protected void paintComponent(Graphics g) {
    String shortcuts = pref.get("fields_shortcuts", "`1234567890qwertyuiopasdfghjkl");
    // paint fields
    Field ef = new Field(Field.EMPTY);
    Field[] fs = new Field[board.getData().getFields().length + 1];
    fs[0] = ef;
    System.arraycopy(board.getData().getFields(), 0, fs, 1, board.getData().getFields().length);
    // ef.paint(g,0,0,fieldW,fieldH);
    for (int i = 0; i < fs.length; i++) {
      Field f = fs[i];
      f.paint(g, i * fieldW, 0, fieldW, fieldH);

      // paint shortcuts
      if (i >= shortcuts.length()) continue;
      Color fieldColor =
          new Color(
              (f.getColor1().getRed() + f.getColor2().getRed()) / 2,
              (f.getColor1().getGreen() + f.getColor2().getGreen()) / 2,
              (f.getColor1().getBlue() + f.getColor2().getBlue()) / 2);
      if (Color.RGBtoHSB(fieldColor.getRed(), fieldColor.getGreen(), fieldColor.getBlue(), null)[2]
          < 0.5) {
        // dark background, bright color
        g.setColor(
            new Color(
                255 - descColor.getRed(), 255 - descColor.getGreen(), 255 - descColor.getBlue()));
      } else {
        // bright background, dark color
        g.setColor(descColor);
      }
      String str = Character.toString(shortcuts.charAt(i));

      int fontSize = (int) (fieldH * 0.5) + 1;
      int strWidth;

      Font font;
      do {
        fontSize--;
        font = new Font(Font.SERIF, Font.PLAIN, fontSize);
      } while ((strWidth = g.getFontMetrics().stringWidth(str)) > 0.9 * fieldW);

      g.setFont(font);
      g.drawString(str, i * fieldW + fieldW / 4 - strWidth / 2, fieldH / 4 + fontSize / 2);
    }

    // paint grid
    g.setColor(lineColor);
    int totalWidth = (board.getData().getFields().length + 1) * fieldW;
    for (int i = 0; i < board.getData().getFields().length + 2; i++) {
      g.drawLine(i * fieldW, 0, i * fieldW, fieldH);
    }
    g.drawLine(0, 0, totalWidth, 0);
    g.drawLine(0, fieldH, totalWidth, fieldH);
  }
  public FieldsList(GriddlerBoard b) {
    board = b;
    pref = MyPreferences.getInstance();
    lineColor = new Color(pref.getInt("lineColor", new Color(0x33, 0x33, 0x33).getRGB()));
    descColor = new Color(pref.getInt("lineColor", new Color(0x00, 0x00, 0x00).getRGB()));

    fieldW = 20;
    fieldH = 20;

    b.getData()
        .addGriddlerDataListener(
            new GriddlerDataListener() {
              public void fieldChanged(int x, int y) {}

              public void fieldsListChanged() {
                setSize(getPreferredSize());
                repaint();
              }

              public void descChanged() {}
            });
    addMouseListener(
        new MouseAdapter() {
          public void mouseClicked(MouseEvent e) {
            // position of mouse in fields
            int x = (int) Math.floor((float) e.getX() / fieldW);
            x--;
            if (e.getButton() == e.BUTTON1) board.setLeftColor(x);
            else if (e.getButton() == e.BUTTON2) board.setMiddleColor(x);
            else if (e.getButton() == e.BUTTON3) board.setRightColor(x);

            if (e.getClickCount() == 2) {
              FieldsManager.getInstance(board.getData(), x);
            }
          }
        });
  }