ComPDFKit Flutter PDF Library

About

ComPDFKit for Flutter, developed and managed by ComPDF, is a powerful PDF library that enables developers to seamlessly integrate PDF viewing, a nnotation, editing, form filling, redaction, and signing into any iOS or Android application. It is available at pub.dev and GitHub.

For more information, please check our developer guides.

Contents

• Requirements
• Steps to Build the Flutter PDF Editor by Integrating ComPDFKit PDF SDK
• Example App
• Support

Requirements

Before starting, please make sure that you have already met the following prerequisites:

Get ComPDFKit License Key

ComPDF offers two types of license keys: a free 30-day trial license and a commercial license.

• Trial License – You can request a 30-day free trial online.
• Commercial License – For advanced features, custom requirements, or quote inquiries, feel free to contact our sales.

For the Flutter PDF SDK, the commercial license must be bound to your application’s ApplicationId and iOS BundleId.

System Requirements

Android

Please install the following required packages:

• The latest stable version of Flutter
• The latest stable version of Android Studio
• The Android NDK
• An Android Virtual Device

Operating Environment Requirements:

• A minSdkVersion of 21 or higher.
• A compileSdkVersion of 34 or higher.
• A targetSdkVersion of 34 or higher.
• Android ABI(s): x86, x86_64, armeabi-v7a, arm64-v8a.

iOS

Please install the following required packages:

• The latest stable version of Flutter
• The latest stable version of Xcode
• The latest stable version of CocoaPods. Follow the CocoaPods installation guide to install it.

Operating Environment Requirements:

• The iOS 12.0 or higher.
• The Xcode 12.0 or newer for Objective-C or Swift.

How to Build the Flutter PDF Editor by Integrating ComPDFKit PDF SDK

Create a new project

Android

1. Create a Flutter project called example with the flutter CLI:

flutter create --org com.compdfkit.flutter example

2. In the terminal app, change the location of the current working directory to your project:

cd example

3. open example/android/app/src/main/AndroidManifest.xml , add Internet Permission and Storage Permission:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.compdfkit.flutter.example">

+    <uses-permission android:name="android.permission.INTERNET"/>
  
    <!-- Required to read and write documents from device storage -->
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
  
    <!-- Optional settings -->
+    <uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE"/>


    <application
+      android:requestLegacyExternalStorage="true">
  
    </application>   
</manifest>

4. Open the app's Gradle build file, android/app/build.gradle:

open android/app/build.gradle

5. Modify the minimum SDK version, All this is done inside the android section:

 android {
     defaultConfig {
-        minSdkVersion flutter.minSdkVersion
+        minSdkVersion 21
         ...
     }
 }

6. Open the project’s main activity class, android/app/src/main/java/com/example/compdfkit/flutter/example/MainActivity.java, Change the base Activity to extend FlutterFragmentActivity:

- import io.flutter.embedding.android.FlutterActivity;
+ import io.flutter.embedding.android.FlutterFragmentActivity;

- public class MainActivity extends FlutterActivity {
+ public class MainActivity extends FlutterFragmentActivity {
}

Alternatively you can update the AndroidManifest.xml file to use FlutterFragmentActivity as the launcher activity:

<activity
-     android:name=".MainActivity" 
+     android:name="io.flutter.embedding.android.FlutterFragmentActivity"
      android:exported="true"
      android:hardwareAccelerated="true"
      android:launchMode="singleTop"
      android:theme="@style/LaunchTheme"
      android:windowSoftInputMode="adjustPan">

Note: FlutterFragmentActivity is not an official part of the Flutter SDK. If you need to use CPDFReaderWidget in ComPDFKit for Flutter, you need to use this part of the code. You can skip this step if you don't need to use.

