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

public class Noodirakend6 extends JApplet implements ActionListener, MetaEventListener{
  Sequence sequence;
  Sequencer sequencer;
  JButton nupp=new JButton("Mängi");
  JCheckBox ruut=new JCheckBox("Korda");
  
  public void init(){
    try{
       ShortMessage lahti = new ShortMessage();
         ShortMessage kinni = new ShortMessage();
         ShortMessage algus = new ShortMessage();
         algus.setMessage(ShortMessage.PROGRAM_CHANGE, 0, 16, 0);
         lahti.setMessage(ShortMessage.NOTE_ON, 0, 65, 93);
         kinni.setMessage(ShortMessage.NOTE_OFF, 0, 65, 93);
         sequence=new Sequence(Sequence.PPQ, 4);
         Track track=sequence.createTrack();
         track.add(new MidiEvent(algus, 0));
         track.add(new MidiEvent(lahti, 0));
         track.add(new MidiEvent(kinni, 4));
         track.add(new MidiEvent(lahti, 8));
         track.add(new MidiEvent(kinni, 11));
         track.add(new MidiEvent(lahti, 12));
         track.add(new MidiEvent(kinni, 15));
         track.add(new MidiEvent(lahti, 16));
         track.add(new MidiEvent(kinni, 31));    
         
         getContentPane().add(nupp, BorderLayout.SOUTH);
         getContentPane().add(ruut, BorderLayout.NORTH);
         nupp.addActionListener(this);
      }catch(Exception e){e.printStackTrace();}
  }

  public void actionPerformed(ActionEvent e){
   try{
         sequencer=MidiSystem.getSequencer();
         sequencer.open();
         sequencer.setSequence(sequence);
         sequencer.addMetaEventListener(this);
         sequencer.start();
   }catch(Exception ex){
     ex.printStackTrace();
     System.out.println(ex);
   }
  }
  
  public void meta(MetaMessage m){
    if(m.getType()==47 && ruut.isSelected()){
      sequencer.start();
    } else {
      sequencer.close();
    }
  }
}


/**
* MetaEventListenerile saadetakse rajalt saabuvad meta-tüüpi teated.
* Üheks selliseks on ka raja lõpp (teade koodiga 47). Et lugu taas otsast algaks
* tuleb sekventserile öelda start. Muul juhul aga vabastab close() muusikaressursid
* teiste programmide tarvis. 
*/