implemented file thumbnails and enhanced file type icons, added reusable FileLeading widget, and updated search to support previews

lib/api/marianumcloud/search/search_files_response.dart

@@ -83,9 +83,49 @@ class SearchFilesEntry {
     return null;
   }
 
+  /// Derives a filename with its extension from the WebDAV-relative path.
+  /// The provider's `title` is often the display name *without* the
+  /// extension, which would defeat extension-based icon mapping.
+  String _nameFromPath(String path) {
+    final stripped = path.replaceAll(RegExp(r'^/+|/+$'), '');
+    if (stripped.isEmpty) return title;
+    final last = stripped.split('/').last;
+    return last.isEmpty ? title : last;
+  }
+
+  /// The files search provider exposes the numeric Nextcloud file id either
+  /// as an attribute, or implicitly in the `?openfile=<id>` query parameter
+  /// of [resourceUrl]. Parses both into an [int] when available — used to
+  /// hit the preview endpoint directly.
+  int? _extractFileId() {
+    final attr = attributes?['fileId'];
+    if (attr is int) return attr;
+    if (attr is String) {
+      final parsed = int.tryParse(attr);
+      if (parsed != null) return parsed;
+    }
+    final url = resourceUrl;
+    if (url != null) {
+      final raw = Uri.tryParse(url)?.queryParameters['openfile'];
+      if (raw != null) return int.tryParse(raw);
+    }
+    return null;
+  }
+
   CacheableFile? toCacheable() {
     final path = webdavPath;
     if (path == null) return null;
-    return CacheableFile(path: path, isDirectory: isDirectory, name: title);
+    final fileId = _extractFileId();
+    return CacheableFile(
+      path: path,
+      isDirectory: isDirectory,
+      name: _nameFromPath(path),
+      fileId: fileId,
+      // Search provider responses don't carry `nc:has-preview`. Probe
+      // optimistically when a fileId is available — the preview endpoint
+      // simply returns 404 for unsupported formats, which the file-leading
+      // widget already falls back from to the typed icon.
+      hasPreview: (!isDirectory && fileId != null) ? true : null,
+    );
   }
 }

