gomp-20050608-branch/libjava/classpath/gnu/java/beans/DummyAppletContext.java

   1 /* gnu.java.beans.DummyAppletContext
   2    Copyright (C) 2004, 2005 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.beans;
  40
  41 import java.applet.Applet;
  42 import java.applet.AppletContext;
  43 import java.applet.AudioClip;
  44 import java.awt.Image;
  45 import java.awt.Toolkit;
  46 import java.io.IOException;
  47 import java.io.InputStream;
  48 import java.net.URL;
  49 import java.util.Collections;
  50 import java.util.Enumeration;
  51 import java.util.Iterator;
  52
  53 /** A placeholder <code>AppletContext</code> implementation that does nothing.
  54  *
  55  * <p>This is the default implementation for GNU Classpath and is used for <code>Applet</code>
  56  * beans being created with {@link java.beans.Beans.instantiate}.</p>
  57  *
  58  * <p>It has no functionality in order to allow it to be used without any dependencies
  59  * (e.g. sound, network access, ...).</p>
  60  *
  61  * @author Robert Schuster
  62  */
  63 class DummyAppletContext implements AppletContext
  64 {
  65   private static final Enumeration EMPTY_ENUMERATION = Collections.enumeration(Collections.EMPTY_SET);
  66
  67   DummyAppletContext()
  68   {
  69   }
  70
  71   /** Implementation is VM neutral and returns a dummy {@link AudioClip} instance
  72    * for every URL that returns a non-<code>null</code> object on
  73    * <code>URL.openConnection()</code>.
  74    *
  75    * @see java.applet.AppletContext#getAudioClip(java.net.URL)
  76    *
  77    * FIXME: When Java Sound API (javax.sound) is included in Classpath or URL is able to handle
  78    * sampled sound this should be adjusted.
  79    */
  80   public AudioClip getAudioClip(URL url)
  81   {
  82     return Applet.newAudioClip(url);
  83   }
  84
  85   /** Loads the <code>Image</code> instance by delegating to
  86    * {@link java.awt.Toolkit.createImage(URL) }.
  87    *
  88    * @see java.applet.AppletContext#getImage(java.net.URL)
  89    * @see java.awt.Toolkit#createImage(java.net.URL)
  90    */
  91   public Image getImage(URL url)
  92   {
  93     return Toolkit.getDefaultToolkit().createImage(url);
  94   }
  95
  96   /** Returns <code>null</code> for every argument.
  97    *
  98    * @see java.applet.AppletContext#getApplet(java.lang.String)
  99    */
 100   public Applet getApplet(String name)
 101   {
 102     return null;
 103   }
 104
 105   /** Returns always an empty <code>Enumeration</code>.
 106    *
 107    * @see java.applet.AppletContext#getApplets()
 108    */
 109   public Enumeration getApplets()
 110   {
 111     return EMPTY_ENUMERATION;
 112   }
 113
 114   /** Does nothing.
 115    *
 116    * @see java.applet.AppletContext#showDocument(java.net.URL)
 117    */
 118   public void showDocument(URL url)
 119   {
 120   }
 121
 122   /** Does nothing.
 123    *
 124    * @see java.applet.AppletContext#showDocument(java.net.URL, java.lang.String)
 125    */
 126   public void showDocument(URL url, String target)
 127   {
 128   }
 129
 130   /** Does nothing.
 131    *
 132    * @see java.applet.AppletContext#showStatus(java.lang.String)
 133    */
 134   public void showStatus(String message)
 135   {
 136   }
 137
 138   /** Does nothing.
 139    *
 140    * @see java.applet.AppletContext#setStream(java.lang.String, java.io.InputStream)
 141    */
 142   public void setStream(String key, InputStream stream)
 143     throws IOException
 144   {
 145     throw new IOException("Dummy implementation imposes zero InputStream associations.");
 146   }
 147
 148   /** Returns <code>null</code> for every argument.
 149    *
 150    * @see java.applet.AppletContext#getStream(java.lang.String)
 151    */
 152   public InputStream getStream(String key)
 153   {
 154     return null;
 155   }
 156
 157   /** Returns always an empty iterator.
 158    *
 159    * @see java.applet.AppletContext#getStreamKeys()
 160    */
 161   public Iterator getStreamKeys()
 162   {
 163     return Collections.EMPTY_SET.iterator();
 164   }
 165 }