info: metadata search

lib/widgets/collection/app_bar.dart

@@ -172,7 +172,7 @@ class _CollectionAppBarState extends State<CollectionAppBar> with SingleTickerPr
   List<Widget> _buildActions() {
     return [
       if (collection.isBrowsing)
-        SearchButton(
+        CollectionSearchButton(
           source,
           parentCollection: collection,
         ),
@@ -361,7 +361,7 @@ class _CollectionAppBarState extends State<CollectionAppBar> with SingleTickerPr
     Navigator.push(
         context,
         SearchPageRoute(
-          delegate: ImageSearchDelegate(
+          delegate: CollectionSearchDelegate(
             source: collection.source,
             parentCollection: collection,
           ),

lib/widgets/common/basic/query_bar.dart

@@ -0,0 +1,79 @@
+import 'package:aves/theme/durations.dart';
+import 'package:aves/theme/icons.dart';
+import 'package:aves/utils/debouncer.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/widgets.dart';
+
+class QueryBar extends StatefulWidget {
+  final ValueNotifier<String> filterNotifier;
+
+  const QueryBar({@required this.filterNotifier});
+
+  @override
+  _QueryBarState createState() => _QueryBarState();
+}
+
+class _QueryBarState extends State<QueryBar> {
+  final Debouncer _debouncer = Debouncer(delay: Durations.searchDebounceDelay);
+  TextEditingController _controller;
+
+  ValueNotifier<String> get filterNotifier => widget.filterNotifier;
+
+  @override
+  void initState() {
+    super.initState();
+    _controller = TextEditingController(text: filterNotifier.value);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final clearButton = IconButton(
+      icon: Icon(AIcons.clear),
+      onPressed: () {
+        _controller.clear();
+        filterNotifier.value = '';
+      },
+      tooltip: 'Clear',
+    );
+
+    return Row(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        Expanded(
+          child: TextField(
+            controller: _controller,
+            decoration: InputDecoration(
+              icon: Padding(
+                padding: EdgeInsetsDirectional.only(start: 16),
+                child: Icon(AIcons.search),
+              ),
+              hintText: MaterialLocalizations.of(context).searchFieldLabel,
+              hintStyle: Theme.of(context).inputDecorationTheme.hintStyle,
+            ),
+            textInputAction: TextInputAction.search,
+            onChanged: (s) => _debouncer(() => filterNotifier.value = s),
+          ),
+        ),
+        ConstrainedBox(
+          constraints: BoxConstraints(minWidth: 16),
+          child: ValueListenableBuilder<TextEditingValue>(
+            valueListenable: _controller,
+            builder: (context, value, child) => AnimatedSwitcher(
+              duration: Durations.appBarActionChangeAnimation,
+              transitionBuilder: (child, animation) => FadeTransition(
+                opacity: animation,
+                child: SizeTransition(
+                  axis: Axis.horizontal,
+                  sizeFactor: animation,
+                  child: child,
+                ),
+              ),
+              child: value.text.isNotEmpty ? clearButton : SizedBox.shrink(),
+            ),
+          ),
+        )
+      ],
+    );
+  }
+}

lib/widgets/common/identity/aves_expansion_tile.dart

@@ -5,13 +5,15 @@ import 'package:flutter/material.dart';
 class AvesExpansionTile extends StatelessWidget {
   final String title;
   final Color color;
-  final List<Widget> children;
   final ValueNotifier<String> expandedNotifier;
+  final bool initiallyExpanded;
+  final List<Widget> children;
 
   const AvesExpansionTile({
     @required this.title,
     this.color,
     this.expandedNotifier,
+    this.initiallyExpanded = false,
     @required this.children,
   });
 
@@ -33,6 +35,9 @@ class AvesExpansionTile extends StatelessWidget {
           enabled: enabled,
         ),
         expandable: enabled,
+        initiallyExpanded: initiallyExpanded,
+        baseColor: Colors.grey[900],
+        expandedColor: Colors.grey[850],
         child: Column(
           crossAxisAlignment: CrossAxisAlignment.start,
           children: [
@@ -41,8 +46,6 @@ class AvesExpansionTile extends StatelessWidget {
             if (enabled) ...children,
           ],
         ),
-        baseColor: Colors.grey[900],
-        expandedColor: Colors.grey[850],
       ),
     );
   }

lib/widgets/filter_grids/album_pick.dart

@@ -3,10 +3,9 @@ import 'package:aves/model/filters/album.dart';
 import 'package:aves/model/settings/settings.dart';
 import 'package:aves/model/source/collection_source.dart';
 import 'package:aves/model/source/enums.dart';
-import 'package:aves/theme/durations.dart';
 import 'package:aves/theme/icons.dart';
-import 'package:aves/utils/debouncer.dart';
 import 'package:aves/widgets/collection/empty.dart';
+import 'package:aves/widgets/common/basic/query_bar.dart';
 import 'package:aves/widgets/dialogs/create_album_dialog.dart';
 import 'package:aves/widgets/filter_grids/albums_page.dart';
 import 'package:aves/widgets/filter_grids/common/chip_set_action_delegate.dart';
@@ -116,84 +115,25 @@ class AlbumPickAppBar extends StatelessWidget {
   }
 }
 
