Swing multicolumns ComboBox

package be.mil.cccis.atdl3.util.renderer;
 
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Font;
 
import javax.swing.BoxLayout;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.ListCellRenderer;
 
import be.mil.cccis.atdl3.domain.generic.Catalog;
/**
 * Provides custom display for ‹code›be.mil.cccis.atdl3.domain.generic.Catalog‹/code›.
 * Paints it contents in two columns CODE and DESCRIPTION.
 * @author gaudry.s
 */
public class CatalogComboBoxRenderer extends JLabel implements ListCellRenderer {
 
	/**
	 *
	 */
	private static final long serialVersionUID = 162343178097966067L;
	private JPanel rendererPanel;
	private JLabel codeLabel;
	private JLabel descriptionLabel;
	/**
	 * Creates new renderer with first column default size of 50
	 *
	 */
	public CatalogComboBoxRenderer(){
		this(50);
	}
	/**
	 * Creates a new renderer with custom first column width
	 * @param codeColumnWidth width of the first column
	 */
	public CatalogComboBoxRenderer(int codeColumnWidth)
	{
		rendererPanel = new JPanel();
		rendererPanel.setLayout(new BoxLayout(rendererPanel, BoxLayout.X_AXIS) );
 
		codeLabel = new JLabel(" ");
		Dimension d = codeLabel.getPreferredSize();
		d.width = codeColumnWidth;
		codeLabel.setMaximumSize(d);
		codeLabel.setOpaque(true);
		codeLabel.setHorizontalAlignment(LEFT);
		codeLabel.setVerticalAlignment(CENTER);
 
		descriptionLabel = new JLabel();
		descriptionLabel.setForeground(Color.gray);
		descriptionLabel.setFont(descriptionLabel.getFont().deriveFont(Font.ITALIC));
		descriptionLabel.setOpaque(true);
		descriptionLabel.setHorizontalAlignment(LEFT);
		descriptionLabel.setVerticalAlignment(CENTER);
 
		rendererPanel.add(codeLabel );
		rendererPanel.add(descriptionLabel );
	}
 
	/* (non-Javadoc)
	 * @see javax.swing.ListCellRenderer#getListCellRendererComponent(javax.swing.JList, java.lang.Object, int, boolean, boolean)
	 */
	public Component getListCellRendererComponent(JList list, Object value,
			int index, boolean isSelected, boolean cellHasFocus) {
		if(value==null){
			codeLabel.setText("");
			descriptionLabel.setText("");
		}
		else {
			if(value instanceof Catalog){
				Catalog item = (Catalog)value;
				codeLabel.setText( item.getCode() );
				descriptionLabel.setText( (index›0 && item.getDescription()!=null)?item.getDescription():"" );
			}
			else{
				codeLabel.setText(value.toString());
				descriptionLabel.setText("");
			}
		}
		codeLabel.setBackground(isSelected ? list.getSelectionBackground() : list.getBackground());
		codeLabel.setForeground(isSelected ? list.getSelectionForeground() : list.getForeground());
		descriptionLabel.setBackground(list.getBackground());
		descriptionLabel.setForeground(list.getForeground());
		return rendererPanel;
	}
 
}

myComboBox.setRenderer(new CatalogComboBoxRenderer());

package be.mil.cccis.atdl3.util.gui;
 
import javax.swing.JComboBox;
import java.util.Date;
import be.mil.cccis.atdl3.domain.generic.Catalog;
import be.mil.cccis.atdl3.util.renderer.CatalogComboBoxRenderer;
import be.mil.cccis.atdl3.util.renderer.DateComboBoxRenderer;
 
/**
 * Provides an unique point to custom all ATDL comboboxes
 * All objects in the ‹code›ComboBox‹/code› ‹b›must have the same type‹/p›
 *
 * TODO :
 * To manage other items classes in the combobox, create a new xxxComboBoxRenderer and
 * set in the decore method the renderer to use for the combobox's items
 * @author gaudry.s
 */
public class JComboBoxDecorator {
 
