Integrate the PDF Viewer Package

compdf_viewer is a ready-to-use Flutter PDF viewer package built on top of ComPDF Flutter SDK. Rather than building PDF viewing UI from scratch, you can drop this package into your project and get a fully interactive PDF reading experience — including annotations, bookmarks, text search, thumbnails, and more — out of the box.

The package uses GetX for routing, state management, and dependency injection, and ships with English and Chinese localizations.

Android	iOS

What's Included

Category	Details
PDF Viewing	Single page, double page, and continuous scroll modes
Annotations	Note, highlight, underline, strikeout, ink drawing, shapes (rectangle, circle, line, arrow), stamps, signatures
Navigation	BOTA panel — Bookmarks, Outlines, Thumbnails, Annotations list
Text Search	Full-text search with context snippets and result highlighting
Document Security	Password protection, encryption, permission settings
Content Editing	Edit PDF text and images directly; undo/redo support
Export	Convert PDF pages to images, flatten annotations
UI	Dark mode support, built-in English and Chinese translations

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Package Structure

The package follows a feature-based architecture with GetX. Each feature is a self-contained module with its own controller, model, and widgets.

lib/
├── compdf_viewer.dart   # Public API & exports
├── core/                # Global settings, SDK initialization, bindings, constants
├── features/
│   ├── viewer/          # Main PDF rendering page + controller
│   ├── annotation/      # Annotation toolbar & property editors
│   ├── bota/            # Bookmarks, Outlines, Thumbnails, Annotations list
│   ├── search/          # Full-text search
│   ├── navigation/      # Side drawer
│   ├── security/        # Password/encryption dialogs
│   ├── convert/         # PDF-to-image export
│   └── info/            # Document metadata display
├── l10n/                # English and Chinese translations
├── router/              # GetX route definitions
├── shared/              # Reusable widgets, controllers, dialogs
└── utils/               # File, page, screen utilities

Key classes:

Class	Role
PdfViewerGlobal	SDK initialization and logger
PdfViewerController	Main PDF viewer state and controls
PdfAnnotationToolBarController	Annotation tool selection and property management
PdfSearchController	Text search state and result navigation
PdfViewerRoutes	Route path constants
PdfViewerPages	GetX page configuration list

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Prerequisites

Requirement	Minimum Version
Flutter	3.3.0
Dart SDK	3.0.5
Android minSdkVersion	21
iOS deployment target	12.0
ComPDF license	Required — get a free trial

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Getting Started

Add the dependency

compdf_viewer is located in the ComPDF Flutter SDK repository under example/packages/compdf_viewer. Copy it into your project, then reference it in pubspec.yaml:

dependencies:
  flutter:
    sdk: flutter
  compdf_viewer:
    path: packages/compdf_viewer
  get: ^4.7.2

Fetch packages

flutter pub get

Add your license file

Copy your ComPDF license file to your app's assets folder (e.g. assets/license_key_flutter.xml) and declare it in pubspec.yaml:

flutter:
  assets:
    - assets/license_key_flutter.xml

Initialize the SDK

Call PdfViewerGlobal.init() before runApp():

import 'package:compdf_viewer/compdf_viewer.dart';
import 'package:flutter/material.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  // Initialize ComPDF with your license file path
  await PdfViewerGlobal.init('assets/license_key_flutter.xml');

  runApp(const MyApp());
}

Register routes and translations

compdf_viewer ships with GetX routing and i18n. Register them in your GetMaterialApp:

import 'package:get/get.dart';
import 'package:compdf_viewer/compdf_viewer.dart';

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return GetMaterialApp(
      // Register translations (English + Chinese)
      translations: PdfViewerTranslations(),
      locale: Get.deviceLocale,
      fallbackLocale: const Locale('en', 'US'),

      // Register PDF viewer routes
      getPages: [
        ...PdfViewerPages.routes,
        // ...your other routes
      ],

      home: const HomePage(),
    );
  }
}

Open a PDF

Navigate to the PDF viewer page by passing the absolute file path:

Get.toNamed(
  PdfViewerRoutes.pdfPage,
  arguments: {'document': '/absolute/path/to/document.pdf'},
);

That's it. The viewer opens with a full annotation toolbar, search, bookmarks, and all built-in features enabled.

Dependencies

Package	Purpose
compdfkit_flutter	PDF rendering and SDK core
get	State management, DI, and routing
shared_preferences	Persistent viewer settings
flutter_colorpicker	Annotation color picker UI
share_plus	Share PDF files
file_picker	Open files from device storage
path_provider	Access device directories
flutter_svg	Render toolbar SVG icons
logger	Debug and error logging

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Further Reading

• Annotation Guide — Learn how the annotation model works and how to use the annotation API directly
• Security Guide — Password protect and apply permissions to documents
• Configuration Reference — Full options for customizing the viewer
• API Reference — ComPDF Flutter SDK public API