Custom drawing implementation

lib/features/sheet_viewer/widgets/touch_navigation_layer.dart

@@ -4,7 +4,7 @@ import '../../../core/models/config.dart';
 import 'pdf_page_display.dart';
 
 /// Callback for page turn events.
-typedef PageTurnCallback = void Function(int delta);
+typedef PageTurnCallback = dynamic Function(int delta);
 
 /// Gesture layer for touch-based navigation over PDF pages.
 ///
@@ -14,6 +14,7 @@ typedef PageTurnCallback = void Function(int delta);
 /// - Right side: Turn page forward (+1 or +2 in two-page mode)
 class TouchNavigationLayer extends StatelessWidget {
   final PdfPageDisplay pageDisplay;
+  final Widget child;
   final Config config;
   final VoidCallback onToggleFullscreen;
   final VoidCallback onExit;
@@ -22,6 +23,7 @@ class TouchNavigationLayer extends StatelessWidget {
   const TouchNavigationLayer({
     super.key,
     required this.pageDisplay,
+    required this.child,
     required this.config,
     required this.onToggleFullscreen,
     required this.onExit,
@@ -33,7 +35,7 @@ class TouchNavigationLayer extends StatelessWidget {
     return GestureDetector(
       behavior: HitTestBehavior.opaque,
       onTapUp: (details) => _handleTap(context, details),
-      child: pageDisplay,
+      child: child,
     );
   }