-class AlbumFilterBar extends StatefulWidget implements PreferredSizeWidget {
+class AlbumFilterBar extends StatelessWidget implements PreferredSizeWidget {
   final ValueNotifier<String> filterNotifier;
 
   static const preferredHeight = kToolbarHeight;
 
-  const AlbumFilterBar({@required this.filterNotifier});
+  const AlbumFilterBar({
+    @required this.filterNotifier,
+  });
 
   @override
   Size get preferredSize => Size.fromHeight(preferredHeight);
 
-  @override
-  _AlbumFilterBarState createState() => _AlbumFilterBarState();
-}
-
-class _AlbumFilterBarState extends State<AlbumFilterBar> {
-  final Debouncer _debouncer = Debouncer(delay: Durations.searchDebounceDelay);
-  TextEditingController _controller;
-
-  ValueNotifier<String> get filterNotifier => widget.filterNotifier;
-
-  @override
-  void initState() {
-    super.initState();
-    _controller = TextEditingController(text: filterNotifier.value);
-  }
-
   @override
   Widget build(BuildContext context) {
-    final clearButton = IconButton(
-      icon: Icon(AIcons.clear),
-      onPressed: () {
-        _controller.clear();
-        filterNotifier.value = '';
-      },
-      tooltip: 'Clear',
-    );
     return Container(
       height: AlbumFilterBar.preferredHeight,
       alignment: Alignment.topCenter,
-      child: Row(
+      child: QueryBar(
-        crossAxisAlignment: CrossAxisAlignment.start,
+        filterNotifier: filterNotifier,
-        children: [
-          // Icon(AIcons.search),
-          Expanded(
-            child: TextField(
-              controller: _controller,
-              decoration: InputDecoration(
-                icon: Padding(
-                  padding: EdgeInsetsDirectional.only(start: 16),
-                  child: Icon(AIcons.search),
-                ),
-                // border: OutlineInputBorder(),
-                hintText: MaterialLocalizations.of(context).searchFieldLabel,
-                hintStyle: Theme.of(context).inputDecorationTheme.hintStyle,
-              ),
-              textInputAction: TextInputAction.search,
-              onChanged: (s) => _debouncer(() => filterNotifier.value = s),
-            ),
-          ),
-          ConstrainedBox(
-            constraints: BoxConstraints(minWidth: 16),
-            child: ValueListenableBuilder<TextEditingValue>(
-              valueListenable: _controller,
-              builder: (context, value, child) => AnimatedSwitcher(
-                duration: Durations.appBarActionChangeAnimation,
-                transitionBuilder: (child, animation) => FadeTransition(
-                  opacity: animation,
-                  child: SizeTransition(
-                    axis: Axis.horizontal,
-                    sizeFactor: animation,
-                    child: child,
-                  ),
-                ),
-                child: value.text.isNotEmpty ? clearButton : SizedBox.shrink(),
-              ),
-            ),
-          )
-        ],
       ),
     );
   }

lib/widgets/filter_grids/common/filter_nav_page.dart

@@ -104,7 +104,7 @@ class FilterNavigationPage<T extends CollectionFilter> extends StatelessWidget {
 
   List<Widget> _buildActions(BuildContext context) {
     return [
-      SearchButton(source),
+      CollectionSearchButton(source),
       PopupMenuButton<ChipSetAction>(
         key: Key('appbar-menu-button'),
         itemBuilder: (context) {
@@ -137,7 +137,7 @@ class FilterNavigationPage<T extends CollectionFilter> extends StatelessWidget {
     Navigator.push(
         context,
         SearchPageRoute(
-          delegate: ImageSearchDelegate(
+          delegate: CollectionSearchDelegate(
             source: source,
           ),
         ));

