feat(web): add Web MIDI API support

lib/flutter_midi_command_web.dart

@@ -0,0 +1,229 @@
+import 'dart:async';
+import 'dart:js_interop';
+import 'dart:js_interop_unsafe';
+import 'dart:typed_data';
+import 'package:flutter_web_plugins/flutter_web_plugins.dart';
+import 'package:flutter_midi_command_platform_interface/flutter_midi_command_platform_interface.dart';
+import 'package:web/web.dart' as web;
+
+@JS('Array.from')
+external JSArray _jsArrayFrom(JSObject obj);
+
+class FlutterMidiCommandWeb extends MidiCommandPlatform {
+  static void registerWith(Registrar registrar) {
+    MidiCommandPlatform.instance = FlutterMidiCommandWeb();
+  }
+
+  web.MIDIAccess? _midiAccess;
+  final _rxStreamController = StreamController<MidiPacket>.broadcast();
+  final _setupStreamController = StreamController<String>.broadcast();
+  final _bluetoothStateStreamController = StreamController<String>.broadcast();
+
+  Future<void> _initMidi() async {
+    if (_midiAccess != null) return;
+    try {
+      final promise = web.window.navigator.requestMIDIAccess(web.MIDIOptions(sysex: true));
+      _midiAccess = await promise.toDart;
+
+      _midiAccess?.onstatechange = (web.Event event) {
+        _setupStreamController.add("deviceFound");
+      }.toJS;
+    } catch (e) {
+      print("Failed to initialize Web MIDI: $e");
+    }
+  }
+
+  List<T> _getMapValues<T extends JSObject>(JSObject mapObject) {
+    final valuesIterator = mapObject.callMethod('values'.toJS);
+    if (valuesIterator == null) return [];
+    final jsArray = _jsArrayFrom(valuesIterator as JSObject);
+
+    final list = <T>[];
+    for (int i = 0; i < jsArray.length; i++) {
+      final item = jsArray.getProperty(i.toJS);
+      if (item != null) {
+        list.add(item as T);
+      }
+    }
+    return list;
+  }
+
+  @override
+  Future<List<MidiDevice>?> get devices async {
+    await _initMidi();
+    final access = _midiAccess;
+    if (access == null) return [];
+
+    final list = <MidiDevice>[];
+
+    // Read inputs
+    final inputs = _getMapValues<web.MIDIInput>(access.inputs);
+    for (final input in inputs) {
+      final device = MidiDevice(
+        input.id,
+        input.name ?? 'Unknown Input',
+        'web',
+        input.connection == 'open',
+      );
+      device.inputPorts.add(MidiPort(0, MidiPortType.IN));
+      list.add(device);
+    }
+
+    // Read outputs
+    final outputs = _getMapValues<web.MIDIOutput>(access.outputs);
+    for (final output in outputs) {
+      final device = MidiDevice(
+        output.id,
+        output.name ?? 'Unknown Output',
+        'web',
+        output.connection == 'open',
+      );
+      device.outputPorts.add(MidiPort(0, MidiPortType.OUT));
+      list.add(device);
+    }
+
+    return list;
+  }
+
+  @override
+  Future<void> connectToDevice(MidiDevice device, {List<MidiPort>? ports}) async {
+    await _initMidi();
+    final access = _midiAccess;
+    if (access == null) return;
+
+    // Search in inputs
+    final inputs = _getMapValues<web.MIDIInput>(access.inputs);
+    final input = inputs.where((i) => i.id == device.id).firstOrNull;
+    if (input != null) {
+      await input.open().toDart;
+
+      input.onmidimessage = (web.Event event) {
+        final messageEvent = event as web.MIDIMessageEvent;
+        final jsData = messageEvent.data;
+        if (jsData != null) {
+          final dartData = jsData.toDart;
+          final activeDevice = MidiDevice(device.id, device.name, device.type, true);
+          activeDevice.inputPorts.add(MidiPort(0, MidiPortType.IN));
+          _rxStreamController.add(MidiPacket(
+            dartData,
+            messageEvent.timeStamp.toInt(),
+            activeDevice,
+          ));
+        }
+      }.toJS;
+
