如何处理旧按钮

Question

CI'm试图使用cell[][]为使用cell JButton，boolean条件和坐标的网格编写Conway的生命游戏计划。我有一个方法可以创建cell个对象的新N x M网格。我可以很容易地把它变大，但是把它做得更小就是一个问题：旧的按钮保持原样。只是归零cell[][]不起作用。我应该用什么来处理旧按钮？

Upd8：一些代码

网格创建：

if(tfSizeX.getText().length() > 0 && tfSizeY.getText().length() > 0 && tfCellSize.getText().length() > 0)
{
    grid = null; // Cell[][] grid;
    int sizeGridX = Integer.parseInt(tfSizeX.getText());
    int sizeGridY = Integer.parseInt(tfSizeY.getText());
    int sizeCell = Integer.parseInt(tfCellSize.getText());
    grid = new Cell[sizeGridX][sizeGridY];
    for(int i = 0; i < sizeGridX; i++)
        for(int j = 0; j < sizeGridY; j++)
            grid[i][j] = new cell(i*(sizeCell+1), j*(sizeCell+1), panel, sizeCell);
    panel.repaint();
}

cell.java

public class Cell 
{
private JButton cell;
private boolean condition;
int locX, locY, size = 24;

public Cell(int locX, int locY, JPanel panel, int size)
{
    this.size = size;

    condition = false;
    cell = new JButton("");
    cell.addActionListener(new ActionListener() 
    {
        public void actionPerformed(ActionEvent arg0) 
        {
            if(!condition)
            {
                cell.setBackground(Color.black);
            }
            else
            {
                cell.setBackground(Color.white);
            }
            condition = !condition;
        }
    });
    cell.setBackground(Color.GRAY);
    cell.setBounds(locX, locY, size, size); 
    panel.add(cell);
    cell.setBackground(Color.white);
}

public void change(boolean condition)
{
    this.condition = condition;
    if(condition)
    {
        cell.setBackground(Color.black);
    }
    else
    {
        cell.setBackground(Color.white);
    }
}
}