lib/widgets/fullscreen/info/info_app_bar.dart

@@ -0,0 +1,53 @@
+import 'package:aves/model/image_entry.dart';
+import 'package:aves/theme/icons.dart';
+import 'package:aves/widgets/common/app_bar_title.dart';
+import 'package:aves/widgets/fullscreen/info/info_search.dart';
+import 'package:aves/widgets/fullscreen/info/metadata/metadata_section.dart';
+import 'package:flutter/material.dart';
+
+class InfoAppBar extends StatelessWidget {
+  final ImageEntry entry;
+  final ValueNotifier<Map<String, MetadataDirectory>> metadataNotifier;
+  final VoidCallback onBackPressed;
+
+  const InfoAppBar({
+    @required this.entry,
+    @required this.metadataNotifier,
+    @required this.onBackPressed,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return SliverAppBar(
+      leading: IconButton(
+        key: Key('back-button'),
+        icon: Icon(AIcons.goUp),
+        onPressed: onBackPressed,
+        tooltip: 'Back to viewer',
+      ),
+      title: TappableAppBarTitle(
+        onTap: () => _goToSearch(context),
+        child: Text('Info'),
+      ),
+      actions: [
+        IconButton(
+          icon: Icon(AIcons.search),
+          onPressed: () => _goToSearch(context),
+          tooltip: 'Search',
+        ),
+      ],
+      titleSpacing: 0,
+      floating: true,
+    );
+  }
+
+  void _goToSearch(BuildContext context) {
+    showSearch(
+      context: context,
+      delegate: InfoSearchDelegate(
+        entry: entry,
+        metadataNotifier: metadataNotifier,
+      ),
+    );
+  }
+}

lib/widgets/fullscreen/info/info_page.dart

@@ -2,9 +2,9 @@ import 'package:aves/model/filters/filters.dart';
 import 'package:aves/model/image_entry.dart';
 import 'package:aves/model/source/collection_lens.dart';
 import 'package:aves/theme/durations.dart';
-import 'package:aves/theme/icons.dart';
 import 'package:aves/widgets/common/providers/media_query_data_provider.dart';
 import 'package:aves/widgets/fullscreen/info/basic_section.dart';
+import 'package:aves/widgets/fullscreen/info/info_app_bar.dart';
 import 'package:aves/widgets/fullscreen/info/location_section.dart';
 import 'package:aves/widgets/fullscreen/info/metadata/metadata_section.dart';
 import 'package:aves/widgets/fullscreen/info/notifications.dart';
@@ -38,17 +38,6 @@ class InfoPageState extends State<InfoPage> {
 
   @override
   Widget build(BuildContext context) {
-    final appBar = SliverAppBar(
-      leading: IconButton(
-        key: Key('back-button'),
-        icon: Icon(AIcons.goUp),
-        onPressed: _goToImage,
-        tooltip: 'Back to viewer',
-      ),
-      title: Text('Info'),
-      floating: true,
-    );
-
     return MediaQueryDataProvider(
       child: Scaffold(
         body: SafeArea(
@@ -68,9 +57,9 @@ class InfoPageState extends State<InfoPage> {
                             entry: entry,
                             visibleNotifier: widget.visibleNotifier,
                             scrollController: _scrollController,
-                            appBar: appBar,
                             split: mqWidth > 400,
                             mqViewInsetsBottom: mqViewInsetsBottom,
+                            goToViewer: _goToViewer,
                           )
                         : SizedBox.shrink();
                   },
@@ -97,7 +86,7 @@ class InfoPageState extends State<InfoPage> {
           _scrollStartFromTop = false;
         } else if (notification is OverscrollNotification) {
           if (notification.overscroll < 0) {
-            _goToImage();
+            _goToViewer();
             _scrollStartFromTop = false;
           }
         }
@@ -106,7 +95,7 @@ class InfoPageState extends State<InfoPage> {
     return false;
   }
 
-  void _goToImage() {
+  void _goToViewer() {
     BackUpNotification().dispatch(context);
     _scrollController.animateTo(
       0,
@@ -121,9 +110,9 @@ class _InfoPageContent extends StatefulWidget {
   final ImageEntry entry;
   final ValueNotifier<bool> visibleNotifier;
   final ScrollController scrollController;
-  final SliverAppBar appBar;
   final bool split;
   final double mqViewInsetsBottom;
+  final VoidCallback goToViewer;
 
   const _InfoPageContent({
     Key key,
@@ -131,9 +120,9 @@ class _InfoPageContent extends StatefulWidget {
     @required this.entry,
     @required this.visibleNotifier,
     @required this.scrollController,
-    @required this.appBar,
     @required this.split,
     @required this.mqViewInsetsBottom,
+    @required this.goToViewer,
   }) : super(key: key);
 
