firka: give chart higher gesture priority over page swipe

firka/lib/routing/app_router.dart

@@ -16,6 +16,7 @@ import 'package:firka/ui/phone/screens/login/login_screen.dart';
 import 'package:firka/ui/phone/screens/message/message_screen.dart';
 import 'package:firka/ui/phone/screens/home/home_screen.dart';
 import 'package:firka/ui/phone/screens/settings/settings_screen.dart';
+import 'package:firka/routing/chart_interaction_scope.dart';
 import 'package:firka/routing/shell_with_nav_bar.dart';
 import 'package:firka/routing/swipable_navigator_container.dart';
 import 'package:go_router/go_router.dart';
@@ -97,9 +98,11 @@ GoRouter createAppRouter() {
           ),
         ),
         navigatorContainerBuilder: (context, navigationShell, children) {
-          return SwipableNavigatorContainer(
-            navigationShell: navigationShell,
-            children: children,
+          return ChartInteractionScope(
+            child: SwipableNavigatorContainer(
+              navigationShell: navigationShell,
+              children: children,
+            ),
           );
         },
         branches: [

firka/lib/routing/chart_interaction_scope.dart

@@ -0,0 +1,48 @@
+import 'package:flutter/material.dart';
+
+class ChartInteractionScope extends StatefulWidget {
+  const ChartInteractionScope({super.key, required this.child});
+
+  final Widget child;
+
+  static ValueNotifier<bool> of(BuildContext context) {
+    final data = context
+        .dependOnInheritedWidgetOfExactType<_ChartInteractionScopeData>();
+    assert(data != null, 'ChartInteractionScope not found in context');
+    return data!.isChartInteracting;
+  }
+
+  @override
+  State<ChartInteractionScope> createState() => _ChartInteractionScopeState();
+}
+
+class _ChartInteractionScopeState extends State<ChartInteractionScope> {
+  final ValueNotifier<bool> _isChartInteracting = ValueNotifier(false);
+
+  @override
+  void dispose() {
+    _isChartInteracting.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return _ChartInteractionScopeData(
+      isChartInteracting: _isChartInteracting,
+      child: widget.child,
+    );
+  }
+}
+
+class _ChartInteractionScopeData extends InheritedWidget {
+  const _ChartInteractionScopeData({
+    required this.isChartInteracting,
+    required super.child,
+  });
+
+  final ValueNotifier<bool> isChartInteracting;
+
+  @override
+  bool updateShouldNotify(_ChartInteractionScopeData oldWidget) =>
+      isChartInteracting != oldWidget.isChartInteracting;
+}

firka/lib/routing/swipable_navigator_container.dart

@@ -1,3 +1,4 @@
+import 'package:firka/routing/chart_interaction_scope.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:go_router/go_router.dart';
@@ -82,11 +83,19 @@ class _SwipableNavigatorContainerState
 
   @override
   Widget build(BuildContext context) {
-    return PageView(
-      controller: _pageController,
-      physics: const ClampingScrollPhysics(),
-      onPageChanged: _onPageChanged,
-      children: widget.children,
+    final isChartInteracting = ChartInteractionScope.of(context);
+    return ValueListenableBuilder<bool>(
+      valueListenable: isChartInteracting,
+      builder: (context, interacting, _) {
+        return PageView(
+          controller: _pageController,
+          physics: interacting
+              ? const NeverScrollableScrollPhysics()
+              : const ClampingScrollPhysics(),
+          onPageChanged: _onPageChanged,
+          children: widget.children,
+        );
+      },
     );
   }
 }

firka/lib/ui/phone/pages/home/home_grades.dart

@@ -1,6 +1,7 @@
 import 'package:firka/api/client/kreta_client.dart';
 import 'package:firka/api/model/generic.dart';
 import 'package:firka/core/average_helper.dart';
+import 'package:firka/routing/chart_interaction_scope.dart';
 import 'package:firka/ui/components/firka_card.dart';
 import 'package:firka/ui/components/grade_helpers.dart';
 import 'package:firka/ui/phone/widgets/grade_chart.dart';
@@ -231,7 +232,16 @@ class _HomeGradesScreen extends FirkaState<HomeGradesScreen> {
               ],
             ),
             // SizedBox(height: 16), // TODO: Add graphs here
-            GradeChart(grades: grades?.response ?? []),
+            Listener(
+              behavior: HitTestBehavior.opaque,
+              onPointerDown: (_) =>
+                  ChartInteractionScope.of(context).value = true,
+              onPointerUp: (_) =>
+                  ChartInteractionScope.of(context).value = false,
+              onPointerCancel: (_) =>
+                  ChartInteractionScope.of(context).value = false,
+              child: GradeChart(grades: grades?.response ?? []),
+            ),
             // ...gradeCards,
             Expanded(
               child: ListView(