simplified code across the app and consolidated duplicated helpers

lib/widget/file_viewer.dart

@@ -20,7 +20,7 @@ import '../utils/screen_bound_image.dart';
 import 'app_progress_indicator.dart';
 import 'async_action_button.dart';
 import 'centered_leading.dart';
-import 'confirm_dialog.dart';
+import 'downloads/stale_download_guard.dart';
 import 'file_viewer/code_line.dart';
 import 'file_viewer/deferred_pdf_viewer.dart';
 import 'file_viewer/file_kind.dart';
@@ -54,15 +54,20 @@ class _FileViewerState extends State<FileViewer> {
   Future<_TextPayload>? _textPayload;
   final PhotoViewController photoViewController = PhotoViewController();
 
-  late SettingsCubit settings = context.read<SettingsCubit>();
   late bool openExternal;
   Future<FileKind>? _fileKind;
 
+  String get _fileName => widget.path.split('/').last;
+
   @override
   void initState() {
     super.initState();
     openExternal =
-        settings.val().fileViewSettings.alwaysOpenExternally ||
+        context
+            .read<SettingsCubit>()
+            .val()
+            .fileViewSettings
+            .alwaysOpenExternally ||
         widget.openExternal;
     if (openExternal) {
       WidgetsBinding.instance.addPostFrameCallback(
@@ -93,31 +98,23 @@ class _FileViewerState extends State<FileViewer> {
   bool _ensureLocalFile() {
     if (File(widget.path).existsSync()) return true;
     final remote = widget.remoteFile;
-    if (remote == null) {
-      InfoDialog.show(
-        context,
-        'Die Datei wurde vom System aus dem Zwischenspeicher entfernt. Bitte lade sie erneut herunter.',
-        title: 'Datei nicht mehr verfügbar',
-      );
-      return false;
-    }
-    ConfirmDialog(
-      title: 'Datei nicht mehr verfügbar',
-      content:
-          'Die Datei wurde vom System aus dem Zwischenspeicher entfernt.\nErneut herunterladen?',
-      confirmButton: 'Herunterladen',
-      onConfirm: () {
-        // Pop the viewer before starting so the fresh download auto-opens.
-        Navigator.of(context).pop();
-        unawaited(
-          DownloadManager.instance.start(
-            remotePath: remote.path,
-            name: remote.name,
-            remoteFile: remote,
-          ),
-        );
-      },
-    ).asDialog(context);
+    showFileGoneDialog(
+      context,
+      subject: 'Die Datei',
+      onRedownload: remote == null
+          ? null
+          : () {
+              // Pop the viewer before starting so the fresh download auto-opens.
+              Navigator.of(context).pop();
+              unawaited(
+                DownloadManager.instance.start(
+                  remotePath: remote.path,
+                  name: remote.name,
+                  remoteFile: remote,
+                ),
+              );
+            },
+    );
     return false;
   }
 
@@ -172,7 +169,7 @@ class _FileViewerState extends State<FileViewer> {
           }
           final bytes = await source.readAsBytes();
           final saved = await FilePicker.saveFile(
-            fileName: widget.path.split('/').last,
+            fileName: _fileName,
             bytes: bytes,
           );
           if (!mounted) return;
@@ -226,7 +223,7 @@ class _FileViewerState extends State<FileViewer> {
     List<Widget> actions = const [],
     bool showActionsMenu = true,
   }) => AppBar(
-    title: Text(widget.path.split('/').last),
+    title: Text(_fileName),
     actions: [
       ...actions,
       if (showActionsMenu)
@@ -253,7 +250,7 @@ class _FileViewerState extends State<FileViewer> {
   Widget build(BuildContext context) {
     if (openExternal) {
       return Scaffold(
-        appBar: AppBar(title: Text(widget.path.split('/').last)),
+        appBar: _appbar(showActionsMenu: false),
         body: const Center(child: AppProgressIndicator.large()),
       );
     }
@@ -347,21 +344,17 @@ class _FileViewerState extends State<FileViewer> {
 
   Widget _buildAudioView() => Scaffold(
     appBar: _appbar(),
-    body: MediaPlayer(
-      path: widget.path,
-      isAudio: true,
-      filename: widget.path.split('/').last,
-    ),
+    body: MediaPlayer(path: widget.path, isAudio: true, filename: _fileName),
   );
 
   Widget _buildTextView() => Scaffold(
     appBar: _appbar(),
     body: FutureBuilder<_TextPayload>(
       // Cached: a future created in build re-read the file on every rebuild.
-      future: _textPayload ??= compute(
-        _loadTextPayload,
-        (widget.path, _textViewMaxBytes),
-      ),
+      future: _textPayload ??= compute(_loadTextPayload, (
+        widget.path,
+        _textViewMaxBytes,
+      )),
       builder: (context, snapshot) {
         if (!snapshot.hasData) {
           return const Center(child: AppProgressIndicator.large());
@@ -428,7 +421,7 @@ class _FileViewerState extends State<FileViewer> {
               UnknownPreviewBlock(remoteFile: widget.remoteFile),
               const SizedBox(height: 16),
               Text(
-                widget.path.split('/').last,
+                _fileName,
                 style: theme.textTheme.titleSmall?.copyWith(
                   fontWeight: FontWeight.w600,
                 ),