universal_thermal_printer 1.0.0

Universal Thermal Printer SDK for Flutter — Bluetooth & Network (WiFi/LAN) ESC/POS thermal printer support with text, QR, barcode, images, and built-in remote license activation.

example/lib/main.dart

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

import 'app_controller.dart';
import 'screens/connect_screen.dart';
import 'screens/gallery_screen.dart';

/// Single shared controller for the whole demo.
final AppController controller = AppController();

void main() {
  // ── License is handled internally — end users never type or see a key ──
  // To unlock unlimited printing, developers pass ONLY a license key:
  //
  //   LicenseManager.instance.configure(licenseKey: 'UTP-XXXX-XXXX-XXXX');
  //
  // (No Firebase details are ever needed here — the SDK already knows its
  // backend.) With no key the SDK still works with a modest daily cap that is
  // never surfaced to end users.
  LicenseManager.instance.configure(appId: 'com.example.utp_demo');

  runApp(const DemoApp());
}

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Universal Thermal Printer',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        colorSchemeSeed: const Color(0xFF3949AB),
        useMaterial3: true,
        brightness: Brightness.light,
      ),
      darkTheme: ThemeData(
        colorSchemeSeed: const Color(0xFF3949AB),
        useMaterial3: true,
        brightness: Brightness.dark,
      ),
      home: const HomeShell(),
    );
  }
}

class HomeShell extends StatefulWidget {
  const HomeShell({super.key});
  @override
  State<HomeShell> createState() => _HomeShellState();
}

class _HomeShellState extends State<HomeShell> {
  int _index = 0;

  @override
  Widget build(BuildContext context) {
    final pages = [
      ConnectScreen(controller: controller),
      GalleryScreen(controller: controller),
    ];
    return Scaffold(
      appBar: AppBar(
        title: const Text('Universal Thermal Printer'),
        actions: [
          // Subtle positive indicator only — nothing is shown to end users
          // about free/trial limits.
          AnimatedBuilder(
            animation: controller,
            builder: (context, _) {
              if (controller.licenseMode != LicenseMode.licensed) {
                return const SizedBox.shrink();
              }
              return Padding(
                padding: const EdgeInsets.only(right: 12),
                child: Tooltip(
                  message: 'Licensed',
                  child: Icon(Icons.verified,
                      color: Theme.of(context).colorScheme.primary),
                ),
              );
            },
          ),
        ],
      ),
      body: pages[_index],
      bottomNavigationBar: NavigationBar(
        selectedIndex: _index,
        onDestinationSelected: (i) => setState(() => _index = i),
        destinations: const [
          NavigationDestination(
              icon: Icon(Icons.print_outlined), label: 'Printer'),
          NavigationDestination(
              icon: Icon(Icons.dashboard_customize_outlined),
              label: 'Templates'),
        ],
      ),
    );
  }
}