file_launcher 0.1.0

Open local files with native viewers on iOS and Android, with a share-sheet fallback and no storage permissions.

example/lib/main.dart

import 'dart:io';
import 'package:file_launcher/file_launcher.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'samples.dart';

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

class FileLauncherExample extends StatelessWidget {
  const FileLauncherExample({super.key});
  @override
  Widget build(BuildContext context) => MaterialApp(
    debugShowCheckedModeBanner: false,
    title: 'File launcher',
    theme: ThemeData(
      colorScheme: ColorScheme.fromSeed(seedColor: const Color(0xff087f72)),
      scaffoldBackgroundColor: const Color(0xfff4f7fa),
      useMaterial3: true,
    ),
    home: const SamplePage(),
  );
}

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

class _SamplePageState extends State<SamplePage> {
  String _status = 'Choose a sample to open on this device.';
  String _category = 'All';
  OpenFileResult? _result;
  bool _busy = false;
  Future<Directory>? _directory;

  Future<void> _open(FileSample sample, {bool missing = false}) async {
    setState(() {
      _busy = true;
      _result = null;
      _status = 'Preparing ${sample.label.toLowerCase()}…';
    });
    try {
      final directory = await (_directory ??= Directory.systemTemp.createTemp(
        'file_launcher_example_',
      ));
      final file = File('${directory.path}/${sample.name}');
      if (!missing) {
        final bytes = await rootBundle.load('assets/${sample.name}');
        await file.writeAsBytes(
          bytes.buffer.asUint8List(bytes.offsetInBytes, bytes.lengthInBytes),
        );
      }
      final watch = Stopwatch()..start();
      final result = await FileLauncher.open(
        file.path,
        title: sample.label,
        mimeType: sample.mimeType,
      );
      if (mounted) {
        setState(() {
          _result = result;
          _status =
              '${result.status.name} · ${watch.elapsedMilliseconds} ms\n${result.message}';
        });
      }
    } catch (error) {
      if (mounted) {
        setState(() => _status = 'Could not prepare sample: $error');
      }
    } finally {
      if (mounted) {
        setState(() => _busy = false);
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    final visible = fileSamples
        .where((sample) => _category == 'All' || sample.category == _category)
        .toList();
    return Scaffold(
      appBar: AppBar(
        backgroundColor: const Color(0xfff4f7fa),
        title: const Text(
          'file_launcher',
          style: TextStyle(fontWeight: FontWeight.w800, fontSize: 20),
        ),
        actions: const [
          Padding(
            padding: EdgeInsets.only(right: 20),
            child: Chip(
              label: Text('EXAMPLE'),
              visualDensity: VisualDensity.compact,
            ),
          ),
        ],
      ),
      body: Center(
        child: ConstrainedBox(
          constraints: const BoxConstraints(maxWidth: 900),
          child: ListView(
            padding: const EdgeInsets.fromLTRB(20, 8, 20, 28),
            children: [
              Container(
                padding: const EdgeInsets.all(24),
                decoration: BoxDecoration(
                  gradient: const LinearGradient(
                    colors: [Color(0xff102f40), Color(0xff096d66)],
                    begin: Alignment.topLeft,
                    end: Alignment.bottomRight,
                  ),
                  borderRadius: BorderRadius.circular(24),
                ),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    const Text(
                      'LOCAL FILES. NATIVE EXPERIENCES.',
                      style: TextStyle(
                        color: Color(0xff8debd3),
                        fontSize: 10,
                        fontWeight: FontWeight.w700,
                        letterSpacing: 1.5,
                      ),
                    ),
                    const SizedBox(height: 12),
                    const Text(
                      'One call.\nOpen possibilities.',
                      style: TextStyle(
                        color: Colors.white,
                        fontSize: 32,
                        fontWeight: FontWeight.w800,
                        height: 1.1,
                      ),
                    ),
                    const SizedBox(height: 14),
                    const Text(
                      'Documents, audio, video and images.\nTry a real file on your device.',
                      style: TextStyle(
                        color: Color(0xffd1e4e9),
                        fontSize: 14,
                        height: 1.5,
                      ),
                    ),
                    const SizedBox(height: 18),
                    Wrap(
                      spacing: 8,
                      runSpacing: 8,
                      children: [
                        for (final label in [
                          'iOS + Android',
                          '${fileSamples.length} samples',
                          'No storage prompts',
                        ])
                          Container(
                            padding: const EdgeInsets.symmetric(
                              horizontal: 10,
                              vertical: 6,
                            ),
                            decoration: BoxDecoration(
                              color: Colors.white.withValues(alpha: .1),
                              borderRadius: BorderRadius.circular(20),
                            ),
                            child: Text(
                              label,
                              style: const TextStyle(
