implemented a comprehensive Nextcloud file sharing system with support for user, group, and public link shares with gating based on server-side permissions; added sharing management interfaces including a share sheet; updated the file list with visual badges for incoming shares and improved OCS API response handling.

lib/view/pages/files/sharing/share_options_sheet.dart

@@ -0,0 +1,299 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+
+import '../../../../api/errors/error_mapper.dart';
+import '../../../../api/marianumcloud/files_sharing/file_sharing_api.dart';
+import '../../../../api/marianumcloud/files_sharing/queries/share/share.dart';
+import '../../../../api/marianumcloud/files_sharing/queries/share/share_update_params.dart';
+import '../../../../api/marianumcloud/files_sharing/share_permissions.dart';
+import '../../../../routing/app_routes.dart';
+import '../../../../state/app/modules/nextcloud_capabilities/bloc/nextcloud_capabilities_cubit.dart';
+import '../../../../utils/clipboard_helper.dart';
+import '../../../../widget/centered_leading.dart';
+import '../../../../widget/confirm_dialog.dart';
+import '../../../../widget/details_bottom_sheet.dart';
+import '../../../../widget/info_dialog.dart';
+import 'share_password_sheet.dart';
+
+/// Two-digit zero-padded helper for building ISO `YYYY-MM-DD` strings (the
+/// format the OCS API expects for `expireDate`).
+String _two(int n) => n.toString().padLeft(2, '0');
+String _isoDate(DateTime d) => '${d.year}-${_two(d.month)}-${_two(d.day)}';
+
+IconData shareIcon(Share share) {
+  if (share.isPublicLink) return Icons.link;
+  if (share.isGroup) return Icons.groups_outlined;
+  if (share.isRoom) return Icons.chat_bubble_outline;
+  if (share.isEmail) return Icons.email_outlined;
+  return Icons.person_outline;
+}
+
+/// Opens the edit/manage sheet for a single [share]. [onChanged] fires after
+/// every successful mutation so the parent share list can refresh.
+void showShareOptionsSheet(
+  BuildContext context,
+  Share share, {
+  required VoidCallback onChanged,
+}) {
+  showDetailsBottomSheet(
+    context,
+    header: ListTile(
+      leading: CenteredLeading(Icon(shareIcon(share))),
+      title: Text(share.displayTitle),
+      subtitle: Text(share.kindLabel),
+    ),
+    children: (sheetCtx) => [
+      _ShareOptionsBody(share: share, onChanged: onChanged),
+    ],
+  );
+}
+
+class _ShareOptionsBody extends StatefulWidget {
+  final Share share;
+  final VoidCallback onChanged;
+
+  const _ShareOptionsBody({required this.share, required this.onChanged});
+
+  @override
+  State<_ShareOptionsBody> createState() => _ShareOptionsBodyState();
+}
+
+class _ShareOptionsBodyState extends State<_ShareOptionsBody> {
+  late Share _share = widget.share;
+  bool _busy = false;
+
+  Future<void> _mutate(Future<Share> Function() action) async {
+    setState(() => _busy = true);
+    try {
+      final updated = await action();
+      if (!mounted) return;
+      setState(() => _share = updated);
+      widget.onChanged();
+    } catch (e) {
+      if (mounted) {
+        InfoDialog.show(
+          context,
+          errorToUserMessage(e),
+          title: 'Fehler',
+          copyable: true,
+        );
+      }
+    } finally {
+      if (mounted) setState(() => _busy = false);
+    }
+  }
+
+  List<SharePreset> _availablePresets() => [
+    SharePreset.readOnly,
+    SharePreset.edit,
+    if (_share.isFolder) SharePreset.fileDrop,
+  ];
+
+  Future<void> _setPreset(SharePreset preset) async {
+    final caps = context.read<NextcloudCapabilitiesCubit>();
+    await _mutate(
+      () => FileSharingApi().update(
+        _share.id,
+        ShareUpdateParams(
+          permissions: permissionsFor(
+            preset,
+            allowReshare: caps.canReshare,
+            isFolder: _share.isFolder,
+          ),
+        ),
+      ),
+    );
+  }
+
+  Future<void> _pickExpiry() async {
+    final caps = context.read<NextcloudCapabilitiesCubit>();
+    final now = DateTime.now();
+    final maxDays = caps.expireDays;
+    final lastDate = maxDays != null && maxDays > 0
+        ? now.add(Duration(days: maxDays))
+        : now.add(const Duration(days: 365 * 5));
+    final picked = await showDatePicker(
