SimpleBeanInfo.java revision 12632:58fde919b6c3 
1/*
2 * Copyright (c) 1996, 2015, 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
28import java.awt.Image;
29import java.awt.Toolkit;
30import java.io.InputStream;
31
32/**
33 * This is a support class to make it easier for people to provide
34 * BeanInfo classes.
35 * <p>
36 * It defaults to providing "noop" information, and can be selectively
37 * overriden to provide more explicit information on chosen topics.
38 * When the introspector sees the "noop" values, it will apply low
39 * level introspection and design patterns to automatically analyze
40 * the target bean.
41 *
42 * @since 1.1
43 */
44
45public class SimpleBeanInfo implements BeanInfo {
46
47    /**
48     * Deny knowledge about the class and customizer of the bean.
49     * You can override this if you wish to provide explicit info.
50     */
51    public BeanDescriptor getBeanDescriptor() {
52        return null;
53    }
54
55    /**
56     * Deny knowledge of properties. You can override this
57     * if you wish to provide explicit property info.
58     */
59    public PropertyDescriptor[] getPropertyDescriptors() {
60        return null;
61    }
62
63    /**
64     * Deny knowledge of a default property. You can override this
65     * if you wish to define a default property for the bean.
66     */
67    public int getDefaultPropertyIndex() {
68        return -1;
69    }
70
71    /**
72     * Deny knowledge of event sets. You can override this
73     * if you wish to provide explicit event set info.
74     */
75    public EventSetDescriptor[] getEventSetDescriptors() {
76        return null;
77    }
78
79    /**
80     * Deny knowledge of a default event. You can override this
81     * if you wish to define a default event for the bean.
82     */
83    public int getDefaultEventIndex() {
84        return -1;
85    }
86
87    /**
88     * Deny knowledge of methods. You can override this
89     * if you wish to provide explicit method info.
90     */
91    public MethodDescriptor[] getMethodDescriptors() {
92        return null;
93    }
94
95    /**
96     * Claim there are no other relevant BeanInfo objects.  You
97     * may override this if you want to (for example) return a
98     * BeanInfo for a base class.
99     */
100    public BeanInfo[] getAdditionalBeanInfo() {
101        return null;
102    }
103
104    /**
105     * Claim there are no icons available.  You can override
106     * this if you want to provide icons for your bean.
107     */
108    public Image getIcon(int iconKind) {
109        return null;
110    }
111
112    /**
113     * This is a utility method to help in loading icon images.
114     * It takes the name of a resource file associated with the
115     * current object's class file and loads an image object
116     * from that file.  Typically images will be GIFs.
117     *
118     * @param resourceName  A pathname relative to the directory
119     *          holding the class file of the current class.  For example,
120     *          "wombat.gif".
121     * @return  an image object.  May be null if the load failed.
122     */
123    public Image loadImage(final String resourceName) {
124        try (InputStream in = getClass().getResourceAsStream(resourceName)) {
125            return Toolkit.getDefaultToolkit().createImage(in.readAllBytes());
126        } catch (final Exception ignored) {
127        }
128        return null;
129    }
130}
131