[教學] Come some of music !－一個小小工程師的心情抒發天地

package com.pcsetting.example;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Label;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.*;
import java.util.*;
import java.util.ArrayList;

import javax.sound.*;
import javax.sound.midi.ControllerEventListener;
import javax.sound.midi.MidiEvent;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.Sequence;
import javax.sound.midi.Sequencer;
import javax.sound.midi.ShortMessage;
import javax.sound.midi.Track;
import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.ScrollPaneConstants;

public class GameLauncher
{
   JPanel mainPanel;
   ArrayList<JCheckBox>checkboxList;
   Sequencer sequencer;
   Sequence sequence ;
   Track track;
   JFrame theFrame;

   String [] instrumentNames =
   {
           "Bass Drum","Closed Hi-Hat","Open Hi-Hat" ,"Acoustic snare" ,"Crash cymbal","Hand Clap",
           "Cowbell","Hi Bongo","Maracas","Whistle","Low Conga",
           "Cowbell","Vibraslap","Low-mid Tom","High Agogo",
           "Open Hi Conga"
   };

   int [] instruments = {35,42,46,38,49,39,50,60,70,72,64,56,58,47,67,63};

   public static void main(String[]args)
   {
       new GameLauncher().buildGUI();
   }
   public void buildGUI()
   {
       theFrame = new JFrame("Cyber BeatBox");
       theFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       BorderLayout layout = new BorderLayout();
       JPanel background = new JPanel(layout);
       background.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));

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

       JButton start = new JButton("Start");
       start.addActionListener(new MyStartListener());
       buttonBox.add(start);

       JButton Stop = new JButton("Stop");
       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);
       for (int i = 0; i < 16 ; i++)
       {
           nameBox.add(new Label(instrumentNames[i]));
       }

       background.add(BorderLayout.EAST,buttonBox);
       background.add(BorderLayout.WEST,nameBox);

       theFrame.getContentPane().add(background);

       GridLayout grid = new GridLayout(16,16);
       grid.setVgap(1);
       grid.setVgap(2);
       mainPanel = new JPanel(grid);
       background.add(BorderLayout.CENTER,mainPanel);

       for (int i = 0 ; i < 256 ; i++)
       {
           JCheckBox c = new JCheckBox();
           c.setSelected(false);
           checkboxList.add(c);
           mainPanel.add(c);
       }
       setUpMidi();

       theFrame.setBounds(50,50,300,300);
       theFrame.pack();
       theFrame.setVisible(true);
   }
   public void setUpMidi()
   {
       try
       {
           sequencer = MidiSystem.getSequencer();
           sequencer.open();
           sequence = new Sequence(Sequence.PPQ,4);
           track = sequence.createTrack();
           sequencer.setTempoInBPM(120);
       }
       catch(Exception e){e.printStackTrace();}
   }
   public void buildTrackAndStart()
   {
       int [] trackList = null;

       sequence.deleteTrack(track);
       track = sequence.createTrack();

       for (int i = 0 ; i< 16 ; i++)
       {
           trackList = new int[16];
           int key = instruments[i];

           for (int j = 0 ; j < 16 ;j++)
           {
               JCheckBox jc = (JCheckBox)checkboxList.get(j+(16*i));
               if(jc.isSelected())
               {
                   trackList[j] = key;
               }
               else
               {
                   trackList[j] = 0 ;
               }
           }
           makeTrack(trackList);
           track.add(makeEvent(176,1,127,0,16));
       }
       track.add(makeEvent(192,9,1,0,15));
       try{
           sequencer.setSequence(sequence);
           sequencer.setLoopCount(sequencer.LOOP_CONTINUOUSLY);
           sequencer.start();
           sequencer.setTempoInBPM(120);
       }catch(Exception e){e.printStackTrace();}
   }
   public class MyStartListener implements ActionListener
   {
       public void actionPerformed(ActionEvent ev)
       {
           buildTrackAndStart();
       }
   }
   public class MyStopListener implements ActionListener
   {
       public void actionPerformed(ActionEvent ev)
       {
           sequencer.stop();
       }
   }
   public class MyUpTempoListener implements ActionListener
   {
       public void actionPerformed(ActionEvent ev)
       {
           float tempoFactor = sequencer.getTempoFactor();
           sequencer.setTempoFactor((float)(tempoFactor * 1.03));
       }
   }
   public class MyDownTempoListener implements ActionListener
   {
       public void actionPerformed(ActionEvent ev)
       {
           float tempoFactor = sequencer.getTempoFactor();
           sequencer.setTempoFactor((float)(tempoFactor * .97));
       }
   }

   public void makeTrack(int [] list)
   {
       for (int i = 0 ;i<16 ;i++)
       {
           int key = list[i];
           if(key!=0)
           {
               track.add(makeEvent(144,9,key,100,i));
               track.add(makeEvent(128,9,key,100,i));
           }
       }
   }
   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;
   }
}