+      context: context,
+      initialDate: now.add(const Duration(days: 7)),
+      firstDate: now,
+      lastDate: lastDate,
+    );
+    if (picked == null) return;
+    await _mutate(
+      () => FileSharingApi().update(
+        _share.id,
+        ShareUpdateParams(expireDate: _isoDate(picked)),
+      ),
+    );
+  }
+
+  Future<void> _clearExpiry() => _mutate(
+    () => FileSharingApi().update(
+      _share.id,
+      const ShareUpdateParams(expireDate: ''),
+    ),
+  );
+
+  Future<void> _changePassword() async {
+    final caps = context.read<NextcloudCapabilitiesCubit>();
+    final value = await promptSharePassword(
+      context,
+      isChange: _share.hasPassword,
+      policyHint: caps.passwordPolicyHint,
+    );
+    if (value == null || value.isEmpty || !mounted) return;
+    await _mutate(
+      () => FileSharingApi().update(
+        _share.id,
+        ShareUpdateParams(password: value),
+      ),
+    );
+  }
+
+  Future<void> _clearPassword() => _mutate(
+    () => FileSharingApi().update(
+      _share.id,
+      const ShareUpdateParams(password: ''),
+    ),
+  );
+
+  void _openInTalk() {
+    final token = _share.shareWith;
+    if (token == null || token.isEmpty) return;
+    AppRoutes.openChatByToken(context, token);
+    if (Navigator.of(context).canPop()) Navigator.of(context).pop();
+  }
+
+  Future<void> _confirmDelete() async {
+    // Use showDialog directly (not asDialog) so we get the AsyncDialogAction's
+    // `true` result and can close the options sheet afterwards — popping inside
+    // onConfirmAsync would target the dialog route, not the sheet.
+    final dialog = ConfirmDialog(
+      title: 'Freigabe löschen?',
+      content: 'Die Freigabe wird aufgehoben.',
+      confirmButton: 'Löschen',
+      onConfirmAsync: () => FileSharingApi().remove(_share.id),
+    );
+    final deleted = await showDialog<bool>(
+      context: context,
+      builder: dialog.build,
+    );
+    if (deleted != true || !mounted) return;
+    widget.onChanged();
+    if (Navigator.of(context).canPop()) Navigator.of(context).pop();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final caps = context.watch<NextcloudCapabilitiesCubit>();
+    final currentPreset = presetFromBitmask(_share.permissions);
+    final theme = Theme.of(context);
+
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      mainAxisSize: MainAxisSize.min,
+      children: [
+        if (_busy) const LinearProgressIndicator(),
+
+        Padding(
+          padding: const EdgeInsets.fromLTRB(16, 12, 16, 4),
+          child: Text('Berechtigung', style: theme.textTheme.labelLarge),
+        ),
+        Padding(
+          padding: const EdgeInsets.symmetric(horizontal: 16),
+          child: Wrap(
+            spacing: 8,
+            children: _availablePresets()
+                .map(
+                  (p) => ChoiceChip(
+                    label: Text(p.label),
+                    selected: currentPreset == p,
+                    onSelected: _busy ? null : (_) => _setPreset(p),
+                  ),
+                )
+                .toList(),
+          ),
+        ),
+
+        if (_share.isRoom && (_share.shareWith?.isNotEmpty ?? false)) ...[
+          const Divider(height: 24),
+          ListTile(
+            leading: const CenteredLeading(Icon(Icons.chat_bubble_outline)),
+            title: const Text('Im Talk-Chat öffnen'),
+            onTap: _busy ? null : _openInTalk,
+          ),
+        ],
+
+        if (_share.isPublicLink) ...[
+          const Divider(height: 24),
+          if (_share.url != null)
+            ListTile(
+              leading: const CenteredLeading(Icon(Icons.link_outlined)),
+              title: const Text('Öffentlicher Link'),
+              subtitle: Text(
+                _share.url!,
+                maxLines: 1,
+                overflow: TextOverflow.ellipsis,
+              ),
+              trailing: IconButton(
+                onPressed: () => copyToClipboard(context, _share.url!),
+                icon: const Icon(Icons.copy_outlined),
+              ),
+            ),
+          ListTile(
+            leading: const CenteredLeading(Icon(Icons.event_outlined)),
+            title: const Text('Ablaufdatum'),
