feat: NesScaffold (#139)

* progress

* progress

CHANGELOG.md

@@ -2,6 +2,7 @@
  - feat: adding different frames to `NesDialog`s
  - feat: allow `NesFileExplorer` to have custom icons
  - feat: adding `NesIcons.alien`
+ - feat: allow `NesScaffold` and allow snackbars to be shown on them.
 
 # 0.19.0
  - feat: adding `NesSectionHeader`

example/lib/advanced/scaffold/scaffold.dart

@@ -0,0 +1,69 @@
+import 'package:flutter/material.dart';
+import 'package:nes_ui/nes_ui.dart';
+
+class NesScaffoldExample extends StatefulWidget {
+  const NesScaffoldExample({super.key});
+
+  static Route<void> route() {
+    return MaterialPageRoute<void>(
+      builder: (_) => const NesScaffoldExample(),
+    );
+  }
+
+  @override
+  State<NesScaffoldExample> createState() => _NesScaffoldExampleState();
+}
+
+class _NesScaffoldExampleState extends State<NesScaffoldExample> {
+  var _counter = 0;
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: NesScaffold(
+        body: Builder(
+          builder: (context) {
+            return Center(
+              child: Row(
+                mainAxisAlignment: MainAxisAlignment.center,
+                children: [
+                  NesButton(
+                    type: NesButtonType.primary,
+                    onPressed: () {
+                      NesScaffoldMessenger.of(context).showSnackBar(
+                        NesSnackbar(
+                          text: 'Hello, World! ${_counter++}',
+                          type: _counter.isOdd
+                              ? NesSnackbarType.success
+                              : NesSnackbarType.warning,
+                        ),
+                        alignment: Alignment.topRight,
+                      );
+                    },
+                    child: const Text('Show Snackbar top Right'),
+                  ),
+                  const SizedBox(width: 8),
+                  NesButton(
+                    type: NesButtonType.primary,
+                    onPressed: () {
+                      NesScaffoldMessenger.of(context).showSnackBar(
+                        NesSnackbar(
+                          text: 'Hello, World! ${_counter++}',
+                          type: _counter.isOdd
+                              ? NesSnackbarType.success
+                              : NesSnackbarType.warning,
+                        ),
+                        alignment: Alignment.topLeft,
+                      );
+                    },
+                    child: const Text('Show Snackbar top Left'),
+                  ),
+                ],
+              ),
+            );
+          },
+        ),
+      ),
+    );
+  }
+}

example/lib/gallery/gallery_page.dart

@@ -7,7 +7,7 @@ class GalleryPage extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return NesScaffold(
+    return NesExampleScaffold(
       child: SingleChildScrollView(
         child: Padding(
           padding: const EdgeInsets.symmetric(horizontal: 32),

example/lib/widgets/nes_scaffold.dart

@@ -1,14 +1,15 @@
 import 'package:example/advanced/container_playground/container_playground.dart';
 import 'package:example/advanced/fixed_viewport/page/fixed_viewport_page.dart';
 import 'package:example/advanced/rpg_menu/rpg_menu.dart';
+import 'package:example/advanced/scaffold/scaffold.dart';
 import 'package:example/advanced/window_manager/window_manager.dart';
 import 'package:example/app/app.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:nes_ui/nes_ui.dart';
 
-class NesScaffold extends StatelessWidget {
-  const NesScaffold({
+class NesExampleScaffold extends StatelessWidget {
+  const NesExampleScaffold({
     super.key,
     required this.child,
   });
@@ -23,6 +24,16 @@ class NesScaffold extends StatelessWidget {
       floatingActionButton: Column(
         mainAxisSize: MainAxisSize.min,
         children: [
+          NesButton(
+            type: NesButtonType.normal,
+            onPressed: () {
+              Navigator.of(context).push(
+                NesScaffoldExample.route(),
+              );
+            },
+            child: NesIcon(iconData: NesIcons.rail),
+          ),
+          const SizedBox(height: 16),
           NesButton(
             type: NesButtonType.normal,
             onPressed: () {

