added support for simultan downloads in files and talk, support for background downloads, enhanced loading in files with retry

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

@@ -10,12 +10,13 @@ import '../../../../model/endpoint_data.dart';
 import '../../../../routing/app_routes.dart';
 import '../../../../share_intent/remote_file_ref.dart';
 import '../../../../state/app/modules/nextcloud_capabilities/bloc/nextcloud_capabilities_cubit.dart';
-import '../../../../utils/download_manager.dart';
+import '../../../../utils/downloads/download_job.dart';
 import '../../../../utils/file_clipboard.dart';
 import '../../../../utils/haptics.dart';
 import '../../../../widget/centered_leading.dart';
 import '../../../../widget/confirm_dialog.dart';
 import '../../../../widget/details_bottom_sheet.dart';
+import '../../../../widget/downloads/download_trigger.dart';
 import '../../../../widget/info_dialog.dart';
 import '../../talk/widgets/highlighted_linkify.dart';
 import '../sharing/share_sheet.dart';
@@ -43,101 +44,32 @@ class FileElement extends StatefulWidget {
   State<FileElement> createState() => _FileElementState();
 }
 
-class _FileElementState extends State<FileElement> {
-  DownloadJob? _job;
+class _FileElementState extends State<FileElement>
+    with DownloadTrigger<FileElement> {
+  @override
+  String? get downloadRemotePath =>
+      widget.file.isDirectory ? null : widget.file.path;
 
   @override
   void initState() {
     super.initState();
-    _attachJob(DownloadManager.instance.jobFor(widget.file.path));
+    initDownloadTrigger();
   }
 
   @override
   void didUpdateWidget(covariant FileElement oldWidget) {
     super.didUpdateWidget(oldWidget);
-    if (oldWidget.file.path != widget.file.path) {
-      _detachJob();
-      _attachJob(DownloadManager.instance.jobFor(widget.file.path));
-    }
+    if (oldWidget.file.path != widget.file.path) refreshDownloadTrigger();
   }
 
   @override
   void dispose() {
-    _detachJob();
+    disposeDownloadTrigger();
     super.dispose();
   }
 
-  void _attachJob(DownloadJob? job) {
-    _job = job;
-    if (job == null) return;
-    job.status.addListener(_onStatusChange);
-    if (job.isFinished) {
-      WidgetsBinding.instance.addPostFrameCallback((_) => _onStatusChange());
-    }
-  }
-
-  void _detachJob() {
-    _job?.status.removeListener(_onStatusChange);
-    _job = null;
-  }
-
-  void _onStatusChange() {
-    if (!mounted) return;
-    final job = _job;
-    if (job == null) return;
-    final status = job.status.value;
-    if (status is DownloadDone) {
-      Haptics.success();
-      DownloadManager.instance.clear(widget.file.path);
-      _detachJob();
-      AppRoutes.openFileViewer(
-        context,
-        status.localPath,
-        remoteFile: RemoteFileRef.fromCacheable(widget.file),
-      );
-      setState(() {});
-    } else if (status is DownloadFailed) {
-      final message = status.message;
-      DownloadManager.instance.clear(widget.file.path);
-      _detachJob();
-      setState(() {});
-      InfoDialog.show(context, message, title: 'Download', copyable: true);
-    } else if (status is DownloadCancelled) {
-      DownloadManager.instance.clear(widget.file.path);
-      _detachJob();
-      setState(() {});
-    } else {
-      setState(() {});
-    }
-  }
-
-  Future<void> _startDownload() async {
-    final job = await DownloadManager.instance.start(
-      remotePath: widget.file.path,
-      name: widget.file.name,
-    );
-    if (!mounted) return;
-    if (_job == job) return;
-    _detachJob();
-    _attachJob(job);
-    setState(() {});
-  }
-
-  void _confirmCancel() {
-    showDialog<void>(
-      context: context,
-      builder: (dialogContext) => ConfirmDialog(
-        title: 'Download abbrechen?',
-        content: 'Möchtest du den Download abbrechen?',
-        cancelButton: 'Nein',
-        confirmButton: 'Ja, Abbrechen',
-        onConfirm: () => _job?.cancel(),
-      ),
-    );
-  }
-
   Widget? _subtitle() {
-    final status = _job?.status.value;
+    final status = downloadJob?.status.value;
     if (status is DownloadInProgress) {
       return Row(
         children: [
@@ -180,12 +112,14 @@ class _FileElementState extends State<FileElement> {
       );
       return;
     }
-    final status = _job?.status.value;
-    if (status is DownloadInProgress) {
-      _confirmCancel();
+    if (isDownloading) {
+      confirmCancelDownload();
       return;
     }
-    _startDownload();
+    startDownload(
+      name: widget.file.name,
+      remoteFile: RemoteFileRef.fromCacheable(widget.file),
+    );
   }
 
   // All paths here are relative to the WebDAV root (matching CacheableFile.path).