+            subtitle: Text(_share.expiration ?? 'Kein Ablaufdatum'),
+            trailing: _share.expiration != null && !caps.expireEnforced
+                ? IconButton(
+                    icon: const Icon(Icons.clear),
+                    tooltip: 'Ablaufdatum entfernen',
+                    onPressed: _busy ? null : _clearExpiry,
+                  )
+                : null,
+            onTap: _busy ? null : _pickExpiry,
+          ),
+          ListTile(
+            leading: CenteredLeading(
+              Icon(
+                _share.hasPassword
+                    ? Icons.lock_outline
+                    : Icons.lock_open_outlined,
+              ),
+            ),
+            title: Text(
+              _share.hasPassword ? 'Passwortgeschützt' : 'Kein Passwort',
+            ),
+            subtitle: Text(
+              caps.passwordEnforced && !_share.hasPassword
+                  ? 'Erforderlich – tippen zum Festlegen'
+                  : _share.hasPassword
+                  ? 'Tippen zum Ändern'
+                  : 'Tippen zum Festlegen',
+            ),
+            trailing: _share.hasPassword && !caps.passwordEnforced
+                ? IconButton(
+                    icon: const Icon(Icons.delete_outline),
+                    tooltip: 'Passwort entfernen',
+                    onPressed: _busy ? null : _clearPassword,
+                  )
+                : null,
+            onTap: _busy ? null : _changePassword,
+          ),
+        ],
+
+        const Divider(height: 24),
+        ListTile(
+          leading: CenteredLeading(
+            Icon(Icons.delete_outline, color: theme.colorScheme.error),
+          ),
+          title: Text(
+            'Freigabe löschen',
+            style: TextStyle(color: theme.colorScheme.error),
+          ),
+          onTap: _busy ? null : _confirmDelete,
+        ),
+      ],
+    );
+  }
+}

lib/view/pages/files/sharing/share_password_sheet.dart

@@ -0,0 +1,103 @@
+import 'package:flutter/material.dart';
+
+import '../../../../widget/centered_leading.dart';
+
+/// Prompts for a link password in a bottom sheet. Resolves to the entered
+/// password, or null if the sheet was dismissed without submitting. Used both
+/// when creating a password-protected link and when setting/changing the
+/// password of an existing one.
+Future<String?> promptSharePassword(
+  BuildContext context, {
+  required bool isChange,
+  String? policyHint,
+}) {
+  return showModalBottomSheet<String>(
+    context: context,
+    isScrollControlled: true,
+    showDragHandle: true,
+    useSafeArea: true,
+    builder: (ctx) =>
+        _SharePasswordSheet(isChange: isChange, policyHint: policyHint),
+  );
+}
+
+class _SharePasswordSheet extends StatefulWidget {
+  final bool isChange;
+  final String? policyHint;
+
+  const _SharePasswordSheet({required this.isChange, this.policyHint});
+
+  @override
+  State<_SharePasswordSheet> createState() => _SharePasswordSheetState();
+}
+
+class _SharePasswordSheetState extends State<_SharePasswordSheet> {
+  final TextEditingController _controller = TextEditingController();
+  bool _obscured = true;
+
+  @override
+  void dispose() {
+    _controller.dispose();
+    super.dispose();
+  }
+
+  void _submit() {
+    final value = _controller.text.trim();
+    if (value.isEmpty) return;
+    Navigator.of(context).pop(value);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final title = widget.isChange ? 'Passwort ändern' : 'Passwort setzen';
+    return SafeArea(
+      child: SingleChildScrollView(
+        padding: EdgeInsets.only(
+          bottom: 16 + MediaQuery.viewInsetsOf(context).bottom,
+        ),
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: [
+            ListTile(
+              leading: const CenteredLeading(Icon(Icons.lock_outline)),
+              title: Text(title),
+            ),
+            const Divider(height: 1),
+            Padding(
+              padding: const EdgeInsets.fromLTRB(16, 16, 16, 8),
+              child: TextField(
+                controller: _controller,
+                obscureText: _obscured,
+                autofocus: true,
+                onSubmitted: (_) => _submit(),
+                decoration: InputDecoration(
+                  labelText: 'Passwort',
