Java Code:
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;

public class Snippet4 {

  public static void main(String[] args) {
    Display display = new Display();
    final Shell shell = new Shell(display);
    Button b = new Button(shell, SWT.PUSH);
    b.setText("Open Dialog ...");
    b.pack();
    b.setLocation(10, 10);
    b.addSelectionListener(new SelectionAdapter() {
      public void widgetSelected(SelectionEvent se) {
        Shell dialog = new Shell(shell, SWT.DIALOG_TRIM);
        dialog.addListener(SWT.Traverse, new Listener() {
          public void handleEvent(Event e) {
            if (e.detail == SWT.TRAVERSE_ESCAPE) {
              e.doit = false;
            }
          }
        });
        dialog.open();
      }
    });
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }

}