refactor: created Launcher to group rocket, plunger and launchramp

lib/game/components/launcher.dart

@@ -0,0 +1,27 @@
+import 'package:flame/components.dart';
+import 'package:flame_forge2d/flame_forge2d.dart';
+import 'package:pinball/game/components/components.dart';
+import 'package:pinball_components/pinball_components.dart' hide Assets;
+
+/// {@template plunger_zone}
+/// A [Blueprint] which groups the [Plunger], [RocketSpriteComponent] and
+/// [LaunchRamp].
+/// {@endtemplate}
+class Launcher extends Forge2DBlueprint {
+  /// {@macro plunger_zone}
+  Launcher();
+
+  /// [Plunger] to launch the [Ball] into the board.
+  late final Plunger plunger;
+
+  @override
+  void build(Forge2DGame gameRef) {
+    plunger = ControlledPlunger(compressionDistance: 12.3)
+      ..initialPosition = Vector2(40.1, -38);
+
+    final _rocket = RocketSpriteComponent()..position = Vector2(43, 62);
+
+    gameRef.addFromBlueprint(LaunchRamp());
+    addAll([_rocket, plunger]);
+  }
+}

lib/game/components/plunger_zone.dart

@@ -1,44 +0,0 @@
-import 'package:flame/components.dart';
-import 'package:flame_forge2d/flame_forge2d.dart';
-import 'package:pinball/game/components/components.dart';
-import 'package:pinball/gen/assets.gen.dart';
-import 'package:pinball_components/pinball_components.dart' hide Assets;
-
-/// {@template plunger_zone}
-/// A [Blueprint] which creates zone for the [Plunger].
-/// {@endtemplate}
-class PlungerZone extends Forge2DBlueprint {
-  /// {@macro plunger_zone}
-  PlungerZone();
-
-  /// [Plunger] to launch the [Ball] into the board.
-  late final Plunger plunger;
-
-  @override
-  void build(Forge2DGame gameRef) {
-    plunger = ControlledPlunger(compressionDistance: 12.3)
-      ..initialPosition = Vector2(40.1, -38);
-
-    final _rocket = _PlungerRocketSpriteComponent();
-
-    addAll([_rocket, plunger]);
-  }
-}
-
-class _PlungerRocketSpriteComponent extends SpriteComponent with HasGameRef {
-  // TODO(ruimiguel): change this priority to be over launcher ramp and bottom
-  // wall.
-  _PlungerRocketSpriteComponent() : super(priority: 5);
-
-  @override
-  Future<void> onLoad() async {
-    await super.onLoad();
-    final sprite = await gameRef.loadSprite(
-      Assets.images.components.rocket.path,
-    );
-    this.sprite = sprite;
-    size = sprite.originalSize / 10;
-    anchor = Anchor.center;
-    position = Vector2(43.5, 62);
-  }
-}