/* * Copyright (c) 1995, 2004, 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; /** * The CheckboxGroup class is used to group together * a set of Checkbox buttons. *

* Exactly one check box button in a CheckboxGroup can * be in the "on" state at any given time. Pushing any * button sets its state to "on" and forces any other button that * is in the "on" state into the "off" state. *

* The following code example produces a new check box group, * with three check boxes: *

*


 * setLayout(new GridLayout(3, 1));
 * CheckboxGroup cbg = new CheckboxGroup();
 * add(new Checkbox("one", cbg, true));
 * add(new Checkbox("two", cbg, false));
 * add(new Checkbox("three", cbg, false));
 * 

*

* This image depicts the check box group created by this example: *

* Shows three checkboxes, arranged vertically, labeled one, two, and three. Checkbox one is in the on state. *

* @author Sami Shaio * @see java.awt.Checkbox * @since JDK1.0 */ public class CheckboxGroup implements java.io.Serializable { /** * The current choice. * @serial * @see #getCurrent() * @see #setCurrent(Checkbox) */ Checkbox selectedCheckbox = null; /* * JDK 1.1 serialVersionUID */ private static final long serialVersionUID = 3729780091441768983L; /** * Creates a new instance of CheckboxGroup. */ public CheckboxGroup() { } /** * Gets the current choice from this check box group. * The current choice is the check box in this * group that is currently in the "on" state, * or null if all check boxes in the * group are off. * @return the check box that is currently in the * "on" state, or null. * @see java.awt.Checkbox * @see java.awt.CheckboxGroup#setSelectedCheckbox * @since JDK1.1 */ public Checkbox getSelectedCheckbox() { return getCurrent(); } /** * @deprecated As of JDK version 1.1, * replaced by getSelectedCheckbox(). */ @Deprecated public Checkbox getCurrent() { return selectedCheckbox; } /** * Sets the currently selected check box in this group * to be the specified check box. * This method sets the state of that check box to "on" and * sets all other check boxes in the group to be off. *

* If the check box argument is null, all check boxes * in this check box group are deselected. If the check box argument * belongs to a different check box group, this method does * nothing. * @param box the Checkbox to set as the * current selection. * @see java.awt.Checkbox * @see java.awt.CheckboxGroup#getSelectedCheckbox * @since JDK1.1 */ public void setSelectedCheckbox(Checkbox box) { setCurrent(box); } /** * @deprecated As of JDK version 1.1, * replaced by setSelectedCheckbox(Checkbox). */ @Deprecated public synchronized void setCurrent(Checkbox box) { if (box != null && box.group != this) { return; } Checkbox oldChoice = this.selectedCheckbox; this.selectedCheckbox = box; if (oldChoice != null && oldChoice != box && oldChoice.group == this) { oldChoice.setState(false); } if (box != null && oldChoice != box && !box.getState()) { box.setStateInternal(true); } } /** * Returns a string representation of this check box group, * including the value of its current selection. * @return a string representation of this check box group. */ public String toString() { return getClass().getName() + "[selectedCheckbox=" + selectedCheckbox + "]"; } }