fix: both `Fipper`s should respond to multi touch taps (#330)

* fix: both flippers should respond to multi touch taps

* fix: both flippers should respond to multi touch taps

Co-authored-by: Tom Arra <tarra3@gmail.com>

lib/game/pinball_game.dart

@@ -81,7 +81,7 @@ class PinballGame extends PinballForge2DGame
     await super.onLoad();
   }
 
-  BoardSide? focusedBoardSide;
+  final focusedBoardSide = <int, BoardSide>{};
 
   @override
   void onTapDown(int pointerId, TapDownInfo info) {
@@ -94,9 +94,10 @@ class PinballGame extends PinballForge2DGame
         descendants().whereType<Plunger>().single.pullFor(2);
       } else {
         final leftSide = info.eventPosition.widget.x < canvasSize.x / 2;
-        focusedBoardSide = leftSide ? BoardSide.left : BoardSide.right;
+        focusedBoardSide[pointerId] =
+            leftSide ? BoardSide.left : BoardSide.right;
         final flippers = descendants().whereType<Flipper>().where((flipper) {
-          return flipper.side == focusedBoardSide;
+          return flipper.side == focusedBoardSide[pointerId];
         });
         flippers.first.moveUp();
       }
@@ -107,23 +108,23 @@ class PinballGame extends PinballForge2DGame
 
   @override
   void onTapUp(int pointerId, TapUpInfo info) {
-    _moveFlippersDown();
+    _moveFlippersDown(pointerId);
     super.onTapUp(pointerId, info);
   }
 
   @override
   void onTapCancel(int pointerId) {
-    _moveFlippersDown();
+    _moveFlippersDown(pointerId);
     super.onTapCancel(pointerId);
   }
 
-  void _moveFlippersDown() {
+  void _moveFlippersDown(int pointerId) {
-    if (focusedBoardSide != null) {
+    if (focusedBoardSide[pointerId] != null) {
       final flippers = descendants().whereType<Flipper>().where((flipper) {
-        return flipper.side == focusedBoardSide;
+        return flipper.side == focusedBoardSide[pointerId];
       });
       flippers.first.moveDown();
-      focusedBoardSide = null;
+      focusedBoardSide.remove(pointerId);
     }
   }
 }

test/game/pinball_game_test.dart

@@ -415,6 +415,51 @@ void main() {
 
         expect(flippers.first.body.linearVelocity.y, isPositive);
       });
+
+      flameTester.test(
+        'multiple touches control both flippers',
+        (game) async {
+          await game.ready();
+
+          final raw = _MockTapDownDetails();
+          when(() => raw.kind).thenReturn(PointerDeviceKind.touch);
+
+          final leftEventPosition = _MockEventPosition();
+          when(() => leftEventPosition.game).thenReturn(Vector2.zero());
+          when(() => leftEventPosition.widget).thenReturn(Vector2.zero());
+
+          final rightEventPosition = _MockEventPosition();
+          when(() => rightEventPosition.game).thenReturn(Vector2.zero());
+          when(() => rightEventPosition.widget).thenReturn(game.canvasSize);
+
+          final leftTapDownEvent = _MockTapDownInfo();
+          when(() => leftTapDownEvent.eventPosition)
+              .thenReturn(leftEventPosition);
+          when(() => leftTapDownEvent.raw).thenReturn(raw);
+
+          final rightTapDownEvent = _MockTapDownInfo();
+          when(() => rightTapDownEvent.eventPosition)
+              .thenReturn(rightEventPosition);
+          when(() => rightTapDownEvent.raw).thenReturn(raw);
+
+          final flippers = game.descendants().whereType<Flipper>();
+          final rightFlipper = flippers.elementAt(0);
+          final leftFlipper = flippers.elementAt(1);
+
+          game.onTapDown(0, leftTapDownEvent);
+          game.onTapDown(1, rightTapDownEvent);
+
+          expect(leftFlipper.body.linearVelocity.y, isNegative);
+          expect(leftFlipper.side, equals(BoardSide.left));
+          expect(rightFlipper.body.linearVelocity.y, isNegative);
+          expect(rightFlipper.side, equals(BoardSide.right));
+
+          expect(
+            game.focusedBoardSide,
+            equals({0: BoardSide.left, 1: BoardSide.right}),
+          );
+        },
+      );
     });
 
     group('plunger control', () {