photos_library_api_client.dart

Future<String> uploadMediaItem(File image) async {
  // Get the filename of the image
  final String filename = path.basename(image.path);
  // Set up the headers required for this request.
  final Map<String, String> headers = <String,String>{};
  headers.addAll(await _authHeaders);
  headers['Content-type'] = 'application/octet-stream';
  headers['X-Goog-Upload-Protocol'] = 'raw';
  headers['X-Goog-Upload-File-Name'] = filename;
  // Make the HTTP request to upload the image. The file is sent in the body.
  return http
      .post(
    'https://photoslibrary.googleapis.com/v1/uploads',
    body: image.readAsBytesSync(),
    headers: await _authHeaders,
  )
      .then((Response response) {
    if (response.statusCode != 200) {
      print(response.reasonPhrase);
      print(response.body);
    }
    return response.body;
  });
}