   @override
@@ -143,6 +132,8 @@ class _InfoPageContent extends StatefulWidget {
 class _InfoPageContentState extends State<_InfoPageContent> {
   static const horizontalPadding = EdgeInsets.symmetric(horizontal: 8);
 
+  final ValueNotifier<Map<String, MetadataDirectory>> _metadataNotifier = ValueNotifier({});
+
   CollectionLens get collection => widget.collection;
 
   ImageEntry get entry => widget.entry;
@@ -178,13 +169,18 @@ class _InfoPageContentState extends State<_InfoPageContent> {
           );
     final metadataSliver = MetadataSectionSliver(
       entry: entry,
+      metadataNotifier: _metadataNotifier,
       visibleNotifier: widget.visibleNotifier,
     );
 
     return CustomScrollView(
       controller: widget.scrollController,
       slivers: [
-        widget.appBar,
+        InfoAppBar(
+          entry: entry,
+          metadataNotifier: _metadataNotifier,
+          onBackPressed: widget.goToViewer,
+        ),
         SliverPadding(
           padding: horizontalPadding + EdgeInsets.only(top: 8),
           sliver: basicAndLocationSliver,

lib/widgets/fullscreen/info/info_search.dart

@@ -0,0 +1,109 @@
+import 'package:aves/model/image_entry.dart';
+import 'package:aves/theme/icons.dart';
+import 'package:aves/widgets/collection/empty.dart';
+import 'package:aves/widgets/fullscreen/info/metadata/metadata_dir_tile.dart';
+import 'package:aves/widgets/fullscreen/info/metadata/metadata_section.dart';
+import 'package:flutter/material.dart';
+
+class InfoSearchDelegate extends SearchDelegate {
+  final ImageEntry entry;
+  final ValueNotifier<Map<String, MetadataDirectory>> metadataNotifier;
+
+  Map<String, MetadataDirectory> get metadata => metadataNotifier.value;
+
+  static const suggestions = {
+    'Date & time': 'date or time or when',
+    'Description': 'abtract or description or comment',
+    'Dimensions': 'width or height or dimension or framesize',
+    'Resolution': 'resolution',
+    'Rights': 'rights or copyright or artist or creator or by-line or credit',
+  };
+
+  InfoSearchDelegate({
+    @required this.entry,
+    @required this.metadataNotifier,
+  }) : super(
+          searchFieldLabel: 'Search metadata',
+        );
+
+  @override
+  ThemeData appBarTheme(BuildContext context) {
+    return Theme.of(context);
+  }
+
+  @override
+  Widget buildLeading(BuildContext context) {
+    return IconButton(
+      icon: AnimatedIcon(
+        icon: AnimatedIcons.menu_arrow,
+        progress: transitionAnimation,
+      ),
+      onPressed: () => Navigator.pop(context),
+      tooltip: MaterialLocalizations.of(context).backButtonTooltip,
+    );
+  }
+
+  @override
+  List<Widget> buildActions(BuildContext context) {
+    return [
+      if (query.isNotEmpty)
+        IconButton(
+          icon: Icon(AIcons.clear),
+          onPressed: () {
+            query = '';
+            showSuggestions(context);
+          },
+          tooltip: 'Clear',
+        ),
+    ];
+  }
+
+  @override
+  Widget buildSuggestions(BuildContext context) => ListView(
+        children: suggestions.entries
+            .map((kv) => ListTile(
+                  title: Text(kv.key),
+                  onTap: () {
+                    query = kv.value;
+                    showResults(context);
+                  },
+                ))
+            .toList(),
+      );
+
+  @override
+  Widget buildResults(BuildContext context) {
+    if (query.isEmpty) {
+      showSuggestions(context);
+      return SizedBox();
+    }
+
+    final effectiveQueries = query.toUpperCase().split(' OR ').map((query) => query.trim());
+    bool testKey(String key) => effectiveQueries.any(key.toUpperCase().contains);
+    final filteredMetadata = Map.fromEntries(metadata.entries.map((kv) {
+      final filteredDir = kv.value.filterKeys(testKey);
+      return MapEntry(kv.key, filteredDir);
+    }));
+
+    final tiles = filteredMetadata.entries
+        .where((kv) => kv.value.tags.isNotEmpty)
+        .map((kv) => MetadataDirTile(
+              entry: entry,
+              title: kv.key,
+              dir: kv.value,
+              initiallyExpanded: true,
+              showPrefixChildren: false,
+            ))
+        .toList();
+    return tiles.isEmpty
+        ? EmptyContent(
+            icon: AIcons.info,
+            text: 'No matching keys',
+          )
+        : ListView.builder(
+            padding: EdgeInsets.all(8),
+            itemBuilder: (context, index) => tiles[index],
+            itemCount: tiles.length,
+          );
+  }
+}

