SWT Java Tutorial

Without FormAttachment objects, the control will be attached to the top-left edges of the parent composite by default.
Button will stack.

import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FormLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
public class FormLayoutFormAttachment {
  public static void main(String[] args) {
    Display display = new Display();
    final Shell shell = new Shell(display);
    shell.setLayout(new FormLayout());
    Button button1 = new Button(shell, SWT.PUSH);
    button1.setText("button1");
    Button button2 = new Button(shell, SWT.PUSH);
    button2.setText("button2");
    shell.setSize(450, 400);
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch()) {
        display.sleep();
      }
    }
    display.dispose();
  }
}