Honeywell Mobility SDK for Flutter & Android

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

class HoneywellScannerView extends StatefulWidget {
  const HoneywellScannerView({Key? key}) : super(key: key);

  @override
  State<HoneywellScannerView> createState() => _HoneywellScannerViewState();
}

class _HoneywellScannerViewState extends State<HoneywellScannerView>
    with WidgetsBindingObserver {
  BarcodeReader? _barcodeReader;
  String _latestBarcode = 'No scans yet';
  bool _isTriggerPressed = false;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
    _initializeScanner();
  }

  Future<void> _initializeScanner() async {
    // Instantiate hardware barcode reader session
    final reader = await HoneywellMobilitySdk.createBarcodeReader(
      onRead: (BarcodeReadEvent event) {
        setState(() {
          _latestBarcode = event.barcodeData;
        });
        debugPrint('Scanned: ${event.barcodeData} (${event.codeId})');
      },
      onFailure: (BarcodeFailureEvent event) {
        debugPrint('Scan decode failure at: ${event.timestamp}');
      },
      onTrigger: (TriggerStateChangeEvent event) {
        setState(() {
          _isTriggerPressed = event.state;
        });
      },
    );

    if (reader != null) {
      _barcodeReader = reader;
      await reader.claim(); // Acquire exclusive hardware scan control
    }
  }

  // Handle Android lifecycle to prevent "Scanner is already claimed" errors
  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    if (_barcodeReader == null) return;

    if (state == AppLifecycleState.resumed) {
      _barcodeReader?.claim(); // Reacquire scan engine
    } else if (state == AppLifecycleState.paused) {
      _barcodeReader?.release(); // Yield control to OS
    }
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    _barcodeReader?.close(); // Cleanly close hardware session
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Honeywell Warehouse Scanner')),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(
              _isTriggerPressed ? Icons.flash_on : Icons.qr_code_scanner,
              size: 64,
              color: _isTriggerPressed ? Colors.amber : Colors.blueGrey,
            ),
            const SizedBox(height: 16),
            Text(
              _latestBarcode,
              style: const TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
            ),
          ],
        ),
      ),
    );
  }
}