lib/view/pages/files/data/file_type_icon.dart

@@ -0,0 +1,242 @@
+import 'package:flutter/material.dart';
+
+import '../../../../api/marianumcloud/webdav/queries/list_files/cacheable_file.dart';
+
+/// Best-effort mapping from a file's MIME type / extension to a Material
+/// icon that visually hints at its kind. Always returns a sensible fallback.
+IconData iconForFile(CacheableFile file) {
+  if (file.isDirectory) return Icons.folder;
+  final mime = file.mimeType?.toLowerCase();
+  if (mime != null && mime.isNotEmpty) {
+    final byMime = _iconForMime(mime);
+    if (byMime != null) return byMime;
+  }
+  final ext = _extensionOf(file.name);
+  if (ext != null) {
+    final byExt = _extensionIcons[ext];
+    if (byExt != null) return byExt;
+  }
+  return Icons.insert_drive_file_outlined;
+}
+
+String? _extensionOf(String name) {
+  final dot = name.lastIndexOf('.');
+  if (dot <= 0 || dot == name.length - 1) return null;
+  return name.substring(dot + 1).toLowerCase();
+}
+
+IconData? _iconForMime(String mime) {
+  // Major media types first — these cover the long tail of variants.
+  if (mime.startsWith('image/')) return Icons.image_outlined;
+  if (mime.startsWith('video/')) return Icons.movie_outlined;
+  if (mime.startsWith('audio/')) return Icons.audiotrack;
+  if (mime.startsWith('font/')) return Icons.font_download_outlined;
+  if (mime.startsWith('text/x-') ||
+      mime.startsWith('text/javascript') ||
+      mime.startsWith('text/css') ||
+      mime.startsWith('text/html')) {
+    return Icons.code;
+  }
+  if (mime.startsWith('text/')) return Icons.article_outlined;
+
+  // Specific application/* types.
+  const map = <String, IconData>{
+    'application/pdf': Icons.picture_as_pdf_outlined,
+
+    // Word processing
+    'application/msword': Icons.description_outlined,
+    'application/vnd.openxmlformats-officedocument.wordprocessingml.document':
+        Icons.description_outlined,
+    'application/vnd.oasis.opendocument.text': Icons.description_outlined,
+    'application/rtf': Icons.description_outlined,
+
+    // Spreadsheets
+    'application/vnd.ms-excel': Icons.table_chart_outlined,
+    'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet':
+        Icons.table_chart_outlined,
+    'application/vnd.oasis.opendocument.spreadsheet':
+        Icons.table_chart_outlined,
+    'application/vnd.ms-excel.sheet.macroenabled.12':
+        Icons.table_chart_outlined,
+
+    // Presentations
+    'application/vnd.ms-powerpoint': Icons.slideshow_outlined,
+    'application/vnd.openxmlformats-officedocument.presentationml.presentation':
+        Icons.slideshow_outlined,
+    'application/vnd.oasis.opendocument.presentation': Icons.slideshow_outlined,
+
+    // Archives
+    'application/zip': Icons.folder_zip_outlined,
+    'application/x-zip-compressed': Icons.folder_zip_outlined,
+    'application/x-rar-compressed': Icons.folder_zip_outlined,
+    'application/vnd.rar': Icons.folder_zip_outlined,
+    'application/x-7z-compressed': Icons.folder_zip_outlined,
+    'application/x-tar': Icons.folder_zip_outlined,
+    'application/gzip': Icons.folder_zip_outlined,
+    'application/x-bzip2': Icons.folder_zip_outlined,
+    'application/x-xz': Icons.folder_zip_outlined,
+    'application/zstd': Icons.folder_zip_outlined,
+
+    // Code / structured data
+    'application/json': Icons.code,
+    'application/ld+json': Icons.code,
