pos_printer_lib 0.0.5

pos_printer_lib: ^0.0.5 copied to clipboard

example/lib/main.dart

import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'dart:async';

import 'package:flutter/services.dart';
import 'package:pos_printer_lib/pos_printer_lib.dart';

import 'dart:ui' as ui;
import 'dart:math' as math;

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

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

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  int _numberOfPrinters = 0;
  bool? _hasPermission;
  final _posPrinterLibPlugin = PosPrinterLib();
  String? _capturedImageBase64;

  final GlobalKey _repaintBoundaryKey = GlobalKey();

  @override
  void initState() {
    super.initState();
    initPlatformState();
  }

  // Platform messages are asynchronous, so we initialize in an async method.
  Future<void> initPlatformState() async {
    int numberOfPrinters = 0;

    // Platform messages may fail, so we use a try/catch PlatformException.
    // We also handle the message potentially returning null.
    try {
      _hasPermission = await _posPrinterLibPlugin.checkPrinterPermission();
      if (_hasPermission != null && _hasPermission!) {
        numberOfPrinters =
            await _posPrinterLibPlugin.getNumberOfPrinters() ?? 0;
      }
    } on Exception {
      numberOfPrinters = 0;
    }

    // If the widget was removed from the tree while the asynchronous platform
    // message was in flight, we want to discard the reply rather than calling
    // setState to update our non-existent appearance.
    if (!mounted) return;

    setState(() {
      _numberOfPrinters = numberOfPrinters;
    });
  }

  Future<void> _captureWidget() async {
    try {
      RenderRepaintBoundary boundary = _repaintBoundaryKey.currentContext!
          .findRenderObject() as RenderRepaintBoundary;

      // Capture the widget with higher quality
      ui.Image image = await boundary.toImage(
          pixelRatio: 3.0); // Increased pixel ratio for better quality

      // Convert to PNG with maximum quality
      ByteData? byteData =
          await image.toByteData(format: ui.ImageByteFormat.png);

      if (byteData != null) {
        Uint8List bytes = byteData.buffer.asUint8List();
        String base64String = base64Encode(bytes);

        print(
            "Base64 image preview: ${base64String.substring(0, math.min(100, base64String.length))}");
        print("Base64 length: ${base64String.length}");
        print("Base64 image: $base64String");

        setState(() {
          _capturedImageBase64 = base64String; // Store the base64 string
        });
        await _posPrinterLibPlugin.printReceipt(base64String);

        // Verify the image starts with PNG header in base64
        if (!base64String.startsWith("iVBORw0KGgo")) {
          print(
              "Warning: Base64 string doesn't appear to be a valid PNG image");
        }
      }
    } catch (e) {
      print("Error capturing widget: $e");
    }
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Plugin printer example app'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            crossAxisAlignment: CrossAxisAlignment.center,
            children: [
              Text(
                  'Number of printers: $_numberOfPrinters \nHas permission: $_hasPermission'),
              RepaintBoundary(
                key: _repaintBoundaryKey,
                child: Container(
                  color: Colors.white,
                  padding: EdgeInsets.all(16),
                  width: 300,
                  child: Column(
                    mainAxisSize: MainAxisSize.min,
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Row(
                        mainAxisAlignment: MainAxisAlignment.spaceBetween,
                        children: [
                          Text(
                            'INVOICE',
                            style: TextStyle(
                              fontSize: 24,
                              fontWeight: FontWeight.bold,
                            ),
                          ),
                          Text(
                            '#INV-001',
                            style: TextStyle(
                              fontSize: 16,
                            ),
                          ),
                        ],
                      ),
                      SizedBox(height: 20),
                      Text(
                        'Date: ${DateTime.now().toString().split(' ')[0]}',
                        style: TextStyle(fontSize: 14),
                      ),
                      SizedBox(height: 20),
                      Table(
                        border: TableBorder.all(),
                        children: [
                          TableRow(
                            children: [
                              Padding(
                                padding: EdgeInsets.all(8),
                                child: Text('Item',
                                    style:
                                        TextStyle(fontWeight: FontWeight.bold)),
                              ),
                              Padding(
                                padding: EdgeInsets.all(8),
                                child: Text('Qty',
                                    style:
                                        TextStyle(fontWeight: FontWeight.bold)),
                              ),
                              Padding(
                                padding: EdgeInsets.all(8),
                                child: Text('Price',
                                    style:
                                        TextStyle(fontWeight: FontWeight.bold)),
                              ),
                            ],
                          ),
                          TableRow(
                            children: [
                              Padding(
                                padding: EdgeInsets.all(8),
                                child: Text('Item 1'),
                              ),
                              Padding(
                                padding: EdgeInsets.all(8),
                                child: Text('2'),
                              ),
                              Padding(
                                padding: EdgeInsets.all(8),
                                child: Text('\$10.00'),
                              ),
                            ],
                          ),
                        ],
                      ),
                      SizedBox(height: 20),
                      Row(
                        mainAxisAlignment: MainAxisAlignment.end,
                        children: [
                          Text(
                            'Total: \$20.00',
                            style: TextStyle(
                              fontSize: 18,
                              fontWeight: FontWeight.bold,
                            ),
                          ),
                        ],
                      ),
                    ],
                  ),
                ),
              ),
              ElevatedButton(
                style: ElevatedButton.styleFrom(
                  backgroundColor: Colors.greenAccent,
                ),
                onPressed: _captureWidget,
                child: Text("Print"),
              ),
              // if (_capturedImageBase64 != null)
              //   Image.memory(
              //     base64Decode(_capturedImageBase64!),
              //     height: 200,
              //   ),
            ],
          ),
        ),
      ),
    );
  }
}