feat: initial zooming

lib/crossword/game/crossword_game.dart

@@ -137,4 +137,21 @@ class CrosswordGame extends FlameGame with PanDetector {
       _updateVisibleSections();
     }
   }
+
+  void zoomOut() {
+    if (camera.viewfinder.zoom <= 0.05) {
+      return;
+    }
+    camera.viewport.position /= 1.05;
+    camera.viewfinder.zoom = camera.viewfinder.zoom - 0.05;
+
+    _updateVisibleSections();
+  }
+
+  void zoomIn() {
+    camera.viewport.position *= 1.05;
+    camera.viewfinder.zoom += 0.05;
+
+    _updateVisibleSections();
+  }
 }

lib/crossword/view/crossword_page.dart

@@ -41,13 +41,65 @@ class CrosswordView extends StatelessWidget {
     } else if (state is CrosswordError) {
       child = const Center(child: Text('Error loading crossword'));
     } else if (state is CrosswordLoaded) {
-      child = GameWidget.controlled(
-        gameFactory: () => CrosswordGame(
-          context.read(),
-        ),
-      );
+      child = const LoadedBoardView();
     }
 
     return Scaffold(body: child);
   }
 }
+
+class LoadedBoardView extends StatefulWidget {
+  const LoadedBoardView({super.key});
+
+  @visibleForTesting
+  static const zoomInKey = Key('game_zoomIn');
+  @visibleForTesting
+  static const zoomOutKey = Key('game_zoomOut');
+
+  @override
+  State<LoadedBoardView> createState() => LoadedBoardViewState();
+}
+
+@visibleForTesting
+class LoadedBoardViewState extends State<LoadedBoardView> {
+  late final CrosswordGame game;
+
+  @override
+  void initState() {
+    super.initState();
+
+    game = CrosswordGame(context.read());
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Stack(
+      children: [
+        GameWidget(game: game),
+        Positioned(
+          right: 16,
+          bottom: 16,
+          child: Column(
+            children: [
+              ElevatedButton(
+                key: LoadedBoardView.zoomInKey,
+                onPressed: () {
+                  game.zoomIn();
+                },
+                child: const Icon(Icons.zoom_in),
+              ),
+              const SizedBox(height: 16),
+              ElevatedButton(
+                key: LoadedBoardView.zoomOutKey,
+                onPressed: () {
+                  game.zoomOut();
+                },
+                child: const Icon(Icons.zoom_out),
+              ),
+            ],
+          ),
+        ),
+      ],
+    );
+  }
+}

test/crossword/game/crossword_game_test.dart

@@ -288,5 +288,61 @@ void main() {
         expect(removed, completes);
       },
     );
+
+    testWithGame(
+      'can zoom in',
+      createGame,
+      (game) async {
+        const state = CrosswordLoaded(
+          width: 40,
+          height: 40,
+          sectionSize: 400,
+          sections: {},
+        );
+        mockState(state);
+
+        await game.ready();
+        game.zoomIn();
+        expect(game.camera.viewfinder.zoom, 1.05);
+      },
+    );
+
+    testWithGame(
+      'can zoom out',
+      createGame,
+      (game) async {
+        const state = CrosswordLoaded(
+          width: 40,
+          height: 40,
+          sectionSize: 400,
+          sections: {},
+        );
+        mockState(state);
+
+        await game.ready();
+        game.zoomOut();
+        expect(game.camera.viewfinder.zoom, .95);
+      },
+    );
+
+    testWithGame(
+      'cannot zoom out more than 0.05',
+      createGame,
+      (game) async {
+        const state = CrosswordLoaded(
+          width: 40,
+          height: 40,
+          sectionSize: 400,
+          sections: {},
+        );
+        mockState(state);
+
+        await game.ready();
+        for (var i = 0; i < 100; i++) {
+          game.zoomOut();
+        }
+        expect(game.camera.viewfinder.zoom, greaterThan(0));
+      },
+    );
   });
 }

test/crossword/view/crossword_page_test.dart

@@ -97,5 +97,54 @@ void main() {
       await tester.pumpCrosswordView(bloc);
       expect(find.byType(GameWidget<CrosswordGame>), findsOneWidget);
     });
+
+    testWidgets('can zoom in', (tester) async {
+      when(() => bloc.state).thenReturn(
+        CrosswordLoaded(
+          width: 40,
+          height: 40,
+          sectionSize: 40,
+          sections: const {},
+        ),
+      );
+
+      await tester.pumpCrosswordView(bloc);
+
+      final crosswordViewState = tester.state<LoadedBoardViewState>(
+        find.byType(LoadedBoardView),
+      );
+      await crosswordViewState.game.loaded;
+
+      await tester.tap(find.byKey(LoadedBoardView.zoomInKey));
+
+      expect(
+        crosswordViewState.game.camera.viewfinder.zoom,
+        greaterThan(1),
+      );
+    });
+
+    testWidgets('can zoom out', (tester) async {
+      when(() => bloc.state).thenReturn(
+        CrosswordLoaded(
+          width: 40,
+          height: 40,
+          sectionSize: 40,
+          sections: const {},
+        ),
+      );
+
+      await tester.pumpCrosswordView(bloc);
+      final crosswordViewState = tester.state<LoadedBoardViewState>(
+        find.byType(LoadedBoardView),
+      );
+      await crosswordViewState.game.loaded;
+
+      await tester.tap(find.byKey(LoadedBoardView.zoomOutKey));
+
+      expect(
+        crosswordViewState.game.camera.viewfinder.zoom,
+        lessThan(1),
+      );
+    });
   });
 }