added filters to app bar

lib/model/collection_filters.dart

@@ -1,9 +1,16 @@
 import 'package:aves/model/image_entry.dart';
+import 'package:flutter/widgets.dart';
+import 'package:outline_material_icons/outline_material_icons.dart';
+import 'package:path/path.dart';
 
 abstract class CollectionFilter {
   const CollectionFilter();
 
   bool filter(ImageEntry entry);
+
+  String get label;
+
+  IconData get icon => null;
 }
 
 class AlbumFilter extends CollectionFilter {
@@ -13,6 +20,21 @@ class AlbumFilter extends CollectionFilter {
 
   @override
   bool filter(ImageEntry entry) => entry.directory == album;
+
+  @override
+  String get label => album.split(separator).last;
+
+  @override
+  IconData get icon => OMIcons.photoAlbum;
+
+  @override
+  bool operator ==(Object other) {
+    if (other.runtimeType != runtimeType) return false;
+    return other is AlbumFilter && other.album == album;
+  }
+
+  @override
+  int get hashCode => hashValues('AlbumFilter', album);
 }
 
 class TagFilter extends CollectionFilter {
@@ -22,6 +44,21 @@ class TagFilter extends CollectionFilter {
 
   @override
   bool filter(ImageEntry entry) => entry.xmpSubjects.contains(tag);
+
+  @override
+  String get label => tag;
+
+  @override
+  IconData get icon => OMIcons.localOffer;
+
+  @override
+  bool operator ==(Object other) {
+    if (other.runtimeType != runtimeType) return false;
+    return other is TagFilter && other.tag == tag;
+  }
+
+  @override
+  int get hashCode => hashValues('TagFilter', tag);
 }
 
 class CountryFilter extends CollectionFilter {
@@ -31,23 +68,74 @@ class CountryFilter extends CollectionFilter {
 
   @override
   bool filter(ImageEntry entry) => entry.isLocated && entry.addressDetails.countryName == country;
+
+  @override
+  String get label => country;
+
+  @override
+  IconData get icon => OMIcons.place;
+
+  @override
+  bool operator ==(Object other) {
+    if (other.runtimeType != runtimeType) return false;
+    return other is CountryFilter && other.country == country;
+  }
+
+  @override
+  int get hashCode => hashValues('CountryFilter', country);
 }
 
 class VideoFilter extends CollectionFilter {
   @override
   bool filter(ImageEntry entry) => entry.isVideo;
+
+  @override
+  String get label => 'Video';
+
+  @override
+  bool operator ==(Object other) {
+    if (other.runtimeType != runtimeType) return false;
+    return other is VideoFilter;
+  }
+
+  @override
+  int get hashCode => 'VideoFilter'.hashCode;
 }
 
 class GifFilter extends CollectionFilter {
   @override
   bool filter(ImageEntry entry) => entry.isGif;
+
+  @override
+  String get label => 'GIF';
+
+  @override
+  bool operator ==(Object other) {
+    if (other.runtimeType != runtimeType) return false;
+    return other is GifFilter;
+  }
+
+  @override
+  int get hashCode => 'GifFilter'.hashCode;
 }
 
 class MetadataFilter extends CollectionFilter {
-  final String value;
+  final String query;
 
-  const MetadataFilter(this.value);
+  const MetadataFilter(this.query);
 
   @override
-  bool filter(ImageEntry entry) => entry.search(value);
+  bool filter(ImageEntry entry) => entry.search(query);
+
+  @override
+  String get label => '"${query}"';
+
+  @override
+  bool operator ==(Object other) {
+    if (other.runtimeType != runtimeType) return false;
+    return other is MetadataFilter && other.query == query;
+  }
+
+  @override
+  int get hashCode => hashValues('MetadataFilter', query);
 }

lib/model/collection_lens.dart

@@ -9,7 +9,7 @@ import 'package:flutter/foundation.dart';
 
 class CollectionLens with ChangeNotifier {
   final CollectionSource source;
-  final List<CollectionFilter> filters;
+  final Set<CollectionFilter> filters;
   GroupFactor groupFactor;
   SortFactor sortFactor;
 
