ReplayCubit<State> class abstract

A specialized Cubit which supports undo and redo operations.

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

A custom ReplayCubit can be created by extending ReplayCubit.

class CounterCubit extends ReplayCubit<int> {
  CounterCubit() : super(0);

  void increment() => emit(state + 1);
}

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

final cubit = CounterCubit();

cubit.increment();
print(cubit.state); // 1

cubit.undo();
print(cubit.state); // 0

cubit.redo();
print(cubit.state); // 1

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

See also:

Inheritance
Mixed in types

Constructors

ReplayCubit(State state, {int? limit})
A specialized Cubit which supports undo and redo operations.

Properties

canRedo → bool
Checks whether the undo/redo stack is at the current change.
no setterinherited
canUndo → bool
Checks whether the undo/redo stack is empty.
no setterinherited
hashCode → int
The hash code for this object.
no setterinherited
isClosed → bool
Whether the bloc is closed.
no setterinherited
limit ← int
Sets the internal undo/redo size limit. By default there is no limit.
no getterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
state → State
The current state.
no setterinherited
stream → Stream<State>
The current stream of states.
no setterinherited

Methods

addError(Object error, [StackTrace? stackTrace]) → void
Reports an error which triggers onError with an optional StackTrace.
inherited
clearHistory() → void
Clear undo/redo history.
inherited
close() → Future<void>
Closes the instance. This method should be called when the instance is no longer needed. Once close is called, the instance can no longer be used.
inherited
emit(State state) → void
Updates the state to the provided state. emit does nothing if the state being emitted is equal to the current state.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
onChange(Change<State> change) → void
Called whenever a change occurs with the given change. A change occurs when a new state is emitted. onChange is called before the state of the cubit is updated. onChange is a great spot to add logging/analytics for a specific cubit.
inherited
onError(Object error, StackTrace stackTrace) → void
Called whenever an error occurs and notifies BlocObserver.onError.
inherited
redo() → void
Redo the previous change.
inherited
shouldReplay(State state) → bool
Checks whether the given state should be replayed from the undo/redo stack.
inherited
toString() → String
A string representation of this object.
inherited
undo() → void
Undo the last change.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited