Java tutorial
/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved. * * The contents of this file are subject to the terms of either the GNU * General Public License Version 2 only ("GPL") or the Common * Development and Distribution License("CDDL") (collectively, the * "License"). You may not use this file except in compliance with the * License. You can obtain a copy of the License at * http://www.netbeans.org/cddl-gplv2.html * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the * specific language governing permissions and limitations under the * License. When distributing the software, include this License Header * Notice in each file and include the License file at * nbbuild/licenses/CDDL-GPL-2-CP. Sun designates this * particular file as subject to the "Classpath" exception as provided * by Sun in the GPL Version 2 section of the License file that * accompanied this code. If applicable, add the following below the * License Header, with the fields enclosed by brackets [] replaced by * your own identifying information: * "Portions Copyrighted [year] [name of copyright owner]" * * Contributor(s): * * The Original Software is NetBeans. The Initial Developer of the Original * Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun * Microsystems, Inc. All Rights Reserved. * * If you wish your version of this file to be governed by only the CDDL * or only the GPL Version 2, indicate your decision by adding * "[Contributor] elects to include this software in this distribution * under the [CDDL or GPL Version 2] license." If you do not indicate a * single choice of license, a recipient has the option to distribute * your version of this file under either the CDDL, the GPL Version 2 or * to extend the choice of license to its licensees as provided above. * However, if you add GPL Version 2 code and therefore, elected the GPL * Version 2 license, then the option applies only if the new code is * made subject to such option by the copyright holder. */ import java.awt.Component; import java.awt.Container; import java.awt.Dimension; import java.awt.Insets; import java.awt.LayoutManager; import java.lang.ref.WeakReference; import javax.swing.JComponent; /** * Special simple layout used in TabbedContainer. Shows component in the * "stack", it means that only one component is visible at any time, others are * always hidden "below" the visible one. Use method showComponent to select * visible component. * * @author Dafe Simonek */ class StackLayout implements LayoutManager { // #100486 - hold visibleComp weakly, because removeLayoutComponent may not // be called and then visibleComp is not freed. See StackLayoutTest for details. /** * Holds currently visible component or null if no comp is visible */ private WeakReference<Component> visibleComp = null; /** * Set the currently displayed component. If passed null for the component, * all contained components will be made invisible (sliding windows do this) * @param c Component to show * @param parent Parent container */ public void showComponent(Component c, Container parent) { Component comp = getVisibleComponent(); if (comp != c) { if (!parent.isAncestorOf(c) && c != null) { parent.add(c); } synchronized (parent.getTreeLock()) { if (comp != null) { comp.setVisible(false); } visibleComp = new WeakReference<Component>(c); if (c != null) { c.setVisible(true); } // trigger re-layout if (c instanceof JComponent) { ((JComponent) c).revalidate(); } else { parent.validate(); //XXX revalidate should work! } } } } /** Allows support for content policies * @return Currently visible component or null */ public Component getVisibleComponent() { return visibleComp == null ? null : visibleComp.get(); } /** * ********** Implementation of LayoutManager interface ********* */ public void addLayoutComponent(String name, Component comp) { synchronized (comp.getTreeLock()) { comp.setVisible(false); // keep consistency if showComponent was already called on this // component before if (comp == getVisibleComponent()) { visibleComp = null; } /*System.out.println("Border dump for " + comp.getName()); borderDump((javax.swing.JComponent)comp, "");*/ } } /*private void borderDump (javax.swing.JComponent comp, String space) { javax.swing.border.Border compBorder = comp.getBorder(); if (compBorder == null) { System.out.println(space + comp.getClass().getName() + " has no border."); } else { System.out.println(space + comp.getClass().getName() + ": " + compBorder.getClass().getName()); } Component curComp; for (int i = 0; i < comp.getComponentCount(); i++) { curComp = comp.getComponent(i); if (curComp instanceof javax.swing.JComponent) { borderDump((javax.swing.JComponent)curComp, space + " "); } } }*/ public void removeLayoutComponent(Component comp) { synchronized (comp.getTreeLock()) { if (comp == getVisibleComponent()) { visibleComp = null; } // kick out removed component as visible, so that others // don't have problems with hidden components comp.setVisible(true); } } public void layoutContainer(Container parent) { Component visibleComp = getVisibleComponent(); if (visibleComp != null) { synchronized (parent.getTreeLock()) { Insets insets = parent.getInsets(); visibleComp.setBounds(insets.left, insets.top, parent.getWidth() - (insets.left + insets.right), parent.getHeight() - (insets.top + insets.bottom)); } } } public Dimension minimumLayoutSize(Container parent) { return getEmptySize(); } public Dimension preferredLayoutSize(Container parent) { return getEmptySize(); } /** * Specifies default size of empty container */ private static Dimension getEmptySize() { return new Dimension(50, 50); } }