0;
}

.motion-demo.motion-demo--drag-to-reorder .motion-state-stack { position: relative; width: min(100%, 18rem); height: 9rem; }
.motion-demo.motion-demo--drag-to-reorder .motion-state { position: absolute; inset: 0; display: grid; place-items: center; padding: 1rem; background: #ffffff; border: 1px solid #e4e4e7; border-radius: 16px; }
.motion-demo.motion-demo--drag-to-reorder .motion-state--to { background: #18181b; color: white; }

.motion-demo.motion-demo--drag-to-reorder .motion-scroll-track > span { color: #71717a; font: 600 0.72rem/1.2 ui-monospace, monospace; letter-spacing: 0.08em; text-transform: uppercase; }
.motion-demo.motion-demo--drag-to-reorder .motion-orbit-item { display: grid; place-items: center; width: 2.5rem; height: 2.5rem; color: white; background: #2563eb; border-radius: 50%; }
.motion-demo.motion-demo--drag-to-reorder .motion-text-stack { position: relative; width: min(100%, 18rem); min-height: 4rem; }
.motion-demo.motion-demo--drag-to-reorder svg { width: min(100%, 20rem); height: auto; }

.motion-demo.motion-demo--drag-to-reorder .motion-list { display: grid; gap: 0.5rem; width: min(100%, 18rem); margin: 0; padding: 0; list-style: none; }
.motion-demo.motion-demo--drag-to-reorder .motion-list-item { position: relative; padding: 0.85rem 1rem; touch-action: none; cursor: grab; background: #ffffff; border: 1px solid #e4e4e7; border-radius: 16px; }
.motion-demo.motion-demo--drag-to-reorder .motion-list-item.is-dragging { cursor: grabbing; border-color: #2563eb; background: rgb(37 99 235 / 8%); box-shadow: none; }
.motion-demo.motion-demo--drag-to-reorder .motion-list-item.is-drop-target { border-color: #2563eb; background: rgb(37 99 235 / 8%); box-shadow: none; }
.motion-demo.motion-demo--drag-to-reorder .motion-list-item.is-keyboard-dragging { outline: 3px solid rgb(37 99 235 / 32%); outline-offset: 3px; }
.motion-demo.motion-demo--drag-to-reorder .motion-drop-placeholder { min-height: 2.75rem; border: 1px dashed #2563eb; border-radius: 16px; background: rgb(37 99 235 / 8%); }

@keyframes motion-drag-to-reorder-reduced-fade {
  from { opacity: 0.84; }
  to { opacity: 1; }
}

.force-reduced-motion .motion-demo.motion-demo--drag-to-reorder {
  animation: motion-drag-to-reorder-reduced-fade 160ms cubic-bezier(0.23, 1, 0.32, 1) both !important;
}

.force-reduced-motion .motion-demo.motion-demo--drag-to-reorder *,
.force-reduced-motion .motion-demo.motion-demo--drag-to-reorder *::before,
.force-reduced-motion .motion-demo.motion-demo--drag-to-reorder *::after {
  animation: none !important;
  animation-delay: 0ms !important;
  animation-iteration-count: 1 !important;
  transition-property: opacity, color, background-color, border-color !important;
  transition-duration: 160ms !important;
  transition-delay: 0ms !important;
  scroll-behavior: auto !important;
}

.force-reduced-motion .motion-demo.motion-demo--drag-to-reorder .motion-button,
.force-reduced-motion .motion-demo.motion-demo--drag-to-reorder [data-reorder-item],
.force-reduced-motion .motion-demo.motion-demo--drag-to-reorder [data-swipe-target],
.force-reduced-motion .motion-demo.motion-demo--drag-to-reorder [data-spring-target] {
  transform: none !important;
}

