adding packages

deprecated/flutter_midi/lib/flutter_midi.dart

@@ -0,0 +1,83 @@
+import 'dart:async';
+import 'dart:io';
+import 'package:flutter/foundation.dart';
+
+import 'package:flutter/services.dart';
+
+import 'src/cache.dart';
+import 'src/platform_interface.dart';
+
+class FlutterMidi extends FlutterMidiPlatform {
+  static const MethodChannel _channel = MethodChannel('flutter_midi');
+
+  /// Needed so that the sound font is loaded
+  /// On iOS make sure to include the sound_font.SF2 in the Runner folder.
+  /// This does not work in the simulator.
+  @override
+  Future<String?> prepare({
+    required ByteData? sf2,
+    String name = 'instrument.sf2',
+  }) async {
+    if (sf2 == null) return Future.value(null);
+    if (kIsWeb) return _channel.invokeMethod('prepare_midi');
+    File? _file = await writeToFile(sf2, name: name);
+    if (_file == null) return null;
+    return _channel.invokeMethod('prepare_midi', {'path': _file.path});
+  }
+
+  /// Needed so that the sound font is loaded
+  /// On iOS make sure to include the sound_font.SF2 in the Runner folder.
+  /// This does not work in the simulator.
+  @override
+  Future<String?> changeSound({
+    required ByteData? sf2,
+    String name = 'instrument.sf2',
+  }) async {
+    if (sf2 == null) return Future.value(null);
+    File? _file = await writeToFile(sf2, name: name);
+    if (_file == null) return null;
+
+    final Map<dynamic, dynamic> mapData = <dynamic, dynamic>{};
+    mapData['path'] = _file.path;
+    debugPrint('Path => ${_file.path}');
+    final String result = await _channel.invokeMethod('change_sound', mapData);
+    debugPrint('Result: $result');
+    return result;
+  }
+
+  /// Unmute the device temporarily even if the mute switch is on or toggled in settings.
+  @override
+  Future<String> unmute() async {
+    final String result = await _channel.invokeMethod('unmute');
+    return result;
+  }
+
+  /// Use this when stopping the sound onTouchUp or to cancel a long file.
+  /// Not needed if playing midi onTap.
+  /// Stop with velocity in the range between 0-127
+  @override
+  Future<String?> stopMidiNote({
+    required int midi,
+    int velocity = 64,
+  }) async {
+    return _channel.invokeMethod('stop_midi_note', {
+      'note': midi,
+      'velocity': velocity,
+    });
+  }
+
+  /// Play a midi note from the sound_font.SF2 library bundled with the application.
+  /// Play a midi note in the range between 0-127
+  /// Play with velocity in the range between 0-127
+  /// Multiple notes can be played at once as separate calls.
+  @override
+  Future<String?> playMidiNote({
+    required int midi,
+    int velocity = 64,
+  }) async {
+    return _channel.invokeMethod('play_midi_note', {
+      'note': midi,
+      'velocity': velocity,
+    });
+  }
+}