size_using_stream.dart

Future<Size> resolveSize(ImageProvider image) async {
  final resultController = StreamController<Size>();

  resolve(image, (info, _) {
    final size = Size(
      info.image.width.toDouble(),
      info.image.height.toDouble(),
    );
    resultController.sink.add(size);
  });

  late Size temp;
  await for (var result in resultController.stream) {
    resultController.close();
    temp = result;
    break;
  }

  return temp;
}