lib/widgets/fullscreen/info/metadata/metadata_dir_tile.dart

@@ -0,0 +1,113 @@
+import 'dart:collection';
+
+import 'package:aves/model/image_entry.dart';
+import 'package:aves/ref/brand_colors.dart';
+import 'package:aves/services/svg_metadata_service.dart';
+import 'package:aves/theme/icons.dart';
+import 'package:aves/utils/color_utils.dart';
+import 'package:aves/utils/constants.dart';
+import 'package:aves/widgets/common/identity/aves_expansion_tile.dart';
+import 'package:aves/widgets/fullscreen/info/common.dart';
+import 'package:aves/widgets/fullscreen/info/metadata/metadata_section.dart';
+import 'package:aves/widgets/fullscreen/info/metadata/metadata_thumbnail.dart';
+import 'package:aves/widgets/fullscreen/info/metadata/xmp_tile.dart';
+import 'package:aves/widgets/fullscreen/source_viewer_page.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+
+class MetadataDirTile extends StatelessWidget {
+  final ImageEntry entry;
+  final String title;
+  final MetadataDirectory dir;
+  final ValueNotifier<String> expandedDirectoryNotifier;
+  final bool initiallyExpanded, showPrefixChildren;
+
+  const MetadataDirTile({
+    @required this.entry,
+    @required this.title,
+    @required this.dir,
+    this.expandedDirectoryNotifier,
+    this.initiallyExpanded = false,
+    this.showPrefixChildren = true,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final tags = dir.tags;
+    if (tags.isEmpty) return SizedBox.shrink();
+
+    final dirName = dir.name;
+    if (dirName == MetadataDirectory.xmpDirectory) {
+      return XmpDirTile(
+        entry: entry,
+        tags: tags,
+        expandedNotifier: expandedDirectoryNotifier,
+        initiallyExpanded: initiallyExpanded,
+      );
+    }
+
+    Widget thumbnail;
+    final prefixChildren = <Widget>[];
+    if (showPrefixChildren) {
+      switch (dirName) {
+        case MetadataDirectory.exifThumbnailDirectory:
+          thumbnail = MetadataThumbnails(source: MetadataThumbnailSource.exif, entry: entry);
+          break;
+        case MetadataDirectory.mediaDirectory:
+          thumbnail = MetadataThumbnails(source: MetadataThumbnailSource.embedded, entry: entry);
+          Widget builder(IconData data) => Padding(
+                padding: EdgeInsets.symmetric(vertical: 4, horizontal: 8),
+                child: Icon(data),
+              );
+          if (tags['Has Video'] == 'yes') prefixChildren.add(builder(AIcons.video));
+          if (tags['Has Audio'] == 'yes') prefixChildren.add(builder(AIcons.audio));
+          if (tags['Has Image'] == 'yes') {
+            int count;
+            if (tags.containsKey('Image Count')) {
+              count = int.tryParse(tags['Image Count']);
+            }
+            prefixChildren.addAll(List.generate(count ?? 1, (i) => builder(AIcons.image)));
+          }
+          break;
+      }
+    }
+
+    return AvesExpansionTile(
+      title: title,
+      color: BrandColors.get(dirName) ?? stringToColor(dirName),
+      expandedNotifier: expandedDirectoryNotifier,
+      initiallyExpanded: initiallyExpanded,
+      children: [
+        if (prefixChildren.isNotEmpty) Wrap(children: prefixChildren),
+        if (thumbnail != null) thumbnail,
+        Padding(
+          padding: EdgeInsets.only(left: 8, right: 8, bottom: 8),
+          child: InfoRowGroup(
+            tags,
+            maxValueLength: Constants.infoGroupMaxValueLength,
+            linkHandlers: dirName == SvgMetadataService.metadataDirectory ? getSvgLinkHandlers(tags) : null,
+          ),
+        ),
+      ],
+    );
+  }
+
+  static Map<String, InfoLinkHandler> getSvgLinkHandlers(SplayTreeMap<String, String> tags) {
+    return {
+      'Metadata': InfoLinkHandler(
+        linkText: 'View XML',
+        onTap: (context) {
+          Navigator.push(
+            context,
+            MaterialPageRoute(
+              settings: RouteSettings(name: SourceViewerPage.routeName),
+              builder: (context) => SourceViewerPage(
+                loader: () => SynchronousFuture(tags['Metadata']),
+              ),
+            ),
+          );
+        },
+      ),
+    };
+  }
+}

