ReplayBloc<Event extends ReplayEvent, State> constructor

ReplayBloc<Event extends ReplayEvent, State>(State state, { int? limit, })

A specialized Bloc which supports undo and redo operations.

ReplayBloc accepts an optional limit which determines the max size of the history.

A custom ReplayBloc can be created by extending ReplayBloc.

abstract class CounterEvent {}
class CounterIncrementPressed extends CounterEvent {}

class CounterBloc extends ReplayBloc<CounterEvent, int> {
  CounterBloc() : super(0) {
    on<CounterIncrementPressed>((event, emit) => emit(state + 1));
  }
}

Then the built-in undo and redo operations can be used.

final bloc = CounterBloc();

bloc.add(CounterIncrementPressed());

bloc.undo();

bloc.redo();

The undo/redo history can be destroyed at any time by calling clear.

See also:

• Bloc for information about the ReplayBloc superclass.

Implementation

ReplayBloc(State state, {int? limit}) : super(state) {
  if (limit != null) {
    this.limit = limit;
  }
}