libjava/classpath/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., 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.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.DataInput;
  44 import java.io.EOFException;
  45 import java.io.FileInputStream;
  46 import java.io.IOException;
  47 import java.io.InputStream;
  48 import java.net.URL;
  49 import java.util.Vector;
  50
  51 public abstract class ImageDecoder implements ImageProducer
  52 {
  53   Vector consumers = new Vector ();
  54   String filename;
  55   URL url;
  56   byte[] data;
  57   int offset;
  58   int length;
  59   InputStream input;
  60   DataInput datainput;
  61
  62   static
  63   {
  64     // FIXME: there was some broken code here that looked like
  65     // it wanted to rely on this property.  I don't have any idea
  66     // what it was intended to do.
  67     // String endian = System.getProperties ().getProperty ("gnu.cpu.endian");
  68   }
  69
  70   public ImageDecoder (String filename)
  71   {
  72     this.filename = filename;
  73   }
  74
  75   public ImageDecoder (URL url)
  76   {
  77     this.url = url;
  78   }
  79
  80   public ImageDecoder (InputStream is)
  81   {
  82     this.input = is;
  83   }
  84
  85   public ImageDecoder (DataInput datainput)
  86   {
  87     this.datainput = datainput;
  88   }
  89
  90   public ImageDecoder (byte[] imagedata, int imageoffset, int imagelength)
  91   {
  92     data = imagedata;
  93     offset = imageoffset;
  94     length = imagelength;
  95   }
  96
  97   public void addConsumer (ImageConsumer ic)
  98   {
  99     consumers.addElement (ic);
 100   }
 101
 102   public boolean isConsumer (ImageConsumer ic)
 103   {
 104     return consumers.contains (ic);
 105   }
 106
 107   public void removeConsumer (ImageConsumer ic)
 108   {
 109     consumers.removeElement (ic);
 110   }
 111
 112   public void startProduction (ImageConsumer ic)
 113   {
 114     if (!isConsumer(ic))
 115       addConsumer(ic);
 116
 117     Vector list = (Vector) consumers.clone ();
 118     try
 119       {
 120         // Create the input stream here rather than in the
 121         // ImageDecoder constructors so that exceptions cause
 122         // imageComplete to be called with an appropriate error
 123         // status.
 124         if (input == null)
 125           {
 126             try
 127               {
 128                 if (url != null)
 129                   input = url.openStream();
 130                 else if (datainput != null)
 131                   input = new DataInputStreamWrapper(datainput);
 132                 else
 133                   {
 134                     if (filename != null)
 135                       input = new FileInputStream (filename);
 136                     else
 137                       input = new ByteArrayInputStream (data, offset, length);
 138                   }
 139                 produce (list, input);
 140               }
 141             finally
 142               {
 143                 input = null;
 144               }
 145           }
 146         else
 147           {
 148             produce (list, input);
 149           }
 150       }
 151     catch (Exception e)
 152       {
 153         for (int i = 0; i < list.size (); i++)
 154           {
 155             ImageConsumer ic2 = (ImageConsumer) list.elementAt (i);
 156             ic2.imageComplete (ImageConsumer.IMAGEERROR);
 157           }
 158       }
 159   }
 160
 161   public void requestTopDownLeftRightResend (ImageConsumer ic)
 162   {
 163   }
 164
 165   public abstract void produce (Vector v, InputStream is) throws IOException;
 166
 167   private static class DataInputStreamWrapper extends InputStream
 168   {
 169     private final DataInput datainput;
 170
 171     DataInputStreamWrapper(DataInput datainput)
 172     {
 173       this.datainput = datainput;
 174     }
 175
 176     public int read() throws IOException
 177     {
 178       try
 179         {
 180           return datainput.readByte() & 0xFF;
 181         }
 182       catch (EOFException eofe)
 183         {
 184           return -1;
 185         }
 186     }
 187   }
 188 }