feat: implemented Flipper in PinballGame

lib/game/components/components.dart

@@ -1,5 +1,6 @@
 export 'anchor.dart';
 export 'ball.dart';
+export 'flipper.dart';
 export 'plunger.dart';
 export 'score_points.dart';
 export 'wall.dart';

lib/game/pinball_game.dart

@@ -1,8 +1,16 @@
+import 'package:flame/input.dart';
 import 'package:flame_bloc/flame_bloc.dart';
 import 'package:flame_forge2d/flame_forge2d.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter/widgets.dart';
 import 'package:pinball/game/game.dart';
 
-class PinballGame extends Forge2DGame with FlameBloc {
+class PinballGame extends Forge2DGame with FlameBloc, KeyboardEvents {
+  late final Flipper _rightFlipper;
+  late final Flipper _leftFlipper;
+  late final RevoluteJoint _leftFlipperRevoluteJoint;
+  late final RevoluteJoint _rightFlipperRevoluteJoint;
+
   void spawnBall() {
     add(Ball(position: ballStartingPosition));
   }
@@ -23,5 +31,112 @@ class PinballGame extends Forge2DGame with FlameBloc {
 
     await add(BottomWall(this));
     addContactCallback(BottomWallBallContactCallback());
+
+    final center = screenToWorld(camera.viewport.effectiveSize / 2);
+    const flipperSpace = 2;
+    await add(
+      _leftFlipper = Flipper(
+        position: Vector2(
+          (center.x - (Flipper.size.x / 2)) - (flipperSpace / 2),
+          center.y,
+        ),
+      ),
+    );
+    final leftFlipperAnchor = Anchor(
+      position: Vector2(
+        _leftFlipper.body.position.x,
+        _leftFlipper.body.position.y - Flipper.size.y / 2,
+      ),
+    );
+    await add(leftFlipperAnchor);
+    final leftFlipperRevoluteJointDef = FlipperAnchorRevoluteJointDef(
+      flipper: _leftFlipper,
+      anchor: leftFlipperAnchor,
+    );
+    // TODO(alestiago): Remove casting once the following is closed:
+    // https://github.com/flame-engine/forge2d/issues/36
+    _leftFlipperRevoluteJoint =
+        world.createJoint(leftFlipperRevoluteJointDef) as RevoluteJoint;
+
+    await add(
+      _rightFlipper = Flipper(
+        position: Vector2(
+          (center.x + (Flipper.size.x / 2)) + (flipperSpace / 2),
+          center.y,
+        ),
+        isMirrored: true,
+      ),
+    );
+    final rightFlipperAnchor = Anchor(
+      position: Vector2(
+        _rightFlipper.body.position.x + Flipper.size.x,
+        _rightFlipper.body.position.y - Flipper.size.y / 2,
+      ),
+    );
+    await add(rightFlipperAnchor);
+    final rightFlipperRevoluteJointDef = FlipperAnchorRevoluteJointDef(
+      flipper: _rightFlipper,
+      anchor: rightFlipperAnchor,
+      isMirrored: true,
+    );
+    _rightFlipperRevoluteJoint =
+        world.createJoint(rightFlipperRevoluteJointDef) as RevoluteJoint;
+  }
+
+  @override
+  Future<void> onMount() async {
+    super.onMount();
+    // TODO(erickzanardo): Clean this once the issue is solved:
+    // https://github.com/flame-engine/flame/issues/1417
+    await Future<void>.delayed(const Duration(milliseconds: 500));
+    await _leftFlipper.hasMounted.future;
+    await _rightFlipper.hasMounted.future;
+
+    _leftFlipperRevoluteJoint.setLimits(
+      _leftFlipperRevoluteJoint.lowerLimit * -1,
+      _leftFlipperRevoluteJoint.upperLimit,
+    );
+    _rightFlipperRevoluteJoint.setLimits(
+      _rightFlipperRevoluteJoint.lowerLimit,
+      _rightFlipperRevoluteJoint.upperLimit * -1,
+    );
+  }
+
+  @override
+  KeyEventResult onKeyEvent(
+    RawKeyEvent event,
+    Set<LogicalKeyboardKey> keysPressed,
+  ) {
+    if (event is RawKeyDownEvent &&
+        (event.data.logicalKey == LogicalKeyboardKey.arrowLeft ||
+            event.data.logicalKey == LogicalKeyboardKey.keyA)) {
+      _leftFlipper.moveUp();
+    }
+
+    if (event is RawKeyUpEvent &&
+        (event.data.logicalKey == LogicalKeyboardKey.arrowLeft ||
+            event.data.logicalKey == LogicalKeyboardKey.keyA)) {
+      _leftFlipper.moveDown();
+    }
+
+    if (event is RawKeyDownEvent &&
+        (event.data.logicalKey == LogicalKeyboardKey.arrowLeft ||
+            event.data.logicalKey == LogicalKeyboardKey.keyA)) {
+      _leftFlipper.moveUp();
+    }
+
+    if (event is RawKeyUpEvent &&
+        (event.data.logicalKey == LogicalKeyboardKey.arrowRight ||
+            event.data.logicalKey == LogicalKeyboardKey.keyD)) {
+      _rightFlipper.moveDown();
+    }
+
+    if (event is RawKeyDownEvent &&
+        (event.data.logicalKey == LogicalKeyboardKey.arrowRight ||
+            event.data.logicalKey == LogicalKeyboardKey.keyD)) {
+      _rightFlipper.moveUp();
+    }
+
+    return KeyEventResult.handled;
   }
 }