dart_pdf_engine

A pure-Dart library for creating, reading, and manipulating PDF documents programmatically. No native dependencies — works on all Flutter platforms (Android, iOS, Web, Desktop).

Features

• ✅ Create PDF documents from scratch with PDF 1.7 compliance
• ✅ Selectable & searchable text — all text uses proper PDF text operators
• ✅ 14 standard PDF fonts — Helvetica, Times, Courier, Symbol, ZapfDingbats
• ✅ TrueType font embedding with Unicode support and ToUnicode CMap
• ✅ JPEG & PNG images — embed from bytes or base64 strings
• ✅ Shapes — lines, rectangles, ellipses, Bezier paths with fill/stroke
• ✅ Tables — PdfGrid with headers, cell styling, borders, alternating rows
• ✅ Lists — ordered and unordered with customizable markers
• ✅ Bookmarks — document outline for navigation
• ✅ Multi-page — standard sizes (A4, Letter, Legal, A3, A5, etc.)
• ✅ Base64 support — load from base64, save as base64
• ✅ PDF Parsing — load existing PDFs from bytes or base64, extract pages, metadata, bookmarks
• ✅ Word wrapping — automatic text wrapping within bounds
• ✅ Text alignment — left, center, right

Installation

Add to your pubspec.yaml:

dependencies:
  dart_pdf_engine: ^1.1.0

Quick Start

import 'dart:io';
import 'package:dart_pdf_engine/dart_pdf_engine.dart';

void main() async {
  // Create a document.
  final document = PdfDocument();

  // Add a page and draw text.
  document.pages.add().graphics.drawString(
    'Hello World!',
    PdfStandardFont(PdfFontFamily.helvetica, 24),
    brush: PdfSolidBrush(PdfColor(0, 0, 0)),
    bounds: const Rect.fromLTWH(50, 50, 400, 40),
  );

  // Save to file.
  File('hello.pdf').writeAsBytesSync(document.save());
  document.dispose();
}

Load & Display PDF from Base64

import 'dart:io';
import 'package:dart_pdf_engine/dart_pdf_engine.dart';

void main() async {
  // Your base64-encoded PDF string.
  final base64Pdf = '...';

  // Parse the PDF from base64.
  final document = PdfDocument.fromBase64(base64Pdf);

  // Inspect parsed data.
  print('Pages: ${document.pages.count}');
  print('Title: ${document.documentInfo.title}');
  print('Author: ${document.documentInfo.author}');
  print('Bookmarks: ${document.bookmarks.bookmarks.length}');

  // Save as a viewable PDF file.
  File('output.pdf').writeAsBytesSync(document.save());
  document.dispose();
}

You can also load from raw bytes:

final bytes = File('input.pdf').readAsBytesSync();
final document = PdfDocument.fromBytes(bytes);
print('Loaded ${document.pages.count} pages');

Usage Examples

Text with Word Wrapping

page.graphics.drawString(
  'This is a long paragraph that will automatically wrap...',
  PdfStandardFont(PdfFontFamily.timesRoman, 12),
  brush: PdfSolidBrush(PdfColor.black),
  bounds: const Rect.fromLTWH(50, 100, 400, 200),
  format: const PdfStringFormat(lineSpacing: 1.5),
);

Images (from file or base64)

// From file bytes:
final imageData = File('photo.jpg').readAsBytesSync();
final image = PdfBitmap(imageData);

// Or from base64:
final image = PdfBitmap.fromBase64(base64String);

page.graphics.drawImage(image, const Rect.fromLTWH(50, 300, 200, 150));

Tables

final grid = PdfGrid();
grid.columns.add(count: 3);

final header = grid.headers.add();
header.ensureCells(3);
header.cells[0].value = 'Name';
header.cells[1].value = 'Age';
header.cells[2].value = 'City';

final row = grid.rows.add();
row.ensureCells(3);
row.cells[0].value = 'Alice';
row.cells[1].value = '30';
row.cells[2].value = 'New York';

grid.draw(page.graphics, bounds: const Rect.fromLTWH(50, 100, 500, 0));

Shapes

// Filled rectangle.
page.graphics.drawRectangle(
  const Rect.fromLTWH(50, 200, 150, 80),
  brush: PdfSolidBrush(PdfColor(41, 128, 185)),
  pen: PdfPen(PdfColor(31, 97, 141), width: 2),
);

// Ellipse.
page.graphics.drawEllipse(
  const Rect.fromLTWH(250, 200, 150, 80),
  brush: PdfSolidBrush(PdfColor(231, 76, 60)),
);

// Dashed line.
page.graphics.drawLine(50, 300, 500, 300,
  PdfPen(PdfColor.gray, width: 1, dashStyle: PdfDashStyle.dash),
);

Bookmarks

document.bookmarks.add('Chapter 1', pageIndex: 0);
document.bookmarks.add('Chapter 2', pageIndex: 1);

Base64 Output

final base64Pdf = document.saveAsBase64();
// Use in web, API responses, etc.

API Overview

Class	Purpose
PdfDocument	Main document — create, save, dispose
PdfPage	Single page with size/orientation
PdfGraphics	Canvas API — drawString, drawImage, drawRectangle, etc.
PdfStandardFont	14 built-in PDF fonts
PdfTrueTypeFont	Embed custom TTF fonts
PdfBitmap	JPEG/PNG image embedding
PdfGrid	Table with headers, rows, styling
PdfOrderedList / PdfUnorderedList	Numbered/bulleted lists
PdfColor / PdfSolidBrush / PdfPen	Colors and styling
PdfBookmarkCollection	Document navigation bookmarks
PdfPath	Bezier paths for complex shapes

License

MIT License. See LICENSE for details.