001 /* AppletContext.java -- access the applet's runtime environment
002 Copyright (C) 1999, 2002, 2004 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039 package java.applet;
040
041 import java.awt.Image;
042 import java.io.IOException;
043 import java.io.InputStream;
044 import java.net.URL;
045 import java.util.Enumeration;
046 import java.util.Iterator;
047
048 /**
049 * This interface allows an applet access to the browser to retrieve
050 * additional data files and display documents. It also allows the
051 * applet to find out other applets in the same document.
052 *
053 * @author Aaron M. Renn (arenn@urbanophile.com)
054 * @since 1.0
055 * @status updated to 1.5
056 */
057 public interface AppletContext
058 {
059 /**
060 * Returns an audio clip from the specified URL.
061 *
062 * @param url the URL of the audio clip
063 * @return the retrieved audio clip
064 * @throws NullPointerException if url is null
065 */
066 AudioClip getAudioClip(URL url);
067
068 /**
069 * Returns an image from the specified URL. Note that the image is not
070 * actually retrieved until the applet attempts to display it, so this
071 * method returns immediately.
072 *
073 * @param url the absolute URL of the image
074 * @return the retrieved image
075 * @throws NullPointerException if url is null
076 */
077 Image getImage(URL url);
078
079 /**
080 * Returns the applet in the document for this object that has the
081 * specified name.
082 *
083 * @param name the applet name
084 * @return the requested applet, or <code>null</code> if not found
085 */
086 Applet getApplet(String name);
087
088 /**
089 * Returns a list of all the applets in the document for this object.
090 *
091 * @return a list of all the applets
092 */
093 Enumeration<Applet> getApplets();
094
095 /**
096 * Displays the web page pointed to by the specified URL in the window
097 * for this object. This page replaces the document that is currently
098 * there.
099 *
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<String> getStreamKeys();
154 } // interface AppletContext