.force-reduced-motion .motion-demo.motion-demo--drag-to-reorder .motion-path { stroke-dashoffset: 0 !important; }
.force-reduced-motion .motion-demo.motion-demo--drag-to-reorder .motion-word--from { opacity: 0 !important; visibility: hidden; }
.force-reduced-motion .motion-demo.motion-demo--drag-to-reorder .motion-word:not(.motion-word--from) { opacity: 1 !important; filter: none !important; transform: none !important; }

@media (prefers-reduced-motion: reduce) {
  .motion-demo.motion-demo--drag-to-reorder {
    animation: motion-drag-to-reorder-reduced-fade 160ms cubic-bezier(0.23, 1, 0.32, 1) both !important;
  }

  .motion-demo.motion-demo--drag-to-reorder *, .motion-demo.motion-demo--drag-to-reorder *::before, .motion-demo.motion-demo--drag-to-reorder *::after {
    animation: none !important;
    animation-delay: 0ms !important;
    animation-iteration-count: 1 !important;
    transition-property: opacity, color, background-color, border-color !important;
    transition-duration: 160ms !important;
    transition-delay: 0ms !important;
    scroll-behavior: auto !important;
  }

  .motion-demo.motion-demo--drag-to-reorder .motion-button,
  .motion-demo.motion-demo--drag-to-reorder [data-reorder-item],
  .motion-demo.motion-demo--drag-to-reorder [data-swipe-target],
  .motion-demo.motion-demo--drag-to-reorder [data-spring-target] {
    transform: none !important;
  }

  .motion-demo.motion-demo--drag-to-reorder .motion-path { stroke-dashoffset: 0 !important; }
  .motion-demo.motion-demo--drag-to-reorder .motion-word--from { opacity: 0 !important; visibility: hidden; }
  .motion-demo.motion-demo--drag-to-reorder .motion-word:not(.motion-word--from) { opacity: 1 !important; filter: none !important; transform: none !important; }
}

(() => {
  const config = {
  "id": "drag-to-reorder",
  "duration": 180,
  "distance": 48,
  "resistance": 65,
  "position": 50,
  "stiffness": 220,
  "damping": 24,
  "mass": 1,
  "velocity": 0,
  "rippleSize": 220,
  "rippleOpacity": 24,
  "dragScale": 103,
  "autoplay": false
};
  const mount = (root, config) => {

    const cleanups = [];
    const addCleanup = (callback) => cleanups.push(callback);
    const cleanup = () => {
      for (let index = cleanups.length - 1; index >= 0; index -= 1) {
        try { cleanups[index](); } catch { /* keep cleanup reentrant */ }
      }
      cleanups.length = 0;
    };
    const on = (target, type, listener, options) => {
      target.addEventListener(type, listener, options);
      addCleanup(() => target.removeEventListener(type, listener, options));
    };
    const reduced = () => root.closest(".force-reduced-motion") !== null ||
      window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    const watchReduced = (callback) => {
      const media = window.matchMedia("(prefers-reduced-motion: reduce)");
      const notify = () => callback(reduced());
      media.addEventListener("change", notify);
      const observer = typeof MutationObserver === "undefined" ? null : new MutationObserver(notify);
      let ancestor = root;
      while (observer && ancestor) {
        observer.observe(ancestor, { attributes: true, attributeFilter: ["class"] });
        ancestor = ancestor.parentElement;
      }
      addCleanup(() => {
        media.removeEventListener("change", notify);
        if (observer) observer.disconnect();
      });
    };

