flutter_jc_printer_plugin/example/lib/main.dart

import 'dart:async';

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_reactive_ble/flutter_reactive_ble.dart';

import 'package:jc_printer/jc_printer.dart';

void main() {
  runApp(const MyApp());
}

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

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: HomePage(),
    );
  }
}

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

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

class _HomePageState extends State<HomePage> {
  final TextEditingController _labelWidthInput = TextEditingController();
  final TextEditingController _labelHeightInput = TextEditingController();
  final TextEditingController _countInput = TextEditingController();
  final TextEditingController _contentInput = TextEditingController();
  final _printer = JcPrinter();
  ConnectState _connectState = ConnectState.none;
  StreamSubscription<ConnectState>? _connectStateSubs;
  StreamSubscription<int>? _printingCountSubs;
  StreamSubscription<Map<String, String>>? _errorInfoSubs;
  DiscoveredDevice? _device;

  String get _title {
    switch (_connectState) {
      case ConnectState.connecting:
        return '连接中';
      case ConnectState.connected:
        return _device?.name ?? '已连接';
      case ConnectState.none:
        return '未连接';
    }
  }

  @override
  void initState() {
    _labelWidthInput.text = '40';
    _labelHeightInput.text = '30';
    _countInput.text = '1';
    _contentInput.text = '歪脖子';
    _connectStateSubs = _printer.connectStateStream.listen(
      _connectStateListener,
    );
    _printingCountSubs = _printer.printingCountStream.listen(
      _printingCountListener,
    );
    _errorInfoSubs = _printer.errorInfoStream.listen(
      _errorInfoListener,
    );
    super.initState();
  }

  @override
  void dispose() {
    _labelWidthInput.dispose();
    _labelHeightInput.dispose();
    _countInput.dispose();
    _contentInput.dispose();
    _connectStateSubs?.cancel();
    _printingCountSubs?.cancel();
    _errorInfoSubs?.cancel();
    super.dispose();
  }

  void _connectStateListener(ConnectState state) {
    setState(() {
      _connectState = state;
    });
  }
  void _printingCountListener(int count) {
    print(count);
  }
  void _errorInfoListener(Map<String, String> error) {
    print(error);
  }

  void _connect() {
    _printer.connect(_device!.name);
  }

  void _startPrint() async {
    final labelWidth = double.tryParse(_labelWidthInput.value.text) ?? 0;
    final labelHeight = double.tryParse(_labelHeightInput.value.text) ?? 0;
    final count = double.tryParse(_countInput.value.text) ?? 0;
    final content = _contentInput.value.text.trim();
    if (content.isEmpty || count <= 0) return;
    _printer.setTotalPrints(3);
    _printer.startPrint(data: '', count: 1);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: _connectState == ConnectState.connecting
            ? const CupertinoActivityIndicator()
            : Text(_title),
        actions: [
          TextButton(
            onPressed: () async {
              if (_connectState == ConnectState.connected) {
                _printer.disconnect();
                return;
              }
              final result = await showDialog<DiscoveredDevice>(
                context: context,
                builder: (BuildContext context) => _DevicesDialog(
                  onTap: Navigator.of(context).pop,
                ),
              );
              if (result == null) return;
              _device = result;
              _connect();
            },
            child: Text(
              _connectState == ConnectState.connected ? '断开' : '连接设备',
              style: const TextStyle(color: Colors.white),
            ),
          ),
        ],
      ),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(20),
        child: Center(
          child: Column(
            children: [
              TextField(
                controller: _labelWidthInput,
                decoration: const InputDecoration(label: Text('标签宽度')),
              ),
              TextField(
                controller: _labelHeightInput,
                decoration: const InputDecoration(label: Text('标签高度')),
              ),
              TextField(
                controller: _countInput,
                decoration: const InputDecoration(label: Text('打印数量')),
              ),
              TextField(
                controller: _contentInput,
                decoration: const InputDecoration(label: Text('内容')),
              ),
              const SizedBox(height: 20),
              ElevatedButton(
                onPressed: _startPrint,
                child: const Text('开始打印'),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

class _DevicesDialog extends StatefulWidget {
  final void Function(DiscoveredDevice device)? onTap;

  const _DevicesDialog({
    Key? key,
    this.onTap,
  }) : super(key: key);

  @override
  State<_DevicesDialog> createState() => _DevicesDialogState();
}

class _DevicesDialogState extends State<_DevicesDialog> {
  final _ble = FlutterReactiveBle();
  final List<DiscoveredDevice> _devices = [];
  StreamSubscription<DiscoveredDevice>? _scanSubs;

  @override
  void initState() {
    _scanSubs = _ble.scanForDevices(
      withServices: [],
    ).listen(_scanListener);
    super.initState();
  }

  @override
  void dispose() {
    _scanSubs?.cancel();
    super.dispose();
  }

  void _scanListener(DiscoveredDevice device) {
    if (device.name.isEmpty) return;
    if (device.connectable != Connectable.available) return;
    final index = _devices.indexWhere(
      (element) => element.id == device.id,
    );
    if (index > -1) {
      _devices[index] = device;
    } else {
      _devices.add(device);
    }
    if (mounted) setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    return Dialog(
      child: ConstrainedBox(
        constraints: const BoxConstraints(maxHeight: 400),
        child: ListView.separated(
          itemBuilder: (BuildContext context, int index) {
            final item = _devices[index];
            return ListTile(
              title: Text(item.name),
              onTap: () => widget.onTap?.call(item),
            );
          },
          itemCount: _devices.length,
          separatorBuilder: (_, __) => const Divider(),
        ),
      ),
    );
  }
}