@@ -23,7 +23,7 @@ class CollectionLens with ChangeNotifier {
     List<CollectionFilter> filters,
     GroupFactor groupFactor,
     SortFactor sortFactor,
-  })  : this.filters = [if (filters != null) ...filters.where((f) => f != null)],
+  })  : this.filters = [if (filters != null) ...filters.where((f) => f != null)].toSet(),
         this.groupFactor = groupFactor ?? GroupFactor.month,
         this.sortFactor = sortFactor ?? SortFactor.date {
     _subscriptions.add(source.eventBus.on<EntryAddedEvent>().listen((e) => onEntryAdded()));

lib/widgets/album/collection_page.dart

@@ -1,6 +1,7 @@
 import 'package:aves/model/collection_lens.dart';
 import 'package:aves/widgets/album/all_collection_app_bar.dart';
 import 'package:aves/widgets/album/collection_drawer.dart';
+import 'package:aves/widgets/album/filter_bar.dart';
 import 'package:aves/widgets/album/thumbnail_collection.dart';
 import 'package:aves/widgets/common/menu_row.dart';
 import 'package:aves/widgets/common/providers/media_query_data_provider.dart';
@@ -31,6 +32,7 @@ class CollectionPage extends StatelessWidget {
                 : SliverAppBar(
                     title: Text(title),
                     actions: _buildActions(),
+                    bottom: FilterBar(collection.filters),
                     floating: true,
                   ),
           ),

lib/widgets/album/filter_bar.dart

@@ -0,0 +1,84 @@
+import 'package:aves/model/collection_filters.dart';
+import 'package:aves/utils/color_utils.dart';
+import 'package:aves/widgets/fullscreen/info/navigation_button.dart';
+import 'package:collection/collection.dart';
+import 'package:flutter/material.dart';
+
+class FilterBar extends StatelessWidget implements PreferredSizeWidget {
+  final List<CollectionFilter> filters;
+
+  final ScrollController _scrollController = ScrollController();
+
+  static const double maxChipWidth = 160;
+  static const EdgeInsets padding = EdgeInsets.only(left: 8, right: 8, bottom: 8);
+
+  @override
+  final Size preferredSize = Size.fromHeight(kMinInteractiveDimension + padding.vertical);
+
+  FilterBar(Set<CollectionFilter> filters)
+      : this.filters = filters.toList()
+          ..sort((a, b) {
+            return compareAsciiUpperCase(a.label, b.label);
+          });
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      // specify transparent as a workaround to prevent
+      // chip border clipping when the floating app bar is fading
+      color: Colors.transparent,
+      padding: padding,
+      height: preferredSize.height,
+      child: NotificationListener<ScrollNotification>(
+        // cancel notification bubbling so that the draggable scrollbar
+        // does not misinterpret filter bar scrolling for collection scrolling
+        onNotification: (notification) => true,
+        child: ListView.separated(
+          scrollDirection: Axis.horizontal,
+          controller: _scrollController,
+          primary: false,
+          physics: const BouncingScrollPhysics(),
+          padding: EdgeInsets.all(NavigationButton.buttonBorderWidth / 2),
+          itemBuilder: (context, index) {
+            if (index >= filters.length) return null;
+            final filter = filters[index];
+            final icon = filter.icon;
+            final label = filter.label;
+            return ConstrainedBox(
+              constraints: const BoxConstraints(maxWidth: maxChipWidth),
+              child: OutlineButton(
+                onPressed: () {},
+                borderSide: BorderSide(
+                  color: stringToColor(label),
+                  width: NavigationButton.buttonBorderWidth,
+                ),
+                shape: RoundedRectangleBorder(
+                  borderRadius: BorderRadius.circular(42),
+                ),
+                child: Row(
+                  mainAxisSize: MainAxisSize.min,
+                  children: [
+                    if (icon != null) ...[
+                      Icon(icon),
+                      const SizedBox(width: 8),
+                    ],
+                    Flexible(
+                      child: Text(
+                        label,
+                        softWrap: false,
+                        overflow: TextOverflow.fade,
+                        maxLines: 1,
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+            );
+          },
+          separatorBuilder: (context, index) => const SizedBox(width: 8),
+          itemCount: filters.length,
+        ),
+      ),
+    );
+  }
+}

lib/widgets/album/thumbnail_collection.dart

@@ -10,7 +10,6 @@ class ThumbnailCollection extends StatelessWidget {
   final Widget appBar;
   final WidgetBuilder emptyBuilder;
 
-  final ScrollController _scrollController = ScrollController();
   final ValueNotifier<int> _columnCountNotifier = ValueNotifier(4);
   final GlobalKey _scrollableKey = GlobalKey();
 
@@ -48,7 +47,7 @@ class ThumbnailCollection extends StatelessWidget {
               builder: (context, columnCount, child) {
                 final scrollView = CustomScrollView(
                   key: _scrollableKey,
-                  controller: _scrollController,
+                  primary: true,
                   slivers: [
                     if (appBar != null) appBar,
                     if (collection.isEmpty && emptyBuilder != null)
@@ -77,7 +76,7 @@ class ThumbnailCollection extends StatelessWidget {
                   heightScrollThumb: avesScrollThumbHeight,
                   backgroundColor: Colors.white,
                   scrollThumbBuilder: avesScrollThumbBuilder(),
-                  controller: _scrollController,
+                  controller: PrimaryScrollController.of(context),
                   padding: EdgeInsets.only(
                     // padding to get scroll thumb below app bar, above nav bar
                     top: topPadding,