improved nav bar visibility

lib/widgets/collection/collection_grid.dart

@@ -350,9 +350,14 @@ class _CollectionScrollViewState extends State<_CollectionScrollView> {
   Widget _buildDraggableScrollView(ScrollView scrollView, CollectionLens collection) {
     return ValueListenableBuilder<double>(
       valueListenable: widget.appBarHeightNotifier,
-      builder: (context, appBarHeight, child) => Selector<MediaQueryData, double>(
+      builder: (context, appBarHeight, child) {
+        return Selector<MediaQueryData, double>(
           selector: (context, mq) => mq.effectiveBottomPadding,
           builder: (context, mqPaddingBottom, child) {
+            return Selector<Settings, bool>(
+              selector: (context, s) => s.showBottomNavigationBar,
+              builder: (context, showBottomNavigationBar, child) {
+                final navBarHeight = showBottomNavigationBar ? AppBottomNavBar.height : 0;
                 return Selector<SectionedListLayout<AvesEntry>, List<SectionLayout>>(
                   selector: (context, layout) => layout.sectionLayouts,
                   builder: (context, sectionLayouts, child) {
@@ -368,7 +373,7 @@ class _CollectionScrollViewState extends State<_CollectionScrollView> {
                       padding: EdgeInsets.only(
                         // padding to keep scroll thumb between app bar above and nav bar below
                         top: appBarHeight,
-                  bottom: mqPaddingBottom,
+                        bottom: navBarHeight + mqPaddingBottom,
                       ),
                       labelTextBuilder: (offsetY) => CollectionDraggableThumbLabel(
                         collection: collection,
@@ -380,7 +385,10 @@ class _CollectionScrollViewState extends State<_CollectionScrollView> {
                   },
                 );
               },
-      ),
+            );
+          },
+        );
+      },
     );
   }
 

lib/widgets/filter_grids/common/filter_grid_page.dart

@@ -512,9 +512,17 @@ class _FilterScrollView<T extends CollectionFilter> extends StatelessWidget {
   }
 
   Widget _buildDraggableScrollView(ScrollView scrollView) {
+    return ValueListenableBuilder<double>(
+      valueListenable: appBarHeightNotifier,
+      builder: (context, appBarHeight, child) {
         return Selector<MediaQueryData, double>(
           selector: (context, mq) => mq.effectiveBottomPadding,
-      builder: (context, mqPaddingBottom, child) => DraggableScrollbar(
+          builder: (context, mqPaddingBottom, child) {
+            return Selector<Settings, bool>(
+              selector: (context, s) => s.showBottomNavigationBar,
+              builder: (context, showBottomNavigationBar, child) {
+                final navBarHeight = showBottomNavigationBar ? AppBottomNavBar.height : 0;
+                return DraggableScrollbar(
                   backgroundColor: Colors.white,
                   scrollThumbSize: Size(avesScrollThumbWidth, avesScrollThumbHeight),
                   scrollThumbBuilder: avesScrollThumbBuilder(
@@ -524,8 +532,8 @@ class _FilterScrollView<T extends CollectionFilter> extends StatelessWidget {
                   controller: scrollController,
                   padding: EdgeInsets.only(
                     // padding to keep scroll thumb between app bar above and nav bar below
-          top: appBarHeightNotifier.value,
+                    top: appBarHeight,
-          bottom: mqPaddingBottom,
+                    bottom: navBarHeight + mqPaddingBottom,
                   ),
                   labelTextBuilder: (offsetY) => FilterDraggableThumbLabel<T>(
                     sortFactor: sortFactor,
@@ -533,7 +541,12 @@ class _FilterScrollView<T extends CollectionFilter> extends StatelessWidget {
                   ),
                   crumbTextBuilder: (offsetY) => const SizedBox(),
                   child: scrollView,
-      ),
+                );
+              },
+            );
+          },
+        );
+      },
     );
   }
 

lib/widgets/navigation/nav_bar/floating.dart

@@ -1,17 +1,21 @@
 import 'dart:async';
+import 'dart:math';
 
 import 'package:aves/widgets/common/basic/draggable_scrollbar.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart';
 
 class FloatingNavBar extends StatefulWidget {
   final ScrollController? scrollController;
   final Stream<DraggableScrollBarEvent> events;
+  final double childHeight;
   final Widget child;
 
   const FloatingNavBar({
     super.key,
     required this.scrollController,
     required this.events,
+    required this.childHeight,
     required this.child,
   });
 
@@ -90,8 +94,6 @@ class _FloatingNavBarState extends State<FloatingNavBar> with SingleTickerProvid
   }
 
   void _onScrollChange() {
-    if (_isDragging) return;
-
     final scrollController = widget.scrollController;
     if (scrollController == null) return;
 
@@ -99,13 +101,22 @@ class _FloatingNavBarState extends State<FloatingNavBar> with SingleTickerProvid
     _delta += offset - (_lastOffset ?? offset);
     _lastOffset = offset;
 
+    if (_isDragging) return;
+
+    final after = scrollController.position.extentAfter;
+    final childHeight = widget.childHeight;
+    if (after < childHeight && scrollController.position.userScrollDirection == ScrollDirection.reverse) {
+      _controller.value = min(_controller.value, after / childHeight);
+      _delta = 0;
+      return;
+    }
+
     if (_delta.abs() > _deltaThreshold) {
       if (_delta > 0) {
         _hide();
       } else {
         _show();
       }
-      _delta = 0;
     }
   }
 
@@ -122,7 +133,13 @@ class _FloatingNavBarState extends State<FloatingNavBar> with SingleTickerProvid
     }
   }
 
-  void _show() => _controller.reverse();
+  void _show() {
+    _controller.reverse();
+    _delta = 0;
+  }
 
-  void _hide() => _controller.forward();
+  void _hide() {
+    _controller.forward();
+    _delta = 0;
+  }
 }

lib/widgets/navigation/nav_bar/nav_bar.dart

@@ -6,6 +6,7 @@ import 'package:aves/model/source/collection_source.dart';
 import 'package:aves/widgets/collection/collection_page.dart';
 import 'package:aves/widgets/common/basic/draggable_scrollbar.dart';
 import 'package:aves/widgets/common/extensions/build_context.dart';
+import 'package:aves/widgets/common/extensions/media_query.dart';
 import 'package:aves/widgets/common/fx/blurred.dart';
 import 'package:aves/widgets/filter_grids/albums_page.dart';
 import 'package:aves/widgets/navigation/nav_bar/floating.dart';
@@ -79,6 +80,7 @@ class AppBottomNavBar extends StatelessWidget {
       child: FloatingNavBar(
         scrollController: PrimaryScrollController.of(context),
         events: events,
+        childHeight: height + context.select<MediaQueryData, double>((mq) => mq.effectiveBottomPadding),
         child: SafeArea(
           child: child,
         ),