Pdf creation library for dart/flutter

This library is divided into two parts:

  • a low-level Pdf creation library that takes care of the pdf bits generation.
  • a Widgets system similar to Flutter’s, for easy high-level Pdf creation.

It can create a full multi-pages document with graphics, images, and text using TrueType fonts. With the ease of use you already know.

See an interactive demo here: https://davbfr.github.io/dart_pdf/.

Example document

The source code for a full demo that can run on any Flutter target, and how to build, it can be found here: https://github.com/DavBfr/dart_pdf/tree/master/demo/

Use the printing package https://pub.dev/packages/printing for full flutter print and share operation.

The coordinate system is using the internal Pdf unit:

  • 1.0 is defined as 1 / 72.0 inch
  • you can use the constants for centimeters, millimeters, and inch defined in PdfPageFormat

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Installing

If you want to print the Pdf document on an actual printer with Flutter, follow the instructions at https://pub.dev/packages/printing

  1. Add this package to your package’s pubspec.yaml file as described on the installation tab

  2. Import the libraries

    import 'package:pdf/pdf.dart';
import 'package:pdf/widgets.dart' as pw;

Examples

final pdf = pw.Document();

pdf.addPage(pw.Page(
      pageFormat: PdfPageFormat.a4,
      build: (pw.Context context) {
        return pw.Center(
          child: pw.Text("Hello World"),
        ); // Center
      })); // Page

To load an image from a file:

final image = pw.MemoryImage(
  File('test.webp').readAsBytesSync(),
);

pdf.addPage(pw.Page(build: (pw.Context context) {
  return pw.Center(
    child: pw.Image(image),
  ); // Center
})); // Page

To load an image from the network using the printing package:

final netImage = await networkImage('https://www.nfet.net/nfet.jpg');

pdf.addPage(pw.Page(build: (pw.Context context) {
  return pw.Center(
    child: pw.Image(netImage),
  ); // Center
})); // Page

To load an SVG:

String svgRaw = '''
<svg viewBox="0 0 50 50" xmlns="http://www.w3.org/2000/svg">
  <ellipse style="fill: grey; stroke: black;" cx="25" cy="25" rx="20" ry="20"></ellipse>
</svg>
''';

final svgImage = pw.SvgImage(svg: svgRaw);

pdf.addPage(pw.Page(build: (pw.Context context) {
  return pw.Center(
    child: svgImage,
  ); // Center
})); // Page

To load the SVG from a Flutter asset, use await rootBundle.loadString('assets/file.svg')

To use a TrueType font:

final Uint8List fontData = File('open-sans.ttf').readAsBytesSync();
final ttf = pw.Font.ttf(fontData.buffer.asByteData());

pdf.addPage(pw.Page(
    pageFormat: PdfPageFormat.a4,
    build: (pw.Context context) {
      return pw.Center(
        child: pw.Text('Hello World', style: pw.TextStyle(font: ttf, fontSize: 40)),
      ); // Center
    })); // Page

Or using the printing package’s PdfGoogleFonts:

final font = await PdfGoogleFonts.nunitoExtraLight();

pdf.addPage(pw.Page(
    pageFormat: PdfPageFormat.a4,
    build: (pw.Context context) {
      return pw.Center(
        child: pw.Text('Hello World', style: pw.TextStyle(font: font, fontSize: 40)),
      ); // Center
    })); // Page

To display emojis:

final emoji = await PdfGoogleFonts.notoColorEmoji();

pdf.addPage(pw.Page(
    pageFormat: PdfPageFormat.a4,
    build: (pw.Context context) {
      return pw.Center(
        child: pw.Text(
          'Hello 🐒💁👌🎍😍🦊👨 world!',
          style: pw.TextStyle(
            fontFallback: [emoji],
            fontSize: 25,
          ),
        ),
      ); // Center
    })); // Page

To save the pdf file:

// On Flutter, use the [path_provider](https://pub.dev/packages/path_provider) library:
//   final output = await getTemporaryDirectory();
//   final file = File("${output.path}/example.pdf");
final file = File("example.pdf");
await file.writeAsBytes(await pdf.save());

Encryption, Digital Signature, and loading a PDF Document

Encryption using RC4-40, RC4-128, AES-128, and AES-256 is fully supported using a separate library. This library also provides SHA1 or SHA-256 Digital Signature using your x509 certificate. The graphic signature is represented by a clickable widget that shows Digital Signature information. It implements a PDF parser to load an existing document and add pages, change pages, and add a signature.

More information here: https://pub.nfet.net/pdf_crypto/

GitHub

View Github