Here you can find the source of decorate(final Window w)
public static void decorate(final Window w)
//package com.java2s; //License from project: Open Source License import java.awt.Dimension; import java.awt.Image; import java.awt.Toolkit; import java.awt.Window; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import java.util.ArrayList; import java.util.List; import javax.swing.JComponent; import javax.swing.JDialog; import javax.swing.KeyStroke; public class Main { private final static List<Image> ICONS = new ArrayList<Image>(); public static void decorate(final Window w) { center(w);//from w w w .ja v a2 s . com setIcon(w); } public static void decorate(final JDialog d, boolean closeOnEscape) { center(d); setIcon(d); if (closeOnEscape) { addEscapeListener(d); } } private static void center(Window w) { Dimension windowSize = w.getSize(); Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); int x = (screenSize.width - windowSize.width) / 2; int y = (screenSize.height - windowSize.height) / 2; w.setLocation(x, y); } private static void setIcon(Window w) { w.setIconImages(ICONS); } public static void addEscapeListener(final JDialog d) { ActionListener al = new ActionListener() { public void actionPerformed(ActionEvent e) { d.setVisible(false); } }; d.getRootPane().registerKeyboardAction(al, KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0), JComponent.WHEN_IN_FOCUSED_WINDOW); } }