feat: library sidenav animation

lib/screens/libraries/libraries_screen.dart

@@ -203,7 +203,12 @@ class _LibrariesScreenState extends State<LibrariesScreen>
       }
 
       if (tabState != null) {
-        (tabState as dynamic).focusFirstItem();
+        // Browse tab has a chips bar - focus that first so DOWN navigates to grid
+        if (_tabController.index == 1) {
+          (tabState as dynamic).focusChipsBar();
+        } else {
+          (tabState as dynamic).focusFirstItem();
+        }
       } else {
         // State not available yet, retry after another frame
         WidgetsBinding.instance.addPostFrameCallback((_) {
@@ -233,7 +238,12 @@ class _LibrariesScreenState extends State<LibrariesScreen>
     }
 
     if (tabState != null) {
-      (tabState as dynamic).focusFirstItem();
+      // Browse tab has a chips bar - focus that first so DOWN navigates to grid
+      if (_tabController.index == 1) {
+        (tabState as dynamic).focusChipsBar();
+      } else {
+        (tabState as dynamic).focusFirstItem();
+      }
     }
   }
 

lib/screens/libraries/tabs/library_browse_tab.dart

@@ -82,15 +82,40 @@ class _LibraryBrowseTabState extends BaseLibraryTabState<PlexMetadata, LibraryBr
   final FocusNode _filtersChipFocusNode = FocusNode(debugLabel: 'filters_chip');
   final FocusNode _sortChipFocusNode = FocusNode(debugLabel: 'sort_chip');
 
+  // Focus tracking for grid items
+  int? _lastFocusedIndex;
+  int _contentVersion = 0;
+  int _lastFocusedContentVersion = 0;
+  final Map<int, FocusNode> _gridItemFocusNodes = {};
+
   @override
   void dispose() {
     _cancelToken?.cancel();
     _groupingChipFocusNode.dispose();
     _filtersChipFocusNode.dispose();
     _sortChipFocusNode.dispose();
+    // Dispose all grid item focus nodes
+    for (final node in _gridItemFocusNodes.values) {
+      node.dispose();
+    }
+    _gridItemFocusNodes.clear();
     super.dispose();
   }
 
+  /// Get or create a focus node for a grid item at the given index
+  FocusNode _getGridItemFocusNode(int index) {
+    return _gridItemFocusNodes.putIfAbsent(index, () => FocusNode(debugLabel: 'browse_grid_item_$index'));
+  }
+
+  /// Clean up focus nodes for items that no longer exist
+  void _cleanupFocusNodes() {
+    final keysToRemove = _gridItemFocusNodes.keys.where((index) => index >= items.length).toList();
+    for (final key in keysToRemove) {
+      _gridItemFocusNodes[key]?.dispose();
+      _gridItemFocusNodes.remove(key);
+    }
+  }
+
   // Override loadData to use our custom _loadContent
   @override
   Future<List<PlexMetadata>> loadData() async {
@@ -136,6 +161,36 @@ class _LibraryBrowseTabState extends BaseLibraryTabState<PlexMetadata, LibraryBr
     }
   }
 
+  /// Focus the chips bar (for navigating from tab bar to content).
+  /// Called by libraries screen when pressing DOWN on tab bar.
+  void focusChipsBar() {
+    // If in folders mode, no chips to focus - go directly to folder tree
+    if (_selectedGrouping == 'folders') {
+      focusFirstItem();
+      return;
+    }
+
+    // Scroll chips into view and focus the grouping chip
+    if (_groupingChipFocusNode.context != null) {
+      Scrollable.ensureVisible(
+        _groupingChipFocusNode.context!,
+        alignment: 0.0,
+        duration: const Duration(milliseconds: 200),
+      ).then((_) {
+        if (mounted) {
+          _groupingChipFocusNode.requestFocus();
+        }
+      });
+    } else {
+      // Context not available yet, try again next frame
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        if (mounted) {
+          _groupingChipFocusNode.requestFocus();
+        }
+      });
+    }
+  }
+
   Future<void> _loadContent() async {
     // Cancel any pending request
     _cancelToken?.cancel();
@@ -219,6 +274,10 @@ class _LibraryBrowseTabState extends BaseLibraryTabState<PlexMetadata, LibraryBr
       isLoading = true;
       if (!loadMore) {
         items = [];
+        // Increment content version when loading fresh content
+        // This invalidates the last focused index
+        _contentVersion++;
+        _cleanupFocusNodes();
       }
     });
 
