a11y(dialog): ARIA-Rolle, Fokus-Falle und Fokus-Rueckgabe ergaenzt ohne Escape/Initial-Fokus zu doppeln

src/js/dialog.js

@@ -40,23 +40,30 @@ const HellionDialog = {
    */
   _show(config) {
     return new Promise(resolve => {
+      const prevFocus = document.activeElement;
       const overlay = document.createElement('div');
       overlay.className = 'dialog-overlay';
 
       const box = document.createElement('div');
       box.className = 'dialog-box';
+      box.setAttribute('role', config.isConfirm ? 'alertdialog' : 'dialog');
+      box.setAttribute('aria-modal', 'true');
+      box.setAttribute('aria-labelledby', 'dialogTitle');
+      box.setAttribute('aria-describedby', 'dialogBody');
 
       // Header
       const header = document.createElement('div');
       header.className = 'dialog-header';
       header.appendChild(this._createIcon(config.type));
       const titleSpan = document.createElement('span');
+      titleSpan.id = 'dialogTitle';
       titleSpan.textContent = config.title;
       header.appendChild(titleSpan);
 
       // Body
       const body = document.createElement('div');
       body.className = 'dialog-body';
+      body.id = 'dialogBody';
       body.textContent = config.message;
 
       // Actions
@@ -69,6 +76,7 @@ const HellionDialog = {
           overlay.classList.remove('active');
           overlay.remove();
         });
+        if (prevFocus && typeof prevFocus.focus === 'function') prevFocus.focus();
         resolve(result);
       }
 
@@ -106,6 +114,18 @@ const HellionDialog = {
           e.preventDefault();
           cleanup(config.isConfirm ? false : undefined);
         }
+        if (e.key === 'Tab') {
+          // Fokus-Falle: nur die Buttons im actions-Container sind fokussierbar
+          const items = Array.from(actions.querySelectorAll('button'));
+          if (items.length === 0) return;
+          const first = items[0];
+          const last  = items[items.length - 1];
+          if (e.shiftKey && document.activeElement === first) {
+            e.preventDefault(); last.focus();
+          } else if (!e.shiftKey && document.activeElement === last) {
+            e.preventDefault(); first.focus();
+          }
+        }
       }
       document.addEventListener('keydown', keyHandler);