feat: added sandbox for multiball

packages/pinball_components/sandbox/lib/main.dart

@@ -30,6 +30,7 @@ void main() {
   addScoreTextStories(dashbook);
   addBackboardStories(dashbook);
   addDinoWallStories(dashbook);
+  addMultiballStories(dashbook);
 
   runApp(dashbook);
 }

packages/pinball_components/sandbox/lib/stories/multiball/multiball_game.dart

@@ -0,0 +1,66 @@
+import 'package:flame/input.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:pinball_components/pinball_components.dart';
+import 'package:sandbox/stories/ball/basic_ball_game.dart';
+
+class MultiballGame extends BallGame with KeyboardEvents {
+  MultiballGame()
+      : super(
+          imagesFileNames: [
+            Assets.images.multiball.a.active.keyName,
+            Assets.images.multiball.a.inactive.keyName,
+            Assets.images.multiball.b.active.keyName,
+            Assets.images.multiball.b.inactive.keyName,
+            Assets.images.multiball.c.active.keyName,
+            Assets.images.multiball.c.inactive.keyName,
+            Assets.images.multiball.d.active.keyName,
+            Assets.images.multiball.d.inactive.keyName,
+          ],
+        );
+
+  static const description = '''
+    Shows how the Multiball are rendered.
+      
+    - Tap anywhere on the screen to spawn a ball into the game.
+    - Press space bar for animate state multiballs.
+''';
+
+  late final Multiball _multiballA;
+  late final Multiball _multiballB;
+  late final Multiball _multiballC;
+  late final Multiball _multiballD;
+
+  @override
+  Future<void> onLoad() async {
+    await super.onLoad();
+
+    camera.followVector2(Vector2.zero());
+
+    await addAll([
+      _multiballA = Multiball.a(),
+      _multiballB = Multiball.b(),
+      _multiballC = Multiball.c(),
+      _multiballD = Multiball.d(),
+    ]);
+    await traceAllBodies();
+  }
+
+  @override
+  KeyEventResult onKeyEvent(
+    RawKeyEvent event,
+    Set<LogicalKeyboardKey> keysPressed,
+  ) {
+    if (event is RawKeyDownEvent &&
+        event.logicalKey == LogicalKeyboardKey.space) {
+      _multiballA.animate();
+      _multiballB.animate();
+      _multiballC.animate();
+      _multiballD.animate();
+
+      return KeyEventResult.handled;
+    }
+
+    return KeyEventResult.ignored;
+  }
+}

packages/pinball_components/sandbox/lib/stories/multiball/stories.dart

@@ -0,0 +1,11 @@
+import 'package:dashbook/dashbook.dart';
+import 'package:sandbox/common/common.dart';
+import 'package:sandbox/stories/multiball/multiball_game.dart';
+
+void addMultiballStories(Dashbook dashbook) {
+  dashbook.storiesOf('Multiball').addGame(
+        title: 'Assets',
+        description: MultiballGame.description,
+        gameBuilder: (_) => MultiballGame(),
+      );
+}

packages/pinball_components/sandbox/lib/stories/stories.dart

@@ -11,6 +11,7 @@ export 'flutter_forest/stories.dart';
 export 'google_word/stories.dart';
 export 'launch_ramp/stories.dart';
 export 'layer/stories.dart';
+export 'multiball/stories.dart';
 export 'plunger/stories.dart';
 export 'score_text/stories.dart';
 export 'slingshot/stories.dart';

test/game/pinball_game_test.dart

@@ -112,6 +112,18 @@ void main() {
         },
       );
 
+      flameTester.test(
+        'has only one Multiball',
+        (game) async {
+          await game.ready();
+
+          expect(
+            game.children.whereType<MultiballGroup>().length,
+            equals(1),
+          );
+        },
+      );
+
       group('controller', () {
         // TODO(alestiago): Write test to be controller agnostic.
         group('listenWhen', () {