feat: made Pathway use InitialPosition

lib/game/components/pathway.dart

@@ -2,20 +2,19 @@ import 'package:flame/extensions.dart';
 import 'package:flame_forge2d/flame_forge2d.dart';
 import 'package:flutter/material.dart';
 import 'package:geometry/geometry.dart';
+import 'package:pinball/game/game.dart';
 
 /// {@template pathway}
 /// [Pathway] creates lines of various shapes.
 ///
 /// [BodyComponent]s such as a Ball can collide and move along a [Pathway].
 /// {@endtemplate}
-class Pathway extends BodyComponent {
+class Pathway extends BodyComponent with InitialPosition {
   Pathway._({
     // TODO(ruialonso): remove color when assets added.
     Color? color,
-    required Vector2 position,
     required List<List<Vector2>> paths,
-  })  : _position = position,
-        _paths = paths {
+  }) : _paths = paths {
     paint = Paint()
       ..color = color ?? const Color.fromARGB(0, 0, 0, 0)
       ..style = PaintingStyle.stroke;
@@ -23,14 +22,12 @@ class Pathway extends BodyComponent {
 
   /// Creates a uniform unidirectional (straight) [Pathway].
   ///
-  /// Does so with two [ChainShape] separated by a [width]. Placed
-  /// at a [position] between [start] and [end] points. Can
+  /// Does so with two [ChainShape] separated by a [width]. Can
   /// be rotated by a given [rotation] in radians.
   ///
   /// If [singleWall] is true, just one [ChainShape] is created.
   factory Pathway.straight({
     Color? color,
-    required Vector2 position,
     required Vector2 start,
     required Vector2 end,
     required double width,
@@ -56,28 +53,25 @@ class Pathway extends BodyComponent {
 
     return Pathway._(
       color: color,
-      position: position,
       paths: paths,
     );
   }
 
   /// Creates an arc [Pathway].
   ///
-  /// The [angle], in radians, specifies the size of the arc. For example, 2*pi
-  /// returns a complete circumference and minor angles a semi circumference.
-  ///
-  /// The center of the arc is placed at [position].
+  /// The [angle], in radians, specifies the size of the arc. For example, two
+  /// pi returns a complete circumference.
   ///
   /// Does so with two [ChainShape] separated by a [width]. Which can be
   /// rotated by a given [rotation] in radians.
   ///
   /// The outer radius is specified by [radius], whilst the inner one is
-  /// equivalent to [radius] - [width].
+  /// equivalent to the [radius] minus the [width].
   ///
   /// If [singleWall] is true, just one [ChainShape] is created.
   factory Pathway.arc({
     Color? color,
-    required Vector2 position,
+    required Vector2 center,
     required double width,
     required double radius,
     required double angle,
@@ -88,7 +82,7 @@ class Pathway extends BodyComponent {
 
     // TODO(ruialonso): Refactor repetitive logic
     final outerWall = calculateArc(
-      center: position,
+      center: center,
       radius: radius,
       angle: angle,
       offsetAngle: rotation,
@@ -97,7 +91,7 @@ class Pathway extends BodyComponent {
 
     if (!singleWall) {
       final innerWall = calculateArc(
-        center: position,
+        center: center,
         radius: radius - width,
         angle: angle,
         offsetAngle: rotation,
@@ -107,7 +101,6 @@ class Pathway extends BodyComponent {
 
     return Pathway._(
       color: color,
-      position: position,
       paths: paths,
     );
   }
@@ -123,7 +116,6 @@ class Pathway extends BodyComponent {
   /// If [singleWall] is true, just one [ChainShape] is created.
   factory Pathway.bezierCurve({
     Color? color,
-    required Vector2 position,
     required List<Vector2> controlPoints,
     required double width,
     double rotation = 0,
@@ -148,19 +140,17 @@ class Pathway extends BodyComponent {
 
     return Pathway._(
       color: color,
-      position: position,
       paths: paths,
     );
   }
 
-  final Vector2 _position;
   final List<List<Vector2>> _paths;
 
   @override
   Body createBody() {
     final bodyDef = BodyDef()
       ..type = BodyType.static
-      ..position = _position;
+      ..position = initialPosition;
 
     final body = world.createBody(bodyDef);
     for (final path in _paths) {

test/game/components/pathway_test.dart

@@ -20,11 +20,10 @@ void main() {
           (game) async {
             await game.ready();
             final pathway = Pathway.straight(
-              position: Vector2.zero(),
               start: Vector2(10, 10),
               end: Vector2(20, 20),
               width: width,
-            );
+            )..initialPosition = Vector2.zero();
             await game.ensureAdd(pathway);
 