+                  helperText: widget.policyHint,
+                  helperMaxLines: 3,
+                  border: const OutlineInputBorder(),
+                  suffixIcon: IconButton(
+                    icon: Icon(
+                      _obscured
+                          ? Icons.visibility_outlined
+                          : Icons.visibility_off_outlined,
+                    ),
+                    tooltip: _obscured ? 'Anzeigen' : 'Verbergen',
+                    onPressed: () => setState(() => _obscured = !_obscured),
+                  ),
+                ),
+              ),
+            ),
+            Padding(
+              padding: const EdgeInsets.symmetric(horizontal: 16),
+              child: FilledButton(
+                onPressed: _submit,
+                child: Text(widget.isChange ? 'Ändern' : 'Setzen'),
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}

lib/view/pages/files/sharing/share_sheet.dart

@@ -0,0 +1,288 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+
+import '../../../../api/errors/error_mapper.dart';
+import '../../../../api/marianumcloud/files_sharing/file_sharing_api.dart';
+import '../../../../api/marianumcloud/files_sharing/file_sharing_api_params.dart';
+import '../../../../api/marianumcloud/files_sharing/ocs_path.dart';
+import '../../../../api/marianumcloud/files_sharing/queries/share/share.dart';
+import '../../../../api/marianumcloud/files_sharing/share_permissions.dart';
+import '../../../../api/marianumcloud/webdav/queries/list_files/cacheable_file.dart';
+import '../../../../routing/app_routes.dart';
+import '../../../../state/app/modules/nextcloud_capabilities/bloc/nextcloud_capabilities_cubit.dart';
+import '../../../../utils/clipboard_helper.dart';
+import '../../../../widget/app_progress_indicator.dart';
+import '../../../../widget/centered_leading.dart';
+import '../../../../widget/details_bottom_sheet.dart';
+import '../../../../widget/info_dialog.dart';
+import '../widgets/file_leading.dart';
+import 'share_options_sheet.dart';
+import 'share_password_sheet.dart';
+
+/// Opens the sharing sheet for a file/folder: lists existing shares and offers
+/// gated actions to create new ones (public link, user/group). Capability
+/// gating mirrors the Nextcloud web UI.
+void showShareSheet(BuildContext context, CacheableFile file) {
+  showDetailsBottomSheet(
+    context,
+    header: ListTile(
+      leading: CenteredLeading(FileLeading(file: file)),
+      title: Text(file.name),
+      subtitle: const Text('Freigeben'),
+    ),
+    children: (sheetCtx) => [_ShareSheetBody(file: file)],
+  );
+}
+
+class _ShareSheetBody extends StatefulWidget {
+  final CacheableFile file;
+
+  const _ShareSheetBody({required this.file});
+
+  @override
+  State<_ShareSheetBody> createState() => _ShareSheetBodyState();
+}
+
+class _ShareSheetBodyState extends State<_ShareSheetBody> {
+  late final String _ocsPath = ocsPathOf(widget.file);
+  Future<List<Share>>? _future;
+  bool _busy = false;
+
+  /// Last resolved share list — used by the create-link gate without depending
+  /// on the FutureBuilder's snapshot.
+  List<Share>? _lastShares;
+
+  @override
+  void initState() {
+    super.initState();
+    _future = FileSharingApi().listForPath(_ocsPath);
+  }
+
+  void _reload() {
+    // Block body: an arrow would return the Future, which setState rejects.
+    setState(() {
+      _future = FileSharingApi().listForPath(_ocsPath);
+    });
+  }
+
+  Future<void> _runCreate(FileSharingApiParams params) async {
+    setState(() => _busy = true);
+    try {
+      await FileSharingApi().share(params);
+      if (!mounted) return;
+      _reload();
+    } catch (e) {
+      if (mounted) {
+        InfoDialog.show(
+          context,
+          errorToUserMessage(e),
+          title: 'Freigabe fehlgeschlagen',
+          copyable: true,
+        );
+      }
+    } finally {
+      if (mounted) setState(() => _busy = false);
+    }
+  }
+
+  Future<void> _createPublicLink() async {
+    final caps = context.read<NextcloudCapabilitiesCubit>();
+    String? password;
+    if (caps.passwordEnforced) {
+      // The server requires a password — collect it before creating, otherwise
+      // the call is rejected.
