downloadFile function

Implementation

Future<DownloadTaskForAll> downloadFile(String url, {File? file}) async {
  var task = DownloadTaskForAll(targetFile: file);

  var httpClient = Client();
  var request = Request('GET', Uri.parse(url));
  var response = await httpClient.send(request);
  List<List<int>> chunks = [];
  int downloaded = 0;
  int sayac = 0;
  task.setDownloadingStream = response.stream.listen((List<int> chunk) {
    if (sayac % 500 == 0) {
      task.updateTask(ProcessTask(
          processed: downloaded,
          total: response.contentLength!,
          state: TaskState.running));
    }
    chunks.add(chunk);
    downloaded += chunk.length;
    sayac++;
  }, onDone: () {
    double percentage = (downloaded / response.contentLength!);
    Uint8List? bytes;
    if (percentage == 1) {
      bytes = Uint8List(response.contentLength!);
      int offset = 0;
      for (List<int> chunk in chunks) {
        bytes.setRange(offset, offset + chunk.length, chunk);
        offset += chunk.length;
      }
      task.updateTask(ProcessTask(
          processed: downloaded,
          total: response.contentLength!,
          state: TaskState.success,
          bytes: bytes));
    }
  }, onError: (e, stackTrace) {
    task.addError(e, stackTrace);
  });
  return task;
}