filter bar: minor fixes

lib/model/collection_filters.dart

@@ -26,6 +26,8 @@ abstract class CollectionFilter implements Comparable<CollectionFilter> {
 
   String get label;
 
+  String get tooltip => label;
+
   Widget iconBuilder(BuildContext context, double size);
 
   Future<Color> color(BuildContext context) => SynchronousFuture(stringToColor(label));
@@ -44,6 +46,8 @@ abstract class CollectionFilter implements Comparable<CollectionFilter> {
 class AlbumFilter extends CollectionFilter {
   static const type = 'album';
 
+  static Map<String, Color> _appColors = Map();
+
   final String album;
 
   const AlbumFilter(this.album);
@@ -54,23 +58,34 @@ class AlbumFilter extends CollectionFilter {
   @override
   String get label => album.split(separator).last;
 
+  @override
+  String get tooltip => album;
+
   @override
   Widget iconBuilder(context, size) {
     return IconUtils.getAlbumIcon(context: context, album: album, size: size) ?? Icon(OMIcons.photoAlbum, size: size);
   }
 
-  Future<Color> color(BuildContext context) async {
+  @override
-    Color color;
+  Future<Color> color(BuildContext context) {
+    // do not use async/await and rely on `SynchronousFuture`
+    // to prevent rebuilding of the `FutureBuilder` listening on this future
     if (androidFileUtils.getAlbumType(album) == AlbumType.App) {
-      final palette = await PaletteGenerator.fromImageProvider(
+      if (_appColors.containsKey(album)) return SynchronousFuture(_appColors[album]);
+
+      return PaletteGenerator.fromImageProvider(
         AppIconImage(
           packageName: androidFileUtils.getAlbumAppPackageName(album),
           size: 24,
         ),
-      );
+      ).then((palette) {
-      color = palette.dominantColor?.color;
+        final color = palette.dominantColor?.color ?? super.color(context);
+        _appColors[album] = color;
+        return color;
+      });
+    } else {
+      return super.color(context);
     }
-    return color ?? super.color(context);
   }
 
   @override

lib/widgets/album/filter_bar.dart

@@ -35,8 +35,8 @@ class FilterBar extends StatelessWidget implements PreferredSizeWidget {
             final filter = filters[index];
             return Center(
               child: AvesFilterChip(
-                filter,
+                filter: filter,
-                clearable: true,
+                removable: true,
                 onPressed: collection.removeFilter,
               ),
             );

lib/widgets/common/aves_filter_chip.dart

@@ -6,7 +6,7 @@ typedef FilterCallback = void Function(CollectionFilter filter);
 
 class AvesFilterChip extends StatefulWidget {
   final CollectionFilter filter;
-  final bool clearable;
+  final bool removable;
   final FilterCallback onPressed;
 
   static const double buttonBorderWidth = 2;
@@ -14,11 +14,12 @@ class AvesFilterChip extends StatefulWidget {
   static const double iconSize = 20;
   static const double padding = 6;
 
-  const AvesFilterChip(
+  const AvesFilterChip({
-    this.filter, {
+    Key key,
-    this.clearable = false,
+    this.filter,
+    this.removable = false,
     @required this.onPressed,
-  });
+  }) : super(key: key);
 
   @override
   _AvesFilterChipState createState() => _AvesFilterChipState();
@@ -29,8 +30,6 @@ class _AvesFilterChipState extends State<AvesFilterChip> {
 
   CollectionFilter get filter => widget.filter;
 
-  String get label => filter.label;
-
   @override
   void initState() {
     super.initState();
@@ -50,7 +49,7 @@ class _AvesFilterChipState extends State<AvesFilterChip> {
   @override
   Widget build(BuildContext context) {
     final leading = filter.iconBuilder(context, AvesFilterChip.iconSize);
-    final trailing = widget.clearable ? Icon(OMIcons.clear, size: AvesFilterChip.iconSize) : null;
+    final trailing = widget.removable ? Icon(OMIcons.clear, size: AvesFilterChip.iconSize) : null;
 
     final child = Row(
       mainAxisSize: MainAxisSize.min,
@@ -61,7 +60,7 @@ class _AvesFilterChipState extends State<AvesFilterChip> {
         ],
         Flexible(
           child: Text(
-            label,
+            filter.label,
             softWrap: false,
             overflow: TextOverflow.fade,
             maxLines: 1,
@@ -81,7 +80,7 @@ class _AvesFilterChipState extends State<AvesFilterChip> {
     return ConstrainedBox(
       constraints: const BoxConstraints(maxWidth: AvesFilterChip.maxChipWidth),
       child: Tooltip(
-        message: label,
+        message: filter.tooltip,
         child: FutureBuilder(
           future: _colorFuture,
           builder: (context, AsyncSnapshot<Color> snapshot) {

lib/widgets/fullscreen/info/basic_section.dart

@@ -49,7 +49,7 @@ class BasicSection extends StatelessWidget {
               spacing: 8,
               children: filters
                   .map((filter) => AvesFilterChip(
-                        filter,
+                        filter: filter,
                         onPressed: onFilter,
                       ))
                   .toList(),

lib/widgets/fullscreen/info/location_section.dart

@@ -113,7 +113,7 @@ class _LocationSectionState extends State<LocationSection> {
                 spacing: 8,
                 children: filters
                     .map((filter) => AvesFilterChip(
-                          filter,
+                          filter: filter,
                           onPressed: widget.onFilter,
                         ))
                     .toList(),