+      password = await promptSharePassword(
+        context,
+        isChange: false,
+        policyHint: caps.passwordPolicyHint,
+      );
+      if (password == null || password.isEmpty || !mounted) return;
+    }
+    await _runCreate(
+      FileSharingApiParams(
+        shareType: kShareTypePublicLink,
+        shareWith: '',
+        path: _ocsPath,
+        permissions: kPermissionRead,
+        password: password,
+      ),
+    );
+  }
+
+  Future<void> _addSharee() async {
+    final caps = context.read<NextcloudCapabilitiesCubit>();
+    final sharee = await AppRoutes.openShareePicker(
+      context,
+      allowUsers: caps.canShareWithUsers,
+      allowGroups: caps.canShareWithGroups,
+    );
+    if (sharee == null || !mounted) return;
+    await _runCreate(
+      FileSharingApiParams(
+        shareType: sharee.shareType,
+        shareWith: sharee.shareWith,
+        path: _ocsPath,
+        permissions: kPermissionRead,
+      ),
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final caps = context.watch<NextcloudCapabilitiesCubit>();
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      mainAxisSize: MainAxisSize.min,
+      children: [
+        if (_busy) const LinearProgressIndicator(),
+        _shareList(),
+        const Divider(height: 1),
+        if (caps.canShareWithUsers || caps.canShareWithGroups)
+          ListTile(
+            leading: const CenteredLeading(Icon(Icons.person_add_outlined)),
+            title: const Text('Person oder Gruppe hinzufügen'),
+            enabled: !_busy,
+            onTap: _busy ? null : _addSharee,
+          ),
+        if (caps.canCreatePublicLinks && _canAddLink(caps))
+          ListTile(
+            leading: const CenteredLeading(Icon(Icons.add_link)),
+            title: const Text('Öffentlichen Link erstellen'),
+            enabled: !_busy,
+            onTap: _busy ? null : _createPublicLink,
+          ),
+      ],
+    );
+  }
+
+  void _openInTalk(Share share) {
+    final token = share.shareWith;
+    if (token == null || token.isEmpty) return;
+    AppRoutes.openChatByToken(context, token);
+    if (Navigator.of(context).canPop()) Navigator.of(context).pop();
+  }
+
+  /// Whether another public link may be created — hidden once one exists on a
+  /// server that disallows multiple links.
+  bool _canAddLink(NextcloudCapabilitiesCubit caps) {
+    if (caps.allowsMultipleLinks) return true;
+    final hasLink = _lastShares?.any((s) => s.isPublicLink) ?? false;
+    return !hasLink;
+  }
+
+  Widget _shareList() {
+    return FutureBuilder<List<Share>>(
+      future: _future,
+      builder: (context, snapshot) {
+        if (snapshot.connectionState == ConnectionState.waiting) {
+          return const Padding(
+            padding: EdgeInsets.all(24),
+            child: Center(child: AppProgressIndicator.medium()),
+          );
+        }
+        if (snapshot.hasError) {
+          return Padding(
+            padding: const EdgeInsets.all(24),
+            child: Column(
+              children: [
+                Text(
+                  errorToUserMessage(snapshot.error),
+                  textAlign: TextAlign.center,
+                ),
+                const SizedBox(height: 12),
+                FilledButton.tonal(
+                  onPressed: _reload,
+                  child: const Text('Erneut versuchen'),
+                ),
+              ],
+            ),
+          );
+        }
+        final shares = snapshot.data ?? const <Share>[];
+        _lastShares = shares;
+        if (shares.isEmpty) {
+          final theme = Theme.of(context);
+          return SizedBox(
+            height: 160,
+            child: Center(
+              child: Padding(
+                padding: const EdgeInsets.symmetric(horizontal: 24),
+                child: Column(
+                  mainAxisSize: MainAxisSize.min,
+                  children: [
+                    Icon(
+                      Icons.lock_outline,
+                      size: 48,
+                      color: theme.colorScheme.outline,
+                    ),
+                    const SizedBox(height: 12),
+                    Text(
+                      'Diese Datei ist noch nicht freigegeben.',
+                      textAlign: TextAlign.center,
+                      style: theme.textTheme.bodyLarge?.copyWith(
+                        color: theme.colorScheme.onSurfaceVariant,
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+            ),
+          );
+        }
+        return Column(
+          mainAxisSize: MainAxisSize.min,
+          children: shares.map(_shareTile).toList(),
+        );
+      },
+    );
+  }
+
+  Widget _shareTile(Share share) {
+    final preset = presetFromBitmask(share.permissions);
+    final subtitleParts = <String>[
+      // For links the URL already identifies the row; for everyone else show
+      // the kind so a Talk share isn't mistaken for a plain person share.
