import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
import jm.music.data.Note;
import jm.music.data.Phrase;
import jm.util.View;

/**
 A utility for recording MIDI music using the keyboard.  Users hit keys
 a-g to generate a note of duration proportional to the amount of time the
 key is held down.  Simultaneously holding Shift creates a sharp, while Alt
 creates a flat.  To go up an octave, hold the first mouse button down.

 This code was written hastily during a workshop.  Be forewarned.
 */
public class Keyboard extends JFrame implements KeyListener {

   private char currNote;
   private double start;
   private double duration;
   private Phrase phrase;
   private int delta;
   private int offset;
   private int[] frequencies = { 57, 59, 60, 62, 64, 65, 67,
                                 69, 71, 72, 74, 76, 77, 79 };

   public static void main(String[] args) {
      Keyboard frame = new Keyboard();
   }

   public Keyboard() {
      addKeyListener(this);
      requestFocusInWindow();
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      setSize(400, 400);
      setVisible(true);
      phrase = new Phrase();
   }

   @Override
   public void keyPressed(KeyEvent e) {
      currNote = e.getKeyChar();
      start = System.currentTimeMillis();

      if ((e.getModifiers() & KeyEvent.SHIFT_MASK) > 0) {
         delta = 1;
      } else if ((e.getModifiers() & KeyEvent.ALT_MASK) > 0) {
         delta = -1;
      } else {
         delta = 0;
      }
      
      if ((e.getModifiersEx() & KeyEvent.BUTTON1_DOWN_MASK) > 0) {
         offset = 7;
      } else {
         offset = 0;
      }
      currNote = Character.toLowerCase(currNote);
      
      if (currNote == 'q') {
         View.notate(phrase);
      }
   }

   @Override
   public void keyReleased(KeyEvent e) {
      if (currNote >= 'a' && currNote <= 'g') {
         duration = System.currentTimeMillis() - start;
         int frequency = frequencies[offset + (currNote - 'a')];
         phrase.addNote(new Note(frequency + delta, duration / 500.0));
      }
   }

   @Override
   public void keyTyped(KeyEvent arg0) {
   }
}