+    'application/xml': Icons.code,
+    'application/x-yaml': Icons.code,
+    'application/javascript': Icons.code,
+    'application/x-sh': Icons.terminal,
+
+    // Calendar / contacts
+    'text/calendar': Icons.calendar_month_outlined,
+    'text/vcard': Icons.contact_page_outlined,
+
+    // E-books
+    'application/epub+zip': Icons.menu_book_outlined,
+    'application/x-mobipocket-ebook': Icons.menu_book_outlined,
+
+    // Executables / installers
+    'application/x-msdownload': Icons.terminal,
+    'application/x-msi': Icons.terminal,
+    'application/x-apple-diskimage': Icons.album_outlined,
+    'application/vnd.android.package-archive': Icons.android_outlined,
+    'application/octet-stream': Icons.insert_drive_file_outlined,
+
+    // Databases
+    'application/x-sqlite3': Icons.storage_outlined,
+    'application/vnd.sqlite3': Icons.storage_outlined,
+
+    // 3D
+    'model/gltf-binary': Icons.view_in_ar_outlined,
+    'model/gltf+json': Icons.view_in_ar_outlined,
+    'model/stl': Icons.view_in_ar_outlined,
+    'model/obj': Icons.view_in_ar_outlined,
+  };
+  return map[mime];
+}
+
+const _extensionIcons = <String, IconData>{
+  // Images
+  'jpg': Icons.image_outlined, 'jpeg': Icons.image_outlined,
+  'png': Icons.image_outlined, 'gif': Icons.image_outlined,
+  'webp': Icons.image_outlined, 'bmp': Icons.image_outlined,
+  'tif': Icons.image_outlined, 'tiff': Icons.image_outlined,
+  'heic': Icons.image_outlined, 'heif': Icons.image_outlined,
+  'avif': Icons.image_outlined, 'ico': Icons.image_outlined,
+  'raw': Icons.image_outlined, 'cr2': Icons.image_outlined,
+  'nef': Icons.image_outlined, 'arw': Icons.image_outlined,
+  'svg': Icons.gesture_outlined, 'eps': Icons.gesture_outlined,
+  'ai': Icons.gesture_outlined,
+
+  // Video
+  'mp4': Icons.movie_outlined, 'm4v': Icons.movie_outlined,
+  'mov': Icons.movie_outlined, 'mkv': Icons.movie_outlined,
+  'avi': Icons.movie_outlined, 'webm': Icons.movie_outlined,
+  'flv': Icons.movie_outlined, 'wmv': Icons.movie_outlined,
+  '3gp': Icons.movie_outlined, 'mpg': Icons.movie_outlined,
+  'mpeg': Icons.movie_outlined, 'ogv': Icons.movie_outlined,
+
+  // Audio
+  'mp3': Icons.audiotrack, 'm4a': Icons.audiotrack, 'aac': Icons.audiotrack,
+  'wav': Icons.audiotrack, 'flac': Icons.audiotrack, 'ogg': Icons.audiotrack,
+  'oga': Icons.audiotrack, 'opus': Icons.audiotrack, 'wma': Icons.audiotrack,
+  'aiff': Icons.audiotrack, 'aif': Icons.audiotrack,
+
+  // Music notation
+  'mscz': Icons.music_note, 'mscx': Icons.music_note,
+  'musicxml': Icons.music_note, 'mxl': Icons.music_note,
+  'midi': Icons.music_note, 'mid': Icons.music_note,
+
+  // PDF
+  'pdf': Icons.picture_as_pdf_outlined,
+
+  // Word
+  'doc': Icons.description_outlined, 'docx': Icons.description_outlined,
+  'odt': Icons.description_outlined, 'rtf': Icons.description_outlined,
+  'pages': Icons.description_outlined,
+
+  // Spreadsheets
+  'xls': Icons.table_chart_outlined, 'xlsx': Icons.table_chart_outlined,
+  'xlsm': Icons.table_chart_outlined, 'ods': Icons.table_chart_outlined,
+  'csv': Icons.table_chart_outlined, 'tsv': Icons.table_chart_outlined,
+  'numbers': Icons.table_chart_outlined,
+
+  // Presentations
+  'ppt': Icons.slideshow_outlined, 'pptx': Icons.slideshow_outlined,
+  'pps': Icons.slideshow_outlined, 'odp': Icons.slideshow_outlined,
+  'key': Icons.slideshow_outlined,
+
+  // Plain text / notes
