ekit/com/hexidec/ekit/component/ImageFileChooserPreview.java

   1 /*
   2 GNU Lesser General Public License
   3
   4 ImageFileChooserPreview
   5 Copyright (C) 2000-2002  Frits Jalvingh & Howard Kistler
   6
   7 This library is free software; you can redistribute it and/or
   8 modify it under the terms of the GNU Lesser General Public
   9 License as published by the Free Software Foundation; either
  10 version 2.1 of the License, or (at your option) any later version.
  11
  12 This library is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 Lesser General Public License for more details.
  16
  17 You should have received a copy of the GNU Lesser General Public
  18 License along with this library; if not, write to the Free Software
  19 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20 */
  21
  22 package com.hexidec.ekit.component;
  23
  24 import java.awt.Dimension;
  25 import java.awt.Graphics;
  26 import java.awt.Image;
  27 import java.io.File;
  28 import javax.swing.ImageIcon;
  29 import javax.swing.JComponent;
  30 import javax.swing.JFileChooser;
  31 import java.beans.PropertyChangeEvent;
  32 import java.beans.PropertyChangeListener;
  33
  34 /** Class provides a preview window for the selected image file
  35   */
  36 class ImageFileChooserPreview extends JComponent implements PropertyChangeListener
  37 {
  38         private static final int previewWidth  = 100;
  39         private static final int previewHeight = 100;
  40
  41         private ImageIcon imageThumb = null;
  42         private File imageFile = null;
  43
  44         /** This class requires a file chooser to register with so this class will
  45           * be notified when a new file is selected in the browser.
  46           * @param JFileChooser that this preview window is used in.
  47           */
  48         public ImageFileChooserPreview(JFileChooser parent)
  49         {
  50                 setPreferredSize(new Dimension(previewWidth , previewHeight));
  51                 parent.addPropertyChangeListener(this);
  52         }
  53
  54         /** Loads a new image into the preview window, and scales it if necessary.
  55           */
  56         public void loadImage()
  57         {
  58                 if(imageFile == null)
  59                 {
  60                         imageThumb = null;
  61                         return;
  62                 }
  63                 imageThumb = new ImageIcon(imageFile.getPath());
  64
  65                 // Check if thumb requires scaling
  66                 if(imageThumb.getIconHeight() < previewHeight && imageThumb.getIconWidth() < previewWidth)
  67                 {
  68                         return;
  69                 }
  70                 int     w = previewWidth;
  71                 int     h = previewHeight;
  72                 if(imageThumb.getIconHeight() > imageThumb.getIconWidth())
  73                 {
  74                         w = -1;
  75                 }
  76                 else
  77                 {
  78                         h = -1;
  79                 }
  80                 imageThumb = new ImageIcon(imageThumb.getImage().getScaledInstance(w, h, Image.SCALE_DEFAULT));
  81         }
  82
  83         /** Callback (event handler) to indicate that a property of the
  84           * JFileChooser has changed. If the selected file has changed cause a new
  85           * thumbnail to load.
  86           */
  87         public void propertyChange(PropertyChangeEvent e)
  88         {
  89                 if(e.getPropertyName().equals(JFileChooser.SELECTED_FILE_CHANGED_PROPERTY))
  90                 {
  91                         imageFile = (File)e.getNewValue();
  92                         if(isShowing())
  93                         {
  94                                 loadImage();
  95                                 repaint();
  96                         }
  97                 }
  98         }
  99
 100         /** Paints the icon of the current image, if one's present..
 101           * @param Graphics object to use when painting the component.
 102           */
 103         public void paintComponent(Graphics g)
 104         {
 105                 if(imageThumb == null)
 106                 {
 107                         loadImage();
 108                 }
 109                 if(imageThumb == null)
 110                 {
 111                         return;
 112                 }
 113                 int     x = (getWidth() - imageThumb.getIconWidth()) / 2;
 114                 int     y = (getHeight() - imageThumb.getIconHeight()) / 2;
 115                 if(y < 0)
 116                 {
 117                         y = 0;
 118                 }
 119                 if(x < 5)
 120                 {
 121                         x = 5;
 122                 }
 123                 imageThumb.paintIcon(this, g, x, y);
 124         }
 125 }
 126