7. Add the ComPDFKit dependency in pubspec.yaml

 dependencies:
   flutter:
     sdk: flutter
+  compdfkit_flutter: ^2.4.7

8. Add the PDF documents you want to display in the project

• create a pdf directory

  mkdir pdfs
  

• Copy your example document into the newly created pdfs directory and name it PDF_Document.pdf

9. Specify the assets directory in pubspec.yaml

 flutter:
+  assets:
+    - pdfs/

10. From the terminal app, run the following command to get all the packages:

flutter pub get

iOS

1. Create a Flutter project called example with the flutter CLI:

flutter create --org com.compdfkit.flutter example

2. In the terminal app, change the location of the current working directory to your project:

cd example

3. Add the ComPDFKit dependency in pubspec.yaml

 dependencies:
   flutter:
     sdk: flutter
+  compdfkit_flutter: ^2.4.7

4. Open your project's Podfile in a text editor:

open ios/Podfile

Note: If SSL network requests fail to download the ComPDFKit library when you run pod install, you can see the processing method in Troubleshooting).

6. Update the platform to iOS 12 and add the ComPDFKit Podspec:

- platform :ios, '9.0'
+ platform :ios, '12.0' 
 ...
 target 'Runner' do
   use_frameworks!
   use_modular_headers!`

   flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
+  pod "ComPDFKit", podspec:'https://file.compdf.com/cocoapods/ios/compdfkit_pdf_sdk/2.4.7/ComPDFKit.podspec'
+  pod "ComPDFKit_Tools", podspec:'https://file.compdf.com/cocoapods/ios/compdfkit_pdf_sdk/2.4.7/ComPDFKit_Tools.podspec'
 end

7. Go to the example/ios folder and run the pod install command:

pod install

8. Add the PDF documents you want to display in the project

• create a pdf directory

  mkdir pdfs
  

• Copy your example document into the newly created pdfs directory and name it PDF_Document.pdf

9. Specify the assets directory in pubspec.yaml

 flutter:
+  assets:
+    - pdfs/

10. To protect user privacy, before accessing the sensitive privacy data, you need to find the "*Info*" configuration in your iOS 10.0 or higher iOS project and configure the relevant privacy terms as shown in the following picture.

<key>NSCameraUsageDescription</key>
<string>Your consent is required before you could access the function.</string>

<key>NSMicrophoneUsageDescription</key>
<string>Your consent is required before you could access the function.</string>

<key>NSPhotoLibraryAddUsageDescription</key>
<string>Your consent is required before you could access the function.</string>

<key>NSPhotoLibraryUsageDescription</key>
<string>Your consent is required before you could access the function.</string>
  
<key>NSAppTransportSecurity</key>
	<dict>
		<key>NSAllowsArbitraryLoads</key>
		<true/>
	</dict>

11. From the terminal app, run the following command to get all the packages:

flutter pub get

Apply the License Key

ComPDFKit PDF SDK currently supports two authentication methods to verify license keys: online authentication and offline authentication.

Learn about:

• What is the authentication mechanism of ComPDFKit's license?

• What are the differences between Online Authentication and Offline Authentication?

Accurately obtaining the license key is crucial for the application of the license.

1. In the email you received, locate the XML file containing the license key.
2. Copy the License.xml file into the assets directory of your Flutter project.

3. Open the pubspec.yaml file of your project and configure the flutter: section to enable the assets directory.

4. Initialize the SDK:

// Include the license in Flutter assets and copy to device storage
// Add `license_key_flutter.xml` to your Flutter project’s assets directory;
File licenseFile = await CPDFFileUtil.extractAsset(context, 'assets/license_key_flutter.xml');
ComPDFKit.initWithPath(licenseFile.path);

Alternative methods (optional)

// Android
// Copy the license_key_flutter.xml file into the `android/app/src/main/assets` directory of your Android project:
ComPDFKit.initWithPath('assets://license_key_flutter.xml');

// iOS
// Copy the license_key_flutter.xml file into your iOS project directory (or a readable location):
ComPDFKit.initWithPath('license_key_flutter.xml');

Run Project

There are 2 different ways to use ComPDFKit Flutter API:

• Present a document via a plugin.
• Show a ComPDFKit document view via a Widget.

