swingx-master/swingx-core/src/main/java/org/jdesktop/swingx/renderer/FormatStringValue.java
/*
 * $Id$
 *
 * Copyright 2006 Sun Microsystems, Inc., 4150 Network Circle,
 * Santa Clara, California 95054, U.S.A. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
package org.jdesktop.swingx.renderer;

import java.text.Format;

/**
 * Base type for <code>Format</code>-backed <code>StringValue</code>. Has
 * static defaults for Date and Number which use the locale-dependent default
 * <code>Format</code>s as returned from xxFormat.getInstance().
 * <p>
 * 
 * This class is intended to ease the handling of formatted cell content.
 * F.i. to show a list of <code>Date</code>s in the default
 * <code>Locale</code>'s FULL version and right align the text:
 * 
 * <pre><code>
 *    StringValue stringValue = new FormatStringValue(
 *        DateFormat.getInstance(DateFormat.FULL));
 *    list.setCellRenderer(
 *        new DefaultListRenderer(stringValue, JLabel.RIGHT);  
 * </code></pre>
 * 
 * 
 * PENDING: need to update on Locale change? How to detect? When?
 * 
 * @author Jeanette Winzenburg
 */
public class FormatStringValue implements StringValue {

    /** the format used in creating the String representation. */
    protected Format format;

    /**
     * Instantiates a formatted converter with null format.
     *
     */
    public FormatStringValue() {
        this(null);
    }
    
    /**
     * Instantiates a formatted converter with the given Format.
     * 
     * @param format the format to use in creating the String representation.
     */
    public FormatStringValue(Format format) {
       this.format = format; 
    }
    
    /**
     * 
     * @return the format used in creating the String representation.
     */
    public Format getFormat() {
        return format;
    }
    
    /**
     * {@inheritDoc}
     */
    @Override
    public String getString(Object value) {
        if (value == null) return "";
        if (format != null) {
            try {
                return format.format(value);
            } catch (IllegalArgumentException e) {
                // didn't work, nothing we can do
            }
        }
        return value.toString();
    }

}
