1 /* 2 * Copyright (c) 1995, 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.applet; 27 28 import java.awt.Image; 29 import java.awt.Graphics; 30 import java.awt.image.ColorModel; 31 import java.net.URL; 32 import java.util.Enumeration; 33 import java.io.InputStream; 34 import java.io.IOException; 35 import java.util.Iterator; 36 37 /** 38 * This interface corresponds to an applet's environment: the 39 * document containing the applet and the other applets in the same 40 * document. 41 * <p> 42 * The methods in this interface can be used by an applet to obtain 43 * information about its environment. 44 * 45 * @author Arthur van Hoff 46 * @since 1.0 47 */ 48 public interface AppletContext { 49 /** 50 * Creates an audio clip. 51 * 52 * @param url an absolute URL giving the location of the audio clip. 53 * @return the audio clip at the specified URL. 54 */ 55 AudioClip getAudioClip(URL url); 56 57 /** 58 * Returns an <code>Image</code> object that can then be painted on 59 * the screen. The <code>url</code> argument that is 60 * passed as an argument must specify an absolute URL. 61 * <p> 62 * This method always returns immediately, whether or not the image 63 * exists. When the applet attempts to draw the image on the screen, 64 * the data will be loaded. The graphics primitives that draw the 65 * image will incrementally paint on the screen. 66 * 67 * @param url an absolute URL giving the location of the image. 68 * @return the image at the specified URL. 69 * @see java.awt.Image 70 */ 71 Image getImage(URL url); 72 73 /** 74 * Finds and returns the applet in the document represented by this 75 * applet context with the given name. The name can be set in the 76 * HTML tag by setting the <code>name</code> attribute. 77 * 78 * @param name an applet name. 79 * @return the applet with the given name, or <code>null</code> if 80 * not found. 81 */ 82 Applet getApplet(String name); 83 84 /** 85 * Finds all the applets in the document represented by this applet 86 * context. 87 * 88 * @return an enumeration of all applets in the document represented by 89 * this applet context. 90 */ 91 Enumeration<Applet> getApplets(); 92 93 /** 94 * Requests that the browser or applet viewer show the Web page 95 * indicated by the <code>url</code> argument. The browser or 96 * applet viewer determines which window or frame to display the 97 * Web page. This method may be ignored by applet contexts that 98 * are not browsers. 99 * 100 * @param url an absolute URL giving the location of the document. 101 */ 102 void showDocument(URL url); 103 104 /** 105 * Requests that the browser or applet viewer show the Web page 106 * indicated by the <code>url</code> argument. The 107 * <code>target</code> argument indicates in which HTML frame the 108 * document is to be displayed. 109 * The target argument is interpreted as follows: 110 * 111 * <center><table border="3" summary="Target arguments and their descriptions"> 112 * <tr><th>Target Argument</th><th>Description</th></tr> 113 * <tr><td><code>"_self"</code> <td>Show in the window and frame that 114 * contain the applet.</tr> 115 * <tr><td><code>"_parent"</code><td>Show in the applet's parent frame. If 116 * the applet's frame has no parent frame, 117 * acts the same as "_self".</tr> 118 * <tr><td><code>"_top"</code> <td>Show in the top-level frame of the applet's 119 * window. If the applet's frame is the 120 * top-level frame, acts the same as "_self".</tr> 121 * <tr><td><code>"_blank"</code> <td>Show in a new, unnamed 122 * top-level window.</tr> 123 * <tr><td><i>name</i><td>Show in the frame or window named <i>name</i>. If 124 * a target named <i>name</i> does not already exist, a 125 * new top-level window with the specified name is created, 126 * and the document is shown there.</tr> 127 * </table> </center> 128 * <p> 129 * An applet viewer or browser is free to ignore <code>showDocument</code>. 130 * 131 * @param url an absolute URL giving the location of the document. 132 * @param target a <code>String</code> indicating where to display 133 * the page. 134 */ 135 public void showDocument(URL url, String target); 136 137 /** 138 * Requests that the argument string be displayed in the 139 * "status window". Many browsers and applet viewers 140 * provide such a window, where the application can inform users of 141 * its current state. 142 * 143 * @param status a string to display in the status window. 144 */ 145 void showStatus(String status); 146 147 /** 148 * Associates the specified stream with the specified key in this 149 * applet context. If the applet context previously contained a mapping 150 * for this key, the old value is replaced. 151 * <p> 152 * For security reasons, mapping of streams and keys exists for each 153 * codebase. In other words, applet from one codebase cannot access 154 * the streams created by an applet from a different codebase 155 * 156 * @param key key with which the specified value is to be associated. 157 * @param stream stream to be associated with the specified key. If this 158 * parameter is <code>null</code>, the specified key is removed 159 * in this applet context. 160 * @throws IOException if the stream size exceeds a certain 161 * size limit. Size limit is decided by the implementor of this 162 * interface. 163 * @since 1.4 164 */ 165 public void setStream(String key, InputStream stream)throws IOException; 166 167 /** 168 * Returns the stream to which specified key is associated within this 169 * applet context. Returns <tt>null</tt> if the applet context contains 170 * no stream for this key. 171 * <p> 172 * For security reasons, mapping of streams and keys exists for each 173 * codebase. In other words, applet from one codebase cannot access 174 * the streams created by an applet from a different codebase 175 * 176 * @return the stream to which this applet context maps the key 177 * @param key key whose associated stream is to be returned. 178 * @since 1.4 179 */ 180 public InputStream getStream(String key); 181 182 /** 183 * Finds all the keys of the streams in this applet context. 184 * <p> 185 * For security reasons, mapping of streams and keys exists for each 186 * codebase. In other words, applet from one codebase cannot access 187 * the streams created by an applet from a different codebase 188 * 189 * @return an Iterator of all the names of the streams in this applet 190 * context. 191 * @since 1.4 192 */ 193 public Iterator<String> getStreamKeys(); 194 }