feat: Added a service for displaying snacks

lib/features/app/app.dart

@@ -1,9 +1,12 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_easy_dialogs/flutter_easy_dialogs.dart';
 import 'package:flutter_localizations/flutter_localizations.dart';
 import 'package:flutter_template/features/navigation/app_router.dart';
+import 'package:flutter_template/features/snack_queue/presentation/snack_queue_provider.dart';
 import 'package:flutter_template/features/theme_mode/presentation/widgets/theme_mode_builder.dart';
 import 'package:flutter_template/l10n/app_localizations.g.dart';
 import 'package:flutter_template/uikit/themes/app_theme_data.dart';
+import 'package:nested/nested.dart';
 import 'package:provider/provider.dart';
 
 /// {@template app.class}
@@ -45,6 +48,28 @@ class _AppState extends State<App> {
           darkTheme: AppThemeData.darkTheme,
           themeMode: themeMode,
 
+          /// For snack and dialogs.
+          builder: (builderContext, widget) {
+            final mediaQueryData = MediaQuery.of(builderContext);
+            final easyDialogsBuilder = FlutterEasyDialogs.builder();
+
+            return Nested(
+              children: const [
+                SnackQueueProvider(),
+              ],
+              child: MediaQuery(
+                data: mediaQueryData.copyWith(textScaler: TextScaler.noScaling),
+                child: Overlay(
+                  initialEntries: [
+                    OverlayEntry(
+                      builder: (overlayContext) => easyDialogsBuilder(overlayContext, widget),
+                    ),
+                  ],
+                ),
+              ),
+            );
+          },
+
           /// Localization.
           locale: _localizations.firstOrNull,
           localizationsDelegates: _localizationsDelegates,

lib/features/debug/presentation/ui_kit/ui_kit_screen.dart

@@ -96,6 +96,9 @@ class UiKitScreen extends ElementaryWidget<IUiKitWM> {
             ),
             child: Text(wm.l10n.uiKitScreenTetradicButtonText),
           ),
+          const SizedBox(width: AppSizes.double8),
+          Text(wm.l10n.uiKitScreenSnackFromScaffoldMessengerText),
+          const SizedBox(width: AppSizes.double8),
           Row(
             children: [
               Expanded(
@@ -121,6 +124,34 @@ class UiKitScreen extends ElementaryWidget<IUiKitWM> {
               ),
             ],
           ),
+          const SizedBox(width: AppSizes.double8),
+          Text(wm.l10n.uiKitScreenSnackFromSnackQueueText),
+          const SizedBox(width: AppSizes.double8),
+          Row(
+            children: [
+              Expanded(
+                child: ElevatedButton(
+                  onPressed: wm.onDangerSnackQueueButtonPressed,
+                  style: ElevatedButton.styleFrom(
+                    foregroundColor: wm.colorScheme.onDanger,
+                    backgroundColor: wm.colorScheme.danger,
+                  ),
+                  child: Text(wm.l10n.uiKitScreenDangerSnackButtonText),
+                ),
+              ),
+              const SizedBox(width: AppSizes.double8),
+              Expanded(
+                child: ElevatedButton(
+                  onPressed: wm.onPositiveSnackQueueButtonPressed,
+                  style: ElevatedButton.styleFrom(
+                    foregroundColor: wm.colorScheme.onPositive,
+                    backgroundColor: wm.colorScheme.positive,
+                  ),
+                  child: Text(wm.l10n.uiKitScreenPositiveSnackButtonText),
+                ),
+              ),
+            ],
+          ),
           const SizedBox(height: AppSizes.double16),
           const _ColorGrid(),
         ]

lib/features/debug/presentation/ui_kit/ui_kit_wm.dart

@@ -5,17 +5,25 @@ import 'package:flutter_template/common/mixin/theme_wm_mixin.dart';
 import 'package:flutter_template/features/app/di/app_scope.dart';
 import 'package:flutter_template/features/debug/presentation/ui_kit/ui_kit_model.dart';
 import 'package:flutter_template/features/debug/presentation/ui_kit/ui_kit_screen.dart';
+import 'package:flutter_template/features/snack_queue/presentation/snack_message_type.dart';
+import 'package:flutter_template/features/snack_queue/presentation/snack_queue_controller.dart';
+import 'package:flutter_template/features/snack_queue/presentation/snack_queue_provider.dart';
 import 'package:flutter_template/features/theme_mode/presentation/theme_mode_provider.dart';
 import 'package:provider/provider.dart';
 
