libjava/gnu/java/awt/image/ImageDecoder.java

   1 /* ImageDecoder.java
   2    Copyright (C) 1999, 2000 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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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.java.awt.image;
  39
  40 import java.awt.*;
  41 import java.awt.image.*;
  42 import java.util.*;
  43 import java.io.*;
  44 import java.net.URL;
  45
  46 public abstract class ImageDecoder implements ImageProducer
  47 {
  48   Vector consumers = new Vector ();
  49   String filename;
  50   URL url;
  51   byte[] data;
  52   int offset;
  53   int length;
  54   InputStream input;
  55
  56   public static ColorModel cm;
  57
  58   static
  59   {
  60     // FIXME: there was some broken code here that looked like
  61     // it wanted to rely on this property.  I don't have any idea
  62     // what it was intended to do.
  63     // String endian = System.getProperties ().getProperty ("gnu.cpu.endian");
  64   }
  65
  66   public ImageDecoder (String filename)
  67   {
  68     this.filename = filename;
  69   }
  70
  71   public ImageDecoder (URL url)
  72   {
  73     this.url = url;
  74   }
  75
  76   public ImageDecoder (byte[] imagedata, int imageoffset, int imagelength)
  77   {
  78     data = imagedata;
  79     offset = imageoffset;
  80     length = imagelength;
  81   }
  82
  83   public void addConsumer (ImageConsumer ic)
  84   {
  85     consumers.addElement (ic);
  86   }
  87
  88   public boolean isConsumer (ImageConsumer ic)
  89   {
  90     return consumers.contains (ic);
  91   }
  92
  93   public void removeConsumer (ImageConsumer ic)
  94   {
  95     consumers.removeElement (ic);
  96   }
  97
  98   public void startProduction (ImageConsumer ic)
  99   {
 100     addConsumer (ic);
 101     Vector list = (Vector) consumers.clone ();
 102     try
 103       {
 104         // Create the input stream here rather than in the
 105         // ImageDecoder constructors so that exceptions cause
 106         // imageComplete to be called with an appropriate error
 107         // status.
 108         if (url != null)
 109           input = url.openStream();
 110         else
 111           {
 112             if (filename != null)
 113               input = new FileInputStream (filename);
 114             else
 115               input = new ByteArrayInputStream (data, offset, length);
 116           }
 117
 118         produce (list, input);
 119       }
 120     catch (Exception e)
 121       {
 122         for (int i = 0; i < list.size (); i++)
 123           {
 124             ImageConsumer ic2 = (ImageConsumer) list.elementAt (i);
 125             ic2.imageComplete (ImageConsumer.IMAGEERROR);
 126           }
 127       }
 128   }
 129
 130   public void requestTopDownLeftRightResend (ImageConsumer ic)
 131   {
 132   }
 133
 134   abstract void produce (Vector v, InputStream is) throws IOException;
 135 }