/*

 * Copyright (c) 1998, 2013, 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 javax.swing;

import java.util.*;

import java.io.Serializable;

/**

 * The default model for combo boxes.

 *

 * @param <E> the type of the elements of this model

 *

 * @author Arnaud Weber

 * @author Tom Santos

 */

public class DefaultComboBoxModel<E> extends AbstractListModel<E> implements MutableComboBoxModel<E>, Serializable {

    Vector<E> objects;

    Object selectedObject;

    /**

     * Constructs an empty DefaultComboBoxModel object.

     */

    public DefaultComboBoxModel() {

        objects = new Vector<E>();

    }

    /**

     * Constructs a DefaultComboBoxModel object initialized with

     * an array of objects.

     *

     * @param items  an array of Object objects

     */

    public DefaultComboBoxModel(final E items[]) {

        objects = new Vector<E>(items.length);

        int i,c;

        for ( i=0,c=items.length;i<c;i++ )

            objects.addElement(items[i]);

        if ( getSize() > 0 ) {

            selectedObject = getElementAt( 0 );

        }

    }

    /**

     * Constructs a DefaultComboBoxModel object initialized with

     * a vector.

     *

     * @param v  a Vector object ...

     */

    public DefaultComboBoxModel(Vector<E> v) {

        objects = v;

        if ( getSize() > 0 ) {

            selectedObject = getElementAt( 0 );

        }

    }

    // implements javax.swing.ComboBoxModel

    /**

     * Set the value of the selected item. The selected item may be null.

     * @param anObject The combo box value or null for no selection.

     */

    public void setSelectedItem(Object anObject) {

        if ((selectedObject != null && !selectedObject.equals( anObject )) ||

            selectedObject == null && anObject != null) {

            selectedObject = anObject;

            fireContentsChanged(this, -1, -1);

        }

    }

    // implements javax.swing.ComboBoxModel

    public Object getSelectedItem() {

        return selectedObject;

    }

    // implements javax.swing.ListModel

    public int getSize() {

        return objects.size();

    }

    // implements javax.swing.ListModel

    public E getElementAt(int index) {

        if ( index >= 0 && index < objects.size() )

            return objects.elementAt(index);

        else

            return null;

    }

    /**

     * Returns the index-position of the specified object in the list.

     *

     * @param anObject

     * @return an int representing the index position, where 0 is

     *         the first position

     */

    public int getIndexOf(Object anObject) {

        return objects.indexOf(anObject);

    }

    // implements javax.swing.MutableComboBoxModel

    public void addElement(E anObject) {

        objects.addElement(anObject);

        fireIntervalAdded(this,objects.size()-1, objects.size()-1);

        if ( objects.size() == 1 && selectedObject == null && anObject != null ) {

            setSelectedItem( anObject );

        }

    }

    // implements javax.swing.MutableComboBoxModel

    public void insertElementAt(E anObject,int index) {

        objects.insertElementAt(anObject,index);

        fireIntervalAdded(this, index, index);

    }

    // implements javax.swing.MutableComboBoxModel

    public void removeElementAt(int index) {

        if ( getElementAt( index ) == selectedObject ) {

            if ( index == 0 ) {

                setSelectedItem( getSize() == 1 ? null : getElementAt( index + 1 ) );

            }

            else {

                setSelectedItem( getElementAt( index - 1 ) );

            }

        }

        objects.removeElementAt(index);

        fireIntervalRemoved(this, index, index);

    }

    // implements javax.swing.MutableComboBoxModel

    public void removeElement(Object anObject) {

        int index = objects.indexOf(anObject);

        if ( index != -1 ) {

            removeElementAt(index);

        }

    }

    /**

     * Empties the list.

     */

    public void removeAllElements() {

        if ( objects.size() > 0 ) {

            int firstIndex = 0;

            int lastIndex = objects.size() - 1;

            objects.removeAllElements();

            selectedObject = null;

            fireIntervalRemoved(this, firstIndex, lastIndex);

        } else {

            selectedObject = null;

        }

    }

}