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