samviva 1.0.0

A Flutter liveness detection library powered by Google ML Kit. Detect live users with configurable probability thresholds via active face challenges.

example/lib/main.dart

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

void main() => runApp(const App());

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Samviva Example',
      debugShowCheckedModeBanner: false,
      theme: ThemeData.dark(),
      home: const HomeScreen(),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Samviva Demo')),
      body: Center(
        child: ElevatedButton(
          onPressed: () => Navigator.push(
            context,
            MaterialPageRoute(builder: (_) => const LivenessScreen()),
          ),
          child: const Text('Start Liveness Check'),
        ),
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SamvivaLivenessView(
        challenges: const [
          SamvivaLivenessChallenge.blink,
          SamvivaLivenessChallenge.smile,
          SamvivaLivenessChallenge.turnLeft,
        ],
        // --- Detection thresholds ---
        // Lower blinkEyeClosedThreshold = eyes must close more = stricter
        // Higher smileThreshold         = must smile more clearly = stricter
        // Higher headTurnAngle          = must turn head further = stricter
        config: const SamvivaLivenessConfig(
          blinkEyeClosedThreshold: 0.3,
          smileThreshold: 0.75,
          headTurnAngle: 20.0,
          challengeTimeout: Duration(seconds: 5),
          totalTimeout: Duration(seconds: 30),
        ),
        onSuccess: (SamvivaLivenessResult result) {
          // Show dialog while LivenessScreen is still active, then pop both
          showDialog(
            context: context,
            barrierDismissible: false,
            builder: (dialogContext) => AlertDialog(
              title: const Text('Liveness Passed ✓'),
              content: Column(
                mainAxisSize: MainAxisSize.min,
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    'Completed: ${result.completedChallenges.map((c) => c.name).join(', ')}',
                  ),
                  Text('Time: ${result.timestamp}'),
                  if (result.capturedImage != null)
                    Padding(
                      padding: const EdgeInsets.only(top: 12),
                      child: Image.memory(result.capturedImage!, height: 160),
                    ),
                ],
              ),
              actions: [
                TextButton(
                  onPressed: () {
                    Navigator.pop(dialogContext);
                    Navigator.pop(context);
                  },
                  child: const Text('OK'),
                ),
              ],
            ),
          );
        },
        onFailure: (SamvivaLivenessFailure failure) {
          final messenger = ScaffoldMessenger.of(context);
          Navigator.pop(context);
          messenger.showSnackBar(
            SnackBar(
              content: Text('Failed: ${failure.message}'),
              backgroundColor: Colors.red,
            ),
          );
        },
        // Optional: monitor raw probabilities per frame
        onChallengeUpdate: (SamvivaLivenessChallengeUpdate update) {
          debugPrint(
            '[samviva] ${update.challenge.name} '
            '— prob: ${update.probability.toStringAsFixed(2)} '
            '/ threshold: ${update.threshold} '
            '— passed: ${update.isPassed}',
          );
        },
        // Optional: override displayed text for localisation
        labels: const SamvivaLivenessLabels(
          blinkLabel: 'Blink',
          smileLabel: 'Smile',
          turnLeftLabel: 'Left',
          turnRightLabel: 'Right',
          blinkInstruction: 'Blink your eyes',
          smileInstruction: 'Give us a smile',
          turnLeftInstruction: 'Turn your head to the left',
          turnRightInstruction: 'Turn your head to the right',
          positionFaceText: 'Position your face in the oval',
          noFaceText: 'No face detected — move closer',
          holdStillText: 'Hold still…',
          successText: 'Verification complete!',
          failureText: 'Verification failed',
        ),
        // Optional: override text styles
        textStyles: const SamvivaLivenessTextStyles(
          titleStyle: TextStyle(
            fontSize: 16,
            fontWeight: FontWeight.w700,
            color: Colors.white,
            letterSpacing: 0.4,
          ),
          instructionStyle: TextStyle(
            fontSize: 15,
            fontWeight: FontWeight.w600,
            color: Colors.white,
          ),
          stepLabelStyle: TextStyle(
            fontSize: 10,
            letterSpacing: 0.4,
          ),
          countdownStyle: TextStyle(
            fontSize: 96,
            fontWeight: FontWeight.w900,
          ),
        ),
        // Optional: customize colors to match your brand
        theme: const SamvivaLivenessTheme(
          activeColor: Color(0xFF4ADE80),
          errorColor: Color(0xFFF87171),
          overlayColor: Color(0xBB000000),
          stepActiveColor: Colors.white,
          stepPendingColor: Colors.white,
          connectorIdleColor: Colors.white24,
        ),
      ),
    );
  }
}