T23: Add modal keyboard accessibility (Escape, focus trap, ARIA) and dropdown outside-click/Escape close

frontend/src/components/PrintPreview/PrintPreview.tsx

@@ -1,4 +1,4 @@
-import React, { useState, useMemo, useCallback } from 'react';
+import React, { useState, useMemo, useCallback, useRef, useEffect } from 'react';
 import type { YjsDocument } from '../../crdt/YjsDocument';
 import {
   preparePrint,
@@ -21,10 +21,16 @@ interface PrintPreviewProps {
 const PAGE_SIZES: PageSize[] = ['a4', 'a3', 'a2', 'a1'];
 const SCALE_PRESETS: ScalePreset[] = ['1:50', '1:100', '1:200', 'custom'];
 
+const FOCUSABLE_SELECTOR =
+  'button:not([disabled]), [href], input:not([disabled]), select:not([disabled]), textarea:not([disabled]), [tabindex]:not([tabindex="-1"])';
+
 const PrintPreview: React.FC<PrintPreviewProps> = ({ yjsDoc, onClose }) => {
   const [settings, setSettings] = useState<PrintSettings>({ ...DEFAULT_PRINT_SETTINGS });
   const [currentPage, setCurrentPage] = useState(0);
 
+  const modalRef = useRef<HTMLDivElement>(null);
+  const previouslyFocusedRef = useRef<HTMLElement | null>(null);
+
   const printResult: PrintResult | null = useMemo(() => {
     const doc = yjsDoc?.current;
     if (!doc) return null;
@@ -49,12 +55,70 @@ const PrintPreview: React.FC<PrintPreviewProps> = ({ yjsDoc, onClose }) => {
     }
   }, [printResult]);
 
+  // Keyboard accessibility: Escape to close, focus trap, focus management
+  useEffect(() => {
+    // Store the element that had focus before the modal opened
+    previouslyFocusedRef.current = document.activeElement as HTMLElement;
+
+    // Focus the first focusable element in the modal
+    const modal = modalRef.current;
+    if (modal) {
+      const focusable = modal.querySelectorAll<HTMLElement>(FOCUSABLE_SELECTOR);
+      if (focusable.length > 0) {
+        focusable[0].focus();
+      } else {
+        modal.focus();
+      }
+    }
+
+    const handleKeyDown = (e: KeyboardEvent) => {
+      if (e.key === 'Escape') {
+        e.preventDefault();
+        onClose();
+        return;
+      }
+
+      if (e.key === 'Tab') {
+        const modalEl = modalRef.current;
+        if (!modalEl) return;
+
+        const focusableElements = modalEl.querySelectorAll<HTMLElement>(FOCUSABLE_SELECTOR);
+        if (focusableElements.length === 0) return;
+
+        const first = focusableElements[0];
+        const last = focusableElements[focusableElements.length - 1];
+
+        if (e.shiftKey) {
+          if (document.activeElement === first || !modalEl.contains(document.activeElement)) {
+            e.preventDefault();
+            last.focus();
+          }
+        } else {
+          if (document.activeElement === last || !modalEl.contains(document.activeElement)) {
+            e.preventDefault();
+            first.focus();
+          }
+        }
+      }
+    };
+
+    document.addEventListener('keydown', handleKeyDown);
+
+    return () => {
+      document.removeEventListener('keydown', handleKeyDown);
+      // Restore focus to the trigger element
+      if (previouslyFocusedRef.current) {
+        previouslyFocusedRef.current.focus();
+      }
+    };
+  }, [onClose]);
+
   if (!printResult) {
     return (
-      <div className="print-preview-overlay" role="dialog" aria-modal="true" aria-label="Print Preview">
+      <div className="print-preview-overlay" ref={modalRef} role="dialog" aria-modal="true" aria-labelledby="print-preview-title" tabIndex={-1}>
         <div className="print-preview-modal">
           <div className="print-preview-header">
-            <h2>Druckvorschau</h2>
+            <h2 id="print-preview-title">Druckvorschau</h2>
             <button className="print-preview-close" onClick={onClose} aria-label="Close">✕</button>
           </div>
           <div className="print-preview-empty">Kein Dokument verfügbar.</div>
@@ -68,11 +132,11 @@ const PrintPreview: React.FC<PrintPreviewProps> = ({ yjsDoc, onClose }) => {
   const previewUrl = page ? svgToDataUrl(page.svg) : '';
 
   return (
-    <div className="print-preview-overlay" role="dialog" aria-modal="true" aria-label="Print Preview">
+    <div className="print-preview-overlay" ref={modalRef} role="dialog" aria-modal="true" aria-labelledby="print-preview-title" tabIndex={-1}>
       <div className="print-preview-modal">
         {/* Header */}
         <div className="print-preview-header">
-          <h2>Druckvorschau</h2>
+          <h2 id="print-preview-title">Druckvorschau</h2>
           <button className="print-preview-close" onClick={onClose} aria-label="Close">✕</button>
         </div>
 
@@ -265,7 +329,7 @@ const PrintPreview: React.FC<PrintPreviewProps> = ({ yjsDoc, onClose }) => {
                         key={i}
                         className={`print-preview-grid-cell ${i === currentPage ? 'active' : ''}`}
                         onClick={() => setCurrentPage(i)}
-                        title={`Seite ${i + 1} (Spalte ${p.col + 1}, Zeile ${p.row + 1})}`}
+                        title={`Seite ${i + 1} (Spalte ${p.col + 1}, Zeile ${p.row + 1})`}
                       >
                         {i + 1}
                       </button>