import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
public class MainClass {
public static void main(String[] a) {
Display d = new Display();
Shell s = new Shell(d);
s.setSize(500,500);
s.open();
ChildShell cs = new ChildShell(s);
while(!s.isDisposed()){
if(!d.readAndDispatch())
d.sleep();
}
d.dispose();
}
}
class ChildShell {
ChildShell(Shell parent){
Shell child = new Shell(parent);
child.setSize(200,200);
child.open();
}
}