iter: d28 drawer 焦点陷阱（Tab/Shift+Tab 回绕、关闭归还焦点）

.ua/index.json

@@ -1,6 +1,6 @@
 {
   "$schema": "ui-arch-registry-index/0.1",
-  "generatedAt": "2026-10-23T09:10:27.467Z",
+  "generatedAt": "2026-10-23T09:11:22.226Z",
   "repoRoot": ".",
   "packages": [
     {

packages/skin/ui/src/drawer.ts

@@ -1,7 +1,7 @@
 import { effect, h } from '@ui-arch/frame';
 import type { DrawerProps } from './types.js';
 
-/*** 抽屉：open 信号驱动侧滑面板，点遮罩 / × / Esc 关闭；与 modal 的分工是不打断主视图、可从侧边保留上下文 ***/
+/*** 抽屉：open 信号驱动侧滑面板，点遮罩 / × / Esc 关闭；Tab 焦点陷阱 + 关闭归还焦点，与 modal 的分工是不打断主视图、可从侧边保留上下文 ***/
 export function drawer(props: DrawerProps, ...children: unknown[]): HTMLElement {
   const close = (): void => {
     if (!props.open()) return; // 卫语句：已关闭不重复触发回调
@@ -28,9 +28,30 @@ export function drawer(props: DrawerProps, ...children: unknown[]): HTMLElement
   );
   overlay.append(panel);
 
+  let lastFocus: HTMLElement | null = null; // 打开前焦点宿主，关闭时归还
+  const focusables = (): HTMLElement[] =>
+    Array.from(panel.querySelectorAll<HTMLElement>('button, [href], input, select, textarea, [tabindex]:not([tabindex="-1"])'))
+      .filter((el) => !el.hasAttribute('disabled')); // 面板内可聚焦元素（排除禁用）
   effect(() => {
-    if (!props.open()) return;
-    (panel.querySelector('button, input, textarea') as HTMLElement | null)?.focus(); // 打开时聚焦首个可交互元素
+    if (props.open()) {
+      lastFocus = document.activeElement as HTMLElement | null; // 记录打开前焦点
+      (panel.querySelector('button, input, textarea') as HTMLElement | null)?.focus(); // 打开时聚焦首个可交互元素
+    } else if (lastFocus) {
+      lastFocus.focus(); // 关闭时归还焦点
+      lastFocus = null;
+    }
+  });
+  overlay.addEventListener('keydown', (e: KeyboardEvent) => {
+    if (e.key !== 'Tab' || !props.open()) return; // 仅处理打开中的 Tab
+    const els = focusables();
+    if (els.length === 0) { e.preventDefault(); return; } // 无可聚焦元素：拦截 Tab 防焦点逃逸
+    const first = els[0];
+    const last = els[els.length - 1];
+    if (e.shiftKey && (document.activeElement === first || !panel.contains(document.activeElement))) {
+      e.preventDefault(); last.focus(); // Shift+Tab 到首位时回绕到末尾
+    } else if (!e.shiftKey && (document.activeElement === last || !panel.contains(document.activeElement))) {
+      e.preventDefault(); first.focus(); // Tab 到末位时回绕到开头
+    }
   });
   document.addEventListener('keydown', (e: KeyboardEvent) => {
     if (e.key === 'Escape' && props.open()) close();