+  'txt': Icons.article_outlined, 'md': Icons.article_outlined,
+  'markdown': Icons.article_outlined, 'log': Icons.article_outlined,
+  'rst': Icons.article_outlined,
+
+  // Code
+  'html': Icons.code, 'htm': Icons.code, 'xhtml': Icons.code,
+  'css': Icons.code, 'scss': Icons.code, 'sass': Icons.code, 'less': Icons.code,
+  'js': Icons.code, 'mjs': Icons.code, 'cjs': Icons.code,
+  'ts': Icons.code, 'jsx': Icons.code, 'tsx': Icons.code,
+  'dart': Icons.code, 'java': Icons.code, 'kt': Icons.code, 'kts': Icons.code,
+  'py': Icons.code, 'rb': Icons.code, 'go': Icons.code, 'rs': Icons.code,
+  'c': Icons.code, 'cpp': Icons.code, 'cc': Icons.code, 'cxx': Icons.code,
+  'h': Icons.code, 'hpp': Icons.code, 'cs': Icons.code, 'm': Icons.code,
+  'mm': Icons.code, 'php': Icons.code, 'pl': Icons.code, 'lua': Icons.code,
+  'r': Icons.code, 'swift': Icons.code, 'scala': Icons.code, 'groovy': Icons.code,
+  'sql': Icons.code, 'graphql': Icons.code, 'gql': Icons.code,
+  'json': Icons.code, 'json5': Icons.code, 'xml': Icons.code,
+  'yaml': Icons.code, 'yml': Icons.code,
+
+  // Shell
+  'sh': Icons.terminal, 'bash': Icons.terminal, 'zsh': Icons.terminal,
+  'fish': Icons.terminal, 'ps1': Icons.terminal, 'bat': Icons.terminal,
+  'cmd': Icons.terminal,
+
+  // Archives
+  'zip': Icons.folder_zip_outlined, 'rar': Icons.folder_zip_outlined,
+  '7z': Icons.folder_zip_outlined, 'tar': Icons.folder_zip_outlined,
+  'gz': Icons.folder_zip_outlined, 'bz2': Icons.folder_zip_outlined,
+  'xz': Icons.folder_zip_outlined, 'tgz': Icons.folder_zip_outlined,
+  'zst': Icons.folder_zip_outlined,
+
+  // Config / settings (the "gear" cases)
+  'ini': Icons.settings_outlined, 'cfg': Icons.settings_outlined,
+  'conf': Icons.settings_outlined, 'env': Icons.settings_outlined,
+  'toml': Icons.settings_outlined, 'plist': Icons.settings_outlined,
+  'properties': Icons.settings_outlined,
+  'editorconfig': Icons.settings_outlined,
+  'gitignore': Icons.settings_outlined,
+  'gitattributes': Icons.settings_outlined,
+  'dockerignore': Icons.settings_outlined,
+  'dockerfile': Icons.settings_outlined,
+
+  // Fonts
+  'ttf': Icons.font_download_outlined, 'otf': Icons.font_download_outlined,
+  'woff': Icons.font_download_outlined, 'woff2': Icons.font_download_outlined,
+  'eot': Icons.font_download_outlined,
+
+  // Calendar / contacts
+  'ics': Icons.calendar_month_outlined, 'ical': Icons.calendar_month_outlined,
+  'vcf': Icons.contact_page_outlined, 'vcard': Icons.contact_page_outlined,
+
+  // E-books
+  'epub': Icons.menu_book_outlined, 'mobi': Icons.menu_book_outlined,
+  'azw': Icons.menu_book_outlined, 'azw3': Icons.menu_book_outlined,
+
+  // 3D
+  'stl': Icons.view_in_ar_outlined, 'obj': Icons.view_in_ar_outlined,
+  'fbx': Icons.view_in_ar_outlined, 'blend': Icons.view_in_ar_outlined,
+  'glb': Icons.view_in_ar_outlined, 'gltf': Icons.view_in_ar_outlined,
+  '3ds': Icons.view_in_ar_outlined,
+
+  // Executables / packages
+  'exe': Icons.terminal, 'msi': Icons.terminal,
+  'app': Icons.terminal, 'deb': Icons.terminal, 'rpm': Icons.terminal,
+  'apk': Icons.android_outlined, 'ipa': Icons.terminal,
+  'appimage': Icons.terminal,
+
+  // Disc images
+  'iso': Icons.album_outlined, 'img': Icons.album_outlined,
+  'dmg': Icons.album_outlined,
+
+  // Databases
+  'db': Icons.storage_outlined, 'sqlite': Icons.storage_outlined,
+  'sqlite3': Icons.storage_outlined,
+};

