improved nav bar visibility

lib/widgets/collection/collection_grid.dart

@@ -350,37 +350,45 @@ 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) {
-        selector: (context, mq) => mq.effectiveBottomPadding,
+        return Selector<MediaQueryData, double>(
-        builder: (context, mqPaddingBottom, child) {
+          selector: (context, mq) => mq.effectiveBottomPadding,
-          return Selector<SectionedListLayout<AvesEntry>, List<SectionLayout>>(
+          builder: (context, mqPaddingBottom, child) {
-            selector: (context, layout) => layout.sectionLayouts,
+            return Selector<Settings, bool>(
-            builder: (context, sectionLayouts, child) {
+              selector: (context, s) => s.showBottomNavigationBar,
-              return DraggableScrollbar(
+              builder: (context, showBottomNavigationBar, child) {
-                backgroundColor: Colors.white,
+                final navBarHeight = showBottomNavigationBar ? AppBottomNavBar.height : 0;
-                scrollThumbSize: Size(avesScrollThumbWidth, avesScrollThumbHeight),
+                return Selector<SectionedListLayout<AvesEntry>, List<SectionLayout>>(
-                scrollThumbBuilder: avesScrollThumbBuilder(
+                  selector: (context, layout) => layout.sectionLayouts,
-                  height: avesScrollThumbHeight,
+                  builder: (context, sectionLayouts, child) {
-                  backgroundColor: Colors.white,
+                    return DraggableScrollbar(
-                ),
+                      backgroundColor: Colors.white,
-                controller: widget.scrollController,
+                      scrollThumbSize: Size(avesScrollThumbWidth, avesScrollThumbHeight),
-                crumbsBuilder: () => _getCrumbs(sectionLayouts),
+                      scrollThumbBuilder: avesScrollThumbBuilder(
-                padding: EdgeInsets.only(
+                        height: avesScrollThumbHeight,
-                  // padding to keep scroll thumb between app bar above and nav bar below
+                        backgroundColor: Colors.white,
-                  top: appBarHeight,
+                      ),
-                  bottom: mqPaddingBottom,
+                      controller: widget.scrollController,
-                ),
+                      crumbsBuilder: () => _getCrumbs(sectionLayouts),
-                labelTextBuilder: (offsetY) => CollectionDraggableThumbLabel(
+                      padding: EdgeInsets.only(
-                  collection: collection,
+                        // padding to keep scroll thumb between app bar above and nav bar below
-                  offsetY: offsetY,
+                        top: appBarHeight,
-                ),
+                        bottom: navBarHeight + mqPaddingBottom,
-                crumbTextBuilder: (label) => DraggableCrumbLabel(label: label),
+                      ),
-                child: scrollView,
+                      labelTextBuilder: (offsetY) => CollectionDraggableThumbLabel(
-              );
+                        collection: collection,
-            },
+                        offsetY: offsetY,
-          );
+                      ),
-        },
+                      crumbTextBuilder: (label) => DraggableCrumbLabel(label: label),
-      ),
+                      child: scrollView,
+                    );
+                  },
+                );
+              },
+            );
+          },
+        );
+      },
     );
   }
 

lib/widgets/filter_grids/common/filter_grid_page.dart

@@ -512,28 +512,41 @@ class _FilterScrollView<T extends CollectionFilter> extends StatelessWidget {
   }
 
   Widget _buildDraggableScrollView(ScrollView scrollView) {
-    return Selector<MediaQueryData, double>(
+    return ValueListenableBuilder<double>(
-      selector: (context, mq) => mq.effectiveBottomPadding,
+      valueListenable: appBarHeightNotifier,
-      builder: (context, mqPaddingBottom, child) => DraggableScrollbar(
+      builder: (context, appBarHeight, child) {
-        backgroundColor: Colors.white,
+        return Selector<MediaQueryData, double>(
-        scrollThumbSize: Size(avesScrollThumbWidth, avesScrollThumbHeight),
+          selector: (context, mq) => mq.effectiveBottomPadding,
-        scrollThumbBuilder: avesScrollThumbBuilder(
+          builder: (context, mqPaddingBottom, child) {
-          height: avesScrollThumbHeight,
+            return Selector<Settings, bool>(
-          backgroundColor: Colors.white,
+              selector: (context, s) => s.showBottomNavigationBar,
-        ),
+              builder: (context, showBottomNavigationBar, child) {
-        controller: scrollController,
+                final navBarHeight = showBottomNavigationBar ? AppBottomNavBar.height : 0;
-        padding: EdgeInsets.only(
+                return DraggableScrollbar(
-          // padding to keep scroll thumb between app bar above and nav bar below
+                  backgroundColor: Colors.white,
-          top: appBarHeightNotifier.value,
+                  scrollThumbSize: Size(avesScrollThumbWidth, avesScrollThumbHeight),
-          bottom: mqPaddingBottom,
+                  scrollThumbBuilder: avesScrollThumbBuilder(
-        ),
+                    height: avesScrollThumbHeight,
-        labelTextBuilder: (offsetY) => FilterDraggableThumbLabel<T>(
+                    backgroundColor: Colors.white,
-          sortFactor: sortFactor,
+                  ),
-          offsetY: offsetY,
+                  controller: scrollController,
-        ),
+                  padding: EdgeInsets.only(
-        crumbTextBuilder: (offsetY) => const SizedBox(),
+                    // padding to keep scroll thumb between app bar above and nav bar below
-        child: scrollView,
+                    top: appBarHeight,
-      ),
+                    bottom: navBarHeight + mqPaddingBottom,
+                  ),
+                  labelTextBuilder: (offsetY) => FilterDraggableThumbLabel<T>(
+                    sortFactor: sortFactor,
+                    offsetY: offsetY,
+                  ),
+                  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,
         ),