| /* |
| * Copyright (c) 1996, 2008, 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.event; |
| |
| import java.awt.Container; |
| import java.awt.Component; |
| |
| /** |
| * A low-level event which indicates that a container's contents |
| * changed because a component was added or removed. |
| * <P> |
| * Container events are provided for notification purposes ONLY; |
| * The AWT will automatically handle changes to the containers |
| * contents internally so that the program works properly regardless of |
| * whether the program is receiving these events or not. |
| * <P> |
| * This low-level event is generated by a container object (such as a |
| * Panel) when a component is added to it or removed from it. |
| * The event is passed to every <code>ContainerListener</code> |
| * or <code>ContainerAdapter</code> object which registered to receive such |
| * events using the component's <code>addContainerListener</code> method. |
| * (<code>ContainerAdapter</code> objects implement the |
| * <code>ContainerListener</code> interface.) Each such listener object |
| * gets this <code>ContainerEvent</code> when the event occurs. |
| * <p> |
| * An unspecified behavior will be caused if the {@code id} parameter |
| * of any particular {@code ContainerEvent} instance is not |
| * in the range from {@code CONTAINER_FIRST} to {@code CONTAINER_LAST}. |
| * |
| * @see ContainerAdapter |
| * @see ContainerListener |
| * @see <a href="http://java.sun.com/docs/books/tutorial/post1.0/ui/containerlistener.html">Tutorial: Writing a Container Listener</a> |
| * |
| * @author Tim Prinzing |
| * @author Amy Fowler |
| * @since 1.1 |
| */ |
| public class ContainerEvent extends ComponentEvent { |
| |
| /** |
| * The first number in the range of ids used for container events. |
| */ |
| public static final int CONTAINER_FIRST = 300; |
| |
| /** |
| * The last number in the range of ids used for container events. |
| */ |
| public static final int CONTAINER_LAST = 301; |
| |
| /** |
| * This event indicates that a component was added to the container. |
| */ |
| public static final int COMPONENT_ADDED = CONTAINER_FIRST; |
| |
| /** |
| * This event indicates that a component was removed from the container. |
| */ |
| public static final int COMPONENT_REMOVED = 1 + CONTAINER_FIRST; |
| |
| /** |
| * The non-null component that is being added or |
| * removed from the Container. |
| * |
| * @serial |
| * @see #getChild() |
| */ |
| Component child; |
| |
| /* |
| * JDK 1.1 serialVersionUID |
| */ |
| private static final long serialVersionUID = -4114942250539772041L; |
| |
| /** |
| * Constructs a <code>ContainerEvent</code> object. |
| * <p> This method throws an |
| * <code>IllegalArgumentException</code> if <code>source</code> |
| * is <code>null</code>. |
| * |
| * @param source The <code>Component</code> object (container) |
| * that originated the event |
| * @param id An integer indicating the type of event. |
| * For information on allowable values, see |
| * the class description for {@link ContainerEvent} |
| * @param child the component that was added or removed |
| * @throws IllegalArgumentException if <code>source</code> is null |
| * @see #getContainer() |
| * @see #getID() |
| * @see #getChild() |
| */ |
| public ContainerEvent(Component source, int id, Component child) { |
| super(source, id); |
| this.child = child; |
| } |
| |
| /** |
| * Returns the originator of the event. |
| * |
| * @return the <code>Container</code> object that originated |
| * the event, or <code>null</code> if the object is not a |
| * <code>Container</code>. |
| */ |
| public Container getContainer() { |
| return (source instanceof Container) ? (Container)source : null; |
| } |
| |
| /** |
| * Returns the component that was affected by the event. |
| * |
| * @return the Component object that was added or removed |
| */ |
| public Component getChild() { |
| return child; |
| } |
| |
| /** |
| * Returns a parameter string identifying this event. |
| * This method is useful for event-logging and for debugging. |
| * |
| * @return a string identifying the event and its attributes |
| */ |
| public String paramString() { |
| String typeStr; |
| switch(id) { |
| case COMPONENT_ADDED: |
| typeStr = "COMPONENT_ADDED"; |
| break; |
| case COMPONENT_REMOVED: |
| typeStr = "COMPONENT_REMOVED"; |
| break; |
| default: |
| typeStr = "unknown type"; |
| } |
| return typeStr + ",child="+child.getName(); |
| } |
| } |