flutter_midi_pro

The flutter_midi_pro plugin provides functions for loading SoundFont (.sf2) files, as well as playing and stopping MIDI notes.

Installation

To use this plugin, add flutter_midi_pro as a dependency in your pubspec.yaml file. For example:

dependencies:
  flutter_midi_pro: ^1.0.0

Usage

Import flutter_midi_pro.dart and use the MidiPro class to access the plugin's functions.

import 'package:flutter_midi_pro/flutter_midi_pro.dart';

Create a MidiPro Variable

final _midiPro = MidiPro();

Load SoundFont File

Use the loadSoundfont function to load a SoundFont file with optional ByteData and a specified name.

final String _path = 'assets/tight_piano.sf2';
Future loadSoundfont(String asset) async {
    ByteData byte = await rootBundle.load(asset);
    _midiPro.loadSoundfont(
    sf2Data: byte, name: _path.replaceAll('assets/', ''));
    }

Play MIDI Note

Use the playMidiNote function to play a MIDI note with a given MIDI value and velocity.

play(int midi, {int velocity = 127}) {
    _midiPro.playMidiNote(midi: midi, velocity: velocity);
  }

Stop MIDI Note

Use the stopMidiNote function to stop a MIDI note with a given MIDI number and velocity.

void stop(int midi) {
    _midiPro.stopMidiNote(midi: midi);
  }

Example

Here's an example of how you could use the flutter_midi_pro plugin to play a piano using a SoundFont file and using the flutter_piano_pro:

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_midi_pro/flutter_midi_pro.dart';
import 'package:flutter_piano_pro/flutter_piano_pro.dart';
import 'package:flutter_piano_pro/note_model.dart';

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

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

class _MyAppState extends State<MyApp> {
  final _midiPro = MidiPro();
  final String _value = 'assets/tight_piano.sf2';
  Map<int, NoteModel> pointerAndNote = {};

  Future<void> load(String asset) async {
    ByteData byte = await rootBundle.load(asset);
    _midiPro.loadSoundfont(
        sf2Data: byte, name: _value.replaceAll('assets/', ''));
  }

  void play(int midi, {int velocity = 127}) {
    _midiPro.playMidiNote(midi: midi, velocity: velocity);
  }

  void stop(int midi) {
    _midiPro.stopMidiNote(midi: midi);
  }

  @override
  void initState() {
    load(_value);
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Flutter Midi Pro Example'),
        ),
        body: Center(
            child: Column(
          crossAxisAlignment: CrossAxisAlignment.center,
          mainAxisSize: MainAxisSize.min,
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            PianoPro(
              noteCount: 15,
              onTapDown: (NoteModel? note, int tapId) {
                if (note == null) return;
                play(note.midiNoteNumber);
                setState(() => pointerAndNote[tapId] = note);
              },
              onTapUpdate: (NoteModel? note, int tapId) {
                if (note == null) return;
                if (pointerAndNote[tapId] == note) return;
                stop(pointerAndNote[tapId]!.midiNoteNumber);
                play(note.midiNoteNumber);
                pointerAndNote[tapId] = note;
              },
              onTapUp: (int tapId) {
                stop(pointerAndNote[tapId]!.midiNoteNumber);
                pointerAndNote.remove(tapId);
              },
            )
          ],
        )),
      ),
    );
  }
}

Contributions

Contributions are welcome! Please feel free to submit a PR or open an issue.

Contact

If you have any questions or suggestions, feel free to contact the package maintainer, Melih Hakan Pektas, via email or through GitHub.

Melih Hakan Pektas

Thank you for contributing to flutter_piano_pro!

License

This project is licensed under the MIT License. See the LICENSE file for details.