1 /* FocusEvent.java -- generated for a focus change 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 43 /** 44 * This class represents an event generated when a focus change occurs for a 45 * component. There are both temporary changes, such as when focus is stolen 46 * during a sroll then returned, and permanent changes, such as when the user 47 * TABs through focusable components. 48 * 49 * @author Aaron M. Renn (arenn@urbanophile.com) 50 * @see FocusAdapter 51 * @see FocusListener 52 * @since 1.1 53 * @status updated to 1.4 54 */ 55 public class FocusEvent extends ComponentEvent 56 { 57 /** 58 * Compatible with JDK 1.1+. 59 */ 60 private static final long serialVersionUID = 523753786457416396L; 61 62 /** This is the first id in the range of ids used by this class. */ 63 public static final int FOCUS_FIRST = 1004; 64 65 /** This is the last id in the range of ids used by this class. */ 66 public static final int FOCUS_LAST = 1005; 67 68 /** This is the event id for a focus gained event. */ 69 public static final int FOCUS_GAINED = 1004; 70 71 /** This is the event id for a focus lost event. */ 72 public static final int FOCUS_LOST = 1005; 73 74 /** 75 * Indicates whether or not the focus change is temporary. 76 * 77 * @see #isTemporary() 78 * @serial true if the focus change is temporary 79 */ 80 private final boolean temporary; 81 82 /** 83 * The other component which is giving up or stealing focus from this 84 * component, if known. 85 * 86 * @see #getOppositeComponent() 87 * @serial the component with the opposite focus event, or null 88 * @since 1.4 89 */ 90 private final Component opposite; 91 92 /** 93 * Initializes a new instance of <code>FocusEvent</code> with the 94 * specified source, id, temporary status, and opposite counterpart. Note 95 * that an invalid id leads to unspecified results. 96 * 97 * @param source the component that is gaining or losing focus 98 * @param id the event id 99 * @param temporary true if the focus change is temporary 100 * @param opposite the component receiving the opposite focus event, or null 101 * @throws IllegalArgumentException if source is null 102 */ FocusEvent(Component source, int id, boolean temporary, Component opposite)103 public FocusEvent(Component source, int id, boolean temporary, 104 Component opposite) 105 { 106 super(source, id); 107 this.temporary = temporary; 108 this.opposite = opposite; 109 } 110 111 /** 112 * Initializes a new instance of <code>FocusEvent</code> with the 113 * specified source, id, and temporary status. Note that an invalid id 114 * leads to unspecified results. 115 * 116 * @param source the component that is gaining or losing focus 117 * @param id the event id 118 * @param temporary true if the focus change is temporary 119 * @throws IllegalArgumentException if source is null 120 */ FocusEvent(Component source, int id, boolean temporary)121 public FocusEvent(Component source, int id, boolean temporary) 122 { 123 this(source, id, temporary, null); 124 } 125 126 /** 127 * Initializes a new instance of <code>FocusEvent</code> with the 128 * specified source and id. Note that an invalid id leads to unspecified 129 * results. 130 * 131 * @param source the component that is gaining or losing focus 132 * @param id the event id 133 * @throws IllegalArgumentException if source is null 134 */ FocusEvent(Component source, int id)135 public FocusEvent(Component source, int id) 136 { 137 this(source, id, false, null); 138 } 139 140 /** 141 * This method tests whether or not the focus change is temporary or 142 * permanent. 143 * 144 * @return true if the focus change is temporary 145 */ isTemporary()146 public boolean isTemporary() 147 { 148 return temporary; 149 } 150 151 /** 152 * Returns the component which received the opposite focus event. If this 153 * component gained focus, the opposite lost focus; likewise if this 154 * component is giving up focus, the opposite is gaining it. If this 155 * information is unknown, perhaps because the opposite is a native 156 * application, this returns null. 157 * 158 * @return the component with the focus opposite, or null 159 * @since 1.4 160 */ getOppositeComponent()161 public Component getOppositeComponent() 162 { 163 return opposite; 164 } 165 166 /** 167 * Returns a string identifying this event. This is formatted as: 168 * <code>(getID() == FOCUS_GAINED ? "FOCUS_GAINED" : "FOCUS_LOST") 169 * + (isTemporary() ? ",temporary," : ",permanent,") + "opposite=" 170 * + getOppositeComponent()</code>. 171 * 172 * @return a string identifying this event 173 */ paramString()174 public String paramString() 175 { 176 return (id == FOCUS_GAINED ? "FOCUS_GAINED" 177 : id == FOCUS_LOST ? "FOCUS_LOST" : "unknown type") 178 + (temporary ? ",temporary,opposite=" : ",permanent,opposite=") 179 + opposite; 180 } 181 } // class FocusEvent 182