+      device.connected = true;
+      _setupStreamController.add("deviceConnected");
+      return;
+    }
+
+    // Search in outputs
+    final outputs = _getMapValues<web.MIDIOutput>(access.outputs);
+    final output = outputs.where((o) => o.id == device.id).firstOrNull;
+    if (output != null) {
+      await output.open().toDart;
+      device.connected = true;
+      _setupStreamController.add("deviceConnected");
+      return;
+    }
+  }
+
+  @override
+  void disconnectDevice(MidiDevice device) {
+    final access = _midiAccess;
+    if (access == null) return;
+
+    final inputs = _getMapValues<web.MIDIInput>(access.inputs);
+    final input = inputs.where((i) => i.id == device.id).firstOrNull;
+    if (input != null) {
+      input.onmidimessage = null;
+      input.close();
+      device.connected = false;
+      _setupStreamController.add("deviceDisconnected");
+      return;
+    }
+
+    final outputs = _getMapValues<web.MIDIOutput>(access.outputs);
+    final output = outputs.where((o) => o.id == device.id).firstOrNull;
+    if (output != null) {
+      output.close();
+      device.connected = false;
+      _setupStreamController.add("deviceDisconnected");
+      return;
+    }
+  }
+
+  @override
+  void sendData(Uint8List data, {int? timestamp, String? deviceId}) {
+    final access = _midiAccess;
+    if (access == null) return;
+
+    final outputs = _getMapValues<web.MIDIOutput>(access.outputs);
+    final JSArray<JSNumber> jsData = data.map((b) => b.toJS).toList().toJS;
+
+    if (deviceId != null) {
+      final output = outputs.where((o) => o.id == deviceId).firstOrNull;
+      if (output != null && output.connection == 'open') {
+        output.send(jsData);
+      }
+    } else {
+      for (final output in outputs) {
+        if (output.connection == 'open') {
+          output.send(jsData);
+        }
+      }
+    }
+  }
+
+  @override
+  void teardown() {
+    final access = _midiAccess;
+    if (access == null) return;
+
+    final inputs = _getMapValues<web.MIDIInput>(access.inputs);
+    for (final input in inputs) {
+      input.onmidimessage = null;
+      input.close();
+    }
+
+    final outputs = _getMapValues<web.MIDIOutput>(access.outputs);
+    for (final output in outputs) {
+      output.close();
+    }
+  }
+
+  @override
+  Stream<MidiPacket>? get onMidiDataReceived => _rxStreamController.stream;
+
+  @override
+  Stream<String>? get onMidiSetupChanged => _setupStreamController.stream;
+
+  @override
+  Stream<String>? get onBluetoothStateChanged => _bluetoothStateStreamController.stream;
+
+  @override
+  Future<void> startBluetoothCentral() async {
+    _bluetoothStateStreamController.add("unsupported");
+  }
+
+  @override
+  Future<String> bluetoothState() async => "unsupported";
+
+  @override
+  Future<void> startScanningForBluetoothDevices() async {}
+
+  @override
+  void stopScanningForBluetoothDevices() {}
+
+  @override
+  void addVirtualDevice({String? name}) {}
+
+  @override
+  void removeVirtualDevice({String? name}) {}
+
+  @override
+  Future<bool?> get isNetworkSessionEnabled async => false;
+
+  @override
+  void setNetworkSessionEnabled(bool enabled) {}
+}

pubspec.yaml

@@ -14,6 +14,9 @@ dependencies:
   flutter_midi_command_platform_interface: ^0.4.1
   flutter_midi_command_linux: ^0.3.0
   flutter_midi_command_windows: ^0.3.0
+  flutter_web_plugins:
+    sdk: flutter
+  web: ^1.1.0
 
 dev_dependencies:
   flutter_test:
@@ -40,4 +43,7 @@ flutter:
       linux:
         default_package: flutter_midi_command_linux
       windows:
-        default_package: flutter_midi_command_windows
+        default_package: flutter_midi_command_windows
+      web:
+        pluginClass: FlutterMidiCommandWeb
+        fileName: flutter_midi_command_web.dart