feat: able to clear all overlays (#1536)

* feat: able to clear all overlays

* feat: able to clear all overlays

Co-authored-by: Lukas Klingsbo <me@lukas.fyi>

packages/flame/lib/src/game/mixins/game.dart

@@ -302,6 +302,12 @@ mixin Game {
 class ActiveOverlaysNotifier extends ChangeNotifier {
   final Set<String> _activeOverlays = {};
 
+  /// Clear all active overlays.
+  void clear() {
+    value.clear();
+    notifyListeners();
+  }
+
   /// Mark a, overlay to be rendered.
   ///
   /// See also:

packages/flame/test/game/active_overlays_notifier_test.dart

@@ -0,0 +1,72 @@
+import 'package:flame/game.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('ActiveOverlaysNotifier', () {
+    test('can be constructed', () {
+      expect(ActiveOverlaysNotifier(), isNotNull);
+    });
+
+    late ActiveOverlaysNotifier notifier;
+
+    setUp(() {
+      notifier = ActiveOverlaysNotifier();
+    });
+
+    group('add', () {
+      test('can add an overlay', () {
+        final result = notifier.add('test');
+
+        expect(result, true);
+        expect(notifier.isActive('test'), true);
+      });
+
+      test('wont add same overlay', () {
+        notifier.add('test');
+        final result = notifier.add('test');
+
+        expect(result, false);
+      });
+    });
+
+    group('remove', () {
+      test('can remove an overlay', () {
+        notifier.add('test');
+
+        final result = notifier.remove('test');
+
+        expect(result, true);
+        expect(notifier.isActive('test'), false);
+      });
+
+      test('wont result in removal if there is nothing to remove', () {
+        final result = notifier.remove('test');
+
+        expect(result, false);
+      });
+    });
+
+    group('isActive', () {
+      test('is true when overlay is active', () {
+        notifier.add('test');
+        expect(notifier.isActive('test'), true);
+      });
+
+      test('is false when overlay is active', () {
+        expect(notifier.isActive('test'), false);
+      });
+    });
+
+    group('clear', () {
+      test('clears all overlays', () {
+        notifier.add('test1');
+        notifier.add('test2');
+
+        notifier.clear();
+
+        expect(notifier.isActive('test1'), false);
+        expect(notifier.isActive('test2'), false);
+      });
+    });
+  });
+}