Here you can find the source of compositeRequestFocus(Component component)
public static Component compositeRequestFocus(Component component)
//package com.java2s; /*/*from ww w .j a v a2 s . c o m*/ * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ import java.awt.*; import javax.swing.*; public class Main { public static Component compositeRequestFocus(Component component) { if (component instanceof Container) { Container container = (Container) component; if (container.isFocusCycleRoot()) { FocusTraversalPolicy policy = container.getFocusTraversalPolicy(); Component comp = policy.getDefaultComponent(container); if (comp != null) { comp.requestFocus(); return comp; } } Container rootAncestor = container.getFocusCycleRootAncestor(); if (rootAncestor != null) { FocusTraversalPolicy policy = rootAncestor.getFocusTraversalPolicy(); Component comp = policy.getComponentAfter(rootAncestor, container); if (comp != null && SwingUtilities.isDescendingFrom(comp, container)) { comp.requestFocus(); return comp; } } } if (component.isFocusable()) { component.requestFocus(); return component; } return null; } }