Source for javax.imageio.spi.IIORegistry

   1: /* IIORegistry.java --
   2:    Copyright (C) 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 javax.imageio.spi;
  40: 
  41: import gnu.classpath.ServiceFactory;
  42: 
  43: import java.awt.Toolkit;
  44: import java.util.HashMap;
  45: import java.util.HashSet;
  46: import java.util.Iterator;
  47: 
  48: import gnu.java.awt.ClasspathToolkit;
  49: import gnu.javax.imageio.bmp.BMPImageReaderSpi;
  50: import gnu.javax.imageio.bmp.BMPImageWriterSpi;
  51: import gnu.javax.imageio.gif.GIFImageReaderSpi;
  52: import gnu.javax.imageio.png.PNGImageReaderSpi;
  53: 
  54: public final class IIORegistry extends ServiceRegistry
  55: {
  56:   private static final HashSet defaultCategories = new HashSet();
  57: 
  58:   private static HashMap instances = new HashMap();
  59: 
  60:   static
  61:   {
  62:     defaultCategories.add(ImageReaderSpi.class);
  63:     defaultCategories.add(ImageWriterSpi.class);
  64:     defaultCategories.add(ImageTranscoderSpi.class);
  65:     defaultCategories.add(ImageInputStreamSpi.class);
  66:     defaultCategories.add(ImageOutputStreamSpi.class);
  67:   }
  68: 
  69:   public static synchronized IIORegistry getDefaultInstance()
  70:   {
  71:     // XXX: This leaks memory if a ThreadGroup isn't available anymore.
  72:     ThreadGroup group = Thread.currentThread().getThreadGroup();
  73:     IIORegistry registry = (IIORegistry) instances.get(group);
  74: 
  75:     if (registry == null)
  76:       {
  77:         registry = new IIORegistry();
  78:         instances.put(group, registry);
  79:       }
  80: 
  81:     return registry;
  82:   }
  83: 
  84:   private IIORegistry()
  85:   {
  86:     super(defaultCategories.iterator());
  87: 
  88:     // XXX: Register built-in Spis here.
  89:     registerServiceProvider(new PNGImageReaderSpi()); // Register PNG decoder.
  90:     registerServiceProvider(new GIFImageReaderSpi()); // Register GIF decoder.
  91:     registerServiceProvider(new BMPImageReaderSpi());
  92:     registerServiceProvider(new BMPImageWriterSpi());
  93: 
  94:     Toolkit toolkit = Toolkit.getDefaultToolkit();
  95:     if (toolkit instanceof ClasspathToolkit)
  96:       ((ClasspathToolkit)toolkit).registerImageIOSpis(this);
  97: 
  98:     registerApplicationClasspathSpis();
  99:   }
 100: 
 101:   /**
 102:    * Registers all available service providers found on the application
 103:    * classpath.
 104:    */
 105:   public void registerApplicationClasspathSpis()
 106:   {
 107:     ClassLoader loader = Thread.currentThread().getContextClassLoader();
 108:     Iterator categories = getCategories();
 109: 
 110:     while (categories.hasNext())
 111:       {
 112:         Class category = (Class) categories.next();
 113:         Iterator providers = ServiceFactory.lookupProviders(category, loader);
 114: 
 115:         while (providers.hasNext())
 116:           registerServiceProvider((IIOServiceProvider) providers.next());
 117:       }
 118:   }
 119: }