org.jdal.swing.list.ListComboBoxModel.java Source code

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Here is the source code for org.jdal.swing.list.ListComboBoxModel.java

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/*
 * Copyright 2008-2014 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jdal.swing.list;

import java.util.ArrayList;
import java.util.List;

import javax.swing.MutableComboBoxModel;

import org.apache.commons.lang.ObjectUtils;

/**
 * A {@link MutableComboBoxModel} that use a List as Container
 * 
 * @author Jose Luis Martin
 */
public class ListComboBoxModel<T> extends ListListModel<T> implements MutableComboBoxModel<T> {

    private static final long serialVersionUID = 1L;
    private Object selectedItem;
    private boolean allowNullSelection = true;

    public ListComboBoxModel() {
        this(new ArrayList<T>());
    }

    public ListComboBoxModel(List<T> list) {
        this(list, true);
    }

    public ListComboBoxModel(List<T> list, boolean allowNullSelection) {
        super(list);
        if (list != null && list.size() > 0)
            setSelectedItem(list.get(0));
        this.allowNullSelection = allowNullSelection;

    }

    @Override
    public void addElement(T element) {
        getList().add(element);
        int index = getList().indexOf(element);
        fireIntervalAdded(this, index, index);

    }

    @Override
    public void insertElementAt(T element, int index) {
        getList().add(index, element);
        fireIntervalAdded(this, index, index);

    }

    @Override
    public void removeElement(Object obj) {
        int index = getList().indexOf(obj);
        if (getList().remove(obj)) {
            fireIntervalRemoved(this, index, index);
        }
        if (ObjectUtils.equals(selectedItem, obj)) {
            selectedItem = getList().size() > 0 ? getList().get(0) : null;
        }
    }

    @Override
    public void removeElementAt(int index) {
        getList().remove(index);

    }

    @Override
    public Object getSelectedItem() {
        return selectedItem;
    }

    @Override
    public void setSelectedItem(Object item) {
        if (item == null) {
            selectNullItem();
            fireContentsChanged(this, -1, -1);
        } else if (!item.equals(selectedItem)) {
            int index = getList().indexOf(item);
            if (index != -1)
                selectedItem = item;
            else
                selectNullItem();

            fireContentsChanged(this, index, index);
        }
    }

    private void selectNullItem() {
        if (allowNullSelection)
            selectedItem = null;
        else {
            if (getList().size() > 0)
                setSelectedItem(getList().get(0));
        }
    }
}