SimpleBeanInfo.java revision 10444:f08705540498 
1/*
2 * Copyright (c) 1996, 2011, 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
26package java.beans;
27
28/**
29 * This is a support class to make it easier for people to provide
30 * BeanInfo classes.
31 * <p>
32 * It defaults to providing "noop" information, and can be selectively
33 * overriden to provide more explicit information on chosen topics.
34 * When the introspector sees the "noop" values, it will apply low
35 * level introspection and design patterns to automatically analyze
36 * the target bean.
37 *
38 * @since 1.1
39 */
40
41public class SimpleBeanInfo implements BeanInfo {
42
43    /**
44     * Deny knowledge about the class and customizer of the bean.
45     * You can override this if you wish to provide explicit info.
46     */
47    public BeanDescriptor getBeanDescriptor() {
48        return null;
49    }
50
51    /**
52     * Deny knowledge of properties. You can override this
53     * if you wish to provide explicit property info.
54     */
55    public PropertyDescriptor[] getPropertyDescriptors() {
56        return null;
57    }
58
59    /**
60     * Deny knowledge of a default property. You can override this
61     * if you wish to define a default property for the bean.
62     */
63    public int getDefaultPropertyIndex() {
64        return -1;
65    }
66
67    /**
68     * Deny knowledge of event sets. You can override this
69     * if you wish to provide explicit event set info.
70     */
71    public EventSetDescriptor[] getEventSetDescriptors() {
72        return null;
73    }
74
75    /**
76     * Deny knowledge of a default event. You can override this
77     * if you wish to define a default event for the bean.
78     */
79    public int getDefaultEventIndex() {
80        return -1;
81    }
82
83    /**
84     * Deny knowledge of methods. You can override this
85     * if you wish to provide explicit method info.
86     */
87    public MethodDescriptor[] getMethodDescriptors() {
88        return null;
89    }
90
91    /**
92     * Claim there are no other relevant BeanInfo objects.  You
93     * may override this if you want to (for example) return a
94     * BeanInfo for a base class.
95     */
96    public BeanInfo[] getAdditionalBeanInfo() {
97        return null;
98    }
99
100    /**
101     * Claim there are no icons available.  You can override
102     * this if you want to provide icons for your bean.
103     */
104    public java.awt.Image getIcon(int iconKind) {
105        return null;
106    }
107
108    /**
109     * This is a utility method to help in loading icon images.
110     * It takes the name of a resource file associated with the
111     * current object's class file and loads an image object
112     * from that file.  Typically images will be GIFs.
113     *
114     * @param resourceName  A pathname relative to the directory
115     *          holding the class file of the current class.  For example,
116     *          "wombat.gif".
117     * @return  an image object.  May be null if the load failed.
118     */
119    public java.awt.Image loadImage(final String resourceName) {
120        try {
121            final Class<?> c = getClass();
122            java.awt.image.ImageProducer ip = (java.awt.image.ImageProducer)
123                java.security.AccessController.doPrivileged(
124                new java.security.PrivilegedAction<Object>() {
125                    public Object run() {
126                        java.net.URL url;
127                        if ((url = c.getResource(resourceName)) == null) {
128                            return null;
129                        } else {
130                            try {
131                                return url.getContent();
132                            } catch (java.io.IOException ioe) {
133                                return null;
134                            }
135                        }
136                    }
137            });
138
139            if (ip == null)
140                return null;
141            java.awt.Toolkit tk = java.awt.Toolkit.getDefaultToolkit();
142            return tk.createImage(ip);
143        } catch (Exception ex) {
144            return null;
145        }
146    }
147
148}
149