lib/widgets/fullscreen/info/metadata/metadata_section.dart

@@ -1,18 +1,12 @@
 import 'dart:collection';
 
 import 'package:aves/model/image_entry.dart';
-import 'package:aves/ref/brand_colors.dart';
 import 'package:aves/services/metadata_service.dart';
 import 'package:aves/services/svg_metadata_service.dart';
 import 'package:aves/theme/durations.dart';
 import 'package:aves/theme/icons.dart';
-import 'package:aves/utils/color_utils.dart';
-import 'package:aves/utils/constants.dart';
-import 'package:aves/widgets/common/identity/aves_expansion_tile.dart';
 import 'package:aves/widgets/fullscreen/info/common.dart';
-import 'package:aves/widgets/fullscreen/info/metadata/metadata_thumbnail.dart';
+import 'package:aves/widgets/fullscreen/info/metadata/metadata_dir_tile.dart';
-import 'package:aves/widgets/fullscreen/info/metadata/xmp_tile.dart';
-import 'package:aves/widgets/fullscreen/source_viewer_page.dart';
 import 'package:collection/collection.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
@@ -21,10 +15,12 @@ import 'package:flutter_staggered_animations/flutter_staggered_animations.dart';
 class MetadataSectionSliver extends StatefulWidget {
   final ImageEntry entry;
   final ValueNotifier<bool> visibleNotifier;
+  final ValueNotifier<Map<String, MetadataDirectory>> metadataNotifier;
 
   const MetadataSectionSliver({
     @required this.entry,
     @required this.visibleNotifier,
+    @required this.metadataNotifier,
   });
 
   @override
@@ -32,7 +28,6 @@ class MetadataSectionSliver extends StatefulWidget {
 }
 
 class _MetadataSectionSliverState extends State<MetadataSectionSliver> with AutomaticKeepAliveClientMixin {
-  Map<String, _MetadataDirectory> _metadata = {};
   final ValueNotifier<String> _loadedMetadataUri = ValueNotifier(null);
   final ValueNotifier<String> _expandedDirectoryNotifier = ValueNotifier(null);
 
@@ -40,10 +35,9 @@ class _MetadataSectionSliverState extends State<MetadataSectionSliver> with Auto
 
   bool get isVisible => widget.visibleNotifier.value;
 
-  // special directory names
+  ValueNotifier<Map<String, MetadataDirectory>> get metadataNotifier => widget.metadataNotifier;
-  static const exifThumbnailDirectory = 'Exif Thumbnail'; // from metadata-extractor
+
-  static const xmpDirectory = 'XMP'; // from metadata-extractor
+  Map<String, MetadataDirectory> get metadata => metadataNotifier.value;
-  static const mediaDirectory = 'Media'; // additional media (video/audio/images) directory
 
   // directory names may contain the name of their parent directory
   // if so, they are separated by this character
@@ -53,6 +47,7 @@ class _MetadataSectionSliverState extends State<MetadataSectionSliver> with Auto
   void initState() {
     super.initState();
     _registerWidget(widget);
+    metadataNotifier.value = {};
     _getMetadata();
   }
 
@@ -96,7 +91,7 @@ class _MetadataSectionSliverState extends State<MetadataSectionSliver> with Auto
           valueListenable: _loadedMetadataUri,
           builder: (context, uri, child) {
             Widget content;
-            if (_metadata.isEmpty) {
+            if (metadata.isEmpty) {
               content = SizedBox.shrink();
             } else {
               content = Column(
@@ -111,7 +106,12 @@ class _MetadataSectionSliverState extends State<MetadataSectionSliver> with Auto
                   ),
                   children: [
                     SectionRow(AIcons.info),
-                    ..._metadata.entries.map((kv) => _buildDirTile(kv.key, kv.value)),
+                    ...metadata.entries.map((kv) => MetadataDirTile(
+                          entry: entry,
+                          title: kv.key,
+                          dir: kv.value,
+                          expandedDirectoryNotifier: _expandedDirectoryNotifier,
+                        )),
                   ],
                 ),
               );
@@ -128,64 +128,9 @@ class _MetadataSectionSliverState extends State<MetadataSectionSliver> with Auto
     );
   }
 
