1/*
2 * Copyright (c) 1998, 2014, 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 */
25package javax.swing;
26
27import java.util.*;
28
29import java.io.Serializable;
30
31/**
32 * The default model for combo boxes.
33 *
34 * @param <E> the type of the elements of this model
35 *
36 * @author Arnaud Weber
37 * @author Tom Santos
38 * @since 1.2
39 */
40@SuppressWarnings("serial") // Superclass is not serializable across versions
41public class DefaultComboBoxModel<E> extends AbstractListModel<E> implements MutableComboBoxModel<E>, Serializable {
42    Vector<E> objects;
43    Object selectedObject;
44
45    /**
46     * Constructs an empty DefaultComboBoxModel object.
47     */
48    public DefaultComboBoxModel() {
49        objects = new Vector<E>();
50    }
51
52    /**
53     * Constructs a DefaultComboBoxModel object initialized with
54     * an array of objects.
55     *
56     * @param items  an array of Object objects
57     */
58    public DefaultComboBoxModel(final E items[]) {
59        objects = new Vector<E>(items.length);
60
61        int i,c;
62        for ( i=0,c=items.length;i<c;i++ )
63            objects.addElement(items[i]);
64
65        if ( getSize() > 0 ) {
66            selectedObject = getElementAt( 0 );
67        }
68    }
69
70    /**
71     * Constructs a DefaultComboBoxModel object initialized with
72     * a vector.
73     *
74     * @param v  a Vector object ...
75     */
76    public DefaultComboBoxModel(Vector<E> v) {
77        objects = v;
78
79        if ( getSize() > 0 ) {
80            selectedObject = getElementAt( 0 );
81        }
82    }
83
84    // implements javax.swing.ComboBoxModel
85    /**
86     * Set the value of the selected item. The selected item may be null.
87     *
88     * @param anObject The combo box value or null for no selection.
89     */
90    public void setSelectedItem(Object anObject) {
91        if ((selectedObject != null && !selectedObject.equals( anObject )) ||
92            selectedObject == null && anObject != null) {
93            selectedObject = anObject;
94            fireContentsChanged(this, -1, -1);
95        }
96    }
97
98    // implements javax.swing.ComboBoxModel
99    public Object getSelectedItem() {
100        return selectedObject;
101    }
102
103    // implements javax.swing.ListModel
104    public int getSize() {
105        return objects.size();
106    }
107
108    // implements javax.swing.ListModel
109    public E getElementAt(int index) {
110        if ( index >= 0 && index < objects.size() )
111            return objects.elementAt(index);
112        else
113            return null;
114    }
115
116    /**
117     * Returns the index-position of the specified object in the list.
118     *
119     * @param anObject the object to return the index of
120     * @return an int representing the index position, where 0 is
121     *         the first position
122     */
123    public int getIndexOf(Object anObject) {
124        return objects.indexOf(anObject);
125    }
126
127    // implements javax.swing.MutableComboBoxModel
128    public void addElement(E anObject) {
129        objects.addElement(anObject);
130        fireIntervalAdded(this,objects.size()-1, objects.size()-1);
131        if ( objects.size() == 1 && selectedObject == null && anObject != null ) {
132            setSelectedItem( anObject );
133        }
134    }
135
136    // implements javax.swing.MutableComboBoxModel
137    public void insertElementAt(E anObject,int index) {
138        objects.insertElementAt(anObject,index);
139        fireIntervalAdded(this, index, index);
140    }
141
142    // implements javax.swing.MutableComboBoxModel
143    public void removeElementAt(int index) {
144        if ( getElementAt( index ) == selectedObject ) {
145            if ( index == 0 ) {
146                setSelectedItem( getSize() == 1 ? null : getElementAt( index + 1 ) );
147            }
148            else {
149                setSelectedItem( getElementAt( index - 1 ) );
150            }
151        }
152
153        objects.removeElementAt(index);
154
155        fireIntervalRemoved(this, index, index);
156    }
157
158    // implements javax.swing.MutableComboBoxModel
159    public void removeElement(Object anObject) {
160        int index = objects.indexOf(anObject);
161        if ( index != -1 ) {
162            removeElementAt(index);
163        }
164    }
165
166    /**
167     * Empties the list.
168     */
169    public void removeAllElements() {
170        if ( objects.size() > 0 ) {
171            int firstIndex = 0;
172            int lastIndex = objects.size() - 1;
173            objects.removeAllElements();
174            selectedObject = null;
175            fireIntervalRemoved(this, firstIndex, lastIndex);
176        } else {
177            selectedObject = null;
178        }
179    }
180}
181