flutter_liveness_detection 0.0.3

A Flutter plugin for real-time liveness detection using face gestures like smile, blink, and head movement. Supports Android and iOS.

example/lib/main.dart

import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_liveness_detection/flutter_liveness_detection.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:camera/camera.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await requestCameraPermission();
  runApp(const MyApp());
}

Future<void> requestCameraPermission() async {
  final status = await Permission.camera.request();
  if (!status.isGranted) {
    runApp(const PermissionDeniedApp());
  }
}

class PermissionDeniedApp extends StatelessWidget {
  const PermissionDeniedApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        appBar: AppBar(
          title: const Text("Permission Denied"),
        ),
        body: Center(
          child: AlertDialog(
            title: const Text("Permission Denied"),
            content: const Text("Camera access is required for verification."),
            actions: [
              TextButton(
                onPressed: () => SystemNavigator.pop(),
                child: const Text("OK"),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Material App',
      home: HomePage(),
    );
  }
}

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

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  File? imageFile;
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white,
      appBar: AppBar(
        backgroundColor: Colors.blueAccent,
        toolbarHeight: 70,
        centerTitle: true,
        title: const Text('Identify'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            const Text('Please click the button below to start verification', textAlign: TextAlign.center, style: TextStyle(fontSize: 20)),
            const SizedBox(height: 30),

            (imageFile != null) ?
            SizedBox(height: 200,width: 150, child: Image.file(imageFile!))
                : SizedBox(),


            ElevatedButton(
              style: ElevatedButton.styleFrom(
                padding: const EdgeInsets.all(20),
                shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(15)),
                foregroundColor: Colors.black,
                backgroundColor: Colors.blueAccent,
              ),
              onPressed: () async {

                /// 1️⃣ Check if the device has any cameras.
                /// (We need at least one front camera to run liveness detection)
                final List<CameraDescription> cameras = await availableCameras();

                if (cameras.isNotEmpty) {

                  /// 2️⃣ Open the liveness detection screen.
                  /// Call the **FlutterLivenessDetection** widget — this is required.
                  /// It will guide the user to blink, smile, or turn their head,
                  /// then take a selfie automatically.
                  final XFile? result = await Navigator.push(
                    context,
                    MaterialPageRoute(builder: (context) => const FlutterLivenessDetection()),
                  );

                  /// 3️⃣ If detection was successful, you will get a selfie image.
                  if (result != null) {
                    /// 4️⃣ Print the selfie image path (you can upload or save this file).
                    print('Selfie path: ${result.path}');

                    /// 5️⃣ Show a success message to the user.
                    ScaffoldMessenger.of(context).showSnackBar(
                      const SnackBar(content: Text('Verification Successful!')),
                    );
                  }
                } else {
                  /// ❌ No camera found → Show an error message.
                  ScaffoldMessenger.of(context).showSnackBar(
                    const SnackBar(content: Text('Camera not active!')),
                  );
                }
              },
              child: const Text('Verify Now',
                style: TextStyle(fontWeight: FontWeight.bold, fontSize: 20),
              ),
            ),
          ],
        ),
      ),
    );
  }
}