-  Widget _buildDirTile(String title, _MetadataDirectory dir) {
-    if (dir.tags.isEmpty) return SizedBox.shrink();
-
-    final dirName = dir.name;
-    if (dirName == xmpDirectory) {
-      return XmpDirTile(
-        entry: entry,
-        tags: dir.tags,
-        expandedNotifier: _expandedDirectoryNotifier,
-      );
-    }
-
-    Widget thumbnail;
-    final prefixChildren = <Widget>[];
-    switch (dirName) {
-      case exifThumbnailDirectory:
-        thumbnail = MetadataThumbnails(source: MetadataThumbnailSource.exif, entry: entry);
-        break;
-      case mediaDirectory:
-        thumbnail = MetadataThumbnails(source: MetadataThumbnailSource.embedded, entry: entry);
-        Widget builder(IconData data) => Padding(
-              padding: EdgeInsets.symmetric(vertical: 4, horizontal: 8),
-              child: Icon(data),
-            );
-        if (dir.tags['Has Video'] == 'yes') prefixChildren.add(builder(AIcons.video));
-        if (dir.tags['Has Audio'] == 'yes') prefixChildren.add(builder(AIcons.audio));
-        if (dir.tags['Has Image'] == 'yes') {
-          int count;
-          if (dir.tags.containsKey('Image Count')) {
-            count = int.tryParse(dir.tags['Image Count']);
-          }
-          prefixChildren.addAll(List.generate(count ?? 1, (i) => builder(AIcons.image)));
-        }
-        break;
-    }
-
-    return AvesExpansionTile(
-      title: title,
-      color: BrandColors.get(dirName) ?? stringToColor(dirName),
-      expandedNotifier: _expandedDirectoryNotifier,
-      children: [
-        if (prefixChildren.isNotEmpty) Wrap(children: prefixChildren),
-        if (thumbnail != null) thumbnail,
-        Padding(
-          padding: EdgeInsets.only(left: 8, right: 8, bottom: 8),
-          child: InfoRowGroup(
-            dir.tags,
-            maxValueLength: Constants.infoGroupMaxValueLength,
-            linkHandlers: dirName == SvgMetadataService.metadataDirectory ? getSvgLinkHandlers(dir.tags) : null,
-          ),
-        ),
-      ],
-    );
-  }
-
   void _onMetadataChanged() {
     _loadedMetadataUri.value = null;
-    _metadata = {};
+    metadataNotifier.value = {};
     _getMetadata();
   }
 
@@ -211,7 +156,7 @@ class _MetadataSectionSliverState extends State<MetadataSectionSliver> with Auto
           final tagName = tagKV.key as String ?? '';
           return MapEntry(tagName, value);
         }).where((kv) => kv != null)));
-        return _MetadataDirectory(directoryName, parent, tags);
+        return MetadataDirectory(directoryName, parent, tags);
       }).toList();
 
       final titledDirectories = directories.map((dir) {
@@ -222,42 +167,36 @@ class _MetadataSectionSliverState extends State<MetadataSectionSliver> with Auto
         return MapEntry(title, dir);
       }).toList()
         ..sort((a, b) => compareAsciiUpperCase(a.key, b.key));
-      _metadata = Map.fromEntries(titledDirectories);
+      metadataNotifier.value = Map.fromEntries(titledDirectories);
       _loadedMetadataUri.value = entry.uri;
     } else {
-      _metadata = {};
+      metadataNotifier.value = {};
       _loadedMetadataUri.value = null;
     }
     _expandedDirectoryNotifier.value = null;
   }
 
-  static Map<String, InfoLinkHandler> getSvgLinkHandlers(SplayTreeMap<String, String> tags) {
-    return {
-      'Metadata': InfoLinkHandler(
-        linkText: 'View XML',
-        onTap: (context) {
-          Navigator.push(
-            context,
-            MaterialPageRoute(
-              settings: RouteSettings(name: SourceViewerPage.routeName),
-              builder: (context) => SourceViewerPage(
-                loader: () => SynchronousFuture(tags['Metadata']),
-              ),
-            ),
-          );
-        },
-      ),
-    };
-  }
-
   @override
   bool get wantKeepAlive => true;
 }
 
-class _MetadataDirectory {
+class MetadataDirectory {
   final String name;
   final String parent;
+  final SplayTreeMap<String, String> allTags;
   final SplayTreeMap<String, String> tags;
 
