    001    /* ========================================================================
    002     * JCommon : a free general purpose class library for the Java(tm) platform
    003     * ========================================================================
    004     *
    005     * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
    006     *
    007     * Project Info:  http://www.jfree.org/jcommon/index.html
    008     *
    009     * This library is free software; you can redistribute it and/or modify it
    010     * under the terms of the GNU Lesser General Public License as published by
    011     * the Free Software Foundation; either version 2.1 of the License, or
    012     * (at your option) any later version.
    013     *
    014     * This library is distributed in the hope that it will be useful, but
    015     * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    016     * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
    017     * License for more details.
    018     *
    019     * You should have received a copy of the GNU Lesser General Public
    020     * License along with this library; if not, write to the Free Software
    021     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
    022     * USA.
    023     *
    024     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
    025     * in the United States and other countries.]
    026     *
    027     * ----------------------------
    028     * AbstractFileSelectionAction.java
    029     * ----------------------------
    030     * (C)opyright 2002-2004, by Thomas Morgner and Contributors.
    031     *
    032     * Original Author:  Thomas Morgner;
    033     * Contributor(s):   David Gilbert (for Object Refinery Limited);
    034     *
    035     * $Id: AbstractFileSelectionAction.java,v 1.4 2005/10/18 13:22:13 mungady Exp $
    036     *
    037     * Changes
    038     * -------
    039     * 21-Nov-2004 : Initial version
    040     *
    041     */
    042    package org.jfree.ui.action;
    043
    044    import java.awt.Component;
    045    import java.io.File;
    046    import javax.swing.JFileChooser;
    047
    048    import org.jfree.ui.ExtensionFileFilter;
    049    import org.jfree.util.StringUtils;
    050
    051    /**
    052     * A base class for all file operations. This implementation provides all methods
    053     * to let the user select a file.
    054     *
    055     * @author Thomas Morgner
    056     */
    057    public abstract class AbstractFileSelectionAction extends AbstractActionDowngrade {
    058        /**
    059         * The FileChooser that is used to perform the selection.
    060         */
    061        private JFileChooser fileChooser;
    062        /**
    063         * The (optional) parent component.
    064         */
    065        private Component parent;
    066
    067        /**
    068         * Creates a new FileSelectionAction with the given optional parent component
    069         * as parent for the file chooser dialog.
    070         *
    071         * @param parent the parent
    072         */
    073        public AbstractFileSelectionAction(final Component parent) {
    074            this.parent = parent;
    075        }
    076
    077        /**
    078         * Returns the file extension that should be used for the operation.
    079         *
    080         * @return the file extension.
    081         */
    082        protected abstract String getFileExtension();
    083
    084        /**
    085         * Returns a descriptive text describing the file extension.
    086         *
    087         * @return the file description.
    088         */
    089        protected abstract String getFileDescription();
    090
    091        /**
    092         * Returns the working directory that should be used when initializing
    093         * the FileChooser.
    094         *
    095         * @return the working directory.
    096         */
    097        protected File getCurrentDirectory() {
    098            return new File(".");
    099        }
    100
    101        /**
    102         * Selects a file to use as target for the operation.
    103         *
    104         * @param selectedFile    the selected file.
    105         * @param dialogType  the dialog type.
    106         * @param appendExtension true, if the file extension should be added if
    107         *                        necessary, false if the unmodified filename should be used.
    108         *
    109         * @return the selected and approved file or null, if the user canceled
    110         *         the operation
    111         */
    112        protected File performSelectFile(final File selectedFile,
    113                                         final int dialogType,
    114                                         final boolean appendExtension) {
    115            if (this.fileChooser == null) {
    116                this.fileChooser = createFileChooser();
    117            }
    118
    119            this.fileChooser.setSelectedFile(selectedFile);
    120            this.fileChooser.setDialogType(dialogType);
    121            final int option = this.fileChooser.showDialog(this.parent, null);
    122            if (option == JFileChooser.APPROVE_OPTION) {
    123                final File selFile = this.fileChooser.getSelectedFile();
    124                String selFileName = selFile.getAbsolutePath();
    125                if (StringUtils.endsWithIgnoreCase(selFileName, getFileExtension()) == false) {
    126                    selFileName = selFileName + getFileExtension();
    127                }
    128                return new File(selFileName);
    129            }
    130            return null;
    131        }
    132
    133        /**
    134         * Creates the file chooser.
    135         *
    136         * @return the initialized file chooser.
    137         */
    138        protected JFileChooser createFileChooser() {
    139            final JFileChooser fc = new JFileChooser();
    140            fc.addChoosableFileFilter(
    141                new ExtensionFileFilter(getFileDescription(), getFileExtension())
    142            );
    143            fc.setMultiSelectionEnabled(false);
    144            fc.setCurrentDirectory(getCurrentDirectory());
    145            return fc;
    146        }
    147
    148    }