selection: select/deselect whole section

lib/model/collection_lens.dart

@@ -10,13 +10,12 @@ import 'package:aves/utils/change_notifier.dart';
 import 'package:collection/collection.dart';
 import 'package:flutter/foundation.dart';
 
-class CollectionLens with ChangeNotifier {
+class CollectionLens with ChangeNotifier, CollectionActivityMixin, CollectionSelectionMixin {
   final CollectionSource source;
   final Set<CollectionFilter> filters;
   GroupFactor groupFactor;
   SortFactor sortFactor;
   final AChangeNotifier filterChangeNotifier = AChangeNotifier();
-  final AChangeNotifier selectionChangeNotifier = AChangeNotifier();
 
   List<ImageEntry> _filteredEntries;
   List<StreamSubscription> _subscriptions = [];
@@ -195,9 +194,15 @@ class CollectionLens with ChangeNotifier {
     _applySort();
     _applyGroup();
   }
+}
 
-  // selection
+enum SortFactor { date, size, name }
 
+enum GroupFactor { album, month, day }
+
+enum Activity { browse, select }
+
+mixin CollectionActivityMixin {
   final ValueNotifier<Activity> _activityNotifier = ValueNotifier(Activity.browse);
 
   ValueNotifier<Activity> get activityNotifier => _activityNotifier;
@@ -206,17 +211,20 @@ class CollectionLens with ChangeNotifier {
 
   bool get isSelecting => _activityNotifier.value == Activity.select;
 
-  void browse() {
+  void browse() => _activityNotifier.value = Activity.browse;
-    _activityNotifier.value = Activity.browse;
-    _clearSelection();
-  }
 
   void select() => _activityNotifier.value = Activity.select;
+}
+
+mixin CollectionSelectionMixin on CollectionActivityMixin {
+  final AChangeNotifier selectionChangeNotifier = AChangeNotifier();
 
   final Set<ImageEntry> _selection = {};
 
   Set<ImageEntry> get selection => _selection;
 
+  bool isSelected(List<ImageEntry> entries) => entries.every(selection.contains);
+
   void addToSelection(List<ImageEntry> entries) {
     _selection.addAll(entries);
     selectionChangeNotifier.notifyListeners();
@@ -227,7 +235,7 @@ class CollectionLens with ChangeNotifier {
     selectionChangeNotifier.notifyListeners();
   }
 
-  void _clearSelection() {
+  void clearSelection() {
     _selection.clear();
     selectionChangeNotifier.notifyListeners();
   }
@@ -238,9 +246,3 @@ class CollectionLens with ChangeNotifier {
     selectionChangeNotifier.notifyListeners();
   }
 }
-
-enum SortFactor { date, size, name }
-
-enum GroupFactor { album, month, day }
-
-enum Activity { browse, select }

lib/widgets/album/app_bar.dart

@@ -100,7 +100,10 @@ class _CollectionAppBarState extends State<CollectionAppBar> with SingleTickerPr
       onPressed = Scaffold.of(context).openDrawer;
       tooltip = MaterialLocalizations.of(context).openAppDrawerTooltip;
     } else if (collection.isSelecting) {
-      onPressed = collection.browse;
+      onPressed = () {
+        collection.clearSelection();
+        collection.browse();
+      };
       tooltip = MaterialLocalizations.of(context).backButtonTooltip;
     }
     return IconButton(
@@ -131,9 +134,8 @@ class _CollectionAppBarState extends State<CollectionAppBar> with SingleTickerPr
       return AnimatedBuilder(
         animation: collection.selectionChangeNotifier,
         builder: (context, child) {
-          final selection = collection.selection;
+          final count = collection.selection.length;
-          final count = selection.length;
+          return Text(Intl.plural(count, zero: 'Select items', one: '${count} item', other: '${count} items'));
-          return Text(selection.isEmpty ? 'Select items' : '${count} ${Intl.plural(count, one: 'item', other: 'items')}');
         },
       );
     }