-  const _MetadataDirectory(this.name, this.parent, this.tags);
+  // special directory names
+  static const exifThumbnailDirectory = 'Exif Thumbnail'; // from metadata-extractor
+  static const xmpDirectory = 'XMP'; // from metadata-extractor
+  static const mediaDirectory = 'Media'; // additional media (video/audio/images) directory
+
+  const MetadataDirectory(this.name, this.parent, SplayTreeMap<String, String> allTags, {SplayTreeMap<String, String> tags})
+      : allTags = allTags,
+        tags = tags ?? allTags;
+
+  MetadataDirectory filterKeys(bool Function(String key) testKey) {
+    final filteredTags = SplayTreeMap.of(Map.fromEntries(allTags.entries.where((kv) => testKey(kv.key))));
+    return MetadataDirectory(name, parent, tags, tags: filteredTags);
+  }
 }

lib/widgets/fullscreen/info/metadata/xmp_structs.dart

@@ -89,7 +89,7 @@ class _XmpStructArrayCardState extends State<XmpStructArrayCard> {
               // without clipping the text
               padding: EdgeInsets.only(left: 8, right: 8, bottom: 8),
               child: InfoRowGroup(
-                structs[_index],
+                structs[_index] ?? {},
                 maxValueLength: Constants.infoGroupMaxValueLength,
                 linkHandlers: widget.linkifier?.call(_index + 1),
               ),

lib/widgets/fullscreen/info/metadata/xmp_tile.dart

@@ -25,11 +25,13 @@ class XmpDirTile extends StatefulWidget {
   final ImageEntry entry;
   final SplayTreeMap<String, String> tags;
   final ValueNotifier<String> expandedNotifier;
+  final bool initiallyExpanded;
 
   const XmpDirTile({
     @required this.entry,
     @required this.tags,
     @required this.expandedNotifier,
+    @required this.initiallyExpanded,
   });
 
   @override
@@ -76,6 +78,7 @@ class _XmpDirTileState extends State<XmpDirTile> with FeedbackMixin {
     return AvesExpansionTile(
       title: 'XMP',
       expandedNotifier: widget.expandedNotifier,
+      initiallyExpanded: widget.initiallyExpanded,
       children: [
         NotificationListener<OpenEmbeddedDataNotification>(
           onNotification: (notification) {

lib/widgets/home_page.dart

@@ -142,7 +142,7 @@ class _HomePageState extends State<HomePage> {
         );
       case SearchPage.routeName:
         return SearchPageRoute(
-          delegate: ImageSearchDelegate(source: _mediaStore),
+          delegate: CollectionSearchDelegate(source: _mediaStore),
         );
       case CollectionPage.routeName:
       default:

lib/widgets/search/search_button.dart

@@ -4,11 +4,11 @@ import 'package:aves/theme/icons.dart';
 import 'package:aves/widgets/search/search_delegate.dart';
 import 'package:flutter/material.dart';
 
-class SearchButton extends StatelessWidget {
+class CollectionSearchButton extends StatelessWidget {
   final CollectionSource source;
   final CollectionLens parentCollection;
 
-  const SearchButton(this.source, {this.parentCollection});
+  const CollectionSearchButton(this.source, {this.parentCollection});
 
   @override
   Widget build(BuildContext context) {
@@ -24,7 +24,7 @@ class SearchButton extends StatelessWidget {
     Navigator.push(
         context,
         SearchPageRoute(
-          delegate: ImageSearchDelegate(
+          delegate: CollectionSearchDelegate(
             source: source,
             parentCollection: parentCollection,
           ),

lib/widgets/search/search_delegate.dart

@@ -20,14 +20,14 @@ import 'package:aves/widgets/search/search_page.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 
-class ImageSearchDelegate {
+class CollectionSearchDelegate {
   final CollectionSource source;
   final CollectionLens parentCollection;
   final ValueNotifier<String> expandedSectionNotifier = ValueNotifier(null);
 
   static const searchHistoryCount = 10;
 
-  ImageSearchDelegate({@required this.source, this.parentCollection});
+  CollectionSearchDelegate({@required this.source, this.parentCollection});
 
   ThemeData appBarTheme(BuildContext context) {
     return Theme.of(context);
@@ -289,7 +289,7 @@ class SearchPageRoute<T> extends PageRoute<T> {
     delegate.route = this;
   }
 
-  final ImageSearchDelegate delegate;
+  final CollectionSearchDelegate delegate;
 
   @override
   Color get barrierColor => null;

lib/widgets/search/search_page.dart

@@ -7,7 +7,7 @@ import 'package:flutter/material.dart';
 class SearchPage extends StatefulWidget {
   static const routeName = '/search';
 
-  final ImageSearchDelegate delegate;
+  final CollectionSearchDelegate delegate;
   final Animation<double> animation;
 
   const SearchPage({
@@ -115,7 +115,7 @@ class _SearchPageState extends State<SearchPage> {
           onSubmitted: (_) => widget.delegate.showResults(context),
           decoration: InputDecoration(
             border: InputBorder.none,
-            hintText: MaterialLocalizations.of(context).searchFieldLabel,
+            hintText: 'Search collection',
             hintStyle: theme.inputDecorationTheme.hintStyle,
           ),
         ),