1: /* ContainerEvent.java -- components added/removed from a container 2: Copyright (C) 1999, 2002, 2005 Free Software Foundation, Inc. 3: 4: This file is part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: 39: package java.awt.event; 40: 41: import java.awt.Component; 42: import java.awt.Container; 43: 44: /** 45: * This event is generated when a component is added or removed from a 46: * container. Applications do not ordinarily need to handle these events 47: * since the AWT system handles them internally. 48: * 49: * @author Aaron M. Renn (arenn@urbanophile.com) 50: * @see ContainerAdapter 51: * @see ContainerListener 52: * @since 1.1 53: * @status updated to 1.4 54: */ 55: public class ContainerEvent extends ComponentEvent 56: { 57: /** 58: * Compatible with JDK 1.1+. 59: */ 60: private static final long serialVersionUID = -4114942250539772041L; 61: 62: /** This is the first id in the id range used by this class. */ 63: public static final int CONTAINER_FIRST = 300; 64: 65: /** This is the last id in the id range used by this class. */ 66: public static final int CONTAINER_LAST = 301; 67: 68: /** This id indicates a component was added to the container. */ 69: public static final int COMPONENT_ADDED = 300; 70: 71: /** This id indicates a component was removed from the container. */ 72: public static final int COMPONENT_REMOVED = 301; 73: 74: /** 75: * The non-null child component that was added or removed. 76: * 77: * @serial the child component that changed 78: */ 79: private final Component child; 80: 81: /** 82: * Initializes a new instance of <code>ContainerEvent</code> with the 83: * specified source and id. Additionally, the affected child component 84: * is also passed as a parameter. Note that an invalid id leads to 85: * unspecified results. 86: * 87: * @param source the source container of the event 88: * @param id the event id 89: * @param child the child component affected by this event 90: * @throws IllegalArgumentException if source is null 91: */ 92: public ContainerEvent(Component source, int id, Component child) 93: { 94: super(source, id); 95: this.child = child; 96: } 97: 98: /** 99: * Returns the source of this event as a <code>Container</code>. 100: * 101: * @return the source of the event 102: * @throws ClassCastException if the source is changed to a non-Container 103: */ 104: public Container getContainer() 105: { 106: return (Container) source; 107: } 108: 109: /** 110: * This method returns the child object that was added or removed from 111: * the container. 112: * 113: * @return the child object added or removed 114: */ 115: public Component getChild() 116: { 117: return child; 118: } 119: 120: /** 121: * This method returns a string identifying this event. It is formatted as: 122: * <code>(getID() == COMPONENT_ADDED ? "COMPONENT_ADDED" 123: * : "COMPONENT_REMOVED") + ",child=" + getChild().getName()</code>. 124: * 125: * @return a string identifying this event 126: */ 127: public String paramString() 128: { 129: // Unlike Sun, we don't throw NullPointerException if child is illegally 130: // null. 131: return (id == COMPONENT_ADDED ? "COMPONENT_ADDED,child=" 132: : id == COMPONENT_REMOVED ? "COMPONENT_REMOVED,child=" 133: : "unknown type,child=") + (child == null ? "" : child.getName()); 134: } 135: } // class ContainerEvent