Here you can find the source of getFrameSize(Component c)
public static Dimension getFrameSize(Component c)
//package com.java2s; /*//from w ww.j a v a 2 s . c o m * Copyright (c) 2002 and later by MH Software-Entwicklung. All Rights Reserved. * * JTattoo is multiple licensed. If your are an open source developer you can use * it under the terms and conditions of the GNU General Public License version 2.0 * or later as published by the Free Software Foundation. * * see: gpl-2.0.txt * * If you pay for a license you will become a registered user who could use the * software under the terms and conditions of the GNU Lesser General Public License * version 2.0 or later with classpath exception as published by the Free Software * Foundation. * * see: lgpl-2.0.txt * see: classpath-exception.txt * * Registered users could also use JTattoo under the terms and conditions of the * Apache License, Version 2.0 as published by the Apache Software Foundation. * * see: APACHE-LICENSE-2.0.txt */ import javax.swing.*; import java.awt.*; public class Main { public static Dimension getFrameSize(Component c) { Container parent = getRootContainer(c); if (parent != null) { return parent.getSize(); } return Toolkit.getDefaultToolkit().getScreenSize(); } public static Container getRootContainer(Component c) { if (c == null) { return null; } Container parent = c.getParent(); while ((parent != null) && !(parent instanceof JPopupMenu) && !(parent instanceof JInternalFrame) && !(parent instanceof Window) && (parent.getParent() != null)) { parent = parent.getParent(); } return parent; } }