listenable_stream

Description:

listenable stream

listenable_stream #

Convert Flutter's Listenable (e.g. ChangeNotifier) to Stream.
Convert Flutter's ValueListenable (e.g. ValueNotifier) to ValueStream (incl. "replay" and "not replay").








✅ Listenable ▶ Stream<Listenable>
✅ ValueListenable<T> ▶ ValueStream<T>

Usage #
Listenable.toStream() #
final ChangeNotifier changeNotifier = ChangeNotifier();
final Stream<ChangeNotifier> stream = changeNotifier.toStream();
stream.listen(print); // prints Instance of 'ChangeNotifier', Instance of 'ChangeNotifier'

changeNotifier.notifyListeners();
changeNotifier.notifyListeners();
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ValueListenable.toValueStream() #
final ValueNotifier<int> valueNotifier = ValueNotifier(0);
final ValueListenableStream<int> stream = valueNotifier.toValueStream();
stream.listen(print); // prints 1, 2

valueNotifier.value = 1;
valueNotifier.value = 2;
print(stream.value); // prints 2
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ValueListenable.toValueStream(replayValue: true) #
final ValueNotifier<int> valueNotifier = ValueNotifier(0);
final ValueListenableStream<int> stream = valueNotifier.toValueStream(replayValue: true);
stream.listen(print); // prints 0, 1, 2

valueNotifier.value = 1;
valueNotifier.value = 2;
print(stream.value); // prints 2
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Note #

All returned Stream is single-subscription Stream (ie. it can only be listened once) and does not emits any errors.
ValueListenableStream always has value (ie. has no error).