Source for gnu.java.awt.image.XBMDecoder

   1: /* XBMDecoder.java -- 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., 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: 
  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.IOException;
  45: import java.io.InputStream;
  46: import java.io.InputStreamReader;
  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:   public static 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: }