| /* |
| * Copyright (c) 1995, 2015, 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. |
| */ |
| package java.awt; |
| |
| import javax.accessibility.*; |
| |
| /** |
| * {@code Panel} is the simplest container class. A panel |
| * provides space in which an application can attach any other |
| * component, including other panels. |
| * <p> |
| * The default layout manager for a panel is the |
| * {@code FlowLayout} layout manager. |
| * |
| * @author Sami Shaio |
| * @see java.awt.FlowLayout |
| * @since 1.0 |
| */ |
| public class Panel extends Container implements Accessible { |
| private static final String base = "panel"; |
| private static int nameCounter = 0; |
| |
| /* |
| * JDK 1.1 serialVersionUID |
| */ |
| private static final long serialVersionUID = -2728009084054400034L; |
| |
| /** |
| * Creates a new panel using the default layout manager. |
| * The default layout manager for all panels is the |
| * {@code FlowLayout} class. |
| */ |
| public Panel() { |
| this(new FlowLayout()); |
| } |
| |
| /** |
| * Creates a new panel with the specified layout manager. |
| * @param layout the layout manager for this panel. |
| * @since 1.1 |
| */ |
| public Panel(LayoutManager layout) { |
| setLayout(layout); |
| } |
| |
| /** |
| * Construct a name for this component. Called by getName() when the |
| * name is null. |
| */ |
| String constructComponentName() { |
| synchronized (Panel.class) { |
| return base + nameCounter++; |
| } |
| } |
| |
| /** |
| * Creates the Panel's peer. The peer allows you to modify the |
| * appearance of the panel without changing its functionality. |
| */ |
| |
| public void addNotify() { |
| synchronized (getTreeLock()) { |
| if (peer == null) |
| peer = getComponentFactory().createPanel(this); |
| super.addNotify(); |
| } |
| } |
| |
| ///////////////// |
| // Accessibility support |
| //////////////// |
| |
| /** |
| * Gets the AccessibleContext associated with this Panel. |
| * For panels, the AccessibleContext takes the form of an |
| * AccessibleAWTPanel. |
| * A new AccessibleAWTPanel instance is created if necessary. |
| * |
| * @return an AccessibleAWTPanel that serves as the |
| * AccessibleContext of this Panel |
| * @since 1.3 |
| */ |
| public AccessibleContext getAccessibleContext() { |
| if (accessibleContext == null) { |
| accessibleContext = new AccessibleAWTPanel(); |
| } |
| return accessibleContext; |
| } |
| |
| /** |
| * This class implements accessibility support for the |
| * {@code Panel} class. It provides an implementation of the |
| * Java Accessibility API appropriate to panel user-interface elements. |
| * @since 1.3 |
| */ |
| protected class AccessibleAWTPanel extends AccessibleAWTContainer { |
| |
| private static final long serialVersionUID = -6409552226660031050L; |
| |
| /** |
| * Get the role of this object. |
| * |
| * @return an instance of AccessibleRole describing the role of the |
| * object |
| */ |
| public AccessibleRole getAccessibleRole() { |
| return AccessibleRole.PANEL; |
| } |
| } |
| |
| } |