lib/src/widgets/nes_scaffold.dart

@@ -0,0 +1,251 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+import 'package:nes_ui/nes_ui.dart';
+
+/// {@template nes_scaffold_messenger}
+/// Manages widgets displayed by a [NesScaffold].
+/// {@endtemplate}
+class NesScaffoldMessenger extends StatefulWidget {
+  /// {@macro nes_scaffold_messenger}
+  const NesScaffoldMessenger({
+    required this.body,
+    super.key,
+  });
+
+  /// The primary content of the scaffold.
+  final Widget body;
+
+  /// Returns the [NesScaffoldMessengerState] in the scope.
+  static NesScaffoldMessengerState of(BuildContext context) {
+    return _NesScaffoldMessengerScope.of(context);
+  }
+
+  @override
+  NesScaffoldMessengerState createState() => NesScaffoldMessengerState();
+}
+
+class _SnackbarMessage {
+  const _SnackbarMessage({
+    required this.id,
+    required this.snackbar,
+    required this.alignment,
+    required this.offset,
+    this.markForRemoval = false,
+  });
+
+  final int id;
+  final NesSnackbar snackbar;
+  final Alignment alignment;
+  final Offset offset;
+  final bool markForRemoval;
+
+  _SnackbarMessage copyWith({
+    int? id,
+    Alignment? alignment,
+    Offset? offset,
+    bool? markForRemoval,
+  }) {
+    return _SnackbarMessage(
+      id: id ?? this.id,
+      snackbar: snackbar,
+      alignment: alignment ?? this.alignment,
+      offset: offset ?? this.offset,
+      markForRemoval: markForRemoval ?? this.markForRemoval,
+    );
+  }
+}
+
+/// Handles the state of a [NesScaffoldMessenger].
+///
+/// This class allows the user to show snackbars and etc.
+class NesScaffoldMessengerState extends State<NesScaffoldMessenger> {
+  late int _snackbarId = 0;
+  final List<Timer> _timers = [];
+
+  Future<void> _waitABit() async {
+    final completer = Completer<void>();
+
+    late final Timer timer;
+
+    timer = Timer(const Duration(seconds: 3), () {
+      completer.complete();
+      _timers.remove(timer);
+      timer.cancel();
+    });
+
+    _timers.add(timer);
+
+    return completer.future;
+  }
+
+  /// Adds a [NesSnackbar] to the [NesScaffold].
+  void showSnackBar(
+    NesSnackbar snackbar, {
+    Alignment alignment = Alignment.bottomCenter,
+  }) {
+    final message = _SnackbarMessage(
+      id: _snackbarId++,
+      snackbar: snackbar,
+      alignment: alignment,
+      offset: Offset(alignment.x, 0),
+    );
+    _snackbars.value = [
+      ..._snackbars.value,
+      message,
+    ];
+
+    WidgetsBinding.instance.addPostFrameCallback((timeStamp) {
+      _snackbars.value = _snackbars.value.map((e) {
+        if (e.id == message.id) {
+          return e.copyWith(
+            offset: Offset.zero,
+          );
+        }
+        return e;
+      }).toList();
+    });
+
+    _waitABit().then((_) {
+      _snackbars.value = _snackbars.value.map((e) {
+        if (e.id == message.id) {
+          return e.copyWith(
+            markForRemoval: true,
+            offset: Offset(alignment.x, 0),
+          );
+        }
+        return e;
+      }).toList();
+    });
+
+    _overlayController.show();
+  }
+
+  late final _snackbars = ValueNotifier<List<_SnackbarMessage>>([]);
+  late final _overlayController = OverlayPortalController();
+
+  void _checkForRemovals() {
+    _snackbars.value = _snackbars.value.where((element) {
+      return !element.markForRemoval;
+    }).toList();
+  }
+
+  @override
+  void dispose() {
+    super.dispose();
+
+    for (final timer in _timers) {
+      timer.cancel();
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return _NesScaffoldMessengerScope(
+      state: this,
+      child: OverlayPortal(
+        overlayChildBuilder: (context) {
+          return ValueListenableBuilder<List<_SnackbarMessage>>(
+            valueListenable: _snackbars,
