add PromptDialog helper for text input dialogs

lib/view/pages/files/widgets/add_file_menu.dart

@@ -1,10 +1,10 @@
 import 'package:flutter/material.dart';
 
 import '../../../../state/app/modules/files/bloc/files_bloc.dart';
-import '../../../../widget/async_action_button.dart';
 import '../../../../widget/demo_restricted.dart';
 import '../../../../widget/details_bottom_sheet.dart';
 import '../../../../widget/file_pick.dart';
+import '../../../../widget/prompt_dialog.dart';
 
 /// Opens the "Element hinzufügen" sheet (create folder, upload, take photo, …).
 /// [onPickedFiles] receives selected/captured file paths (gallery, file picker
@@ -59,27 +59,15 @@ void showAddFileSheet(
 }
 
 void showCreateFolderDialog(BuildContext context, FilesBloc bloc) {
-  final inputController = TextEditingController();
-  showDialog(
-    context: context,
-    builder: (dialogCtx) => AlertDialog(
-      title: const Text('Neuer Ordner'),
-      content: TextField(
-        controller: inputController,
-        decoration: const InputDecoration(labelText: 'Name'),
-        autofocus: true,
-      ),
-      actions: [
-        AsyncDialogAction(
-          confirmLabel: 'Ordner erstellen',
-          onConfirm: () async {
-            if (inputController.text.trim().isEmpty) {
-              throw Exception('Bitte einen Namen eingeben.');
-            }
-            await bloc.createFolder(inputController.text.trim());
-          },
-        ),
-      ],
-    ),
+  showPromptDialog(
+    context,
+    title: 'Neuer Ordner',
+    confirmButton: 'Ordner erstellen',
+    onConfirm: (name) async {
+      if (name.isEmpty) {
+        throw Exception('Bitte einen Namen eingeben.');
+      }
+      await bloc.createFolder(name);
+    },
   );
 }

lib/view/pages/files/widgets/file_element.dart

@@ -19,6 +19,7 @@ import '../../../../widget/demo_restricted.dart';
 import '../../../../widget/details_bottom_sheet.dart';
 import '../../../../widget/downloads/download_trigger.dart';
 import '../../../../widget/info_dialog.dart';
+import '../../../../widget/prompt_dialog.dart';
 import '../../talk/widgets/highlighted_linkify.dart';
 import '../sharing/share_sheet.dart';
 import 'file_details_sheet.dart';
@@ -136,52 +137,30 @@ class _FileElementState extends State<FileElement>
   String _joinPath(String folder, String name, {required bool isDirectory}) =>
       isDirectory ? '$folder$name/' : '$folder$name';
 
-  Future<void> _rename() async {
+  void _rename() {
     if (guardDemoAction(context)) return;
-    final controller = TextEditingController(text: widget.file.name);
-    try {
-      final newName = await showDialog<String>(
-        context: context,
-        builder: (dialogCtx) => AlertDialog(
-          title: const Text('Umbenennen'),
-          content: TextField(
-            controller: controller,
-            decoration: const InputDecoration(labelText: 'Neuer Name'),
-            autofocus: true,
-          ),
-          actions: [
-            TextButton(
-              onPressed: () => Navigator.of(dialogCtx).pop(),
-              child: const Text('Abbrechen'),
-            ),
-            TextButton(
-              onPressed: () =>
-                  Navigator.of(dialogCtx).pop(controller.text.trim()),
-              child: const Text('Umbenennen'),
-            ),
-          ],
-        ),
-      );
-      if (newName == null || newName.isEmpty || newName == widget.file.name) {
-        return;
-      }
-
-      final parent = _parentPathOf(widget.file.path);
-      final destination = _joinPath(
-        parent,
-        newName,
-        isDirectory: widget.file.isDirectory,
-      );
-      await _runWebdavOp(() async {
+    showPromptDialog(
+      context,
+      title: 'Umbenennen',
+      label: 'Neuer Name',
+      confirmButton: 'Umbenennen',
+      initialValue: widget.file.name,
+      onConfirm: (newName) async {
+        if (newName.isEmpty || newName == widget.file.name) return;
+        final parent = _parentPathOf(widget.file.path);
+        final destination = _joinPath(
+          parent,
+          newName,
+          isDirectory: widget.file.isDirectory,
+        );
         final webdav = await WebdavApi.webdav;
         await webdav.move(
           PathUri.parse(widget.file.path),
           PathUri.parse(destination),
         );
-      }, errorTitle: 'Umbenennen fehlgeschlagen');
-    } finally {
-      controller.dispose();
-    }
+        widget.refetch();
+      },
+    );
   }
 
   void _putOnClipboard({required bool copy}) {
@@ -218,19 +197,6 @@ class _FileElementState extends State<FileElement>
     );
   }
 
-  Future<void> _runWebdavOp(
-    Future<void> Function() action, {
-    required String errorTitle,
-  }) async {
-    try {
-      await action();
-      widget.refetch();
-    } on Object catch (e) {
-      if (!mounted) return;
-      InfoDialog.show(context, e.toString(), title: errorTitle, copyable: true);
-    }
-  }
-
   void _showActionSheet() {
     Haptics.longPress();
     showDetailsBottomSheet(

lib/widget/prompt_dialog.dart

@@ -0,0 +1,37 @@
+import 'package:flutter/material.dart';
+
+import 'async_action_button.dart';
+
+/// Single-line text-input dialog. The confirm action runs [onConfirm] with the
+/// trimmed input via [AsyncDialogAction], so it shows a spinner and an inline
+/// error and only closes on success. Throw inside [onConfirm] to keep the
+/// dialog open with a message (e.g. for empty or duplicate input).
+void showPromptDialog(
+  BuildContext context, {
+  required String title,
+  required String confirmButton,
+  required Future<void> Function(String value) onConfirm,
+  String label = 'Name',
+  String initialValue = '',
+  AsyncErrorBuilder? errorBuilder,
+}) {
+  final controller = TextEditingController(text: initialValue);
+  showDialog(
+    context: context,
+    builder: (dialogCtx) => AlertDialog(
+      title: Text(title),
+      content: TextField(
+        controller: controller,
+        decoration: InputDecoration(labelText: label),
+        autofocus: true,
+      ),
+      actions: [
+        AsyncDialogAction(
+          confirmLabel: confirmButton,
+          onConfirm: () => onConfirm(controller.text.trim()),
+          errorBuilder: errorBuilder,
+        ),
+      ],
+    ),
+  ).whenComplete(controller.dispose);
+}