 /// Factory for [UiKitWM].
 UiKitWM uiKitScreenWMFactory(BuildContext context) {
   final appScope = context.read<IAppScope>();
   final scaffoldMessenger = ScaffoldMessenger.of(context);
+  final snackQueueController = SnackQueueProvider.of(context);
 
   final model = UiKitModel(logWriter: appScope.logger);
 
-  return UiKitWM(model, scaffoldMessenger: scaffoldMessenger);
+  return UiKitWM(
+    model,
+    scaffoldMessenger: scaffoldMessenger,
+    snackQueueController: snackQueueController,
+  );
 }
 
 /// Interface for [UiKitWM].
@@ -40,19 +48,28 @@ abstract interface class IUiKitWM with ILocalizationMixin, ThemeIModelMixin impl
 
   /// Callback of pressing the positive snack button.
   void onPositiveSnackButtonPressed();
+
+  /// Callback of pressing the danger snack button.
+  void onDangerSnackQueueButtonPressed();
+
+  /// Callback of pressing the positive snack button.
+  void onPositiveSnackQueueButtonPressed();
 }
 
 /// {@template ui_kit_widget_model.class}
 /// [WidgetModel] for [UiKitScreen].
 /// {@endtemplate}
 class UiKitWM extends WidgetModel<UiKitScreen, UiKitModel> with LocalizationMixin, ThemeWMMixin implements IUiKitWM {
   final ScaffoldMessengerState _scaffoldMessenger;
+  final SnackQueueController _snackQueueController;
 
   /// {@macro ui_kit_widget_model.class}
   UiKitWM(
     super._model, {
     required ScaffoldMessengerState scaffoldMessenger,
-  }) : _scaffoldMessenger = scaffoldMessenger;
+    required SnackQueueController snackQueueController,
+  })  : _scaffoldMessenger = scaffoldMessenger,
+        _snackQueueController = snackQueueController;
 
   @override
   Future<void> switchTheme() => ThemeModeProvider.of(context).switchThemeMode();
@@ -102,4 +119,20 @@ class UiKitWM extends WidgetModel<UiKitScreen, UiKitModel> with LocalizationMixi
       ),
     );
   }
+
+  @override
+  void onDangerSnackQueueButtonPressed() {
+    _snackQueueController.addSnack(
+      l10n.uiKitScreenDangerSnackText,
+      messageType: SnackMessageType.error,
+    );
+  }
+
+  @override
+  void onPositiveSnackQueueButtonPressed() {
+    _snackQueueController.addSnack(
+      l10n.uiKitScreenPositiveSnackText,
+      messageType: SnackMessageType.success,
+    );
+  }
 }

lib/features/snack_queue/presentation/default_snack_controller.dart

@@ -0,0 +1,80 @@
+// ignore_for_file: no-equal-arguments
+import 'package:flutter/material.dart';
+import 'package:flutter_easy_dialogs/flutter_easy_dialogs.dart';
+import 'package:flutter_template/features/snack_queue/presentation/snack_message_type.dart';
+import 'package:flutter_template/uikit/app_sizes.dart';
+import 'package:flutter_template/uikit/colors/app_color_scheme.dart';
+import 'package:flutter_template/uikit/text/app_text_scheme.dart';
+
+/// Default controller for displaying messages.
+class DefaultSnackController {
+  /// Create an instance [DefaultSnackController].
+  const DefaultSnackController();
+
+  /// Show the message.
+  Future<void> showSnack({
+    required SnackMessageType messageType,
+    required String message,
+    required BuildContext context,
+    required EasyDialogDecoration dialogDecoration,
+    required EasyDialogAnimationConfiguration animationConfiguration,
+    Duration? autoHideDuration,
+  }) {
+    final colorScheme = AppColorScheme.of(context);
+    final textScheme = AppTextScheme.of(context);
+    final topPadding = MediaQuery.of(context).viewPadding.top;
+    return FlutterEasyDialogs.show(
+      EasyDialog.positioned(
+        decoration: dialogDecoration,
+        content: SizedBox(
+          width: double.infinity,
+          child: DecoratedBox(
+            decoration: BoxDecoration(
+              color: switch (messageType) {
+                // TODO(anyone): Set up colors according to your theme.
+                SnackMessageType.error => colorScheme.danger,
+                SnackMessageType.success => colorScheme.positive,
+                SnackMessageType.warning => colorScheme.dangerSecondary,
+              },
+            ),
+            child: Padding(
+              padding: EdgeInsets.fromLTRB(
+                AppSizes.double16,
+                topPadding + AppSizes.double8,
+                AppSizes.double16,
+                AppSizes.double16,
+              ),
+              child: Text(
+                message,
+                style: textScheme.label.copyWith(
+                  color: switch (messageType) {
+                    // TODO(anyone): Set up colors according to your theme.
+                    SnackMessageType.error => colorScheme.onDanger,
+                    SnackMessageType.success => colorScheme.onPositive,
+                    SnackMessageType.warning => colorScheme.onDanger,
+                  },
+                ),
+                textAlign: TextAlign.center,
+              ),
+            ),
+          ),
+        ),
+        autoHideDuration: autoHideDuration,
+        animationConfiguration: animationConfiguration,
+      ).swipe(
+        direction: DismissDirection.up,
+        willDismiss: () => true,
+      ),
+    );
+  }
+
+  /// Hide Snack.
+  Future<void> hideSnack() {
+    return FlutterEasyDialogs.hide(
+      PositionedDialog.identifier(
+        position: EasyDialogPosition.top,
+      ),
+      instantly: true,
+    );
+  }
+}

