package BeatBox;


public class BeatBox {
    GUI gui;
    Midi midi;

    public BeatBox(){
        midi = new Midi();
        gui = new GUI(midi);
        midi.setUpMidi();
    }

    public static void main(String[] args) {
        new BeatBox();
    }
}

package BeatBox;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;

public class GUI {
    private Midi midi;

    public GUI(Midi midi){
        this.midi = midi;
        buildGUI();
    }

    // buildGUI - creates the GUI for the beat box program
    void buildGUI(){
        JFrame frame = new JFrame("Cyber BeatBox");
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.setMinimumSize(new Dimension(600, 350));
        JPanel panel = new JPanel(new BorderLayout());
        panel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
        frame.setContentPane(panel);

        // Instrument names
        Box nameBox = new Box(BoxLayout.Y_AXIS);
        for(int i = 0; i < BeatBoxConstants.NUM_INSTRUMENTS; i++){
            nameBox.add(new Label(BeatBoxConstants.instrumentNames[i]));
        }

        // Check box
        GridLayout grid = new GridLayout(16, 16);
        grid.setVgap(0);
        grid.setHgap(2);
        JPanel checkBoxPanel = new JPanel(grid);
        for(int i = 0; i < BeatBoxConstants.NUM_INSTRUMENTS; i++){
            for(int j = 0; j < BeatBoxConstants.NUM_BEATS; j++) {
                JCheckBox checkBox = new JCheckBox();
                checkBoxPanel.add(checkBox);
                midi.checkBoxArray[i][j] = checkBox;
            }
        }

        // Buttons
        JPanel buttonsPanel = new JPanel();
        buttonsPanel.setLayout(new BoxLayout(buttonsPanel, BoxLayout.Y_AXIS));
        JButton startButton = new JButton("Start");
        JButton pauseButton = new JButton("Pause");

        startButton.addActionListener(new StartButtonListener());
        pauseButton.addActionListener(new GUI.PauseButtonListener());

        buttonsPanel.add(startButton);
        buttonsPanel.add(pauseButton);

        // Add everything to the frame
        frame.add(BorderLayout.WEST, nameBox);
        frame.add(BorderLayout.CENTER, checkBoxPanel);
        frame.add(BorderLayout.EAST, buttonsPanel);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    // LISTENERS
    private class StartButtonListener implements ActionListener{
        @Override
        public void actionPerformed(ActionEvent ev){
            midi.buildTrackAndStart();
            midi.startSequencer();
        }
    }

    private class PauseButtonListener implements ActionListener{
        @Override
        public void actionPerformed(ActionEvent ev){
            midi.pauseSequencer();
        }
    }
}

package BeatBox;

import javax.sound.midi.*;
import javax.swing.JCheckBox;

public class Midi {
    private Sequencer sequencer;
    private Sequence seq;
    private Track track;
    JCheckBox[][] checkBoxArray = new JCheckBox[BeatBoxConstants.NUM_INSTRUMENTS][BeatBoxConstants.NUM_BEATS];

    // buildTrackAndStart - used to create and begin playing the newly created track
    void buildTrackAndStart(){
        try {
            seq.deleteTrack(track);
            track = seq.createTrack();
            makeTrack();
            sequencer.setSequence(seq);
            sequencer.setLoopCount(Sequencer.LOOP_CONTINUOUSLY);
        }catch(InvalidMidiDataException invalidMidiDataException){
            invalidMidiDataException.printStackTrace();
        }
    }

    // makeBeat - this creates the noteOn and noteOff beats
    private void makeBeat(int key, int tick) throws InvalidMidiDataException{
        track.add(makeEvent(144, 9, key, 100, tick));
        track.add(makeEvent(128, 9, key, 100, tick + 2));
    }

    // makeEvent - creates the notes for the track
    private MidiEvent makeEvent(int comd, int chan, int one, int two, int tick) throws InvalidMidiDataException{
        ShortMessage a = new ShortMessage();
        a.setMessage(comd, chan, one, two);
        return new MidiEvent(a, tick);
    }

    // makeTrack - creates the sound track based on the check boxes selected by the user
    private void makeTrack() throws InvalidMidiDataException{
        for(int i = 0; i < BeatBoxConstants.NUM_INSTRUMENTS; i++){
            for(int j = 0; j < BeatBoxConstants.NUM_BEATS; j++){
                if(checkBoxArray[i][j].isSelected()){
                    makeBeat(BeatBoxConstants.instruments[i], j);
                }
            }
        }
        // Added to ensure that beat box completes the whole 16 beats before it loops again
        track.add(makeEvent(192, 9, 1, 0, BeatBoxConstants.NUM_BEATS - 1));
    }

    // setUpMidi - this sets up the sound system for the user to edit
    void setUpMidi(){
        try {
            sequencer = MidiSystem.getSequencer();
            sequencer.open();
            seq = new Sequence(Sequence.PPQ, 4);
            track = seq.createTrack();
        }catch(InvalidMidiDataException invalidMidiDataException){
            invalidMidiDataException.printStackTrace();
        }catch(MidiUnavailableException midiUnavailableException){
            midiUnavailableException.printStackTrace();
        }
    }

    // startSequencer - starts playing the sequencer
    void startSequencer(){
        sequencer.start();
    }

    // pauseSequencer - pauses the sequencer. This does not stop the sound, rather it pauses it.
    void pauseSequencer(){
        sequencer.stop();
    }
}

package BeatBox;

public class BeatBoxConstants {
    static final String[] instrumentNames = {"Bass Drum", "Closed Hi-Hat", "Open Hi-Hat", "Acoustic Snare", "Crash Cymbal",
            "Hand Clap", "High Tom",  "Hi Bongo", "Maracas", "Whistle", "Low Conga", "Cowbell", "Vibraslap", "Low-mid Tom",
            "High Agogo", "Open Hi Conga"};
    static final int[] instruments = {35, 42, 46, 38, 49, 39, 50, 60, 70, 72, 64, 56, 58, 47, 67, 63};

    static final int NUM_BEATS = 16;
    static final int NUM_INSTRUMENTS = instrumentNames.length;
}