feat: complete TASK-WP4-06 accessibility

2026-08-03 15:23:17 +08:00
parent d09fda13c5
commit a1b82ecdc4
9 changed files with 428 additions and 30 deletions
@@ -0,0 +1,56 @@
+import { useLayoutEffect, useRef, type RefObject } from "react";
+
+const focusableSelector = [
+  "a[href]", "button:not([disabled])", "input:not([disabled])", "select:not([disabled])", "textarea:not([disabled])",
+  '[tabindex]:not([tabindex="-1"])',
+].join(",");
+
+function focusableElements(dialog: HTMLElement) {
+  return [...dialog.querySelectorAll<HTMLElement>(focusableSelector)].filter((element) => !element.hidden && element.getClientRects().length > 0);
+}
+
+export function useDialogFocus(onClose: () => void): RefObject<HTMLElement | null> {
+  const dialogRef = useRef<HTMLElement>(null);
+  const onCloseRef = useRef(onClose);
+  onCloseRef.current = onClose;
+
+  useLayoutEffect(() => {
+    const dialog = dialogRef.current;
+    if (!dialog) return undefined;
+    const returnTarget = document.activeElement instanceof HTMLElement ? document.activeElement : null;
+    const initial = dialog.querySelector<HTMLElement>("[data-dialog-initial-focus]") ?? focusableElements(dialog)[0] ?? dialog;
+    initial.focus();
+
+    const handleKeyDown = (event: globalThis.KeyboardEvent) => {
+      if (event.key === "Escape") {
+        event.preventDefault();
+        event.stopPropagation();
+        onCloseRef.current();
+        return;
+      }
+      if (event.key !== "Tab") return;
+      const focusable = focusableElements(dialog);
+      if (focusable.length === 0) {
+        event.preventDefault();
+        dialog.focus();
+        return;
+      }
+      const first = focusable[0]!;
+      const last = focusable.at(-1)!;
+      if (event.shiftKey && (document.activeElement === first || !dialog.contains(document.activeElement))) {
+        event.preventDefault();
+        last.focus();
+      } else if (!event.shiftKey && (document.activeElement === last || !dialog.contains(document.activeElement))) {
+        event.preventDefault();
+        first.focus();
+      }
+    };
+    document.addEventListener("keydown", handleKeyDown, true);
+    return () => {
+      document.removeEventListener("keydown", handleKeyDown, true);
+      if (returnTarget?.isConnected) returnTarget.focus();
+    };
+  }, []);
+
+  return dialogRef;
+}