Source for gnu.javax.activation.viewers.ImageViewer

   1: /* ImageViewer.java -- Simple image display component.
   2:    Copyright (C) 2004 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: package gnu.javax.activation.viewers;
  39: 
  40: import java.awt.Component;
  41: import java.awt.Dimension;
  42: import java.awt.Image;
  43: import java.awt.Graphics;
  44: import java.awt.MediaTracker;
  45: import java.awt.Toolkit;
  46: import java.io.ByteArrayOutputStream;
  47: import java.io.InputStream;
  48: import java.io.IOException;
  49: 
  50: import javax.activation.CommandObject;
  51: import javax.activation.DataHandler;
  52: 
  53: /**
  54:  * Simple image display component.
  55:  *
  56:  * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
  57:  * @version 1.0.2
  58:  */
  59: public class ImageViewer extends Component
  60:   implements CommandObject
  61: {
  62: 
  63:   private Image image;
  64: 
  65:   /**
  66:    * Returns the preferred size for this component (the image size).
  67:    */
  68:   public Dimension getPreferredSize()
  69:     {
  70:       Dimension ps = new Dimension(0, 0);
  71:       if (image != null)
  72:         {
  73:           ps.width = image.getWidth(this);
  74:           ps.height = image.getHeight(this);
  75:         }
  76:       return ps;
  77:     }
  78: 
  79:   public void setCommandContext(String verb, DataHandler dh)
  80:     throws IOException
  81:   {
  82:     // Read image into a byte array
  83:     InputStream in = dh.getInputStream();
  84:     ByteArrayOutputStream bytes = new ByteArrayOutputStream();
  85:     byte[] buf = new byte[4096];
  86:     for (int len = in.read(buf); len != -1; len = in.read(buf))
  87:       bytes.write(buf, 0, len);
  88:     in.close();
  89:     // Create and prepare the image
  90:     Toolkit toolkit = getToolkit();
  91:     Image img = toolkit.createImage(bytes.toByteArray());
  92:     try
  93:       {
  94:         MediaTracker tracker = new MediaTracker(this);
  95:         tracker.addImage(img, 0);
  96:         tracker.waitForID(0);
  97:       }
  98:     catch (InterruptedException e)
  99:       {
 100:       }
 101:     toolkit.prepareImage(img, -1, -1, this);
 102:   }
 103: 
 104:   /**
 105:    * Image bits arrive.
 106:    */
 107:   public boolean imageUpdate(Image image, int flags, int x, int y,
 108:                              int width, int height)
 109:   {
 110:     if ((flags & ALLBITS) != 0)
 111:       {
 112:         this.image = image;
 113:         invalidate();
 114:         repaint();
 115:         return false;
 116:       }
 117:     return ((flags & ERROR) == 0);
 118:   }
 119: 
 120:   /**
 121:    * Scale the image into this component's bounds.
 122:    */
 123:   public void paint(Graphics g)
 124:   {
 125:     if (image != null)
 126:       {
 127:         Dimension is = new Dimension(image.getWidth(this),
 128:                                      image.getHeight(this));
 129:         if (is.width > -1 && is.height > -1)
 130:           {
 131:             Dimension cs = getSize();
 132:             g.drawImage(image, 0, 0, cs.width, cs.height,
 133:                         0, 0, is.width, is.height, this);
 134:           }
 135:       }
 136:   }
 137: 
 138: }