ValueStreamController<T> constructor
ValueStreamController<T> ({
- T? initialValue,
- bool initiallyNull = false,
Create a new ValueStreamController with an optional initial value.
initialValueIsNull
must be set to true
, if the initial value is
null
. This ensures that the Stream emits a null
value when a
listener subscribes.
Implementation
ValueStreamController({
T? initialValue,
bool initiallyNull = false,
}) : _controller = StreamController<T>.broadcast() {
if (initialValue != null || initiallyNull) {
_lastValue = initialValue;
_hasValue = true;
}
_controller.onListen = () => onListen?.call();
_controller.onCancel = () => onCancel?.call();
}