001    /*
002     * $Id: IconValues.java 3152 2008-12-23 18:12:39Z kschaefe $
003     *
004     * Copyright 2008 Sun Microsystems, Inc., 4150 Network Circle,
005     * Santa Clara, California 95054, U.S.A. All rights reserved.
006     *
007     * This library is free software; you can redistribute it and/or
008     * modify it under the terms of the GNU Lesser General Public
009     * License as published by the Free Software Foundation; either
010     * version 2.1 of the License, or (at your option) any later version.
011     * 
012     * This library is distributed in the hope that it will be useful,
013     * but WITHOUT ANY WARRANTY; without even the implied warranty of
014     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
015     * Lesser General Public License for more details.
016     * 
017     * You should have received a copy of the GNU Lesser General Public
018     * License along with this library; if not, write to the Free Software
019     * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
020     */
021    package org.jdesktop.swingx.renderer;
022    
023    import java.io.File;
024    
025    import javax.swing.Icon;
026    import javax.swing.filechooser.FileSystemView;
027    
028    /**
029     * A collection of common {@code IconValue} implementations.
030     * 
031     * @author Karl George Schaefer
032     * @author Jeanette Winzenburg
033     */
034    public final class IconValues {
035        /**
036         * Always NULL_ICON. This is useful to indicate that we really want
037         * no icon instead of f.i. a default provided by the CellContext. 
038         */
039        @SuppressWarnings("serial")
040        public static final IconValue NONE = new IconValue() {
041        
042            public Icon getIcon(Object value) {
043                return IconValue.NULL_ICON;
044            }
045            
046        };
047    
048        /**
049         * Returns the value as Icon if possible or null.
050         */
051        @SuppressWarnings("serial")
052        public static final IconValue ICON = new IconValue() {
053        
054            public Icon getIcon(Object value) {
055                if (value instanceof Icon) {
056                    return (Icon) value;
057                }
058                return null;
059            }
060        };
061        
062        /**
063         * An {@code IconValue} that presents the current L&F icon for a given file.
064         * If the value passed to {@code FILE_ICON} is not a {@link File}, this has
065         * the same effect as {@link IconValues#NONE}.
066         */
067        @SuppressWarnings("serial")
068        public static final IconValue FILE_ICON = new IconValue() {
069            public Icon getIcon(Object value) {
070                if (value instanceof File) {
071                    FileSystemView fsv = FileSystemView.getFileSystemView();
072    
073                    return fsv.getSystemIcon((File) value);
074                }
075    
076                return IconValues.NONE.getIcon(value);
077            }
078        };
079        
080        private IconValues() {
081            // does nothing
082        }
083    }