Source for gnu.javax.imageio.jpeg.JPEGImageReader

   1: /* JPEGImageReader.java --
   2:    Copyright (C)  2006  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.imageio.jpeg;
  39: 
  40: import java.io.IOException;
  41: import javax.imageio.*;
  42: import javax.imageio.spi.*;
  43: import javax.imageio.metadata.*;
  44: import javax.imageio.stream.ImageInputStream;
  45: import java.util.Iterator;
  46: import java.awt.image.BufferedImage;
  47: 
  48: public class JPEGImageReader extends ImageReader
  49: {
  50:   JPEGDecoder decoder;
  51: 
  52:   protected JPEGImageReader(ImageReaderSpi originatingProvider)
  53:   {
  54:     super(originatingProvider);
  55:     System.out.println("JPEGIMAGEREADER!!!");
  56:   }
  57: 
  58:   // Abstract ImageReader methods.
  59:   public int getHeight(int imageIndex)
  60:     throws IOException
  61:   {
  62:     checkIndex(imageIndex);
  63:     decodeStream();
  64:     return decoder.getHeight();
  65:   }
  66: 
  67:   public IIOMetadata getImageMetadata(int imageIndex)
  68:     throws IOException
  69:   {
  70:     // FIXME: handle metadata
  71:     checkIndex(imageIndex);
  72:     return null;
  73:   }
  74: 
  75:   public Iterator getImageTypes(int imageIndex)
  76:     throws IOException
  77:   {
  78:     return null;
  79:   }
  80: 
  81:   public int getNumImages(boolean allowSearch)
  82:     throws IOException
  83:   {
  84:     return 1;
  85:   }
  86: 
  87:   public IIOMetadata getStreamMetadata()
  88:     throws IOException
  89:   {
  90:     // FIXME: handle metadata
  91:     return null;
  92:   }
  93: 
  94:   public int getWidth(int imageIndex)
  95:     throws IOException
  96:   {
  97:     checkIndex(imageIndex);
  98:     decodeStream();
  99:     return decoder.getWidth();
 100:   }
 101: 
 102:   public BufferedImage read(int imageIndex, ImageReadParam param)
 103:     throws IOException
 104:   {
 105:     checkIndex(imageIndex);
 106:     decodeStream();
 107:     return decoder.getImage();
 108:   }
 109: 
 110:   // private helper methods
 111:   private void checkIndex(int imageIndex)
 112:     throws IndexOutOfBoundsException
 113:   {
 114:     if (imageIndex != 0)
 115:       throw new IndexOutOfBoundsException();
 116:   }
 117: 
 118:   private void checkStream() throws IOException
 119:   {
 120:     if (!(input instanceof ImageInputStream))
 121:       throw new IllegalStateException("Input not an ImageInputStream.");
 122:     if(input == null)
 123:       throw new IllegalStateException("No input stream.");
 124:   }
 125: 
 126:   private void decodeStream()
 127:     throws IOException, IIOException
 128:   {
 129:     System.out.println("DECONDING 1");
 130:     if (decoder != null)
 131:       return;
 132: 
 133:     System.out.println("DECONDING 2");
 134:     checkStream();
 135: 
 136:     System.out.println("DECONDING 3");
 137:     decoder = new JPEGDecoder((ImageInputStream)input);
 138:     System.out.println("DECONDING 4");
 139:     decoder.decode();
 140:   }
 141: }