better loading indicators for timetables, talk and files

lib/view/pages/files/fileElement.dart

@@ -1,5 +1,6 @@
 import 'dart:io';
 
+import 'package:dio/dio.dart';
 import 'package:filesize/filesize.dart';
 import 'package:flowder/flowder.dart';
 import 'package:flutter/foundation.dart';
@@ -12,6 +13,7 @@ import 'package:path_provider/path_provider.dart';
 
 import '../../../api/marianumcloud/webdav/queries/listFiles/cacheableFile.dart';
 import '../../../api/marianumcloud/webdav/webdavApi.dart';
+import '../../../model/accountData.dart';
 import '../../../model/endpointData.dart';
 import '../../../widget/centeredLeading.dart';
 import '../../../widget/confirmDialog.dart';
@@ -41,6 +43,7 @@ class FileElement extends StatefulWidget {
       file: File(local),
       progress: ProgressImplementation(),
       deleteOnCancel: true,
+      client: Dio(BaseOptions(headers: AccountData().authHeaders())),
       onDone: () {
         //Future<OpenResult> result = OpenFile.open(local); // TODO legacy - refactor: remove onDone parameter
         Navigator.of(context).push(MaterialPageRoute(builder: (context) => FileViewer(path: local)));
@@ -52,7 +55,7 @@ class FileElement extends StatefulWidget {
     );
 
     return await Flowder.download(
-      '${await WebdavApi.webdavConnectString}$encodedPath',
+      '${WebdavApi.buildWebdavUrl()}$encodedPath',
       options,
     );
   }

lib/view/pages/files/files.dart

@@ -164,9 +164,9 @@ class _FilesViewState extends State<_FilesView> {
         child: const Icon(Icons.add),
       ),
       body: LoadableStateConsumer<FilesBloc, FilesState>(
+        isReady: (state) => state.listing != null,
         child: (state, _) {
-          final listing = state.listing;
-          if (listing == null) return const SizedBox.shrink();
+          final listing = state.listing!;
           if (listing.files.isEmpty) {
             return const PlaceholderView(icon: Icons.folder_off_rounded, text: 'Der Ordner ist leer');
           }