Usage Plugin

Open lib/main.dart,replace the entire file with the following:

import 'dart:io';

import 'package:compdfkit_flutter/compdfkit.dart';
import 'package:compdfkit_flutter/configuration/cpdf_configuration.dart';
import 'package:compdfkit_flutter/util/cpdf_file_util.dart';
import 'package:flutter/material.dart';

const String _documentPath = 'pdfs/PDF_Document.pdf';

void main() {
  runApp(const MyApp());
}

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

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  @override
  void initState() {
    super.initState();
    _init();
  }

  void _init() async {
    File licenseFile = await CPDFFileUtil.extractAsset(context, 'assets/license_key_flutter.xml');
    ComPDFKit.initWithPath(licenseFile.path);
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: SafeArea(
          child: Center(
            child: ElevatedButton(
              onPressed: () async {
                showDocument(context);
              },
              child: const Text(
                'Open Document',
              )),
          ))),
    );
  }

  void showDocument(BuildContext context) async {
    var pdfFile = await CPDFFileUtil.extractAsset(_documentPath);
    var configuration = CPDFConfiguration();
    // Present a document via a plugin.
    ComPDFKit.openDocument(pdfFile.path,
                           password: '', configuration: configuration);
  }
}

Usage Widget

Open lib/main.dart,replace the entire file with the following:

import 'dart:io';

import 'package:compdfkit_flutter/compdfkit.dart';
import 'package:compdfkit_flutter/configuration/cpdf_configuration.dart';
import 'package:compdfkit_flutter/widgets/cpdf_reader_widget.dart';
import 'package:compdfkit_flutter/util/cpdf_file_util.dart';
import 'package:flutter/material.dart';

const String _documentPath = 'pdfs/PDF_Document.pdf';

void main() {
  runApp(const MyApp());
}

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

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String? _document;

  @override
  void initState() {
    super.initState();
    _init();
    _getDocumentPath().then((value) {
      setState(() {
        _document = value;
      });
    });
  }

  void _init() async {
    /// Please replace it with your ComPDFKit license
    File licenseFile = await CPDFFileUtil.extractAsset(context, 'assets/license_key_flutter.xml');
    ComPDFKit.initWithPath(licenseFile.path);
  }

  Future<String> _getDocumentPath() async {
    var file = await CPDFFileUtil.extractAsset('pdfs/PDF_Document.pdf');
    return file.path;
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        resizeToAvoidBottomInset: false,
        appBar: AppBar(
          title: const Text('CPDFReaderWidget Example'),
        ),
        body: _document == null
        ? Container()
        : CPDFReaderWidget(
          document: _document!,
          configuration: CPDFConfiguration(),
          onCreated: (_create) => {})));
  }
}

Start your Android emulator, or connect a device, Run the app with:

flutter run

Example APP

To see ComPDFKit for Flutter in action, check out our Flutter example app and API reference

Showing a PDF document inside your Flutter app is as simple as this:

/// First. Please replace it with your ComPDFKit license

// Include the license in Flutter assets and copy to device storage
// Add `license_key_flutter.xml` to your Flutter project’s assets directory;
File licenseFile = await CPDFFileUtil.extractAsset('assets/license_key_flutter.xml');
ComPDFKit.initWithPath(licenseFile.path);

/// open pdf document
ComPDFKit.openDocument(tempDocumentPath, password: '', configuration:  CPDFConfiguration());

/// Here’s how you can open a PDF document using CPDFReaderWidget:
Scaffold(
  resizeToAvoidBottomInset: false,
  appBar: AppBar(title: const Text('CPDFReaderWidget Example'),),
  body: CPDFReaderWidget(
    document: widget.documentPath,
    configuration: CPDFConfiguration()
  ));

Support

ComPDF has a professional R&D team that produces comprehensive technical documentation and guides to help developers. Also, you can get an immediate response when reporting your problems to our support team.

• For detailed information, please visit our Guides page.
• Stay updated with the latest improvements through our Changelog.
• For technical assistance, please reach out to our Technical Support.
• To get more details and an accurate quote, please contact our Sales Team.

Thanks for reading, The ComPDF Team