+      if (share.isPublicLink && share.url != null)
+        share.url!
+      else
+        share.kindLabel,
+      if (preset != null) preset.label,
+      if (share.hasPassword) 'passwortgeschützt',
+      if (share.expiration != null) 'bis ${share.expiration}',
+    ];
+    return ListTile(
+      leading: CenteredLeading(Icon(shareIcon(share))),
+      title: Text(share.displayTitle),
+      subtitle: subtitleParts.isEmpty
+          ? null
+          : Text(
+              subtitleParts.join(' · '),
+              maxLines: 1,
+              overflow: TextOverflow.ellipsis,
+            ),
+      trailing: Row(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          if (share.isPublicLink && share.url != null)
+            IconButton(
+              icon: const Icon(Icons.copy_outlined),
+              tooltip: 'Link kopieren',
+              onPressed: () => copyToClipboard(context, share.url!),
+            ),
+          if (share.isRoom && (share.shareWith?.isNotEmpty ?? false))
+            IconButton(
+              icon: const Icon(Icons.chat_bubble_outline),
+              tooltip: 'Im Talk-Chat öffnen',
+              onPressed: () => _openInTalk(share),
+            ),
+          IconButton(
+            icon: const Icon(Icons.settings_outlined),
+            tooltip: 'Freigabe bearbeiten',
+            onPressed: () =>
+                showShareOptionsSheet(context, share, onChanged: _reload),
+          ),
+        ],
+      ),
+    );
+  }
+}

lib/view/pages/files/sharing/sharee_picker_page.dart

@@ -0,0 +1,228 @@
+import 'package:flutter/material.dart';
+
+import '../../../../api/errors/error_mapper.dart';
+import '../../../../api/marianumcloud/autocomplete/autocomplete_api.dart';
+import '../../../../api/marianumcloud/autocomplete/autocomplete_response.dart';
+import '../../../../api/marianumcloud/files_sharing/queries/share/share.dart';
+import '../../../../model/endpoint_data.dart';
+import '../../../../utils/debouncer.dart';
+import '../../../../utils/haptics.dart';
+import '../../../../widget/app_progress_indicator.dart';
+
+/// Result of [ShareePickerPage]: a recipient to create a share for.
+class ShareeRef {
+  final int shareType;
+  final String shareWith;
+  final String label;
+
+  const ShareeRef({
+    required this.shareType,
+    required this.shareWith,
+    required this.label,
+  });
+}
+
+/// Full-screen search for a user or group to share with. Which kinds are
+/// offered is gated by [allowUsers]/[allowGroups] (derived from the Nextcloud
+/// sharing capabilities at the call site).
+class ShareePickerPage extends StatefulWidget {
+  final bool allowUsers;
+  final bool allowGroups;
+
+  const ShareePickerPage({
+    required this.allowUsers,
+    required this.allowGroups,
+    super.key,
+  });
+
+  @override
+  State<ShareePickerPage> createState() => _ShareePickerPageState();
+}
+
+class _ShareePickerPageState extends State<ShareePickerPage> {
+  final TextEditingController _searchController = TextEditingController();
+  static const String _debounceTag = 'sharee_picker_search';
+
+  String _query = '';
+
+  /// `null` = search every allowed kind at once. Only meaningful when both
+  /// users and groups are allowed (otherwise the single allowed type is forced).
+  int? _selectedShareType;
+
+  Future<AutocompleteResponse>? _future;
+
+  @override
+  void initState() {
+    super.initState();
+    // When only one kind is allowed there is nothing to choose — force it.
