Implemented theme brightness picker

implemented `ThemeProvider`

implemented theme switching

save selected theme type

lib/application.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_localizations/flutter_localizations.dart';
 import 'package:lightmeter/data/ev_source/ev_source_type.dart';
+import 'package:lightmeter/data/models/theme_type.dart';
 import 'package:lightmeter/data/permissions_service.dart';
 import 'package:lightmeter/screens/settings/settings_screen.dart';
 import 'package:provider/provider.dart';
@@ -52,11 +53,10 @@ class _ApplicationState extends State<Application> {
             child: Provider(
               create: (context) => PermissionsService(),
               child: StopTypeProvider(
-                child: MaterialApp(
-                  theme: ThemeData(
-                    useMaterial3: true,
-                    colorScheme: lightColorScheme,
-                  ),
+                child: ThemeProvider(
+                  initialPrimaryColor: const Color(0xFF2196f3),
+                  builder: (context, child) => MaterialApp(
+                    theme: context.watch<ThemeData>(),
                     localizationsDelegates: const [
                       S.delegate,
                       GlobalMaterialLocalizations.delegate,
@@ -76,6 +76,7 @@ class _ApplicationState extends State<Application> {
                   ),
                 ),
               ),
+            ),
           );
         }
         return const SizedBox();

lib/data/models/theme_type.dart

@@ -0,0 +1 @@
+enum ThemeType {light, dark, systemDefault}

lib/data/shared_prefs_service.dart

@@ -1,4 +1,5 @@
 import 'package:lightmeter/data/models/nd_value.dart';
+import 'package:lightmeter/data/models/theme_type.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
 import 'models/iso_value.dart';
@@ -7,6 +8,8 @@ class UserPreferencesService {
   static const _isoKey = "ISO";
   static const _ndFilterKey = "ND";
 
+  static const _themeTypeKey = "ThemeType";
+
   final SharedPreferences _sharedPreferences;
 
   UserPreferencesService(this._sharedPreferences);
@@ -16,4 +19,7 @@ class UserPreferencesService {
 
   NdValue get ndFilter => ndValues.firstWhere((v) => v.value == (_sharedPreferences.getInt(_ndFilterKey) ?? 0));
   set ndFilter(NdValue value) => _sharedPreferences.setInt(_ndFilterKey, value.value);
+
+  ThemeType get themeType => ThemeType.values[_sharedPreferences.getInt(_themeTypeKey) ?? 0];
+  set themeType(ThemeType value) => _sharedPreferences.setInt(_themeTypeKey, value.index);
 }

lib/l10n/intl_en.arb

@@ -19,5 +19,10 @@
     "thirdStops": "1/3",
     "caffeine": "Caffeine",
     "keepsScreenOn": "Keeps screen on",
-    "haptics": "Haptics"
+    "haptics": "Haptics",
+    "theme": "Theme",
+    "chooseTheme": "Choose theme",
+    "themeLight": "Light",
+    "themeDark": "Dark",
+    "themeSystemDefault": "System default"
 }

lib/res/theme.dart

@@ -1,9 +1,92 @@
 import 'package:flutter/material.dart';
+import 'package:flutter/scheduler.dart';
+import 'package:lightmeter/data/models/theme_type.dart';
+import 'package:lightmeter/data/shared_prefs_service.dart';
 import 'package:material_color_utilities/material_color_utilities.dart';
 
-ColorScheme get lightColorScheme {
-  final scheme = Scheme.light(0xFF2196f3);
-  return ColorScheme.light(
+import 'package:provider/provider.dart';
+
+class ThemeProvider extends StatefulWidget {
+  final Color initialPrimaryColor;
+  final Widget? child;
+  final TransitionBuilder? builder;
+
+  const ThemeProvider({
+    required this.initialPrimaryColor,
+    this.child,
+    this.builder,
+    super.key,
+  });
+
+  static ThemeProviderState of(BuildContext context) {
+    return context.findAncestorStateOfType<ThemeProviderState>()!;
+  }
+
+  @override
+  State<ThemeProvider> createState() => ThemeProviderState();
+}
+
+class ThemeProviderState extends State<ThemeProvider> {
+  late ThemeType _themeType;
+  late Color _primaryColor = widget.initialPrimaryColor;
+
+  @override
+  void initState() {
+    super.initState();
+    _themeType = context.read<UserPreferencesService>().themeType;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Provider.value(
+      value: _themeType,
+      child: Provider.value(
+        value: _themeFromColor(
+          _primaryColor,
+          _mapThemeTypeToBrightness(_themeType),
+        ),
+        builder: widget.builder,
+        child: widget.child,
+      ),
+    );
+  }
+
+  void setThemeType(ThemeType themeType) {
+    if (themeType == _themeType) {
+      return;
+    }
+
+    setState(() {
+      _themeType = themeType;
+    });
+    context.read<UserPreferencesService>().themeType = themeType;
+  }
+
+  void setPrimaryColor(Color color) {
+    if (color == _primaryColor) {
+      return;
+    }
+
+    setState(() {
+      _primaryColor = color;
+    });
+  }
+
+  Brightness _mapThemeTypeToBrightness(ThemeType themeType) {
+    switch (themeType) {
+      case ThemeType.light:
+        return Brightness.light;
+      case ThemeType.dark:
+        return Brightness.dark;
+      case ThemeType.systemDefault:
+        return SchedulerBinding.instance.platformDispatcher.platformBrightness;
+    }
+  }
+
+  ThemeData _themeFromColor(Color color, Brightness brightness) {
+    final scheme = brightness == Brightness.light ? Scheme.light(color.value) : Scheme.dark(color.value);
+    final colorScheme = ColorScheme(
+      brightness: brightness,
       primary: Color(scheme.primary),
       onPrimary: Color(scheme.onPrimary),
       primaryContainer: Color(scheme.primaryContainer),
@@ -19,4 +102,9 @@ ColorScheme get lightColorScheme {
       surfaceVariant: Color.alphaBlend(Color(scheme.primary).withOpacity(0.5), Color(scheme.background)),
       onSurfaceVariant: Color(scheme.onSurfaceVariant),
     );
+    return ThemeData(
+      useMaterial3: true,
+      colorScheme: colorScheme,
+    );
+  }
 }