lib/widgets/album/collection_page.dart

@@ -20,6 +20,7 @@ class CollectionPage extends StatelessWidget {
           body: WillPopScope(
             onWillPop: () {
               if (collection.isSelecting) {
+                collection.clearSelection();
                 collection.browse();
                 return SynchronousFuture(false);
               }

lib/widgets/album/grid/header_album.dart

@@ -26,6 +26,7 @@ class AlbumSectionHeader extends StatelessWidget {
       );
     }
     return TitleSectionHeader(
+      sectionKey: folderPath,
       leading: albumIcon,
       title: albumName,
       trailing: androidFileUtils.isOnSD(folderPath)

lib/widgets/album/grid/header_date.dart

@@ -4,10 +4,13 @@ import 'package:flutter/material.dart';
 import 'package:intl/intl.dart';
 
 class DaySectionHeader extends StatelessWidget {
+  final DateTime date;
   final String text;
 
-  DaySectionHeader({Key key, DateTime date})
+  DaySectionHeader({
-      : text = _formatDate(date),
+    Key key,
+    @required this.date,
+  })  : text = _formatDate(date),
         super(key: key);
 
   // Examples (en_US):
@@ -32,15 +35,21 @@ class DaySectionHeader extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return TitleSectionHeader(title: text);
+    return TitleSectionHeader(
+      sectionKey: date,
+      title: text,
+    );
   }
 }
 
 class MonthSectionHeader extends StatelessWidget {
+  final DateTime date;
   final String text;
 
-  MonthSectionHeader({Key key, DateTime date})
+  MonthSectionHeader({
-      : text = _formatDate(date),
+    Key key,
+    @required this.date,
+  })  : text = _formatDate(date),
         super(key: key);
 
   static DateFormat m = DateFormat.MMMM();
@@ -54,6 +63,9 @@ class MonthSectionHeader extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return TitleSectionHeader(title: text);
+    return TitleSectionHeader(
+      sectionKey: date,
+      title: text,
+    );
   }
 }

lib/widgets/album/grid/header_generic.dart

@@ -7,8 +7,11 @@ import 'package:aves/utils/constants.dart';
 import 'package:aves/widgets/album/grid/header_album.dart';
 import 'package:aves/widgets/album/grid/header_date.dart';
 import 'package:aves/widgets/common/fx/outlined_text.dart';
+import 'package:aves/widgets/common/icons.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
+import 'package:flutter/scheduler.dart';
+import 'package:provider/provider.dart';
 
 class SectionHeader extends StatelessWidget {
   final CollectionLens collection;
@@ -45,11 +48,7 @@ class SectionHeader extends StatelessWidget {
         header = _buildAlbumSectionHeader();
         break;
     }
-    return header != null
+    return header ?? const SizedBox.shrink();
-        ? IgnorePointer(
-            child: header,
-          )
-        : const SizedBox.shrink();
   }
 
   Widget _buildAlbumSectionHeader() {
@@ -95,13 +94,15 @@ class SectionHeader extends StatelessWidget {
 }
 
 class TitleSectionHeader extends StatelessWidget {
+  final dynamic sectionKey;
   final Widget leading, trailing;
   final String title;
 
   const TitleSectionHeader({
     Key key,
+    @required this.sectionKey,
     this.leading,
-    this.title,
+    @required this.title,
     this.trailing,
   }) : super(key: key);
 