    const list = root.querySelector("[data-reorder-list]");
    const status = root.querySelector("[data-motion-status]");
    if (!list) return cleanup;
    const items = Array.from(list.querySelectorAll("[data-reorder-item]"));
    const initialStatus = status ? status.textContent : "";
    const animations = new Set();
    let pointerId = null;
    let activeItem = null;
    let placeholder = null;
    let originalNext = null;
    let dropTarget = null;
    let startX = 0;
    let startY = 0;
    let keyboardItem = null;
    let keyboardStart = -1;
    const announce = (message) => { if (status) status.textContent = message; };
    const resetStyles = (item) => {
      item.classList.remove("is-dragging");
      ["position", "inset", "width", "height", "zIndex", "pointerEvents", "transform", "opacity"].forEach((property) => {
        item.style[property] = "";
      });
    };
    const clearTarget = () => {
      if (dropTarget) dropTarget.classList.remove("is-drop-target");
      dropTarget = null;
    };
    const finish = (cancelled) => {
      if (pointerId === null || !activeItem || !placeholder) return;
      if (root.hasPointerCapture(pointerId)) root.releasePointerCapture(pointerId);
      const item = activeItem;
      const from = item.getBoundingClientRect();
      if (cancelled) list.insertBefore(placeholder, originalNext);
      placeholder.replaceWith(item);
      resetStyles(item);
      const to = item.getBoundingClientRect();
      if (cancelled) {
        announce(item.dataset.cancelLabel || "Move cancelled");
      } else {
        const animation = item.animate(
          [
            { transform: "translate3d(" + String(from.left - to.left) + "px, " + String(from.top - to.top) + "px, 0)", opacity: 0.94 },
            { transform: "translate3d(0, 0, 0)", opacity: 1 }
          ],
          { duration: Math.min(180, config.duration || 180), easing: "cubic-bezier(0.23, 1, 0.32, 1)" }
        );
        animations.add(animation);
        const forget = () => animations.delete(animation);
        animation.addEventListener("finish", forget, { once: true });
        animation.addEventListener("cancel", forget, { once: true });
        announce(item.dataset.dropLabel || "Item moved");
        item.dispatchEvent(new CustomEvent("motion:reorder", {
          bubbles: true,
          detail: { order: Array.from(list.querySelectorAll("[data-reorder-item]")).indexOf(item) }
        }));
      }
      clearTarget();
      pointerId = null;
      activeItem = null;
      placeholder = null;
      originalNext = null;
      item.focus();
    };
    const canonical = () => {
      animations.forEach((animation) => animation.cancel());
      clearTarget();
      if (activeItem && placeholder) {
        if (pointerId !== null && root.hasPointerCapture(pointerId)) root.releasePointerCapture(pointerId);
        list.insertBefore(placeholder, originalNext);
        placeholder.replaceWith(activeItem);
        resetStyles(activeItem);
      }
      if (keyboardItem && keyboardStart >= 0) {
        const siblings = Array.from(list.querySelectorAll("[data-reorder-item]")).filter((item) => item !== keyboardItem);
        list.insertBefore(keyboardItem, siblings[keyboardStart] || null);
      }
      items.forEach((item) => {
        resetStyles(item);
        item.classList.remove("is-drop-target", "is-keyboard-dragging");
        item.setAttribute("aria-grabbed", "false");
      });
      if (placeholder) placeholder.remove();
      pointerId = null;
      activeItem = null;
      placeholder = null;
      originalNext = null;
      keyboardItem = null;
      keyboardStart = -1;
      if (status) status.textContent = initialStatus || "";
    };
    addCleanup(canonical);
    const pointerDown = (event) => {
      if (!event.isPrimary || event.button !== 0 || pointerId !== null) return;
      const item = event.currentTarget;
      const rect = item.getBoundingClientRect();
      pointerId = event.pointerId;
      activeItem = item;
      originalNext = item.nextSibling;
      startX = event.clientX;
      startY = event.clientY;
      placeholder = document.createElement("li");
      placeholder.className = "motion-drop-placeholder";
      placeholder.setAttribute("aria-hidden", "true");