	/**
	 * Set comboboxrenderer
	 * @param comboBox ‹code›JComboBox‹/code› to decore
	 */
	public static void decore(JComboBox comboBox){
		if(comboBox.getItemCount()›0){
			//
			// Get the first object to test
			//
			Object firstItem = comboBox.getItemAt(0);
			//
			// Set one of the renderers
			//
			if(firstItem instanceof Catalog){
				comboBox.setRenderer(new CatalogComboBoxRenderer());
			}
			else if(firstItem instanceof Date){
				comboBox.setRenderer(new DateComboBoxRenderer());
			}
		}
	}
}

@SuppressWarnings("unchecked")
	@Override
	public void initData() {
		List‹Operation› operations = taskerRepository.getOperations();
		MVCComboBoxModel‹Operation› operationModel = new MVCComboBoxModel‹Operation›(operations);
		getView().jComboBoxOperation.setModel(operationModel);
		JComboBoxDecorator.decore(getView().jComboBoxOperation);
		getView().jComboBoxOperation.setSelectedIndex(-1);
 
		List‹ExecutingAgency› executingAgencies = taskerRepository.getExecutingAgencies();
		MVCComboBoxModel‹ExecutingAgency› executingAgencyModel = new MVCComboBoxModel‹ExecutingAgency›(executingAgencies);
		getView().jComboBoxExecutingAgency.setModel(executingAgencyModel);
		JComboBoxDecorator.decore(getView().jComboBoxExecutingAgency);
		getView().jComboBoxExecutingAgency.setSelectedIndex(-1);
	}

package be.mil.cccis.atdl3.domain.generic;
 
import org.hibernate.validator.NotNull;
 
/**
 * Abstract generalization of all catalogues which have a code and a
 * descritpion.‹br›
 * Implements Serializable to permit use through the network (eg http)
 */
public abstract class Catalog extends AbstractDTO implements LogicalDeletionOnly {
	/**
	 * code of the catalogue item (if it is not specific, it will be equal to
	 * the description). for the extending class CallSign, this attribute has
	 * max 8 chars for the extending class CreditCode, this attribute has max 3
	 * chars for the extending class FreightType, this attribute has max 6 chars
	 * for the extending class Icao, this attribute has exact 4 chars for the
	 * extending class VIPStatus, this attribute has max 4 chars
	 */
	protected String code;
 
	/**
	 * description of the catalogue item. for the extending class Icao, this
	 * attribute has 50 chars for the extending class RequestAndLegPurpose, this
	 * attribute has 50 chars for the extending class RequestAndLegType, this
	 * attribute has 50 chars for the extending class VIPStatus, this attribute
	 * has 50 chars
	 */
	protected String description;
 
	/**
	 * boolean for logical delete (=false)
	 */
	@NotNull
	protected Boolean inUse;
 
	public Catalog() {
		inUse = true;
	}
 
	/**
	 * @param code
	 * @param description
	 */
	public Catalog(String code, String description) {
		this();
		this.code = code;
		this.description = description;
	}
 
	/**
	 * @return the boolean inUse (false : item deleted)
	 */
	public Boolean isInUse() {
		return inUse;
	}
 
	/**
	 * sets the boolean inUse (false : deleted)
	 * 
	 * @param newInUse
	 */
	public void setInUse(Boolean newInUse) {
		inUse = newInUse;
	}
 
	public abstract String getCode();
 
	/**
	 * sets the code of the catalogue item
	 * 
	 * @param newCode
	 */
	public void setCode(String newCode) {
		code = newCode;
	}
 
	/**
	 * @return the description of the catalogue item
	 */
	public abstract String getDescription();
 
	/**
	 * sets the description of the catalogue item
	 * 
	 * @param newDescription
	 */
	public void setDescription(String newDescription) {
		description = newDescription;
	}
 
	@Override
	public int hashCode() {
		if (getId() != null) return getId();
 
		final int PRIME = 31;
		int result = 1;
		result += PRIME * ((code == null) ? 0 : code.hashCode());
 
		return (result == 1) ? System.identityHashCode(this): result;
	}
 
	@Override
	public String toString() {
		if (inUse)
			return code;
		return "‹html›‹strike›" + code + "‹/strike›‹/html›";
	}
}