c2pa_view

A Flutter package for reading and displaying C2PA (Coalition for Content Provenance and Authenticity) manifests in your Flutter applications.

Overview

C2PA is an open technical standard that provides publishers, creators, and consumers with tools to trace the origin of different types of media. This Flutter package allows you to:

• 📃 Read C2PA manifests from local files, URLs, or raw bytes
• 🎨 Display content credentials in a customizable UI
• 🔍 Access detailed information about media provenance, including:
  • Content format and generator information
  • Actions performed on the content
  • Ingredients (source files) used
  • Assertions about the content
  • Signature information

Example

In the example directory we use the following code to show a C2PA manifest from a local file:

// We make a preview (optional) for showing the content with the manifest
final preview = Image.file(
  file,
  height: 200,
  fit: BoxFit.cover,
  errorBuilder: (context, error, stackTrace) {
    return const Text('Error loading image');
  },
);

// Get manifest store from file
final manifestStore = ManifestStore.fromLocalPath(file.path);

// Check if manifest store is null (if there is no manifest)
if (manifestStore == null) {
  return const SingleChildScrollView(
    child: Text('No manifest found'),
  );
}

// Make content credentials widget with manifest store and preview
// We wrap in scrollable as the manifest can be long
final ccw = SingleChildScrollView(
  child: ContentCredentialsWidget(
    manifestStore: manifestStore,
    contentPreview: preview,
  ),
);

The ManifestStrore can be created in multiple ways:

// From a local path
final store = ManifestStore.fromLocalPath('/local/path/to/file.jpg');

// From bytes and format / mime-type
final bytes = [...]; // Your image bytes
final store4 = ManifestStore.fromBytes(bytes, 'image/jpeg');

// From a URL
final store = await ManifestStore.fromUrl('https://example.com/image.jpg');

Customization

The ContentCredentialsWidget supports various styling options:

ContentCredentialsWidget(
  source: path,
  contentPreview: preview,
  titleStyle: TextStyle(...),
  sectionTitleStyle: TextStyle(...),
  contentLabelStyle: TextStyle(...),
  contentStyle: TextStyle(...),
)

Note

This package was created during a Hackathon sprint and is in a very early stage. We hope to develop further and provide more features in the future 😁