code: /*
   * Computoser is a music-composition algorithm and a website to present the results
   * Copyright (C) 2012-2014  Bozhidar Bozhanov
   *
   * Computoser is free software: you can redistribute it and/or modify
   * it under the terms of the GNU Affero General Public License as
   * published by the Free Software Foundation, either version 3 of the
   * License, or (at your option) any later version.
   *
   * Computoser is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU Affero General Public License for more details.
   *
   * You should have received a copy of the GNU Affero General Public License
   * along with Computoser.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package com.music.tools;
  
  import java.awt.Color;
  import java.awt.Graphics;
  import java.io.File;
  import java.io.FileReader;
  import java.io.Reader;
  import java.util.ArrayList;
  import java.util.List;
  
  import javax.swing.JFrame;
  import javax.swing.JPanel;
  
  import org.xml.sax.InputSource;
  import org.xml.sax.XMLReader;
  import org.xml.sax.helpers.XMLReaderFactory;
  
  import com.music.tools.SongDBAnalyzer.NoteContentHandler;
  
  
  public class SongChart {
  
      public static void main(String[] args) throws Exception {
          File file = new File("C:\\workspace\\music\\analysis\\db\\" + "21.xml");
  
          XMLReader xr = XMLReaderFactory.createXMLReader();
          NoteContentHandler handler = new NoteContentHandler();
          xr.setContentHandler(handler);
          try (Reader reader = new FileReader(file)) {
              try {
                  xr.parse(new InputSource(reader));
              } catch (Exception ex) {
                  System.out.println(file.getName());
                  throw ex;
              }
          }
          List<NoteElement> noteList = handler.getNotes();
          List<Integer> pitches = new ArrayList<Integer>();
          for (NoteElement element : noteList) {
              if (element != null && !element.isRest()) {
                  pitches.add(60 + element.getScaleDegree() + element.getOctave() * 7);
              }
          }
  
          JFrame frame = new JFrame();
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          frame.setBounds(0, 0, 500, 500);
          frame.setVisible(true);
          GraphicsPanel gp = new GraphicsPanel(pitches);
          frame.setContentPane(gp);
      }
  
      public static class GraphicsPanel extends JPanel {
          private List<Integer> notes;
          public GraphicsPanel(List<Integer> notes) {
              this.notes = notes;
          }
  
          @Override
          protected void paintComponent(Graphics g) {
              Integer previousNote = null;
              int currentX = 20;
              g.setColor(Color.RED);
              for (Integer note : notes) {
                  if (previousNote == null) {
                      previousNote = note;
                      continue;
                  }
                  g.drawLine(currentX - 20, (80 - previousNote) * 4, currentX, (80 - note) * 4);
                  previousNote = note;
                  currentX += 20;
              }
          }
      }
  }
  