      placeholder.style.height = String(rect.height) + "px";
      list.insertBefore(placeholder, item);
      root.append(item);
      item.classList.add("is-dragging");
      Object.assign(item.style, {
        position: "fixed",
        inset: String(rect.top) + "px auto auto " + String(rect.left) + "px",
        width: String(rect.width) + "px",
        height: String(rect.height) + "px",
        zIndex: "10",
        pointerEvents: "none",
        opacity: "0.94",
        transform: "translate3d(0, 0, 0)"
      });
      root.setPointerCapture(event.pointerId);
      announce(item.dataset.pickupLabel || "Item picked up");
    };
    const pointerMove = (event) => {
      if (event.pointerId !== pointerId || !activeItem || !placeholder) return;
      const dx = event.clientX - startX;
      const dy = event.clientY - startY;
      activeItem.style.transform = "translate3d(" + String(dx) + "px, " + String(dy) + "px, 0) scale(" + String(Math.max(1, config.dragScale / 100)) + ")";
      const element = document.elementFromPoint(event.clientX, event.clientY);
      const candidate = element ? element.closest("[data-reorder-item]") : null;
      if (!candidate || candidate === activeItem || candidate.parentElement !== list) return;
      clearTarget();
      dropTarget = candidate;
      candidate.classList.add("is-drop-target");
      const rect = candidate.getBoundingClientRect();
      list.insertBefore(placeholder, event.clientY < rect.top + rect.height / 2 ? candidate : candidate.nextSibling);
    };
    const pointerUp = (event) => { if (event.pointerId === pointerId) finish(false); };
    const pointerCancel = (event) => { if (event.pointerId === pointerId) finish(true); };
    const rootKeyDown = (event) => {
      if (event.key === "Escape" && pointerId !== null) { event.preventDefault(); finish(true); }
    };
    const itemKeyDown = (event) => {
      const item = event.currentTarget;
      if (event.key === " " || event.key === "Enter") {
        event.preventDefault();
        if (keyboardItem === item) {
          item.classList.remove("is-keyboard-dragging");
          item.setAttribute("aria-grabbed", "false");
          announce(item.dataset.dropLabel || "Item moved");
          keyboardItem = null;
          keyboardStart = -1;
        } else if (!keyboardItem) {
          keyboardItem = item;
          keyboardStart = Array.from(list.querySelectorAll("[data-reorder-item]")).indexOf(item);
          item.classList.add("is-keyboard-dragging");
          item.setAttribute("aria-grabbed", "true");
          announce(item.dataset.pickupLabel || "Item picked up");
        }
        return;
      }
      if (keyboardItem !== item) return;
      if (event.key === "Escape") {
        event.preventDefault();
        const siblings = Array.from(list.querySelectorAll("[data-reorder-item]")).filter((candidate) => candidate !== item);
        list.insertBefore(item, siblings[keyboardStart] || null);
        item.classList.remove("is-keyboard-dragging");
        item.setAttribute("aria-grabbed", "false");
        announce(item.dataset.cancelLabel || "Move cancelled");
        keyboardItem = null;
        keyboardStart = -1;
        return;
      }
      if (event.key !== "ArrowUp" && event.key !== "ArrowDown") return;
      event.preventDefault();
      const siblings = Array.from(list.querySelectorAll("[data-reorder-item]"));
      const index = siblings.indexOf(item);
      const next = event.key === "ArrowUp" ? index - 1 : index + 1;
      if (next < 0 || next >= siblings.length) return;
      list.insertBefore(item, event.key === "ArrowUp" ? siblings[next] : siblings[next].nextSibling);
      announce(item.dataset.moveLabel || "Position " + String(next + 1));
    };
    items.forEach((item) => {
      on(item, "pointerdown", pointerDown);
      on(item, "keydown", itemKeyDown);
    });
    on(root, "pointermove", pointerMove);
    on(root, "pointerup", pointerUp);
    on(root, "pointercancel", pointerCancel);
    on(root.ownerDocument, "keydown", rootKeyDown);
    return cleanup;
  };
  document.querySelectorAll("[data-motion=\"drag-to-reorder\"]").forEach((root) => {
    const cleanupKey = "__motionLexiconCleanup";
    if (typeof root[cleanupKey] === "function") root[cleanupKey]();
    root[cleanupKey] = mount(root, config);
  });
})();