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

@@ -5,6 +5,7 @@ import '../../../../api/marianumcloud/webdav/queries/list_files/cacheable_file.d
 import '../../../../extensions/date_time.dart';
 import '../../../../utils/clipboard_helper.dart';
 import '../../../../widget/details_bottom_sheet.dart';
+import 'file_leading.dart';
 
 /// Shows a modal bottom sheet with technical metadata about a single file or
 /// folder: full path, MIME type, size, timestamps, ETag.
@@ -12,10 +13,7 @@ void showFileDetailsSheet(BuildContext context, CacheableFile file) {
   showDetailsBottomSheet(
     context,
     header: ListTile(
-      leading: Icon(
+      leading: FileLeading(file: file, size: 40),
-        file.isDirectory ? Icons.folder : Icons.description_outlined,
-        size: 32,
-      ),
       title: Text(
         file.name,
         style: const TextStyle(fontWeight: FontWeight.bold),

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

@@ -16,6 +16,7 @@ import '../../../../widget/details_bottom_sheet.dart';
 import '../../../../widget/info_dialog.dart';
 import '../../talk/widgets/highlighted_linkify.dart';
 import 'file_details_sheet.dart';
+import 'file_leading.dart';
 
 class FileElement extends StatefulWidget {
   final CacheableFile file;
@@ -372,9 +373,7 @@ class _FileElementState extends State<FileElement> {
 
   @override
   Widget build(BuildContext context) => ListTile(
-    leading: CenteredLeading(
+    leading: CenteredLeading(FileLeading(file: widget.file)),
-      Icon(widget.file.isDirectory ? Icons.folder : Icons.description_outlined),
-    ),
     title: _title(context),
     subtitle: _subtitle(),
     trailing: Icon(widget.file.isDirectory ? Icons.arrow_right : null),

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

@@ -0,0 +1,51 @@
+import 'package:cached_network_image/cached_network_image.dart';
+import 'package:flutter/material.dart';
+
+import '../../../../api/marianumcloud/webdav/queries/list_files/cacheable_file.dart';
+import '../../../../model/account_data.dart';
+import '../../../../model/endpoint_data.dart';
+import '../data/file_type_icon.dart';
+
+/// Leading slot for a file row: shows the Nextcloud thumbnail when the
+/// server can render one (`nc:has-preview`), otherwise a typed file icon.
+/// Always reserves the same square so rows stay aligned regardless of
+/// whether a preview is present.
+class FileLeading extends StatelessWidget {
+  final CacheableFile file;
+
+  /// Edge length of the rendered square. Defaults to the regular row size;
+  /// use a larger value (e.g. in detail sheets) where appropriate.
+  final double size;
+
+  const FileLeading({required this.file, this.size = 28, super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final icon = Icon(iconForFile(file), size: size);
+    final fileId = file.fileId;
+    return SizedBox(
+      width: size,
+      height: size,
+      child: (file.isDirectory || file.hasPreview != true || fileId == null)
+          ? Center(child: icon)
+          : ClipRRect(
+              borderRadius: BorderRadius.circular(4),
+              child: CachedNetworkImage(
+                imageUrl:
+                    'https://${EndpointData().nextcloud().full()}'
+                    '/index.php/core/preview'
+                    '?fileId=$fileId&x=128&y=128&a=0',
+                httpHeaders: AccountData().authHeaders(),
+                fit: BoxFit.cover,
+                fadeInDuration: Duration.zero,
+                fadeOutDuration: Duration.zero,
+                errorListener: (_) {},
+                // Icon doubles as the loading placeholder so the list doesn't
+                // pop a spinner per row while thumbnails stream in.
+                placeholder: (_, _) => Center(child: icon),
+                errorWidget: (_, _, _) => Center(child: icon),
+              ),
+            ),
+    );
+  }
+}

lib/view/pages/share_intent/share_folder_picker.dart

@@ -19,6 +19,7 @@ import '../../../widget/placeholder_view.dart';
 import '../files/data/sort_options.dart';
 import '../files/files_upload_dialog.dart';
 import '../files/widgets/add_file_menu.dart';
+import '../files/widgets/file_leading.dart';
 import '../files/widgets/files_sort_actions.dart';
 
 typedef _FolderConfirmedCallback =
@@ -181,7 +182,7 @@ class _ShareFolderPickerViewState extends State<_ShareFolderPickerView> {
             final entry = entries[i];
             if (entry.isDirectory) {
               return ListTile(
-                leading: const Icon(Icons.folder_outlined),
+                leading: FileLeading(file: entry),
                 title: Text(entry.name),
                 trailing: const Icon(Icons.chevron_right),
                 onTap: () => _enter(bloc, state.currentPath, entry.name),
@@ -189,7 +190,7 @@ class _ShareFolderPickerViewState extends State<_ShareFolderPickerView> {
             }
             return ListTile(
               enabled: false,
-              leading: const Icon(Icons.description_outlined),
+              leading: FileLeading(file: entry),
               title: Text(entry.name),
             );
           },