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

   1 /* ImageDecoder.java
   2    Copyright (C) 1999, 2000, 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., 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.image.ImageConsumer;
  41 import java.awt.image.ImageProducer;
  42 import java.io.ByteArrayInputStream;
  43 import java.io.FileInputStream;
  44 import java.io.InputStream;
  45 import java.io.IOException;
  46 import java.net.URL;
  47 import java.util.Vector;
  48
  49 public abstract class ImageDecoder implements ImageProducer
  50 {
  51   Vector consumers = new Vector ();
  52   String filename;
  53   URL url;
  54   byte[] data;
  55   int offset;
  56   int length;
  57   InputStream input;
  58
  59   static
  60   {
  61     // FIXME: there was some broken code here that looked like
  62     // it wanted to rely on this property.  I don't have any idea
  63     // what it was intended to do.
  64     // String endian = System.getProperties ().getProperty ("gnu.cpu.endian");
  65   }
  66
  67   public ImageDecoder (String filename)
  68   {
  69     this.filename = filename;
  70   }
  71
  72   public ImageDecoder (URL url)
  73   {
  74     this.url = url;
  75   }
  76
  77   public ImageDecoder (InputStream is)
  78   {
  79     this.input = is;
  80   }
  81
  82   public ImageDecoder (byte[] imagedata, int imageoffset, int imagelength)
  83   {
  84     data = imagedata;
  85     offset = imageoffset;
  86     length = imagelength;
  87   }
  88
  89   public void addConsumer (ImageConsumer ic)
  90   {
  91     consumers.addElement (ic);
  92   }
  93
  94   public boolean isConsumer (ImageConsumer ic)
  95   {
  96     return consumers.contains (ic);
  97   }
  98
  99   public void removeConsumer (ImageConsumer ic)
 100   {
 101     consumers.removeElement (ic);
 102   }
 103
 104   public void startProduction (ImageConsumer ic)
 105   {
 106     if (!isConsumer(ic))
 107       addConsumer(ic);
 108
 109     Vector list = (Vector) consumers.clone ();
 110     try
 111       {
 112         // Create the input stream here rather than in the
 113         // ImageDecoder constructors so that exceptions cause
 114         // imageComplete to be called with an appropriate error
 115         // status.
 116         if (input == null)
 117           {
 118             try
 119               {
 120                 if (url != null)
 121                   input = url.openStream();
 122                 else
 123                   {
 124                     if (filename != null)
 125                       input = new FileInputStream (filename);
 126                     else
 127                       input = new ByteArrayInputStream (data, offset, length);
 128                   }
 129                 produce (list, input);
 130               }
 131             finally
 132               {
 133                 input = null;
 134               }
 135           }
 136         else
 137           {
 138             produce (list, input);
 139           }
 140       }
 141     catch (Exception e)
 142       {
 143         for (int i = 0; i < list.size (); i++)
 144           {
 145             ImageConsumer ic2 = (ImageConsumer) list.elementAt (i);
 146             ic2.imageComplete (ImageConsumer.IMAGEERROR);
 147           }
 148       }
 149   }
 150
 151   public void requestTopDownLeftRightResend (ImageConsumer ic)
 152   {
 153   }
 154
 155   public abstract void produce (Vector v, InputStream is) throws IOException;
 156 }