Java SE (Java Platform, Standard Edition)

The JButton will hold full cell in JTable, how to implement JButton hold only half a cell ??

such as following image.
http://www.500images.com/uploads/1460253590output.png

import java.awt.Component;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.DefaultCellEditor;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.UIManager;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableCellRenderer;


public class JButtonTableExample extends JFrame {

  public JButtonTableExample() {
    super("JButtonTable Example");

    DefaultTableModel dm = new DefaultTableModel();
    dm.setDataVector(new Object[][] { { "button 1", "foo" },
        { "button 2", "bar" } }, new Object[] { "Button", "String" });

    JTable table = new JTable(dm);
    table.getColumn("Button").setCellRenderer(new ButtonRenderer());
    table.getColumn("Button").setCellEditor(
        new ButtonEditor(new JCheckBox()));
    JScrollPane scroll = new JScrollPane(table);
    getContentPane().add(scroll);
    setSize(400, 100);
    setVisible(true);
  }

  public static void main(String[] args) {


    JButtonTableExample frame = new JButtonTableExample();
    frame.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
  }
}


class ButtonRenderer extends JButton implements TableCellRenderer {

  public ButtonRenderer() {
    setOpaque(true);
  }

  public Component getTableCellRendererComponent(JTable table, Object value,
      boolean isSelected, boolean hasFocus, int row, int column) {
    if (isSelected) {
      setForeground(table.getSelectionForeground());
      setBackground(table.getSelectionBackground());
    } else {
      setForeground(table.getForeground());
      setBackground(UIManager.getColor("Button.background"));
    }
    setText((value == null) ? "" : value.toString());
    return this;
  }
}


class ButtonEditor extends DefaultCellEditor {
  protected JButton button;

  private String label;

  private boolean isPushed;

  public ButtonEditor(JCheckBox checkBox) {
    super(checkBox);
    button = new JButton();
    button.setOpaque(true);
    button.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        fireEditingStopped();
      }
    });
  }

  public Component getTableCellEditorComponent(JTable table, Object value,
      boolean isSelected, int row, int column) {
    if (isSelected) {
      button.setForeground(table.getSelectionForeground());
      button.setBackground(table.getSelectionBackground());
    } else {
      button.setForeground(table.getForeground());
      button.setBackground(table.getBackground());
    }
    label = (value == null) ? "" : value.toString();
    button.setText(label);
    isPushed = true;
    return button;
  }

  public Object getCellEditorValue() {
    if (isPushed) {
      //
      //
      JOptionPane.showMessageDialog(button, label + ": Ouch!");
      // System.out.println(label + ": Ouch!");
    }
    isPushed = false;
    return new String(label);
  }

  public boolean stopCellEditing() {
    isPushed = false;
    return super.stopCellEditing();
  }

  protected void fireEditingStopped() {
    super.fireEditingStopped();
  }
}