1 /* 2 * Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package java.awt; 26 27 /** 28 * The <code>CheckboxGroup</code> class is used to group together 29 * a set of <code>Checkbox</code> buttons. 30 * <p> 31 * Exactly one check box button in a <code>CheckboxGroup</code> can 32 * be in the "on" state at any given time. Pushing any 33 * button sets its state to "on" and forces any other button that 34 * is in the "on" state into the "off" state. 35 * <p> 36 * The following code example produces a new check box group, 37 * with three check boxes: 38 * 39 * <hr><blockquote><pre> 40 * setLayout(new GridLayout(3, 1)); 41 * CheckboxGroup cbg = new CheckboxGroup(); 42 * add(new Checkbox("one", cbg, true)); 43 * add(new Checkbox("two", cbg, false)); 44 * add(new Checkbox("three", cbg, false)); 45 * </pre></blockquote><hr> 46 * <p> 47 * This image depicts the check box group created by this example: 48 * <p> 49 * <img src="doc-files/CheckboxGroup-1.gif" 50 * alt="Shows three checkboxes, arranged vertically, labeled one, two, and three. Checkbox one is in the on state." 51 * style="float:center; margin: 7px 10px;"> 52 * <p> 53 * @author Sami Shaio 54 * @see java.awt.Checkbox 55 * @since JDK1.0 56 */ 57 public class CheckboxGroup implements java.io.Serializable { 58 /** 59 * The current choice. 60 * @serial 61 * @see #getCurrent() 62 * @see #setCurrent(Checkbox) 63 */ 64 Checkbox selectedCheckbox = null; 65 66 /* 67 * JDK 1.1 serialVersionUID 68 */ 69 private static final long serialVersionUID = 3729780091441768983L; 70 71 /** 72 * Creates a new instance of <code>CheckboxGroup</code>. 73 */ CheckboxGroup()74 public CheckboxGroup() { 75 } 76 77 /** 78 * Gets the current choice from this check box group. 79 * The current choice is the check box in this 80 * group that is currently in the "on" state, 81 * or <code>null</code> if all check boxes in the 82 * group are off. 83 * @return the check box that is currently in the 84 * "on" state, or <code>null</code>. 85 * @see java.awt.Checkbox 86 * @see java.awt.CheckboxGroup#setSelectedCheckbox 87 * @since JDK1.1 88 */ getSelectedCheckbox()89 public Checkbox getSelectedCheckbox() { 90 return getCurrent(); 91 } 92 93 /** 94 * @deprecated As of JDK version 1.1, 95 * replaced by <code>getSelectedCheckbox()</code>. 96 */ 97 @Deprecated getCurrent()98 public Checkbox getCurrent() { 99 return selectedCheckbox; 100 } 101 102 /** 103 * Sets the currently selected check box in this group 104 * to be the specified check box. 105 * This method sets the state of that check box to "on" and 106 * sets all other check boxes in the group to be off. 107 * <p> 108 * If the check box argument is <tt>null</tt>, all check boxes 109 * in this check box group are deselected. If the check box argument 110 * belongs to a different check box group, this method does 111 * nothing. 112 * @param box the <code>Checkbox</code> to set as the 113 * current selection. 114 * @see java.awt.Checkbox 115 * @see java.awt.CheckboxGroup#getSelectedCheckbox 116 * @since JDK1.1 117 */ setSelectedCheckbox(Checkbox box)118 public void setSelectedCheckbox(Checkbox box) { 119 setCurrent(box); 120 } 121 122 /** 123 * @deprecated As of JDK version 1.1, 124 * replaced by <code>setSelectedCheckbox(Checkbox)</code>. 125 */ 126 @Deprecated setCurrent(Checkbox box)127 public synchronized void setCurrent(Checkbox box) { 128 if (box != null && box.group != this) { 129 return; 130 } 131 Checkbox oldChoice = this.selectedCheckbox; 132 this.selectedCheckbox = box; 133 if (oldChoice != null && oldChoice != box && oldChoice.group == this) { 134 oldChoice.setState(false); 135 } 136 if (box != null && oldChoice != box && !box.getState()) { 137 box.setStateInternal(true); 138 } 139 } 140 141 /** 142 * Returns a string representation of this check box group, 143 * including the value of its current selection. 144 * @return a string representation of this check box group. 145 */ toString()146 public String toString() { 147 return getClass().getName() + "[selectedCheckbox=" + selectedCheckbox + "]"; 148 } 149 150 } 151