Swing/InterIdeographJustify のバックアップ(No.7)

class InterIdeographJustifyCellRenderer implements TableCellRenderer {
  private final JustifiedLabel l = new JustifiedLabel();
  @Override public Component getTableCellRendererComponent(
      JTable table, Object value, boolean selected, boolean focused,
      int row, int column) {
    l.setBorder(BorderFactory.createEmptyBorder(0, 5, 0, 5));
    l.setText(Objects.toString(value, ""));
    return l;
  }
}

class JustifiedLabel extends JLabel {
  private transient TextLayout layout;
  private int prevWidth = -1;
  public JustifiedLabel() {
    this(null);
  }

  public JustifiedLabel(String str) {
    super(str);
  }

  @Override public void setText(String text) {
    super.setText(text);
    prevWidth = -1;
  }

  @Override protected void paintComponent(Graphics g) {
    Graphics2D g2 = (Graphics2D) g.create();
    Font font = getFont();
    Insets ins = getInsets();
    Dimension d = getSize();
    int w = d.width - ins.left - ins.right;
    if (w != prevWidth) {
      prevWidth = w;
      String s = getText();
      TextLayout tl = new TextLayout(s, font, g2.getFontRenderContext());
      layout = tl.getJustifiedLayout((float) w);
    }
    g2.setPaint(getBackground());
    g2.fillRect(0, 0, d.width, d.height);
    g2.setPaint(getForeground());
    int baseline = ins.top + font.getSize();
    layout.draw(g2, (float) ins.left, (float) baseline);
    g2.dispose();
  }
}