lib/screens/settings/components/shared/dialog_picker.dart

@@ -0,0 +1,74 @@
+import 'package:flutter/material.dart';
+import 'package:lightmeter/generated/l10n.dart';
+import 'package:lightmeter/res/dimens.dart';
+
+class DialogPicker<T> extends StatefulWidget {
+  final String title;
+  final T selectedValue;
+  final List<T> values;
+  final String Function(BuildContext context, T value) titleAdapter;
+
+  const DialogPicker({
+    required this.title,
+    required this.selectedValue,
+    required this.values,
+    required this.titleAdapter,
+    super.key,
+  });
+
+  @override
+  State<DialogPicker<T>> createState() => _DialogPickerState<T>();
+}
+
+class _DialogPickerState<T> extends State<DialogPicker<T>> {
+  late T _selected = widget.selectedValue;
+
+  @override
+  Widget build(BuildContext context) {
+    return AlertDialog(
+      titlePadding: const EdgeInsets.fromLTRB(
+        Dimens.paddingL,
+        Dimens.paddingL,
+        Dimens.paddingL,
+        Dimens.paddingM,
+      ),
+      title: Text(widget.title),
+      contentPadding: EdgeInsets.zero,
+      content: Column(
+        mainAxisSize: MainAxisSize.min,
+        children: widget.values
+            .map(
+              (e) => RadioListTile(
+                value: e,
+                groupValue: _selected,
+                title: Text(widget.titleAdapter(context, e)),
+                onChanged: (T? value) {
+                  if (value != null) {
+                    setState(() {
+                      _selected = value;
+                    });
+                  }
+                },
+              ),
+            )
+            .toList(),
+      ),
+      actionsPadding: const EdgeInsets.fromLTRB(
+        Dimens.paddingL,
+        Dimens.paddingM,
+        Dimens.paddingL,
+        Dimens.paddingL,
+      ),
+      actions: [
+        TextButton(
+          onPressed: Navigator.of(context).pop,
+          child: Text(S.of(context).cancel),
+        ),
+        TextButton(
+          onPressed: () => Navigator.of(context).pop(_selected),
+          child: Text(S.of(context).select),
+        ),
+      ],
+    );
+  }
+}

lib/screens/settings/components/theme_type_tile.dart

@@ -0,0 +1,48 @@
+import 'package:flutter/material.dart';
+import 'package:lightmeter/data/models/theme_type.dart';
+import 'package:lightmeter/data/shared_prefs_service.dart';
+import 'package:lightmeter/generated/l10n.dart';
+import 'package:lightmeter/res/theme.dart';
+import 'package:lightmeter/utils/stop_type_provider.dart';
+import 'package:provider/provider.dart';
+
+import 'shared/dialog_picker.dart';
+
+class ThemeTypeListTile extends StatelessWidget {
+  const ThemeTypeListTile({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return ListTile(
+      leading: const Icon(Icons.brightness_6),
+      title: Text(S.of(context).theme),
+      trailing: Text(_typeToString(context, context.watch<ThemeType>())),
+      onTap: () {
+        showDialog<ThemeType>(
+          context: context,
+          builder: (_) => DialogPicker<ThemeType>(
+            title: S.of(context).chooseTheme,
+            selectedValue: context.read<ThemeType>(),
+            values: ThemeType.values,
+            titleAdapter: _typeToString,
+          ),
+        ).then((value) {
+          if (value != null) {
+            ThemeProvider.of(context).setThemeType(value);
+          }
+        });
+      },
+    );
+  }
+
+  String _typeToString(BuildContext context, ThemeType themeType) {
+    switch (themeType) {
+      case ThemeType.light:
+        return S.of(context).themeLight;
+      case ThemeType.dark:
+        return S.of(context).themeDark;
+      case ThemeType.systemDefault:
+        return S.of(context).themeSystemDefault;
+    }
+  }
+}

lib/screens/settings/settings_screen.dart

@@ -5,6 +5,7 @@ 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';
+import 'components/theme_type_tile.dart';
 
 class SettingsScreen extends StatelessWidget {
   const SettingsScreen({super.key});
@@ -40,6 +41,7 @@ class SettingsScreen extends StatelessWidget {
                 const FractionalStopsListTile(),
                 const CaffeineListTile(),
                 const HapticsListTile(),
+                const ThemeTypeListTile(),
               ],
             ),
           ),