Android Print Service #

Flutter plugin to print documents on Android devices using native print service.
This plugin supports both sharing documents while the app is running and when the app is closed.

Features #

• Receive documents shared from other apps.
• Preview received files inside your Flutter app.
• Works on Android with proper system alert window permission.

Installation #

Add this to your pubspec.yaml:

dependencies:
  android_printer_service: ^0.0.1

Demo #

[Android Print Service Demo]

Usage #

Below is a concise example showing how to handle shared documents and preview them:

import 'dart:async';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:android_printer_service/android_printer_service.dart';
import 'package:permission_handler/permission_handler.dart';

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

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  // Subscription to listen for documents shared while app is in memory
  late StreamSubscription<PrintFile?> _subscription;

  // Store path of received file
  String pathFile = '';

  @override
  void initState() {
    super.initState();
    // Wait until first frame is rendered
    WidgetsBinding.instance.addPostFrameCallback((_) {
      // Request permission for system alert window (needed on Android)
      _requestSystemAlertPermission();

      // Delay a bit then start listening for shared documents
      Future.delayed(const Duration(milliseconds: 320), _listenSharedDocs);
    });
  }

  // Listen to documents shared while app is running and get initial document if app was closed
  void _listenSharedDocs() {
    _subscription = ForwardPrinter.getDocumentStream().listen(_onFileReceived);
    ForwardPrinter.getInitialDocument().then(_onFileReceived);
  }

  // Handle received file
  void _onFileReceived(PrintFile? file) {
    if (file?.path != null) {
      setState(() {
        pathFile = file!.path; // Update UI with received file path
      });
    }
  }

  // Request Android system alert window permission if not granted
  Future<void> _requestSystemAlertPermission() async {
    if (!Platform.isAndroid) return; // Only needed on Android
    final status = await Permission.systemAlertWindow.status;
    if (status != PermissionStatus.granted && context.mounted) {
      Future.delayed(
        const Duration(milliseconds: 150),
        () async => await Permission.systemAlertWindow.request(),
      );
    }
  }

  @override
  void dispose() {
    _subscription.cancel(); // Cancel stream subscription to prevent memory leaks
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Android Print Service Demo')),
      body: Center(
        child: pathFile.isEmpty
            ? const Text('No file received') // Show message if no file
            : Text('Received file: $pathFile'), // Display received file path
      ),
    );
  }
}