Application: gvSIG desktop

/*

 * Copyright (C) 2017 gvSIG Association

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */

package org.gvsig.app.gui;

import java.awt.Color;

import java.awt.Dimension;

import java.awt.Graphics;

import java.awt.Image;

import java.beans.PropertyChangeEvent;

import java.beans.PropertyChangeListener;

import java.io.File;

import java.util.zip.ZipEntry;

import java.util.zip.ZipFile;

import javax.imageio.ImageIO;

import javax.swing.JFileChooser;

import javax.swing.JPanel;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

public class ProjectPreviewPanel extends JPanel

        implements PropertyChangeListener {

    private static final Logger LOG = LoggerFactory.getLogger(ProjectPreviewPanel.class);

    private static final long serialVersionUID = -8314273002829710953L;

    private int width, height;

//    private ImageIcon icon;

    private Image image;

    private static final int ACCSIZE = 155;

    private final Color bg;

    public ProjectPreviewPanel() {

        setPreferredSize(new Dimension(ACCSIZE, -1));

        bg = getBackground();

    }

    @Override

    public void propertyChange(PropertyChangeEvent e) {

        String propertyName = e.getPropertyName();

        // Make sure we are responding to the right event.

        if (propertyName.equals(JFileChooser.SELECTED_FILE_CHANGED_PROPERTY)) {

            File selection = (File)e.getNewValue();

            if (selection == null) {

                return;

            }

            String name = selection.getAbsolutePath();

            if ( name != null ) {

                try {

                    ZipFile zfile = new ZipFile(name);

                    ZipEntry entry = zfile.getEntry("preview.jpg");

                    if( entry != null ) {

                        image = ImageIO.read(zfile.getInputStream(entry));

                        scaleImage();

                    } else {

                        image = null;

                    }

                    repaint();

                } catch(Throwable ex) {

                    LOG.warn("Can't load project preview. Ignore preview.",ex);

                }

            }

        }

    }

    private void scaleImage() {

        width = image.getWidth(this);

        height = image.getHeight(this);

        double ratio = 1.0;

        /* 

         * Determine how to scale the image. Since the accessory can expand

         * vertically make sure we don't go larger than 150 when scaling

         * vertically.

         */

        if (width >= height) {

            ratio = (double)(ACCSIZE-5) / width;

            width = ACCSIZE-5;

            height = (int)(height * ratio);

        }

        else {

            if (getHeight() > 150) {

                ratio = (double)(ACCSIZE-5) / height;

                height = ACCSIZE-5;

                width = (int)(width * ratio);

            }

            else {

                ratio = (double)getHeight() / height;

                height = getHeight();

                width = (int)(width * ratio);

            }

        }

        image = image.getScaledInstance(width, height, Image.SCALE_DEFAULT);

    }

    @Override

    public void paintComponent(Graphics g) {

        g.setColor(bg);

        /*

         * If we don't do this, we will end up with garbage from previous

         * images if they have larger sizes than the one we are currently

         * drawing. Also, it seems that the file list can paint outside

         * of its rectangle, and will cause odd behavior if we don't clear

         * or fill the rectangle for the accessory before drawing. This might

         * be a bug in JFileChooser.

         */

        g.fillRect(0, 0, ACCSIZE, getHeight());

        if( image != null ) {

            g.drawImage(image, getWidth() / 2 - width / 2 + 5,

                    getHeight() / 2 - height / 2, this);

        }

    }

}