svs 0.2.0

Streams and renders Aperio SVS whole-slide pathology images: pan/zoom, LOD tile streaming, JPEG & JPEG2000, no full-image load.

example/lib/main.dart

import 'dart:async';

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

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

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'svs example',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.teal),
      ),
      home: const SvsViewerPage(),
    );
  }
}

/// Enter the path to a local .svs (or tiled TIFF) file and view it with
/// pan/zoom, a minimap, and a physical scale bar — everything `SvsImageView`
/// provides out of the box.
///
/// For a full-featured demo app (file picker, associated-image previews,
/// metadata inspector), see https://github.com/kiu-chan/svs_example.
class SvsViewerPage extends StatefulWidget {
  const SvsViewerPage({super.key});

  @override
  State<SvsViewerPage> createState() => _SvsViewerPageState();
}

class _SvsViewerPageState extends State<SvsViewerPage> {
  final _pathController = TextEditingController();
  SvsFile? _svsFile;
  String? _error;
  bool _loading = false;

  @override
  void dispose() {
    _pathController.dispose();
    unawaited(_svsFile?.close());
    super.dispose();
  }

  Future<void> _open() async {
    final path = _pathController.text.trim();
    if (path.isEmpty) return;

    setState(() => _loading = true);
    final previous = _svsFile;
    try {
      final svsFile = await SvsFile.open(path);
      await previous?.close();
      setState(() {
        _svsFile = svsFile;
        _error = null;
        _loading = false;
      });
    } catch (e) {
      setState(() {
        _error = '$e';
        _loading = false;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('svs example')),
      body: Column(
        children: [
          Padding(
            padding: const EdgeInsets.all(12),
            child: Row(
              children: [
                Expanded(
                  child: TextField(
                    controller: _pathController,
                    decoration: const InputDecoration(
                      labelText: 'Path to a .svs file',
                      border: OutlineInputBorder(),
                    ),
                    onSubmitted: (_) => _open(),
                  ),
                ),
                const SizedBox(width: 12),
                FilledButton(
                  onPressed: _loading ? null : _open,
                  child: const Text('Open'),
                ),
              ],
            ),
          ),
          Expanded(child: _buildBody()),
        ],
      ),
    );
  }

  Widget _buildBody() {
    if (_loading) return const Center(child: CircularProgressIndicator());
    final error = _error;
    if (error != null) {
      return Center(
        child: Padding(
          padding: const EdgeInsets.all(24),
          child: Text(error, textAlign: TextAlign.center),
        ),
      );
    }
    final svsFile = _svsFile;
    if (svsFile == null) {
      return const Center(child: Text('Enter a path above and tap Open.'));
    }
    return SvsImageView(svsFile: svsFile);
  }
}