Flutter

Setup

The flutter based Vision SDK is an on-device computer vision and NLP based toolkit designed to scan barcodes, QR codes, and extract structured information from logistics documents such as shipping labels, bills of lading (BOLs), and inventory/item labels. Built for real-time performance, it enables fast, offline processing without relying on cloud services. The SDK also supports advanced use cases including item retrieval, price tag extraction, and item counting, making it ideal for warehouse, retail, and logistics applications. With a focus on accuracy, speed, and device-level intelligence, the Vision SDK empowers developers to build seamless and efficient vision-based workflows directly on mobile and embedded devices.

# Development Requirements

# iOS

• iOS 13.0+
• Swift: 5.4.2+
• Xcode Version: 13.0+

# Android

• Android: 10+
• Java: 17+
• Kotlin: 1.9.0+
• Android Gradle Plugin Version: 8.1.0+

# Installation

# pubspec.yaml

Add the following dependency in your pubspec.yaml file:

fluttervisionsdkplugin: ^1.3.1

# Usage

Since VisionSDK uses camera, your app needs to have camera permission in order for VisionSDK to work.

# iOS

Add Privacy - Camera Usage Description to Info.plist file

# Android

Add the following permission in your app's AndroidManifest.xml file:

<uses-permission android:name="android.permission.CAMERA" />

# Initialization

In order to setup VisionSDK in your project, you need to initialized it before accessing it.

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

  @override
  State<MainApp> createState() => _MainAppState();
}

class _MainAppState extends State<MainApp> {

  @override
  void initState() {
    super.initState();
    VisionSDK().initialize(Environment.sandbox); // <== Initialize VisionSDK before accessing it.
  }

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: Scaffold(
        body: VisionSDKView(),
      ),
    );
  }
}

      

# Open Camera

After initialization, you can use VisionCameraWidget to open camera and get its feed previewed on screen. Be sure that you have granted the camera permission before you can use VisionCameraWidget.

Check out the code below to understand how VisionCameraWidget works, how to send data to and from it using communicators.

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

  @override
  State<VisionSDKView> createState() => VisionSDKState();
}

class VisionSDKState extends State<VisionSDKView> {
  @override
  Widget build(BuildContext context) {
    return VisionCameraWidget(
      listener: MyPluginToFlutterCommunicator(),
      onViewCreated: (FlutterToPluginCommunicator sender) {
        sender.startCamera();
      }
    );
  }
}

class MyPluginToFlutterCommunicator implements PluginToFlutterCommunicator {}

      

Note that we have two communicators here:

• FlutterToPluginCommunicator: You receive this communicator when VisionCameraWidget is created. This communicator can be used to send data to VisionSDK plugin.
• PluginToFlutterCommunicator: You create an object of this communicator and override its methods to receive data from VisionSDK plugin.

# FlutterToPluginCommunicator

Here is the list of all publicly available functions that you can call from FlutterToPluginCommunicator:

• setMultipleScanEnabled
• setScanAuto
• setScanManual
• setCaptureModeBarcode
• setCaptureModeQrCode
• setCaptureModeOCR
• setFocusSettings
• setObjectDetectionSettings
• setCameraSettings
• startCamera
• stopCamera
• capturePhoto
• rescan
• callShippingLabelApi
• callBolApi
• callItemLabelApi

# PluginToFlutterCommunicator

Here is the list of all callbacks, in which VisionSDK responds:

• onCameraStarted
• onCameraStopped
• onScanError
• onCodesReceived
• onDetectionResult
• onImageCaptured
• onOnlineSLResult
• onOnlineBOLResult
• onOnlineItemLabelResult
• onOnlineDocumentClassificationResult

More details on how these communicators work is on next pages.