libjava/gnu/java/awt/image/XBMDecoder.java

   1 /* XBMDecoder -- Decodes X-bitmaps
   2    Copyright (C) 1999, 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
  39 package gnu.java.awt.image;
  40
  41 import java.awt.image.ColorModel;
  42 import java.awt.image.ImageConsumer;
  43 import java.io.BufferedReader;
  44 import java.io.InputStream;
  45 import java.io.InputStreamReader;
  46 import java.io.IOException;
  47 import java.io.Reader;
  48 import java.net.URL;
  49 import java.util.StringTokenizer;
  50 import java.util.Vector;
  51
  52 public class XBMDecoder extends ImageDecoder
  53 {
  54   BufferedReader reader;
  55   static final ColorModel cm = ColorModel.getRGBdefault ();
  56   static final int black = 0xff000000;
  57   static final int transparent = 0x00000000;
  58   static final int masktable[] = { 0x01, 0x02, 0x04, 0x08,
  59                                    0x10, 0x20, 0x40, 0x80 };
  60
  61   public XBMDecoder (String filename)
  62   {
  63     super (filename);
  64   }
  65
  66   public XBMDecoder (URL url)
  67   {
  68     super (url);
  69   }
  70
  71   public void produce (Vector v, InputStream is) throws IOException
  72   {
  73     reader = new BufferedReader (new InputStreamReader (is));
  74     int width = -1, height = -1;
  75
  76     for (int i = 0; i < 2; i++)
  77       {
  78         String line = reader.readLine ();
  79         StringTokenizer st = new StringTokenizer (line);
  80
  81         st.nextToken ();                // #define
  82         st.nextToken ();                // name_[width|height]
  83         if (i == 0)
  84           width = Integer.parseInt (st.nextToken (), 10);
  85         else
  86           height = Integer.parseInt (st.nextToken (), 10);
  87       }
  88
  89     for (int i = 0; i < v.size (); i++)
  90       {
  91         ImageConsumer ic = (ImageConsumer) v.elementAt (i);
  92
  93         ic.setDimensions (width, height);
  94         ic.setColorModel (cm);
  95         ic.setHints (ImageConsumer.COMPLETESCANLINES
  96                      | ImageConsumer.SINGLEFRAME
  97                      | ImageConsumer.SINGLEPASS
  98                      | ImageConsumer.TOPDOWNLEFTRIGHT);
  99       }
 100
 101     /* skip to the byte array */
 102     while (reader.read () != '{') { }
 103
 104     /* loop through each scanline */
 105     for (int line = 0; line < height; line++)
 106       {
 107         int scanline[] = getScanline (reader, width);
 108
 109         for (int i = 0; i < v.size (); i++)
 110           {
 111             ImageConsumer ic = (ImageConsumer) v.elementAt (i);
 112             ic.setPixels (0, 0 + line, width, 1, cm, scanline, 0, width);
 113           }
 114       }
 115
 116     /* tell each ImageConsumer that we're finished */
 117     for (int i = 0; i < v.size (); i++)
 118       {
 119         ImageConsumer ic = (ImageConsumer) v.elementAt (i);
 120         ic.imageComplete (ImageConsumer.STATICIMAGEDONE);
 121       }
 122   }
 123
 124   static public int[] getScanline (Reader in, int len) throws IOException
 125   {
 126     char byteStr[] = new char[2];
 127     int scanline[] = new int[len];
 128     int x = 0;
 129
 130     while (x < len)
 131       {
 132         int ch = in.read ();
 133         if (ch == '0')
 134           {
 135             in.read ();         // 'x'
 136
 137             byteStr[0] = (char) in.read ();
 138             byteStr[1] = (char) in.read ();
 139
 140             int byteVal = Integer.parseInt (new String (byteStr), 16);
 141
 142             for (int i = 0; i < 8; i++, x++)
 143               {
 144                 if (x == len)   // condition occurs if bitmap is padded
 145                   return scanline;
 146
 147                 scanline[x] = ((byteVal & masktable[i]) != 0) ?
 148                                black : transparent;
 149               }
 150           }
 151       }
 152
 153     return scanline;
 154   }
 155 }