Show a subtle donation snackbar

app/lib/entity/pref.dart

@@ -118,6 +118,8 @@ enum PrefKey implements PrefKeyInterface {
   viewerAppBarButtons,
   viewerBottomAppBarButtons,
   homeCollectionsNavBarButtons,
+  lastDonationDialogTime,
+  shouldRemindDonationLater,
   ;
 
   @override
@@ -218,6 +220,10 @@ enum PrefKey implements PrefKeyInterface {
         return "viewerBottomAppBarButtons";
       case PrefKey.homeCollectionsNavBarButtons:
         return "homeCollectionsNavBarButtons";
+      case PrefKey.lastDonationDialogTime:
+        return "lastDonationDialogTime";
+      case PrefKey.shouldRemindDonationLater:
+        return "shouldRemindDonationLater";
     }
   }
 }

app/lib/entity/pref/extension.dart

@@ -165,6 +165,24 @@ extension PrefExtension on Pref {
       (key, value) => provider.setBool(key, value));
 
   bool? isNewHttpEngine() => provider.getBool(PrefKey.isNewHttpEngine);
+
+  int? getLastDonationDialogTime() =>
+      provider.getInt(PrefKey.lastDonationDialogTime);
+  int getLastDonationDialogTimeOr(int def) =>
+      getLastDonationDialogTime() ?? def;
+  Future<bool> setLastDonationDialogTime(int value) => _set<int>(
+      PrefKey.lastDonationDialogTime,
+      value,
+      (key, value) => provider.setInt(key, value));
+
+  bool? shouldRemindDonationLater() =>
+      provider.getBool(PrefKey.shouldRemindDonationLater);
+  bool shouldRemindDonationLaterOr([bool def = false]) =>
+      shouldRemindDonationLater() ?? def;
+  Future<bool> setShouldRemindDonationLater(bool value) => _set<bool>(
+      PrefKey.shouldRemindDonationLater,
+      value,
+      (key, value) => provider.setBool(key, value));
 }
 
 extension AccountPrefExtension on AccountPref {

app/lib/widget/donation_dialog.dart

@@ -0,0 +1,50 @@
+import 'package:clock/clock.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:nc_photos/app_localizations.dart';
+import 'package:nc_photos/controller/pref_controller.dart';
+import 'package:nc_photos/entity/pref.dart';
+import 'package:nc_photos/k.dart' as k;
+import 'package:nc_photos/snack_bar_manager.dart';
+
+class DonationDialogHandler {
+  Future<void> showIfNeeded(BuildContext context) async {
+    final prefController = context.read<PrefController>();
+    final lastMs = Pref().getLastDonationDialogTime();
+    if (lastMs == null) {
+      // first time
+      final firstRun = prefController.firstRunTimeValue ?? clock.now().toUtc();
+      final now = clock.now().toUtc();
+      if (now.isAfter(firstRun) &&
+          now.difference(firstRun) < const Duration(days: 7)) {
+        // unnecessary
+        return;
+      } else {
+        return _show(context);
+      }
+    } else {
+      final last = DateTime.fromMillisecondsSinceEpoch(lastMs, isUtc: true);
+      final now = clock.now().toUtc();
+      if (now.isAfter(last) &&
+          now.difference(last) < const Duration(days: 365)) {
+        return;
+      } else {
+        // 1 year later...
+        return _show(context);
+      }
+    }
+  }
+
+  Future<void> _show(BuildContext context) async {
+    SnackBarManager().showSnackBar(SnackBar(
+      content: Text(L10n.global().donationShortMessage),
+      action: SnackBarAction(
+        label: L10n.global().donationButtonLabel,
+        onPressed: () {},
+      ),
+      duration: k.snackBarDurationNormal,
+    ));
+    await Pref()
+        .setLastDonationDialogTime(clock.now().toUtc().millisecondsSinceEpoch);
+  }
+}

app/lib/widget/home_photos2.dart

@@ -46,6 +46,7 @@ import 'package:nc_photos/theme/dimension.dart';
 import 'package:nc_photos/url_launcher_util.dart';
 import 'package:nc_photos/widget/collection_browser.dart';
 import 'package:nc_photos/widget/collection_picker.dart';
+import 'package:nc_photos/widget/donation_dialog.dart';
 import 'package:nc_photos/widget/double_tap_exit_container/double_tap_exit_container.dart';
 import 'package:nc_photos/widget/file_sharer_dialog.dart';
 import 'package:nc_photos/widget/finger_listener.dart';
@@ -288,6 +289,10 @@ class _BodyState extends State<_Body> {
   void initState() {
     super.initState();
     _onBackToTopListener.begin();
+
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      DonationDialogHandler().showIfNeeded(context);
+    });
   }
 
   @override