Flame Bloc 🔥🧱

flame_bloc offers a simple and natural (as in similar to flutter_bloc) way to use blocs and cubits inside a FlameGame.

For a migration guide from the previous API to the current one, check this article.

How to use

Lets assume we have a bloc that handles player inventory, first we need to make it available to our components.

We can do that by using FlameBlocProvider component:

class MyGame extends FlameGame {
  @override
  Future<void> onLoad() async {
    await add(
      FlameBlocProvider<PlayerInventoryBloc, PlayerInventoryState>(
        create: () => PlayerInventoryBloc(),
        children: [
          Player(),
          // ...
        ],
      ),
    );
  }
}

With the above changes, the Player component will now have access to our bloc.

If more than one bloc needs to be provided, FlameMultiBlocProvider can be used in a similar fashion:

class MyGame extends FlameGame {
  @override
  Future<void> onLoad() async {
    await add(
      FlameMultiBlocProvider(
        providers: [
          FlameBlocProvider<PlayerInventoryBloc, PlayerInventoryState>(
            create: () => PlayerInventoryBloc(),
          ),
          FlameBlocProvider<PlayerStatsBloc, PlayerStatsState>(
            create: () => PlayerStatsBloc(),
          ),
        ],
        children: [
          Player(),
          // ...
        ],
      ),
    );
  }
}

Listening to states changes at the component level can be done with two approaches:

By using FlameBlocListener component:

class Player extends PositionComponent {
  @override
  Future<void> onLoad() async {
    await add(
      FlameBlocListener<PlayerInventoryBloc, PlayerInventoryState>(
        listener: (state) {
          updateGear(state);
        },
      ),
    );
  }
}

Or by using FlameBlocListenable mixin:

class Player extends PositionComponent
  with FlameBlocListenable<PlayerInventoryBloc, PlayerInventoryState> {

  @override
  void onNewState(state) {
    updateGear(state);
  }
}

If all your component need is to simply access a bloc, the FlameBlocReader mixin can be applied to a component:

class Player extends PositionComponent
  with FlameBlocReader<PlayerStatsBloc, PlayerStatsState> {

  void takeHit() {
    bloc.add(const PlayerDamaged());
  }
}

Note that one limitation of the mixin is that it can access only a single bloc.

For a full example, check the example folder

Libraries

flame_bloc