             expect(game.contains(pathway), isTrue);
@@ -44,11 +43,10 @@ void main() {
 
             final pathway = Pathway.straight(
               color: defaultColor,
-              position: Vector2.zero(),
               start: Vector2(10, 10),
               end: Vector2(20, 20),
               width: width,
-            );
+            )..initialPosition = Vector2.zero();
             await game.ensureAdd(pathway);
 
             expect(game.contains(pathway), isTrue);
@@ -63,11 +61,10 @@ void main() {
         (game) async {
           await game.ready();
           final pathway = Pathway.straight(
-            position: Vector2.zero(),
             start: Vector2(10, 10),
             end: Vector2(20, 20),
             width: width,
-          );
+          )..initialPosition = Vector2.zero();
           await game.ensureAdd(pathway);
 
           expect(game.contains(pathway), isTrue);
@@ -81,15 +78,14 @@ void main() {
             await game.ready();
             final position = Vector2.all(10);
             final pathway = Pathway.straight(
-              position: position,
               start: Vector2(10, 10),
               end: Vector2(20, 20),
               width: width,
-            );
+            )..initialPosition = position;
             await game.ensureAdd(pathway);
 
             game.contains(pathway);
-            expect(pathway.body.position, position);
+            expect(pathway.body.position, equals(position));
           },
         );
 
@@ -98,11 +94,10 @@ void main() {
           (game) async {
             await game.ready();
             final pathway = Pathway.straight(
-              position: Vector2.zero(),
               start: Vector2(10, 10),
               end: Vector2(20, 20),
               width: width,
-            );
+            )..initialPosition = Vector2.zero();
             await game.ensureAdd(pathway);
 
             expect(pathway.body.bodyType, equals(BodyType.static));
@@ -116,12 +111,11 @@ void main() {
           (game) async {
             await game.ready();
             final pathway = Pathway.straight(
-              position: Vector2.zero(),
               start: Vector2(10, 10),
               end: Vector2(20, 20),
               width: width,
               singleWall: true,
-            );
+            )..initialPosition = Vector2.zero();
             await game.ensureAdd(pathway);
 
             expect(pathway.body.fixtures.length, 1);
@@ -136,11 +130,10 @@ void main() {
           (game) async {
             await game.ready();
             final pathway = Pathway.straight(
-              position: Vector2.zero(),
               start: Vector2(10, 10),
               end: Vector2(20, 20),
               width: width,
-            );
+            )..initialPosition = Vector2.zero();
             await game.ensureAdd(pathway);
 
             expect(pathway.body.fixtures.length, 2);
@@ -159,11 +152,11 @@ void main() {
         (game) async {
           await game.ready();
           final pathway = Pathway.arc(
-            position: Vector2.zero(),
+            center: Vector2.zero(),
             width: width,
             radius: 100,
             angle: math.pi / 2,
-          );
+          )..initialPosition = Vector2.zero();
           await game.ensureAdd(pathway);
 
           expect(game.contains(pathway), isTrue);
@@ -177,11 +170,11 @@ void main() {
             await game.ready();
             final position = Vector2.all(10);
             final pathway = Pathway.arc(
-              position: position,
+              center: position,
               width: width,
               radius: 100,
               angle: math.pi / 2,
-            );
+            )..initialPosition = position;
             await game.ensureAdd(pathway);
 
             game.contains(pathway);
@@ -194,11 +187,11 @@ void main() {
           (game) async {
             await game.ready();
             final pathway = Pathway.arc(
-              position: Vector2.zero(),
+              center: Vector2.zero(),
               width: width,
               radius: 100,
               angle: math.pi / 2,
-            );
+            )..initialPosition = Vector2.zero();
             await game.ensureAdd(pathway);
 
             expect(pathway.body.bodyType, equals(BodyType.static));
@@ -220,10 +213,9 @@ void main() {
         (game) async {
           await game.ready();
           final pathway = Pathway.bezierCurve(
-            position: Vector2.zero(),
             controlPoints: controlPoints,
             width: width,
-          );
+          )..initialPosition = Vector2.zero();
           await game.ensureAdd(pathway);
 
           expect(game.contains(pathway), isTrue);
@@ -237,10 +229,9 @@ void main() {
             await game.ready();
             final position = Vector2.all(10);
             final pathway = Pathway.bezierCurve(
-              position: position,
               controlPoints: controlPoints,
               width: width,
-            );
+            )..initialPosition = position;
             await game.ensureAdd(pathway);
 
             game.contains(pathway);
@@ -253,10 +244,9 @@ void main() {
           (game) async {
             await game.ready();
             final pathway = Pathway.bezierCurve(
-              position: Vector2.zero(),
               controlPoints: controlPoints,
               width: width,
-            );
+            )..initialPosition = Vector2.zero();
             await game.ensureAdd(pathway);
 
             expect(pathway.body.bodyType, equals(BodyType.static));