fix: improve homepage scrolling behavior and clean up logic

lib/src/screens/home/index.dart

@@ -6,6 +6,17 @@ import 'package:furman_now/src/screens/home/content.dart';
 import 'package:furman_now/src/screens/home/state.dart';
 import 'package:provider/provider.dart';
 
+class HomeScreenProvider extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return ChangeNotifierProvider(
+      create: (context) => HomePageState(),
+      child: const HomeScreen(),
+    );
+  }
+  
+}
+
 class HomeScreen extends StatefulWidget {
   const HomeScreen({Key? key}) : super(key: key);
 
@@ -28,10 +39,11 @@ class _HomeScreenState extends State<HomeScreen> {
 
   updateScrollPosition() {
     // bottom overscroll
-    if (_controller.position.pixels > _controller.position.maxScrollExtent) {
-      setState(() {
-        overscrollBottomAmount =
+    var bottomOverscroll =
         _controller.position.pixels - _controller.position.maxScrollExtent;
+    if (bottomOverscroll > 0) {
+      setState(() {
+        overscrollBottomAmount = bottomOverscroll;
       });
     } else {
       if (overscrollBottomAmount != 0) {
@@ -42,10 +54,10 @@ class _HomeScreenState extends State<HomeScreen> {
     }
 
     // top overscroll
-    if (_controller.position.pixels < 0) {
+    var topOverscroll = -_controller.position.pixels;
+    if (topOverscroll > 0) {
       setState(() {
-        overscrollTopAmount =
-            _controller.position.pixels.abs();
+        overscrollTopAmount = topOverscroll;
       });
     } else {
       if (overscrollTopAmount != 0) {
@@ -54,37 +66,39 @@ class _HomeScreenState extends State<HomeScreen> {
         });
       }
     }
+
+    handleTopOverscroll(topOverscroll);
   }
 
-  handleScrollEvent(BuildContext context) {
+  handleTopOverscroll(double overscrollTopAmount) {
     const scrollMessageSensitivity = 20;
     const pageSwitchSensitivity = 60;
-    var offsetAmount = overscrollTopAmount.abs();
+    var collapsed = context.read<HomePageState>().collapse;
 
-    if (overscrollTopAmount != 0) {
-      if (offsetAmount > pageSwitchSensitivity) {
+    if (!collapsed) {
+      if (overscrollTopAmount > pageSwitchSensitivity) {
+        // switch to student ID page
         context.router.navigate(const StudentIdRoute());
         context.read<HomePageState>().collapse = true;
-      } else if (offsetAmount > scrollMessageSensitivity) {
+      } else if (overscrollTopAmount > scrollMessageSensitivity) {
+        // show student ID hint
         context.read<HomePageState>().showScrollMessage = true;
       } else {
+        // hide student ID hint
         context.read<HomePageState>().showScrollMessage = false;
       }
-    } else {
-      context.read<HomePageState>().showScrollMessage = false;
+    }
 
-      if (_controller.position.pixels > pageSwitchSensitivity) {
+    if (collapsed && -overscrollTopAmount > pageSwitchSensitivity) {
+      // switch back to home page
       context.router.navigate(const HomeRoute());
       context.read<HomePageState>().collapse = false;
     }
   }
-  }
 
   @override
   Widget build(BuildContext context) {
-    return ChangeNotifierProvider(
-      create: (context) => HomePageState(),
-      builder: (context, _) => Scaffold(
+    return Scaffold(
       body: AnnotatedRegion<SystemUiOverlayStyle>(
         value: SystemUiOverlayStyle.light,
         child: Container(
@@ -95,6 +109,12 @@ class _HomeScreenState extends State<HomeScreen> {
               child: Stack(
                 fit: StackFit.loose,
                 children: [
+                  const AutoTabsRouter(
+                    routes: [
+                      HomeRoute(),
+                      StudentIdRoute(),
+                    ],
+                  ),
                   // overscroll indicator color
                   Align(
                     alignment: Alignment.bottomCenter,
@@ -103,20 +123,7 @@ class _HomeScreenState extends State<HomeScreen> {
                       color: Colors.grey.shade50,
                     ),
                   ),
-                      const AutoTabsRouter(
-                        routes: [
-                          HomeRoute(),
-                          StudentIdRoute(),
-                        ],
-                      ),
-                      NotificationListener<ScrollNotification>(
-                        onNotification: (notification) {
-                          if (notification is ScrollUpdateNotification) {
-                            handleScrollEvent(context);
-                          }
-                          return true;
-                        },
-                        child: Consumer<HomePageState>(
+                  Consumer<HomePageState>(
                     builder: (context, state, _) =>
                       ClipRect(child: HomeContent(
                         controller: _controller,
@@ -124,15 +131,12 @@ class _HomeScreenState extends State<HomeScreen> {
                       ),
                     ),
                   ),
-                      ),
                 ],
               ),
             ),
           ),
         ),
       ),
-        ),
     );
   }
 }
-