                                color: Colors.white,
                                fontSize: 11,
                              ),
                            ),
                          ),
                      ],
                    ),
                  ],
                ),
              ),
              const SizedBox(height: 18),
              Container(
                padding: const EdgeInsets.all(16),
                decoration: BoxDecoration(
                  color: Colors.white,
                  borderRadius: BorderRadius.circular(16),
                  border: Border.all(color: const Color(0xffdce5ea)),
                ),
                child: Row(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Icon(
                      _result == null
                          ? Icons.touch_app_outlined
                          : _result!.isSuccess
                          ? Icons.check_circle_outline
                          : Icons.info_outline,
                      color: const Color(0xff087f72),
                    ),
                    const SizedBox(width: 12),
                    Expanded(
                      child: Text(
                        _status,
                        key: const Key('status'),
                        style: const TextStyle(fontSize: 13, height: 1.5),
                      ),
                    ),
                  ],
                ),
              ),
              if (_busy) const LinearProgressIndicator(),
              const SizedBox(height: 24),
              const Text(
                'Explore file types',
                style: TextStyle(
                  fontSize: 21,
                  fontWeight: FontWeight.w800,
                  color: Color(0xff102f40),
                ),
              ),
              const SizedBox(height: 10),
              SingleChildScrollView(
                scrollDirection: Axis.horizontal,
                child: Row(
                  children: [
                    for (final category in [
                      'All',
                      'Documents',
                      'Audio',
                      'Video',
                      'Images',
                      'Data',
                      'Other',
                    ])
                      Padding(
                        padding: const EdgeInsets.only(right: 8),
                        child: ChoiceChip(
                          label: Text(category),
                          selected: _category == category,
                          onSelected: (_) =>
                              setState(() => _category = category),
                        ),
                      ),
                  ],
                ),
              ),
              const SizedBox(height: 12),
              for (final sample in visible)
                Padding(
                  padding: const EdgeInsets.only(bottom: 9),
                  child: Material(
                    color: Colors.white,
                    borderRadius: BorderRadius.circular(16),
                    child: ListTile(
                      shape: RoundedRectangleBorder(
                        borderRadius: BorderRadius.circular(16),
                      ),
                      contentPadding: const EdgeInsets.symmetric(
                        horizontal: 14,
                        vertical: 5,
                      ),
                      leading: Container(
                        width: 42,
                        height: 46,
                        decoration: BoxDecoration(
                          color: const Color(0xffe8f5f0),
                          borderRadius: BorderRadius.circular(12),
                        ),
                        child: Icon(
                          sample.icon,
                          color: const Color(0xff087f72),
                        ),
                      ),
                      title: Text(
                        sample.label,
                        style: const TextStyle(
                          fontSize: 14,
                          fontWeight: FontWeight.w700,
                        ),
                      ),
                      subtitle: Text(
                        '${sample.name} · ${sample.detail}',
                        style: const TextStyle(
                          fontSize: 11,
                          color: Color(0xff5c7180),
                        ),
                      ),
                      trailing: const Icon(
                        Icons.north_east,
                        size: 18,
                        color: Color(0xff087f72),
                      ),
                      onTap: _busy ? null : () => _open(sample),
                    ),
                  ),
                ),
              const SizedBox(height: 10),
              const Text(
                'iOS uses Quick Look. Android uses an installed viewer. When no viewer is available, the system share sheet is the fallback. Close native UI before opening another sample.',
                style: TextStyle(
                  fontSize: 12,
                  height: 1.5,
                  color: Color(0xff5c7180),
                ),
              ),
              TextButton(
                onPressed: _busy
                    ? null
                    : () => _open(
                        const FileSample(
                          'missing.pdf',
                          'Missing file',
                          'Other',
                          '',
                          Icons.error_outline,
                        ),
                        missing: true,
                      ),
                child: const Text('Test a missing file'),
              ),
            ],
          ),
        ),
      ),
    );
  }
}