addState<S extends Object> method

@override AppBuilder addState<S extends Object>(S initial)

Registers state S with initial.

Implementation

@override
AppBuilder addState<S extends Object>(S initial) {
  _assertOpen();
  if (world.resources.contains<CurrentState<S>>()) {
    throw StateError(
      'A state machine for $S has already been added. Each state type is '
      'registered exactly once; use a second enum for an orthogonal machine.',
    );
  }
  final machine = StateMachineRuntime<S>(initial);
  world.resources
    ..insert<CurrentState<S>>(machine.current)
    ..insert<NextState<S>>(machine.next);
  // Registered eagerly so game code can `commands.insert<DespawnOnExit>`
  // without any system having queried the type first.
  world.ensureObjectStore<DespawnOnExit>();
  _stateMachines.add(machine);
  return this;
}