+            builder: (context, snackbars, child) {
+              final values = List<_SnackbarMessage>.from(snackbars)
+                ..sort((a, b) {
+                  return a.id.compareTo(b.id);
+                });
+              return Stack(
+                children: [
+                  for (var i = 0; i < values.length; i++)
+                    Align(
+                      alignment: values[i].alignment,
+                      child: AnimatedSlide(
+                        key: ValueKey('slide_${values[i].id}'),
+                        onEnd: _checkForRemovals,
+                        duration: const Duration(milliseconds: 300),
+                        offset: values[i].offset,
+                        child: AnimatedPadding(
+                          key: ValueKey('padding_${values[i].id}'),
+                          duration: const Duration(milliseconds: 300),
+                          padding: EdgeInsets.only(
+                            top: 32 * i + 16,
+                            left: 16,
+                            right: 16,
+                          ),
+                          child: NesDropshadow(
+                            child: snackbars[i].snackbar,
+                          ),
+                        ),
+                      ),
+                    ),
+                ],
+              );
+            },
+          );
+        },
+        controller: _overlayController,
+        child: widget.body,
+      ),
+    );
+  }
+}
+
+class _NesScaffoldMessengerScope extends InheritedWidget {
+  const _NesScaffoldMessengerScope({
+    required super.child,
+    required this.state,
+  });
+
+  final NesScaffoldMessengerState state;
+
+  /// Returns the current message.
+  static NesScaffoldMessengerState of(BuildContext context) {
+    final result = context
+        .dependOnInheritedWidgetOfExactType<_NesScaffoldMessengerScope>()
+        ?.state;
+
+    if (result == null) {
+      throw FlutterError(
+        'NesScaffoldMessenger.of() called with a context that does not contain '
+        'a NesScaffoldMessenger.\n'
+        'No NesScaffoldMessengerState ancestor could be found starting from '
+        'the context that was passed to NesScaffoldMessenger.of().\n'
+        'The context used was:\n'
+        '  $context',
+      );
+    }
+
+    return result;
+  }
+
+  @override
+  bool updateShouldNotify(_NesScaffoldMessengerScope oldWidget) =>
+      state != oldWidget.state;
+}
+
+/// {@template nes_scaffold}
+/// A Nes UI system scaffold widget.
+///
+/// Right now it doesn't replace the [Scaffold] widget, so we
+/// advise to use it in combination with Material's [Scaffold].
+///
+/// That might change as we develop the library.
+///
+/// To interact with the [NesScaffold] state, use a [NesScaffoldMessenger].
+///
+/// {@endtemplate}
+class NesScaffold extends StatelessWidget {
+  /// {@macro nes_scaffold}
+  const NesScaffold({
+    required this.body,
+    super.key,
+  });
+
+  /// The primary content of the scaffold.
+  final Widget body;
+
+  @override
+  Widget build(BuildContext context) {
+    return NesScaffoldMessenger(
+      body: body,
+    );
+  }
+}

lib/src/widgets/nes_snackbar.dart

@@ -43,9 +43,12 @@ class NesSnackbar extends StatelessWidget {
       SnackBar(
         backgroundColor: Colors.transparent,
         elevation: 0,
-        content: NesSnackbar(
-          text: text,
-          type: type,
+        content: SizedBox(
+          width: double.infinity,
+          child: NesSnackbar(
+            text: text,
+            type: type,
+          ),
         ),
       ),
     );
@@ -73,7 +76,6 @@ class NesSnackbar extends StatelessWidget {
     }
 
     return NesContainer(
-      width: double.infinity,
       backgroundColor: color,
       child: Text(
         text,