value property

@override T value

The current value stored in this notifier.

When the value is replaced with something that is not equal to the old value as evaluated by the equality operator ==, this class notifies its listeners.

Throws a StateError, when trying to read this value and isEmpty is true.

Implementation

@override
T get value {
  if (isEmpty)
    throw StateError(
      "Cannot access the value of this EmptyValueNotifier, "
      "because isEmpty is true. "
      "The value has to be set before accessing it, "
      "if the constructor EmptyValueNotifier.empty was used.",
    );

  return _value!;
}

@override void value=(T newValue)

Implementation

@override
set value(T newValue) {
  // Return if this notifier is not empty and the new
  // value is equal to the current one.
  if (isNotEmpty && _compare(_value, newValue)) return;

  _isEmpty = false;

  _value = newValue;
  notifyListeners();
}