content: package sk.fourq.otaupdate;
  
  import okhttp3.MediaType;
  import okhttp3.ResponseBody;
  import okio.Buffer;
  import okio.BufferedSource;
  import okio.ForwardingSource;
  import okio.Okio;
  import okio.Source;
  import org.jetbrains.annotations.NotNull;
  
  import java.io.IOException;
  
  /**
   * OK http response implementation that calls {@link ProgressListener}
   *
   * Note: Adapted from
   * https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/Progress.java
   */
  public class ProgressResponseBody extends ResponseBody {
  
      private final ResponseBody responseBody;
      private final ProgressListener progressListener;
      private BufferedSource bufferedSource;
  
      ProgressResponseBody(ResponseBody responseBody, ProgressListener progressListener) {
          this.responseBody = responseBody;
          this.progressListener = progressListener;
      }
  
      @Override
      public MediaType contentType() {
          return responseBody.contentType();
      }
  
      @Override
      public long contentLength() {
          return responseBody.contentLength();
      }
  
      @NotNull
      @Override
      public BufferedSource source() {
          if (bufferedSource == null) {
              bufferedSource = Okio.buffer(source(responseBody.source()));
          }
          return bufferedSource;
      }
  
      private Source source(Source source) {
          return new ForwardingSource(source) {
              long totalBytesRead = 0L;
  
              @Override public long read(@NotNull Buffer sink, long byteCount) throws IOException {
                  long bytesRead = super.read(sink, byteCount);
                  // read() returns the number of bytes read, or -1 if this source is exhausted.
                  totalBytesRead += bytesRead != -1 ? bytesRead : 0;
                  progressListener.onDownloadProgress(totalBytesRead, responseBody.contentLength(), bytesRead == -1);
                  return bytesRead;
              }
          };
      }
  }
  