lib/features/snack_queue/presentation/snack_message_type.dart

@@ -0,0 +1,11 @@
+/// The type of message on the snack bar.
+enum SnackMessageType {
+  /// Successfully completed.
+  success,
+
+  /// Error.
+  error,
+
+  /// Warning.
+  warning,
+}

lib/features/snack_queue/presentation/snack_queue_controller.dart

@@ -0,0 +1,17 @@
+import 'package:flutter_easy_dialogs/flutter_easy_dialogs.dart';
+import 'package:flutter_template/features/snack_queue/presentation/snack_message_type.dart';
+
+/// The controller for displaying snacks.
+/// Will be available to descendants.
+abstract interface class SnackQueueController {
+  /// Add Snack to Queue.
+  void addSnack(
+    String message, {
+    required SnackMessageType messageType,
+    EasyDialogDecoration? dialogDecoration,
+    EasyDialogAnimationConfiguration? animationConfiguration,
+  });
+
+  /// Clears the snack queue from potential displays that were queued before [closeTime].
+  void clearSnackQueue(DateTime closeTime);
+}

lib/features/snack_queue/presentation/snack_queue_model.dart

@@ -0,0 +1,13 @@
+import 'package:elementary/elementary.dart';
+import 'package:flutter_template/core/architecture/presentation/base_model.dart';
+import 'package:flutter_template/features/snack_queue/presentation/snack_queue_widget.dart';
+
+/// {@template snack_queue_model.class}
+/// [ElementaryModel] for [SnackQueueWidget].
+/// {@endtemplate}
+final class SnackQueueModel extends BaseModel {
+  /// {@macro snack_queue_model.class}
+  SnackQueueModel({
+    required super.logWriter,
+  });
+}

lib/features/snack_queue/presentation/snack_queue_provider.dart

@@ -0,0 +1,22 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_template/features/snack_queue/presentation/snack_queue_controller.dart';
+import 'package:flutter_template/features/snack_queue/presentation/snack_queue_widget.dart';
+import 'package:nested/nested.dart';
+import 'package:provider/provider.dart';
+
+/// {@template snack_queue_provider.class}
+/// Provides [SnackQueueController] to its descendants.
+/// {@endtemplate}
+class SnackQueueProvider extends SingleChildStatelessWidget {
+  /// {@macro snack_queue_provider.class}
+  const SnackQueueProvider({super.key});
+
+  /// Get the [SnackQueueController] from the [BuildContext].
+  // ignore: prefer-widget-private-members
+  static SnackQueueController of(BuildContext context) => Provider.of<SnackQueueController>(context, listen: false);
+
+  @override
+  Widget buildWithChild(BuildContext context, Widget? child) {
+    return SnackQueueWidget(child: child ?? const SizedBox.shrink());
+  }
+}

lib/features/snack_queue/presentation/snack_queue_widget.dart

@@ -0,0 +1,28 @@
+import 'package:elementary/elementary.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_template/features/snack_queue/presentation/snack_queue_controller.dart';
+import 'package:flutter_template/features/snack_queue/presentation/snack_queue_wm.dart';
+import 'package:provider/provider.dart';
+
+/// {@template snack_queue_widget.class}
+/// SnackQueueWidget.
+/// {@endtemplate}
+class SnackQueueWidget extends ElementaryWidget<ISnackQueueWM> {
+  /// {@macro snack_queue_widget.class}
+  const SnackQueueWidget({
+    required this.child,
+    super.key,
+    WidgetModelFactory wmFactory = defaultSnackQueueWMFactory,
+  }) : super(wmFactory);
+
+  /// Child.
+  final Widget child;
+
+  @override
+  Widget build(ISnackQueueWM wm) {
+    return Provider<SnackQueueController>.value(
+      value: wm,
+      child: child,
+    );
+  }
+}