1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173
/* * @(#)ButtonGroup.java 1.39 05/11/17 * * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */ package javax.swing; import java.awt.event.*; import java.util.Vector; import java.util.Enumeration; import java.io.Serializable; /** * This class is used to create a multiple-exclusion scope for * a set of buttons. Creating a set of buttons with the * same <code>ButtonGroup</code> object means that * turning "on" one of those buttons * turns off all other buttons in the group. * <p> * A <code>ButtonGroup</code> can be used with * any set of objects that inherit from <code>AbstractButton</code>. * Typically a button group contains instances of * <code>JRadioButton</code>, * <code>JRadioButtonMenuItem</code>, * or <code>JToggleButton</code>. * It wouldn't make sense to put an instance of * <code>JButton</code> or <code>JMenuItem</code> * in a button group * because <code>JButton</code> and <code>JMenuItem</code> * don't implement the selected state. * <p> * Initially, all buttons in the group are unselected. * <p> * For examples and further information on using button groups see * <a href="http://java.sun.com/docs/books/tutorial/uiswing/components/button.html#radiobutton">How to Use Radio Buttons</a>, * a section in <em>The Java Tutorial</em>. * <p> * <strong>Warning:</strong> * Serialized objects of this class will not be compatible with * future Swing releases. The current serialization support is * appropriate for short term storage or RMI between applications running * the same version of Swing. As of 1.4, support for long term storage * of all JavaBeans<sup><font size="-2">TM</font></sup> * has been added to the <code>java.beans</code> package. * Please see {@link java.beans.XMLEncoder}. * * @version 1.39 11/17/05 * @author Jeff Dinkins */ public class ButtonGroup implements Serializable { // the list of buttons participating in this group protected Vector<AbstractButton> buttons = new Vector(); /** * The current selection. */ ButtonModel selection = null; /** * Creates a new <code>ButtonGroup</code>. */ public ButtonGroup() {} /** * Adds the button to the group. * @param b the button to be added */ public void add(AbstractButton b) { if(b == null) { return; } buttons.addElement(b); if (b.isSelected()) { if (selection == null) { selection = b.getModel(); } else { b.setSelected(false); } } b.getModel().setGroup(this); } /** * Removes the button from the group. * @param b the button to be removed */ public void remove(AbstractButton b) { if(b == null) { return; } buttons.removeElement(b); if(b.getModel() == selection) { selection = null; } b.getModel().setGroup(null); } /** * Clears the selection such that none of the buttons * in the <code>ButtonGroup</code> are selected. * * @since 1.6 */ public void clearSelection() { if (selection != null) { ButtonModel oldSelection = selection; selection = null; oldSelection.setSelected(false); } } /** * Returns all the buttons that are participating in * this group. * @return an <code>Enumeration</code> of the buttons in this group */ public Enumeration<AbstractButton> getElements() { return buttons.elements(); } /** * Returns the model of the selected button. * @return the selected button model */ public ButtonModel getSelection() { return selection; } /** * Sets the selected value for the <code>ButtonModel</code>. * Only one button in the group may be selected at a time. * @param m the <code>ButtonModel</code> * @param b <code>true</code> if this button is to be * selected, otherwise <code>false</code> */ public void setSelected(ButtonModel m, boolean b) { if (b && m != null && m != selection) { ButtonModel oldSelection = selection; selection = m; if (oldSelection != null) { oldSelection.setSelected(false); } m.setSelected(true); } } /** * Returns whether a <code>ButtonModel</code> is selected. * @return <code>true</code> if the button is selected, * otherwise returns <code>false</code> */ public boolean isSelected(ButtonModel m) { return (m == selection); } /** * Returns the number of buttons in the group. * @return the button count * @since 1.3 */ public int getButtonCount() { if (buttons == null) { return 0; } else { return buttons.size(); } } }