attachCancellable method

  1. @mustCallSuper
void attachCancellable(
  1. Cancellable cancellable
)

Attaches a Cancellable to this token.

Before attaching to a CancellationToken, you should check if it's already been cancelled by using isCancelled.

Implementation

@mustCallSuper
void attachCancellable(Cancellable cancellable) {
  assert(
    !isCancelled,
    'Attampted to attach to a $runtimeType that has already been cancelled.\n'
    'Check isCancelled or use the CancellableMixin\'s maybeAttach() method '
    'to check if the token\'s already been cancelled before attaching to it.',
  );
  if (!isCancelled && !_attachedCancellables.contains(cancellable)) {
    _attachedCancellables.add(cancellable);
  }
}