Added stop fraction picker

TODO: fix `MeteringScreen` double build on fraction change

lib/l10n/intl_en.arb

@@ -13,6 +13,10 @@
     "cancel": "Cancel",
     "select": "Select",
     "settings": "Settings",
+    "fractionalStops": "Fractional stops",
+    "showFractionalStops": "Show fractional stops",
+    "halfStops": "1/2",
+    "thirdStops": "1/3",
     "caffeine": "Caffeine",
     "keepsScreenOn": "Keeps screen on",
     "haptics": "Haptics"

lib/screens/metering/metering_bloc.dart

@@ -13,12 +13,12 @@ import 'metering_event.dart';
 import 'metering_state.dart';
 
 class MeteringBloc extends Bloc<MeteringEvent, MeteringState> {
-  final StopType stopType;
-  late final _apertureValues = apertureValues.whereStopType(stopType);
-  late final _shutterSpeedValues = shutterSpeedValues.whereStopType(stopType);
-  late final _isoValues = isoValues.whereStopType(stopType);
+  List<ApertureValue> get _apertureValues => apertureValues.whereStopType(stopType);
+  List<ShutterSpeedValue> get _shutterSpeedValues => shutterSpeedValues.whereStopType(stopType);
   final _random = Random();
 
+  StopType stopType;
+
   MeteringBloc(this.stopType)
       : super(
           MeteringState(
@@ -29,6 +29,7 @@ class MeteringBloc extends Bloc<MeteringEvent, MeteringState> {
             exposurePairs: [],
           ),
         ) {
+    on<StopTypeChangedEvent>(_onStopTypeChanged);
     on<IsoChangedEvent>(_onIsoChanged);
     on<NdChangedEvent>(_onNdChanged);
     on<MeasureEvent>(_onMeasure);
@@ -36,6 +37,17 @@ class MeteringBloc extends Bloc<MeteringEvent, MeteringState> {
     add(const MeasureEvent());
   }
 
+  void _onStopTypeChanged(StopTypeChangedEvent event, Emitter emit) {
+    stopType = event.stopType;
+    emit(MeteringState(
+      iso: state.iso,
+      ev: state.ev,
+      evCompensation: state.evCompensation,
+      nd: state.nd,
+      exposurePairs: _buildExposureValues(state.ev),
+    ));
+  }
+
   void _onIsoChanged(IsoChangedEvent event, Emitter emit) {
     final ev = state.ev + log2(event.isoValue.value / state.iso.value);
     emit(MeteringState(
@@ -62,7 +74,7 @@ class MeteringBloc extends Bloc<MeteringEvent, MeteringState> {
   void _onMeasure(_, Emitter emit) {
     final aperture = _apertureValues[_random.nextInt(_apertureValues.length)];
     final shutterSpeed = _shutterSpeedValues[_random.nextInt(_shutterSpeedValues.thirdStops().length)];
-    final iso = _isoValues[_random.nextInt(_isoValues.thirdStops().length)];
+    final iso = isoValues[_random.nextInt(isoValues.thirdStops().length)];
 
     final evAtSystemIso = log2(pow(aperture.value, 2).toDouble() / shutterSpeed.value);
     final ev = evAtSystemIso - log2(iso.value / state.iso.value);

lib/screens/metering/metering_event.dart

@@ -1,10 +1,17 @@
 import 'package:lightmeter/models/iso_value.dart';
 import 'package:lightmeter/models/nd_value.dart';
+import 'package:lightmeter/models/photography_value.dart';
 
 abstract class MeteringEvent {
   const MeteringEvent();
 }
 
+class StopTypeChangedEvent extends MeteringEvent {
+  final StopType stopType;
+
+  const StopTypeChangedEvent(this.stopType);
+}
+
 class IsoChangedEvent extends MeteringEvent {
   final IsoValue isoValue;
 

lib/screens/metering/metering_screen.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:lightmeter/models/photography_value.dart';
 import 'package:lightmeter/res/dimens.dart';
 import 'package:lightmeter/screens/settings/settings_page_route_builder.dart';
 
@@ -43,6 +44,12 @@ class _MeteringScreenState extends State<MeteringScreen> {
     });
   }
 
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    context.read<MeteringBloc>().add(StopTypeChangedEvent(context.watch<StopType>()));
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(

lib/screens/settings/components/fractional_stops/dialog_fractional_stops.dart

@@ -0,0 +1,50 @@
+import 'package:flutter/material.dart';
+import 'package:lightmeter/generated/l10n.dart';
+import 'package:lightmeter/models/photography_value.dart';
+
+class FractionalStopsDialog extends StatefulWidget {
+  final StopType selectedType;
+
+  const FractionalStopsDialog({required this.selectedType, super.key});
+
+  @override
+  State<FractionalStopsDialog> createState() => _FractionalStopsDialogState();
+}
+
+class _FractionalStopsDialogState extends State<FractionalStopsDialog> {
+  late StopType _selected = widget.selectedType;
+
+  @override
+  Widget build(BuildContext context) {
+    return SimpleDialog(
+      title: Text(S.of(context).showFractionalStops),
+      children: [
+        RadioListTile<StopType>(
+          value: StopType.full,
+          groupValue: _selected,
+          title: Text(S.of(context).none),
+          onChanged: _onChanged,
+        ),
+        RadioListTile<StopType>(
+          value: StopType.half,
+          groupValue: _selected,
+          title: Text(S.of(context).halfStops),
+          onChanged: _onChanged,
+        ),
+        RadioListTile<StopType>(
+          value: StopType.third,
+          groupValue: _selected,
+          title: Text(S.of(context).thirdStops),
+          onChanged: _onChanged,
+        ),
+      ],
+    );
+  }
+
+  void _onChanged(StopType? value) {
+    setState(() {
+      _selected = value!;
+    });
+    Navigator.of(context).pop(_selected);
+  }
+}

lib/screens/settings/components/fractional_stops/list_tile_fractional_stops.dart

@@ -0,0 +1,45 @@
+import 'package:flutter/material.dart';
+import 'package:lightmeter/generated/l10n.dart';
+import 'package:lightmeter/models/photography_value.dart';
+import 'package:lightmeter/utils/stop_type_provider.dart';
+import 'package:provider/provider.dart';
+
+import 'dialog_fractional_stops.dart';
+
+class FractionalStopsListTile extends StatefulWidget {
+  const FractionalStopsListTile({super.key});
+
+  @override
+  State<FractionalStopsListTile> createState() => _FractionalStopsListTileState();
+}
+
+class _FractionalStopsListTileState extends State<FractionalStopsListTile> {
+  @override
+  Widget build(BuildContext context) {
+    return ListTile(
+      title: Text(S.of(context).fractionalStops),
+      trailing: Text(selectedType),
+      onTap: () {
+        showDialog(
+          context: context,
+          builder: (_) => FractionalStopsDialog(selectedType: context.read<StopType>()),
+        ).then((value) {
+          if (value != null) {
+            StopTypeProvider.of(context).set(value);
+          }
+        });
+      },
+    );
+  }
+
+  String get selectedType {
+    switch (context.watch<StopType>()) {
+      case StopType.full:
+        return S.of(context).none;
+      case StopType.half:
+        return S.of(context).halfStops;
+      case StopType.third:
+        return S.of(context).thirdStops;
+    }
+  }
+}

lib/screens/settings/settings_screen.dart

@@ -4,6 +4,7 @@ import 'package:lightmeter/res/dimens.dart';
 
 import 'components/caffeine_tile.dart';
 import 'components/haptics_tile.dart';
+import 'components/fractional_stops/list_tile_fractional_stops.dart';
 
 class SettingsScreen extends StatelessWidget {
   const SettingsScreen({super.key});
@@ -36,6 +37,7 @@ class SettingsScreen extends StatelessWidget {
           SliverList(
             delegate: SliverChildListDelegate(
               [
+                const FractionalStopsListTile(),
                 const CaffeineListTile(),
                 const HapticsListTile(),
               ],

lib/utils/stop_type_provider.dart

@@ -7,27 +7,30 @@ class StopTypeProvider extends StatefulWidget {
 
   const StopTypeProvider({this.child, super.key});
 
+  static StopTypeProviderState of(BuildContext context) {
+    return context.findAncestorStateOfType<StopTypeProviderState>()!;
+  }
+
   @override
   State<StopTypeProvider> createState() => StopTypeProviderState();
 }
 
 class StopTypeProviderState extends State<StopTypeProvider> {
-  StopType stopType = StopType.full;
+  StopType _stopType = StopType.third;
+
+  StopType get stopType => _stopType;
+
+  void set(StopType type) {
+    setState(() {
+      _stopType = type;
+    });
+  }
 
   @override
   Widget build(BuildContext context) {
     return Provider.value(
-      value: stopType,
-      child: Provider.value(
-        value: this,
-        child: widget.child,
-      ),
+      value: _stopType,
+      child: widget.child,
     );
   }
-
-  void setStopType(StopType type) {
-    setState(() {
-      stopType = type;
-    });
-  }
 }