dynamic_signature_pad 0.0.1

Capture handwritten signatures as dynamic time-series data (vector strokes with velocity and optional pressure). Lossless JSON/SVG export and PNG rendering. Pure Dart/Flutter, no native code, no third [...]

example/lib/main.dart

import 'dart:typed_data';

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

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

/// Demo application for `dynamic_signature_pad`.
class ExampleApp extends StatelessWidget {
  /// Creates the demo app.
  const ExampleApp({super.key});

  @override
  Widget build(BuildContext context) => const MaterialApp(
        title: 'dynamic_signature_pad',
        home: HomePage(),
      );
}

/// Home page: opens the full-screen, landscape-locked capture screen and shows
/// the result.
class HomePage extends StatefulWidget {
  /// Creates the home page.
  const HomePage({super.key});

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

class _HomePageState extends State<HomePage> {
  Uint8List? _png;
  String _info = '';

  Future<void> _capture() async {
    final SignatureResult? result =
        await showDynamicSignature(context, title: 'Sign here');
    if (!mounted) return;
    if (result == null) {
      setState(() => _info = 'Cancelled');
      return;
    }
    setState(() {
      _png = result.pngBytes;
      _info = 'points: ${result.signature.pointCount} · '
          'json: ${result.strokeJson.length} B · svg: ${result.svg.length} B';
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Dynamic Signature Pad')),
      body: Center(
        child: Padding(
          padding: const EdgeInsets.all(24),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              ElevatedButton.icon(
                onPressed: _capture,
                icon: const Icon(Icons.edit),
                label: const Text('Capture signature'),
              ),
              const SizedBox(height: 16),
              Text(_info, textAlign: TextAlign.center),
              if (_png != null) ...<Widget>[
                const SizedBox(height: 16),
                DecoratedBox(
                  decoration:
                      BoxDecoration(border: Border.all(color: Colors.grey)),
                  child: Image.memory(_png!, height: 120, fit: BoxFit.contain),
                ),
              ],
            ],
          ),
        ),
      ),
    );
  }
}