@@ -117,14 +118,17 @@ class TitleSectionHeader extends StatelessWidget {
       padding: padding,
       constraints: const BoxConstraints(minHeight: leadingDimension),
       child: OutlinedText(
-        leadingBuilder: leading != null
+        leadingBuilder: (context, isShadow) => SectionSelectableLeading(
-            ? (context, isShadow) => Container(
+          sectionKey: sectionKey,
+          browsingBuilder: leading != null
+              ? (context) => Container(
                     padding: leadingPadding,
                     width: leadingDimension,
                     height: leadingDimension,
                     child: isShadow ? null : leading,
                   )
               : null,
+        ),
         text: title,
         trailingBuilder: trailing != null
             ? (context, isShadow) => Container(
@@ -138,3 +142,75 @@ class TitleSectionHeader extends StatelessWidget {
     );
   }
 }
+
+class SectionSelectableLeading extends StatelessWidget {
+  final dynamic sectionKey;
+  final WidgetBuilder browsingBuilder;
+
+  static final WidgetBuilder _defaultBrowsingBuilder = (context) => const SizedBox.shrink();
+
+  SectionSelectableLeading({
+    Key key,
+    @required this.sectionKey,
+    WidgetBuilder browsingBuilder,
+  })  : browsingBuilder = browsingBuilder ?? _defaultBrowsingBuilder,
+        super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    final collection = Provider.of<CollectionLens>(context);
+    return ValueListenableBuilder<Activity>(
+      valueListenable: collection.activityNotifier,
+      builder: (context, activity, child) {
+        final child = collection.isSelecting
+            ? AnimatedBuilder(
+                animation: collection.selectionChangeNotifier,
+                builder: (context, child) {
+                  final sectionEntries = collection.sections[sectionKey];
+                  final selected = collection.isSelected(sectionEntries);
+                  final child = IconButton(
+                    key: ValueKey(selected),
+                    iconSize: 26,
+                    padding: const EdgeInsets.only(top: 1),
+                    alignment: Alignment.topLeft,
+                    icon: Icon(selected ? AIcons.selected : AIcons.unselected),
+                    onPressed: () {
+                      if (selected) {
+                        collection.removeFromSelection(sectionEntries);
+                      } else {
+                        collection.addToSelection(sectionEntries);
+                      }
+                    },
+                    tooltip: selected ? 'Deselect section' : 'Select section',
+                    constraints: const BoxConstraints(
+                      minHeight: TitleSectionHeader.leadingDimension,
+                      minWidth: TitleSectionHeader.leadingDimension,
+                    ),
+                  );
+                  return AnimatedSwitcher(
+                    duration: Duration(milliseconds: (300 * timeDilation).toInt()),
+                    switchInCurve: Curves.easeOutBack,
+                    switchOutCurve: Curves.easeOutBack,
+                    transitionBuilder: (child, animation) => ScaleTransition(
+                      child: child,
+                      scale: animation,
+                    ),
+                    child: child,
+                  );
+                },
+              )
+            : browsingBuilder(context);
+        return AnimatedSwitcher(
+          duration: Duration(milliseconds: (300 * timeDilation).toInt()),
+          switchInCurve: Curves.easeOutBack,
+          switchOutCurve: Curves.easeOutBack,
+          transitionBuilder: (child, animation) => ScaleTransition(
+            child: child,
+            scale: animation,
+          ),
+          child: child,
+        );
+      },
+    );
+  }
+}

lib/widgets/album/search/search_delegate.dart

@@ -25,12 +25,12 @@ class ImageSearchDelegate extends SearchDelegate<CollectionFilter> {
   @override
   Widget buildLeading(BuildContext context) {
     return IconButton(
-      tooltip: 'Back',
       icon: AnimatedIcon(
         icon: AnimatedIcons.menu_arrow,
         progress: transitionAnimation,
       ),
       onPressed: () => close(context, null),
+      tooltip: 'Back',
     );
   }
 
@@ -39,12 +39,12 @@ class ImageSearchDelegate extends SearchDelegate<CollectionFilter> {
     return [
       if (query.isNotEmpty)
         IconButton(
-          tooltip: 'Clear',
           icon: const Icon(OMIcons.clear),
           onPressed: () {
             query = '';
             showSuggestions(context);
           },
+          tooltip: 'Clear',
         ),
     ];
   }

lib/widgets/album/thumbnail/overlay.dart

@@ -66,7 +66,7 @@ class ThumbnailSelectionOverlay extends StatelessWidget {
             ? AnimatedBuilder(
                 animation: collection.selectionChangeNotifier,
                 builder: (context, child) {
-                  final selected = collection.selection.contains(entry);
+                  final selected = collection.isSelected([entry]);
                   final child = OverlayIcon(
                     key: ValueKey(selected),
                     icon: selected ? AIcons.selected : AIcons.unselected,