如何在SWT GridLayout中替换网格单元格的内容？

import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;

public class GridLayoutExample {

    public static void main(String[] args) {
        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setText("GridLayout Example");
        shell.setLayout(new GridLayout(3, false));

        // 创建原始控件
        Label originalLabel = new Label(shell, SWT.NONE);
        originalLabel.setText("Original Label");
        originalLabel.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 1, 1));

        // 替换网格单元格内容
        Text newText = new Text(shell, SWT.NONE);
        newText.setText("New Text");
        GridData newTextGridData = new GridData(SWT.FILL, SWT.FILL, true, true, 1, 1);
        newTextGridData.horizontalSpan = 2; // 跨越两列
        newText.setLayoutData(newTextGridData);

        shell.pack();
        shell.open();

        while (!shell.isDisposed()) {
            if (!display.readAndDispatch()) {
                display.sleep();
            }
        }
        display.dispose();
    }
}