added support for dark / light mode switch

lib/constants/themes.dart

@@ -0,0 +1,35 @@
+import 'package:flutter/material.dart';
+
+final LIGHT_THEME = ThemeData(
+  textTheme: ThemeData().textTheme.copyWith(
+        headline1: const TextStyle(
+          fontSize: 32,
+          fontWeight: FontWeight.w500,
+        ),
+      ),
+  inputDecorationTheme: InputDecorationTheme(
+    filled: true,
+    helperMaxLines: 10,
+    errorMaxLines: 10,
+    border: OutlineInputBorder(
+      borderRadius: BorderRadius.circular(8),
+    ),
+  ),
+);
+
+final DARK_THEME = ThemeData.dark().copyWith(
+  textTheme: ThemeData.dark().textTheme.copyWith(
+        headline1: const TextStyle(
+          fontSize: 32,
+          fontWeight: FontWeight.w500,
+        ),
+      ),
+  inputDecorationTheme: InputDecorationTheme(
+    filled: true,
+    helperMaxLines: 10,
+    errorMaxLines: 10,
+    border: OutlineInputBorder(
+      borderRadius: BorderRadius.circular(8),
+    ),
+  ),
+);

lib/main.dart

@@ -2,6 +2,7 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:provider/provider.dart';
+import 'package:quid_faciam_hodie/constants/themes.dart';
 import 'package:quid_faciam_hodie/screens/calendar_screen.dart';
 import 'package:quid_faciam_hodie/screens/grant_permission_screen.dart';
 import 'package:quid_faciam_hodie/screens/login_screen.dart';
@@ -20,7 +21,7 @@ void main() async {
     DeviceOrientation.portraitDown,
   ]);
 
-  runApp(MyApp());
+  runApp(const MyApp());
 }
 
 class MyApp extends StatefulWidget {
@@ -41,22 +42,9 @@ class _MyAppState extends State<MyApp> {
       value: memories,
       child: MaterialApp(
         title: 'Quid faciam hodie?',
-        theme: ThemeData.dark().copyWith(
+        theme: LIGHT_THEME,
-          textTheme: ThemeData.dark().textTheme.copyWith(
+        darkTheme: DARK_THEME,
-                headline1: const TextStyle(
+        themeMode: ThemeMode.system,
-                  fontSize: 32,
-                  fontWeight: FontWeight.w500,
-                ),
-              ),
-          inputDecorationTheme: InputDecorationTheme(
-            filled: true,
-            helperMaxLines: 10,
-            errorMaxLines: 10,
-            border: OutlineInputBorder(
-              borderRadius: BorderRadius.circular(8),
-            ),
-          ),
-        ),
         routes: {
           WelcomeScreen.ID: (context) => const WelcomeScreen(),
           MainScreen.ID: (context) => const MainScreen(),

lib/screens/server_loading_screen.dart

@@ -25,6 +25,8 @@ class _ServerLoadingScreenState extends State<ServerLoadingScreen> {
   @override
   void initState() {
     super.initState();
+
+    load();
   }
 
   Future<void> load() async {

lib/widgets/calendar_month.dart

@@ -40,8 +40,8 @@ class MonthCalendarBuilder extends CalendarBuilder {
     }();
 
     final delay = Duration(
-        microseconds:
+      microseconds: Random().nextInt(CALENDAR_DATE_IN_MAX_DELAY.inMicroseconds),
-            Random().nextInt(CALENDAR_DATE_IN_MAX_DELAY.inMicroseconds));
+    );
 
     return DelayRender(
       delay: delay,
@@ -163,7 +163,7 @@ class CalendarMonth extends StatelessWidget {
         // Background color
         selectedDayTextColor: theme.textTheme.bodyText1!.color!,
         // Foreground color
-        focusedDayTextColor: theme.bottomAppBarColor,
+        focusedDayTextColor: theme.dialogBackgroundColor,
       ),
     );
   }

lib/widgets/memory.dart

@@ -79,9 +79,16 @@ class _MemoryViewState extends State<MemoryView> {
 
   @override
   Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
     if (status == MemoryFetchStatus.error) {
-      return const Center(
+      return Center(
-        child: Text('Memory could not be loaded.'),
+        child: Text(
+          'Memory could not be loaded.',
+          style: theme.textTheme.bodyText2!.copyWith(
+            color: Colors.white,
+          ),
+        ),
       );
     }
 
@@ -122,7 +129,12 @@ class _MemoryViewState extends State<MemoryView> {
         () {
           switch (status) {
             case MemoryFetchStatus.downloading:
-              return const Text('Downloading memory');
+              return Text(
+                'Downloading memory',
+                style: theme.textTheme.bodyText2!.copyWith(
+                  color: Colors.white,
+                ),
+              );
             default:
               return const SizedBox();
           }

lib/widgets/status.dart

@@ -74,7 +74,9 @@ class _StatusState extends State<Status> with TickerProviderStateMixin {
 
   @override
   Widget build(BuildContext context) {
-    return Stack(
+    return Container(
+      color: Colors.black,
+      child: Stack(
         fit: StackFit.expand,
         children: <Widget>[
           widget.child,
@@ -115,6 +117,7 @@ class _StatusState extends State<Status> with TickerProviderStateMixin {
             ),
           ),
         ],
+      ),
     );
   }
 }

lib/widgets/timeline_overlay.dart

@@ -36,7 +36,9 @@ class TimelineOverlay extends StatelessWidget {
             child: Text(
               DateFormat('dd. MMMM yyyy').format(date),
               textAlign: TextAlign.center,
-              style: Theme.of(context).textTheme.headline1,
+              style: Theme.of(context).textTheme.headline1!.copyWith(
+                    color: Colors.white,
+                  ),
             ),
           ),
         ),
@@ -58,12 +60,15 @@ class TimelineOverlay extends StatelessWidget {
                     child: Icon(
                       Icons.public,
                       size: theme.textTheme.titleSmall!.fontSize,
+                      color: Colors.white,
                     ),
                   ),
                   const SizedBox(width: SMALL_SPACE),
                   Text(
                     '$memoryIndex/$memoriesAmount',
-                    style: Theme.of(context).textTheme.titleSmall,
+                    style: Theme.of(context).textTheme.titleSmall!.copyWith(
+                          color: Colors.white,
+                        ),
                   )
                 ],
               ),