import java.awt.*;
import javax.swing.*;
import javax.sound.midi.*;
import java.util.*;
import java.awt.event.*;


public class BeatBoxApplet extends JApplet {     

    JPanel mainPanel;
    ArrayList checkboxList;
    int bpm = 120;
    Sequencer sequencer;
    Sequence sequence;
    Track track;
    int numTicks;
    static final int NUM_INSTRUMENTS=18;

    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",  
       	"Low-mid Tom", 
       	"High Agogo", 
        "Open Hi Conga", 
       	"Low Bongo", 
       	"Low Floor Tom", 
       	"Tambourine" };
    int[] instruments = {35,42,46,38,49,39,50,60,70,72,64,56,47,67,63,61,41,54};
    
    JButton[] instrumentButtons;

    public void init() { 

        Container container = getContentPane();  //dfw
       
        BorderLayout layout = new BorderLayout();
        JPanel background = new JPanel(layout);
        background.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));

        checkboxList = new ArrayList();
        Box buttonBox = new Box(BoxLayout.Y_AXIS);

       
        JButton start = new JButton("ReStart Loop");
        start.addActionListener(new MyStartListener());
        buttonBox.add(start);         
         
        JLabel dummyLabel2 = new JLabel(".");
        buttonBox.add(dummyLabel2);
         
        JButton stop = new JButton("Stop sound");
        stop.addActionListener(new MyStopListener());
        buttonBox.add(stop);

 /*       JButton upTempo = new JButton("Tempo Up");
        upTempo.addActionListener(new MyUpTempoListener());
        buttonBox.add(upTempo);

        JButton downTempo = new JButton("Tempo Down");
        downTempo.addActionListener(new MyDownTempoListener());
        buttonBox.add(downTempo);
*/
        Box nameBox = new Box(BoxLayout.Y_AXIS);
        //JLabel dummyLabel = new JLabel("Tick#");
        //nameBox.add(dummyLabel);
        instrumentButtons = new JButton[NUM_INSTRUMENTS+1];
        for (int i = 0; i < NUM_INSTRUMENTS; i++) {
              instrumentButtons[i] = new JButton(instrumentNames[i]);
              instrumentButtons[i].addActionListener(new InstrumentButtonListener());
              nameBox.add(instrumentButtons[i]);
        }
     
        background.add(BorderLayout.EAST, buttonBox);
        background.add(BorderLayout.WEST, nameBox);

        container.add(background);   //dfw
        
        String input = JOptionPane.showInputDialog("Number of ticks per loop","16");   
        numTicks = Integer.parseInt(input);
        
        GridLayout grid = new GridLayout(NUM_INSTRUMENTS+1,numTicks);
        grid.setVgap(1);
        grid.setHgap(2);
        mainPanel = new JPanel(grid);
        background.add(BorderLayout.CENTER, mainPanel);
   
        //for (int i = 1; i <= numTicks; i++) {     //first row of grid               
          //  JLabel c = new JLabel(""+i);
          //  mainPanel.add(c);            
        //} 
        	
        for (int i=0; i<NUM_INSTRUMENTS*numTicks; i++) {   
            JCheckBox c = new JCheckBox();
            c.setSelected(false);
            checkboxList.add(c);
            mainPanel.add(c);            
        } 
    
        setUpMidi();

    } 


     public void setUpMidi() {
       try {
        sequencer = MidiSystem.getSequencer();
        sequencer.open();
        sequence = new Sequence(Sequence.PPQ,4);
        track = sequence.createTrack();
        sequencer.setTempoInBPM(bpm);
       } catch(Exception e) {e.printStackTrace();}
    } 


     public void buildTrackAndStart() {
        int[] trackList = null;
    
        sequence.deleteTrack(track);
        track = sequence.createTrack();
        //track.add(makeEvent(192,10,1,0,0)); // be sure drums are set

        // now loop through and make an event on and off
        // for each thing that's checked
       for (int i = 0; i < NUM_INSTRUMENTS; i++) {
          trackList = new int[numTicks];
 
          int key = instruments[i];   

          for (int j = 0; j < numTicks; j++ ) {         
              JCheckBox jc = (JCheckBox) checkboxList.get(j + (numTicks*i));
              if ( jc.isSelected()) {
                 trackList[j] = key;
              } else {
                 trackList[j] = 0;
              }                    
           } 
         
           makeTracks(trackList);
       } 

       track.add(makeEvent(192,9,1,0,numTicks));    //event in last tick, else skips to start  
       try {
           
           sequencer.setSequence(sequence);                    
           sequencer.setLoopCount(Sequencer.LOOP_CONTINUOUSLY );  //DFW
           sequencer.start();
           sequencer.setTempoInBPM(bpm);

       } catch(Exception e) {e.printStackTrace();}
    } 
            
    public void makeTracks(int[] list) {        
       
       for (int i = 0; i < numTicks; i++) {
          int key = list[i];

          if (key != 0) {
             track.add(makeEvent(144,9,key, 100, i));
             track.add(makeEvent(128,9,key, 100, i+1));
          }
       }
    }
        
    public  MidiEvent makeEvent(int comd, int chan, int one, int two, int tick) {
        MidiEvent event = null;
        try {
            ShortMessage a = new ShortMessage();
            a.setMessage(comd, chan, one, two);
            event = new MidiEvent(a, tick);
            
            } catch(Exception e) {e.printStackTrace(); }
        return event;
    }


           
    public class MyStartListener implements ActionListener {
        public void actionPerformed(ActionEvent a) {
            buildTrackAndStart();
        }
    } 

    public class MyStopListener implements ActionListener {
        public void actionPerformed(ActionEvent a) {
            sequencer.stop();
           // instrument_sequencer.stop();
        }
    } 

/*    public class MyUpTempoListener implements ActionListener {
        public void actionPerformed(ActionEvent a) {
            bpm += 3;          
        }
     } 

     public class MyDownTempoListener implements ActionListener {
         public void actionPerformed(ActionEvent a) {
             bpm -= 3;
        }
    } 
*/
    public class InstrumentButtonListener implements ActionListener {
         public void actionPerformed(ActionEvent a) {
             
             sequence.deleteTrack(track);
             track = sequence.createTrack();

                 for (int i = 0; i < NUM_INSTRUMENTS; i++)      //which instrument button pressed
             	     if ( a.getSource() == instrumentButtons[i] ) {
                        try {
                            ShortMessage a1 = new ShortMessage();
                            a1.setMessage(144, 9, instruments[i], 100);
                            MidiEvent noteOn = new MidiEvent(a1, 1); 
                           // instrument_track.add(noteOn);
                            track.add(noteOn);

                            ShortMessage b = new ShortMessage();
                            b.setMessage(128, 9, instruments[i], 100);
                            MidiEvent noteOff = new MidiEvent(b, 2); 
                            //instrument_track.add(noteOff);
                            track.add(noteOff);
        
                             sequencer.setSequence(sequence);
                            sequencer.setLoopCount(Sequencer.LOOP_CONTINUOUSLY ); 
                            sequencer.start();

                      } catch (Exception ex) {ex.printStackTrace();}             		
             	
             	      break;  //out of for loop
             }
        }
    } 
    
}