@@ -432,11 +491,17 @@ class _LibraryBrowseTabState extends BaseLibraryTabState<PlexMetadata, LibraryBr
     );
   }
 
-  /// Navigate focus from chips down to the first grid item
+  /// Navigate focus from chips down to the grid item.
+  /// Restores focus to the previously focused item if content hasn't changed.
   void _navigateToGrid() {
-    if (items.isNotEmpty) {
-      firstItemFocusNode.requestFocus();
-    }
+    if (items.isEmpty) return;
+
+    // Check if we should restore focus to the last focused item
+    final shouldRestoreFocus =
+        _lastFocusedIndex != null && _lastFocusedContentVersion == _contentVersion && _lastFocusedIndex! < items.length;
+
+    final targetIndex = shouldRestoreFocus ? _lastFocusedIndex! : 0;
+    _getGridItemFocusNode(targetIndex).requestFocus();
   }
 
   /// Navigate focus from grid up to the grouping chip
@@ -624,13 +689,25 @@ class _LibraryBrowseTabState extends BaseLibraryTabState<PlexMetadata, LibraryBr
       );
     }
     final item = items[index];
+
+    // Use firstItemFocusNode for index 0 to maintain compatibility with base class
+    // All other items get managed focus nodes for restoration
+    final focusNode = index == 0 ? firstItemFocusNode : _getGridItemFocusNode(index);
+
     return FocusableMediaCard(
       key: Key(item.ratingKey),
       item: item,
-      focusNode: index == 0 ? firstItemFocusNode : null,
+      focusNode: focusNode,
       onRefresh: updateItem,
       onNavigateUp: isFirstRow ? _navigateToChips : null,
       onBack: widget.onBack,
+      onFocusChange: (hasFocus) {
+        if (hasFocus) {
+          // Track the focused index and current content version
+          _lastFocusedIndex = index;
+          _lastFocusedContentVersion = _contentVersion;
+        }
+      },
     );
   }
 }

lib/widgets/side_navigation_rail.dart

@@ -610,30 +610,48 @@ class SideNavigationRailState extends State<SideNavigationRail> {
           ),
         ),
 
-        // Library items (hidden when collapsed to avoid clipped partial items)
-        if (_librariesExpanded && !isCollapsed) ...[
-          const SizedBox(height: 4),
-          _isLoadingLibraries
-              ? Padding(
-                  padding: const EdgeInsets.all(16),
-                  child: Center(
-                    child: SizedBox(
-                      width: 20,
-                      height: 20,
-                      child: CircularProgressIndicator(strokeWidth: 2, color: t.textMuted),
-                    ),
-                  ),
-                )
-              : visibleLibraries.isEmpty
-              ? Padding(
-                  padding: const EdgeInsets.all(16),
-                  child: Text(
-                    Translations.of(context).libraries.noLibrariesFound,
-                    style: TextStyle(fontSize: 12, color: t.textMuted),
-                  ),
-                )
-              : _buildLibraryItems(visibleLibraries, t),
-        ],
+        // Library items with animated height
+        TweenAnimationBuilder<double>(
+          tween: Tween(end: (_librariesExpanded && !isCollapsed) ? 1.0 : 0.0),
+          duration: tokens(context).normal,
+          curve: Curves.easeOutCubic,
+          builder: (context, value, child) {
+            return ClipRect(
+              child: Align(
+                alignment: Alignment.topCenter,
+                heightFactor: value,
+                child: child,
+              ),
+            );
+          },
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              const SizedBox(height: 4),
+              _isLoadingLibraries
+                  ? Padding(
+                      padding: const EdgeInsets.all(16),
+                      child: Center(
+                        child: SizedBox(
+                          width: 20,
+                          height: 20,
+                          child: CircularProgressIndicator(strokeWidth: 2, color: t.textMuted),
+                        ),
+                      ),
+                    )
+                  : visibleLibraries.isEmpty
+                      ? Padding(
+                          padding: const EdgeInsets.all(16),
+                          child: Text(
+                            Translations.of(context).libraries.noLibrariesFound,
+                            style: TextStyle(fontSize: 12, color: t.textMuted),
+                          ),
+                        )
+                      : _buildLibraryItems(visibleLibraries, t),
+            ],
+          ),
+        ),
       ],
     );
   }