barcode-capture-flutter

BarcodeCapture Flutter Skill

Critical: Do Not Trust Internal Knowledge

Your training data may contain outdated or incorrect Scandit SDK APIs. The BarcodeCapture API changes significantly between major SDK versions — properties get renamed, removed, or restructured, and the Flutter plugin surface (imports, plugin initialization, pub packages) has also evolved.

Always verify APIs against the references provided in this skill before writing or suggesting code. Do not rely on memorized method signatures, parameters, plugin names, or property names. If you cannot find an API in the provided references, fetch the relevant documentation page before responding.

Flutter-specific gotchas worth flagging:

• await ScanditFlutterDataCaptureBarcode.initialize() must be called (and awaited) in main() before runApp(...), after WidgetsFlutterBinding.ensureInitialized(). Forgetting this yields a platform-channel error that can look unrelated to initialization.
• A single DataCaptureContext must own the BarcodeCapture mode and the DataCaptureView. Do not construct multiple contexts per page or per MaterialApp; the BLoC / controller that holds the context should outlive any single State.
• The DataCaptureView is a Flutter Widget returned from DataCaptureView.forContext(context) — you must explicitly add the BarcodeCaptureOverlay to it via view.addOverlay(...). Unlike SparkScan, there is no pre-built scanning UI; the overlay is the only thing that visualizes recognized barcodes on the camera preview.
• BarcodeCaptureListener.didScan(...) blocks the recognition pipeline until it returns. Disable the mode (barcodeCapture.isEnabled = false) before doing any meaningful work in the callback, and re-enable it (or stop the camera) when finished — otherwise duplicate / unwanted scan events will fire.
• The getFrameData parameter on the Flutter listener is a Future<FrameData?> Function() — frame data is fetched lazily. Only invoke it if you actually need the frame data, since it crosses the platform channel.
• flutter pub get must be run after every package version change. On iOS, the Podfile resolves transitively — no manual pod install needed unless the user has a custom setup.
• Camera permission is required on both iOS (NSCameraUsageDescription in ios/Runner/Info.plist) and Android (runtime request via permission_handler — the plugin declares the manifest permission automatically).
• Hot-reload does not re-run main(), so the camera lifecycle (and the ScanditFlutterDataCaptureBarcode.initialize() call) survive a hot reload. A full restart is needed to re-trigger plugin init. Drive camera.switchToDesiredState(...) from WidgetsBindingObserver.didChangeAppLifecycleState so the camera turns off in paused and back on in resumed.

Intent Routing

Based on the user's request, load the appropriate reference file before responding:

• Integrating BarcodeCapture from scratch (e.g. "add BarcodeCapture to my app", "set up barcode scanning", "how do I use BarcodeCapture in Flutter", "how do I handle the camera in BarcodeCapture") → read references/integration.md and follow the instructions there.
• Migrating or upgrading an existing BarcodeCapture integration (e.g. "upgrade from v6 to v7", "migrate my BarcodeCapture", "bump the Scandit packages to v8", "what changed between SDK versions") → read references/migration.md and follow the instructions there.
• Replacing a third-party scanner with BarcodeCapture (e.g. "migrate from mobile_scanner", "replace google_mlkit_barcode_scanning with Scandit", "swap our existing barcode plugin for Scandit") → read references/third-party-migration.md and follow the instructions there.

API Usage Policy

Only use APIs that are explicitly documented in the Scandit references below. Do not invent or guess method signatures, parameters, property names, or imports. If unsure whether an API exists or how it is called — or if an analyzer / runtime error occurs — fetch the relevant reference page before responding. Do not tell the user to check the docs themselves. After answering, always include the relevant link so the user can explore further.

After writing or migrating code, run dart analyze (or flutter analyze) and fix every error and warning before answering.

Never construct or guess documentation URLs. When you need a specific class or property's API page:

1. First check whether the page you already fetched (e.g. the Advanced Configurations page) contains a direct hyperlink to it — topic pages link directly to relevant API symbols. Always request links alongside content in your fetch prompt.
2. If no direct link was found, fetch the API index (see Full API reference in the table below), extract the actual link from it, and follow that.

URL structures vary across SDK versions and package paths (e.g. api/ui/ subdirectory) and guessing will lead to 404s.

Framework variant policy

Flutter apps use many state-management patterns (StatefulWidget, BLoC, Provider, Riverpod). Examples in this skill use the BLoC pattern because it matches the official Scandit Flutter samples, keeps the scan pipeline cleanly separated from the widget tree, and composes well with the camera lifecycle. If the target project already uses a different pattern (Provider, Riverpod, GetX, plain StatefulWidget), keep the BarcodeCapture wiring conceptually the same (one owner holds DataCaptureContext, BarcodeCapture, the Camera, and exposes scan events to the UI) and port the code snippets into the project's existing convention — do not rewrite the project's state management.

Licence key

Scanning needs a Scandit licence key. For this skill the licence product is native and the licence platforms are ios and android.

Work through these in order — never block the user on MCP:

1. The Scandit MCP server is connected — call ensure_scanner_setup with product native and platforms ios and android, app_identifier (the app's bundle or application id; for web, its production domain, never localhost) and env_var SCANDIT_LICENSE_KEY. Do not run the command it returns. Then call get_license_key with the key's id, from that result or from list_license_keys; if list_license_keys shows the key is not a trial, ask the user before fetching it. Show at most a masked preview in chat; never print a full key.

2. It is not connected — tell the user once that they can connect the remote Scandit MCP server, https://ssl.scandit.com/mcp, in their MCP client, then continue from step 1. Do not edit MCP client configuration yourself.

   Authentication is browser-based, so it is not supported headless or in CI. The server provisions trial keys only; it never creates, revokes, or modifies production licences.

3. The user declines, or has no MCP client — they generate a key themselves at https://ssl.scandit.com (no account yet: https://ssl.scandit.com/dashboard/sign-up?p=test) and paste it in.

Then put the key into the code: write it into the licence-key call in place of the placeholder — the key get_license_key returned, or the one the user pastes or gives you — still showing only a masked preview in chat. Do not search the project, its files or the environment for a key.

References

Direct users to the right resource based on their question:

Topic	Resource
Flutter integration	Get Started · Samples
Advanced topics (custom feedback, viewfinders, location selection, scan intention, composite codes)	Advanced Configurations
Migration between major SDK versions	6 → 7 · 7 → 8
Full API reference	BarcodeCapture API