onCancel property
VoidCallback?
onCancel
"Cancel" callback. If the exception has a cause, will return a merged callback.
Implementation
VoidCallback? get onCancel {
VoidCallback? onCancelCause =
(cause is UserException) ? (cause as UserException).onCancel : null;
if (onCancelCause == null)
return _onCancel;
else if (_onCancel == null)
return onCancelCause;
else
return () {
_onCancel!();
onCancelCause();
};
}