+    if (widget.allowUsers != widget.allowGroups) {
+      _selectedShareType = widget.allowUsers ? kShareTypeUser : kShareTypeGroup;
+    }
+  }
+
+  @override
+  void dispose() {
+    Debouncer.cancel(_debounceTag);
+    _searchController.dispose();
+    super.dispose();
+  }
+
+  List<int> _effectiveShareTypes() {
+    if (_selectedShareType != null) return [_selectedShareType!];
+    return [
+      if (widget.allowUsers) kShareTypeUser,
+      if (widget.allowGroups) kShareTypeGroup,
+    ];
+  }
+
+  void _runSearch() {
+    final query = _query;
+    if (query.isEmpty) {
+      setState(() => _future = null);
+      return;
+    }
+    setState(() {
+      _future = AutocompleteApi().find(
+        query,
+        shareTypes: _effectiveShareTypes(),
+      );
+    });
+  }
+
+  void _onQueryChanged(String value) {
+    _query = value.trim();
+    Debouncer.debounce(_debounceTag, const Duration(milliseconds: 350), () {
+      if (mounted) _runSearch();
+    });
+  }
+
+  void _pick(AutocompleteResponseObject object) {
+    Haptics.selection();
+    Navigator.of(context).pop(
+      ShareeRef(
+        shareType: shareTypeFromSource(object.source),
+        shareWith: object.id,
+        label: object.label,
+      ),
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final showChips = widget.allowUsers && widget.allowGroups;
+    return Scaffold(
+      appBar: AppBar(title: const Text('Teilen mit…')),
+      body: Column(
+        children: [
+          Padding(
+            padding: const EdgeInsets.fromLTRB(16, 12, 16, 8),
+            child: TextField(
+              controller: _searchController,
+              autofocus: true,
+              onChanged: _onQueryChanged,
+              decoration: InputDecoration(
+                hintText: 'Name suchen…',
+                prefixIcon: const Icon(Icons.search),
+                suffixIcon: _query.isEmpty
+                    ? null
+                    : IconButton(
+                        icon: const Icon(Icons.clear),
+                        onPressed: () {
+                          _searchController.clear();
+                          _query = '';
+                          _runSearch();
+                        },
+                      ),
+                border: const OutlineInputBorder(),
+                isDense: true,
+              ),
+            ),
+          ),
+          if (showChips) ...[
+            SizedBox(height: 40, child: _typeSelector()),
+            const SizedBox(height: 8),
+          ],
+          Expanded(child: _results()),
+        ],
+      ),
+    );
+  }
+
+  Widget _typeSelector() => ListView(
+    scrollDirection: Axis.horizontal,
+    padding: const EdgeInsets.symmetric(horizontal: 16),
+    children: [
+      _typeChip(null, 'Alle', Icons.apps),
+      _typeChip(kShareTypeUser, 'Personen', Icons.person_outline),
+      _typeChip(kShareTypeGroup, 'Gruppen', Icons.groups_outlined),
+    ],
+  );
+
+  Widget _typeChip(int? type, String label, IconData icon) => Padding(
+    padding: const EdgeInsets.only(right: 8),
+    child: ChoiceChip(
+      avatar: Icon(icon, size: 18),
+      showCheckmark: false,
+      label: Text(label),
+      selected: _selectedShareType == type,
+      onSelected: (_) {
+        Haptics.selection();
+        setState(() => _selectedShareType = type);
+        _runSearch();
+      },
+    ),
+  );
+
+  Widget _results() {
+    if (_future == null) {
+      return const Center(child: Text('Tippe, um nach Personen zu suchen.'));
+    }
+    return FutureBuilder<AutocompleteResponse>(
+      future: _future,
+      builder: (context, snapshot) {
+        if (snapshot.connectionState == ConnectionState.waiting) {
+          return const Center(child: AppProgressIndicator.medium());
+        }
+        if (snapshot.hasError) {
+          return Center(
+            child: Padding(
+              padding: const EdgeInsets.all(24),
+              child: Text(
+                errorToUserMessage(snapshot.error),
+                textAlign: TextAlign.center,
+              ),
+            ),
+          );
+        }
+        final results = snapshot.data?.data ?? const [];
+        if (results.isEmpty) {
+          return const Center(child: Text('Keine Treffer.'));
+        }
+        return ListView.builder(
+          itemCount: results.length,
+          itemBuilder: (context, index) => _resultTile(results[index]),
+        );
+      },
+    );
+  }
+
+  Widget _resultTile(AutocompleteResponseObject object) {
+    final isGroup = shareTypeFromSource(object.source) == kShareTypeGroup;
+    final leading = isGroup
+        ? const CircleAvatar(child: Icon(Icons.groups_outlined))
+        : CircleAvatar(
+            foregroundImage: Image.network(
+              'https://${EndpointData().nextcloud().full()}/avatar/${object.id}/128',
+            ).image,
+            backgroundColor: Theme.of(context).primaryColor,
+            foregroundColor: Colors.white,
+            child: const Icon(Icons.person),
+          );
+    return ListTile(
+      leading: leading,
+      title: Text(object.label),
+      subtitle: Text(isGroup ? 'Gruppe' : object.id),
+      onTap: () => _pick(object),
+    );
+  }
+}

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

@@ -1,5 +1,6 @@
 import 'package:filesize/filesize.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:nextcloud/nextcloud.dart';
 
 import '../../../../api/marianumcloud/webdav/queries/list_files/cacheable_file.dart';
@@ -8,6 +9,7 @@ import '../../../../extensions/date_time.dart';
 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/file_clipboard.dart';
 import '../../../../utils/haptics.dart';
@@ -16,6 +18,7 @@ import '../../../../widget/confirm_dialog.dart';
 import '../../../../widget/details_bottom_sheet.dart';
 import '../../../../widget/info_dialog.dart';
 import '../../talk/widgets/highlighted_linkify.dart';
+import '../sharing/share_sheet.dart';
 import 'file_details_sheet.dart';
 import 'file_leading.dart';
 
@@ -329,7 +332,7 @@ class _FileElementState extends State<FileElement> {
         if (!widget.file.isDirectory)
           ListTile(
             leading: const CenteredLeading(Icon(Icons.chat_bubble_outline)),
-            title: const Text('Im Talk-Chat teilen'),
+            title: const Text('Im Talk-Chat versenden'),
             onTap: () {
               Navigator.of(sheetCtx).pop();
               AppRoutes.openInternalShareToChat(
@@ -338,9 +341,26 @@ class _FileElementState extends State<FileElement> {
               );
             },
           ),
+        if (context.read<NextcloudCapabilitiesCubit>().canShareAtAll)
+          ListTile(
+            leading: const CenteredLeading(Icon(Icons.person_add_outlined)),
+            title: const Text('Freigeben'),
+            onTap: () {
+              Navigator.of(sheetCtx).pop();
+              showShareSheet(context, widget.file);
+            },
+          ),
         ListTile(
-          leading: const CenteredLeading(Icon(Icons.delete_outline)),
-          title: const Text('Löschen'),
+          leading: CenteredLeading(
+            Icon(
+              Icons.delete_outline,
+              color: Theme.of(sheetCtx).colorScheme.error,
+            ),
+          ),
+          title: Text(
+            'Löschen',
+            style: TextStyle(color: Theme.of(sheetCtx).colorScheme.error),
+          ),
           onTap: () {
             Navigator.of(sheetCtx).pop();
             _delete();

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

@@ -23,7 +23,7 @@ class FileLeading extends StatelessWidget {
   Widget build(BuildContext context) {
     final icon = Icon(iconForFile(file), size: size);
     final fileId = file.fileId;
-    return SizedBox(
+    final base = SizedBox(
       width: size,
       height: size,
       child: (file.isDirectory || file.hasPreview != true || fileId == null)
@@ -47,5 +47,31 @@ class FileLeading extends StatelessWidget {
               ),
             ),
     );
+
+    // Badge incoming shares (shared with the user by someone else).
+    if (file.isSharedWithMe != true) return base;
+    final colors = Theme.of(context).colorScheme;
+    return Stack(
+      clipBehavior: Clip.none,
+      children: [
+        base,
+        Positioned(
+          right: -3,
+          bottom: -3,
+          child: Container(
+            decoration: BoxDecoration(
+              color: colors.errorContainer,
+              shape: BoxShape.circle,
+            ),
+            padding: const EdgeInsets.all(1),
+            child: Icon(
+              Icons.people,
+              size: size * 0.45,
+              color: colors.onErrorContainer,
+            ),
+          ),
+        ),
+      ],
+    );
   }
 }