001 /*
002 * Copyright 1995-2006 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package java.applet;
027
028 import java.awt.Image;
029 import java.awt.Graphics;
030 import java.awt.image.ColorModel;
031 import java.net.URL;
032 import java.util.Enumeration;
033 import java.io.InputStream;
034 import java.io.IOException;
035 import java.util.Iterator;
036
037 /**
038 * This interface corresponds to an applet's environment: the
039 * document containing the applet and the other applets in the same
040 * document.
041 * <p>
042 * The methods in this interface can be used by an applet to obtain
043 * information about its environment.
044 *
045 * @author Arthur van Hoff
046 * @version 1.41, 05/05/07
047 * @since JDK1.0
048 */
049 public interface AppletContext {
050 /**
051 * Creates an audio clip.
052 *
053 * @param url an absolute URL giving the location of the audio clip.
054 * @return the audio clip at the specified URL.
055 */
056 AudioClip getAudioClip(URL url);
057
058 /**
059 * Returns an <code>Image</code> object that can then be painted on
060 * the screen. The <code>url</code> argument<code> </code>that is
061 * passed as an argument must specify an absolute URL.
062 * <p>
063 * This method always returns immediately, whether or not the image
064 * exists. When the applet attempts to draw the image on the screen,
065 * the data will be loaded. The graphics primitives that draw the
066 * image will incrementally paint on the screen.
067 *
068 * @param url an absolute URL giving the location of the image.
069 * @return the image at the specified URL.
070 * @see java.awt.Image
071 */
072 Image getImage(URL url);
073
074 /**
075 * Finds and returns the applet in the document represented by this
076 * applet context with the given name. The name can be set in the
077 * HTML tag by setting the <code>name</code> attribute.
078 *
079 * @param name an applet name.
080 * @return the applet with the given name, or <code>null</code> if
081 * not found.
082 */
083 Applet getApplet(String name);
084
085 /**
086 * Finds all the applets in the document represented by this applet
087 * context.
088 *
089 * @return an enumeration of all applets in the document represented by
090 * this applet context.
091 */
092 Enumeration<Applet> getApplets();
093
094 /**
095 * Requests that the browser or applet viewer show the Web page
096 * indicated by the <code>url</code> argument. The browser or
097 * applet viewer determines which window or frame to display the
098 * Web page. This method may be ignored by applet contexts that
099 * are not browsers.
100 *
101 * @param url an absolute URL giving the location of the document.
102 */
103 void showDocument(URL url);
104
105 /**
106 * Requests that the browser or applet viewer show the Web page
107 * indicated by the <code>url</code> argument. The
108 * <code>target</code> argument indicates in which HTML frame the
109 * document is to be displayed.
110 * The target argument is interpreted as follows:
111 * <p>
112 * <center><table border="3" summary="Target arguments and their descriptions">
113 * <tr><th>Target Argument</th><th>Description</th></tr>
114 * <tr><td><code>"_self"</code> <td>Show in the window and frame that
115 * contain the applet.</tr>
116 * <tr><td><code>"_parent"</code><td>Show in the applet's parent frame. If
117 * the applet's frame has no parent frame,
118 * acts the same as "_self".</tr>
119 * <tr><td><code>"_top"</code> <td>Show in the top-level frame of the applet's
120 * window. If the applet's frame is the
121 * top-level frame, acts the same as "_self".</tr>
122 * <tr><td><code>"_blank"</code> <td>Show in a new, unnamed
123 * top-level window.</tr>
124 * <tr><td><i>name</i><td>Show in the frame or window named <i>name</i>. If
125 * a target named <i>name</i> does not already exist, a
126 * new top-level window with the specified name is created,
127 * and the document is shown there.</tr>
128 * </table> </center>
129 * <p>
130 * An applet viewer or browser is free to ignore <code>showDocument</code>.
131 *
132 * @param url an absolute URL giving the location of the document.
133 * @param target a <code>String</code> indicating where to display
134 * the page.
135 */
136 public void showDocument(URL url, String target);
137
138 /**
139 * Requests that the argument string be displayed in the
140 * "status window". Many browsers and applet viewers
141 * provide such a window, where the application can inform users of
142 * its current state.
143 *
144 * @param status a string to display in the status window.
145 */
146 void showStatus(String status);
147
148 /**
149 * Associates the specified stream with the specified key in this
150 * applet context. If the applet context previously contained a mapping
151 * for this key, the old value is replaced.
152 * <p>
153 * For security reasons, mapping of streams and keys exists for each
154 * codebase. In other words, applet from one codebase cannot access
155 * the streams created by an applet from a different codebase
156 * <p>
157 * @param key key with which the specified value is to be associated.
158 * @param stream stream to be associated with the specified key. If this
159 * parameter is <code>null</code>, the specified key is removed
160 * in this applet context.
161 * @throws <code>IOException</code> if the stream size exceeds a certain
162 * size limit. Size limit is decided by the implementor of this
163 * interface.
164 * @since 1.4
165 */
166 public void setStream(String key, InputStream stream)
167 throws IOException;
168
169 /**
170 * Returns the stream to which specified key is associated within this
171 * applet context. Returns <tt>null</tt> if the applet context contains
172 * no stream for this key.
173 * <p>
174 * For security reasons, mapping of streams and keys exists for each
175 * codebase. In other words, applet from one codebase cannot access
176 * the streams created by an applet from a different codebase
177 * <p>
178 * @return the stream to which this applet context maps the key
179 * @param key key whose associated stream is to be returned.
180 * @since 1.4
181 */
182 public InputStream getStream(String key);
183
184 /**
185 * Finds all the keys of the streams in this applet context.
186 * <p>
187 * For security reasons, mapping of streams and keys exists for each
188 * codebase. In other words, applet from one codebase cannot access
189 * the streams created by an applet from a different codebase
190 * <p>
191 * @return an Iterator of all the names of the streams in this applet
192 * context.
193 * @since 1.4
194 */
195 public Iterator<String> getStreamKeys();
196 }
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