rewriteDocument method

Future<PdfRewriteResult> rewriteDocument(PdfDocumentParser source, { int? bytesBefore, bool useIsolate = false, })

Rewrites a document already opened by a parser.

Useful when the file came from a reader and is not entirely in memory; in that case pass bytesBefore so the report knows the size of the source.

Implementation

Future<PdfRewriteResult> rewriteDocument(
  PdfDocumentParser source, {
  int? bytesBefore,
  bool useIsolate = false,
}) async {
  if (source.isEncrypted) {
    throw PdfMergeException(
      'O documento está criptografado. A leitura de PDFs criptografados '
      'ainda não é suportada, e regravar sem descriptografar produziria '
      'conteúdo corrompido.',
    );
  }

  final signatureFields = _countSignatureFields(source);
  if (signatureFields > 0 && options.rejectSignedSources) {
    throw PdfMergeException(
      'O documento tem $signatureFields assinatura(s) digital(is). '
      'Regravar invalidaria todas elas e rejectSignedSources está ligado.',
    );
  }

  final destination = PdfDocument(
    compress: compress,
    verbose: verbose,
    version: version,
    deflate: deflate,
  );

  final merger = PdfDocumentMerger(
    destination,
    options: options.toMergeOptions(),
  );
  merger.append(source, label: 'documento');
  merger.finish();

  final output = await destination.save(useIsolate: useIsolate);

  return PdfRewriteResult(
    bytes: output,
    report: PdfRewriteReport(
      objectsBefore: _liveObjectCount(source),
      objectsAfter: destination.objects.where((e) => e.inUse).length,
      // `reader.length` instead of `source.bytes.length`: the latter would
      // materialize the whole file in memory just to measure it.
      bytesBefore: bytesBefore ?? source.reader.length,
      bytesAfter: output.length,
      pagesBefore: source.pageCount,
      pagesAfter: destination.pdfPageList.pages.length,
      signatureFieldsBefore: signatureFields,
      warnings: merger.warnings,
    ),
  );
}