libjava/java/applet/AppletContext.java

   1 /* AppletContext.java -- access the applet's runtime environment
   2    Copyright (C) 1999, 2002 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 java.applet;
  40
  41 import java.awt.Image;
  42 import java.io.InputStream;
  43 import java.io.IOException;
  44 import java.net.URL;
  45 import java.util.Enumeration;
  46 import java.util.Iterator;
  47
  48 /**
  49  * This interface allows an applet access to the browser to retrieve
  50  * additional data files and display documents.  It also allows the
  51  * applet to find out other applets in the same document.
  52  *
  53  * @author Aaron M. Renn (arenn@urbanophile.com)
  54  * @since 1.0
  55  * @status updated to 1.4
  56  */
  57 public interface AppletContext
  58 {
  59   /**
  60    * Returns an audio clip from the specified URL.
  61    *
  62    * @param url the URL of the audio clip
  63    * @return the retrieved audio clip
  64    * @throws NullPointerException if url is null
  65    */
  66   AudioClip getAudioClip(URL url);
  67
  68   /**
  69    * Returns an image from the specified URL.  Note that the image is not
  70    * actually retrieved until the applet attempts to display it, so this
  71    * method returns immediately.
  72    *
  73    * @param url the absolute URL of the image
  74    * @return the retrieved image
  75    * @throws NullPointerException if url is null
  76    */
  77   Image getImage(URL url);
  78
  79   /**
  80    * Returns the applet in the document for this object that has the
  81    * specified name.
  82    *
  83    * @param name the applet name
  84    * @return the requested applet, or <code>null</code> if not found
  85    */
  86   Applet getApplet(String name);
  87
  88   /**
  89    * Returns a list of all the applets in the document for this object.
  90    *
  91    * @return a list of all the applets
  92    */
  93   Enumeration getApplets();
  94
  95   /**
  96    * Displays the web page pointed to by the specified URL in the window
  97    * for this object.  This page replaces the document that is currently
  98    * there.
  99    *
 100    * @param url the URL of the web page to load; unspecified on an error
 101    */
 102   void showDocument(URL url);
 103
 104   /**
 105    * Displays the web page pointed to be the sepcified URL in the window
 106    * with the specified name.  The standard names "_top", "_blank",
 107    * "_parent", and "_self" are allowed. An applet viewer may disregard
 108    * this request.
 109    *
 110    * @param url the URL of the web page to load
 111    * @param target the target window
 112    */
 113   void showDocument(URL url, String target);
 114
 115   /**
 116    * Displays the specified message in the status window if that window
 117    * exists.
 118    *
 119    * @param message the status message, may be null
 120    */
 121   void showStatus(String message);
 122
 123   /**
 124    * Associate a stream to a key for this applet context, possibly replacing
 125    * the old value. Stream associations are local to the applet context, for
 126    * security purposes.
 127    *
 128    * @param key the key to associate with
 129    * @param stream the stream value to tie to the key, or null to remove
 130    * @throws IOException if the stream is too large
 131    * @since 1.4
 132    */
 133   void setStream(String key, InputStream stream) throws IOException;
 134
 135   /**
 136    * Return the stream associated with a given key in this applet context, or
 137    * null if nothing is associated. Stream associations are local to the
 138    * applet context, for security purposes.
 139    *
 140    * @param key the key to look up
 141    * @return the associated stream, or null
 142    * @since 1.4
 143    */
 144   InputStream getStream(String key);
 145
 146   /**
 147    * Iterate over all keys that have associated streams. Stream associated
 148    * are local to the applet context, for security purposes.
 149    *
 150    * @return an iterator over the association keys
 151    * @since 1.4
 152    */
 153   Iterator getStreamKeys();
 154 } // interface AppletContext