001 /* java.beans.BeanInfo 002 Copyright (C) 1998 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.beans; 040 041 /** 042 ** BeanInfo can be implemented in order to provide explicit information to the Introspector. 043 ** 044 ** When you write a BeanInfo class, you implement this interface 045 ** and provide explicit information by returning a non-null 046 ** value from the appropriate method. If you wish the 047 ** Introspector to determine certain information in the normal 048 ** way, just return null (or in the case of int methods, return 049 ** -1). There is a class called SimpleBeanInfo which returns 050 ** null from all methods, which you may extend and only 051 ** override the methods you wish to override.<P> 052 ** 053 ** When you have written the class, give it the name 054 ** <CODE><Bean Class Name>BeanInfo</CODE> and place it in 055 ** the same package as the Bean, or in the bean info search path 056 ** (see Introspector for information on search paths).<P> 057 ** 058 ** A simple note about the way the Introspector interacts with 059 ** BeanInfo. Introspectors look at a Bean class and determine 060 ** if there is a BeanInfo class with it. If there is not a 061 ** BeanInfo class, it will behave as if the BeanInfo class 062 ** provided was a SimpleBeanInfo class (i.e. it will determine 063 ** all information automatically).<P>If there is a BeanInfo 064 ** class, then any methods that do *not* return null are 065 ** regarded as providing definitive information about the class 066 ** and all of its superclasses for those information types. 067 ** Even if a parent BeanInfo class explicitly returns that 068 ** information, it will not be used. 069 ** 070 ** @author John Keiser 071 ** @since JDK1.1 072 ** @version 1.1.0, 28 Jul 1998 073 **/ 074 075 public interface BeanInfo { 076 /** Use this as a parameter for the getIcon() command to retrieve a certain type of icon. **/ 077 int ICON_COLOR_16x16 = 1; 078 /** Use this as a parameter for the getIcon() command to retrieve a certain type of icon. **/ 079 int ICON_COLOR_32x32 = 2; 080 /** Use this as a parameter for the getIcon() command to retrieve a certain type of icon. **/ 081 int ICON_MONO_16x16 = 3; 082 /** Use this as a parameter for the getIcon() command to retrieve a certain type of icon. **/ 083 int ICON_MONO_32x32 = 4; 084 085 /** Get the general description of this Bean type. 086 ** @return the BeanDescriptor for the Bean, or null if 087 ** the BeanDescriptor should be obtained by 088 ** Introspection. 089 **/ 090 BeanDescriptor getBeanDescriptor(); 091 092 /** Get the events this Bean type fires. 093 ** @return the EventDescriptors representing events this 094 ** Bean fires. Returns <CODE>null</CODE> if the 095 ** events are to be acquired by Introspection. 096 **/ 097 EventSetDescriptor[] getEventSetDescriptors(); 098 099 /** Get the "default" event, basically the one a RAD tool 100 ** user is most likely to select. 101 ** @return the index into the getEventSetDescriptors() 102 ** that the user is most likely to use. Returns 103 ** <CODE>-1</CODE> if there is no default event. 104 **/ 105 int getDefaultEventIndex(); 106 107 /** Get the properties (get/set method pairs) this Bean 108 ** type supports. 109 ** @return the PropertyDescriptors representing the 110 ** properties this Bean type supports. 111 ** Returns <CODE>null</CODE> if the properties 112 ** are to be obtained by Introspection. 113 **/ 114 PropertyDescriptor[] getPropertyDescriptors(); 115 116 /** Get the "default" property, basically the one a RAD 117 ** tool user is most likely to select. 118 ** @return the index into the getPropertyDescriptors() 119 ** that the user is most likely to use. Returns 120 ** <CODE>-1</CODE> if there is no default event. 121 **/ 122 int getDefaultPropertyIndex(); 123 124 /** Get the methods this Bean type supports. 125 ** @return the MethodDescriptors representing the 126 ** methods this Bean type supports. Returns 127 ** <CODE>null</CODE> if the methods are to be 128 ** obtained by Introspection. 129 **/ 130 MethodDescriptor[] getMethodDescriptors(); 131 132 /** Get additional BeanInfos representing this Bean. 133 ** In this version of JavaBeans, this method is used so 134 ** that space and time can be saved by reading a BeanInfo 135 ** for each class in the hierarchy (super, super(super), 136 ** and so on).<P> 137 ** 138 ** The order of precedence when two pieces of BeanInfo 139 ** conflict (such as two PropertyDescriptors that have 140 ** the same name), in order from highest precedence to 141 ** lowest, is: 142 ** <OL> 143 ** <LI>This BeanInfo object.</LI> 144 ** <LI><CODE>getAdditionalBeanInfo()[getAdditionalBeanInfo().length]</CODE></LI> 145 ** <LI> ... </LI> 146 ** <LI><CODE>getAdditionalBeanInfo()[1]</CODE></LI> 147 ** <LI><CODE>getAdditionalBeanInfo()[0]</CODE></LI> 148 ** </OL><P> 149 ** 150 ** <STRONG>Spec Note:</STRONG> It is possible that 151 ** returning <CODE>null</CODE> from this method could 152 ** stop Introspection in its tracks, but it is unclear 153 ** from the spec whether this is the case. 154 ** 155 ** @return additional BeanInfos representing this Bean. 156 ** <CODE>null</CODE> may be returned (see Spec 157 ** Note, above). 158 **/ 159 BeanInfo[] getAdditionalBeanInfo(); 160 161 /** Get a visual icon for this Bean. 162 ** A Bean does not have to support icons, and if it does 163 ** support icons, it does not have to support every single 164 ** type. Sun recommends that if you only support one 165 ** type, you support 16x16 color. Sun also notes that you 166 ** should try to use a type (like GIF) that allows for 167 ** transparent pixels, so that the background of the RAD 168 ** tool can show through.<P> 169 ** 170 ** <STRONG>Spec Note:</STRONG> If you do not support the 171 ** type of icon that is being asked for, but you do 172 ** support another type, it is unclear whether you should 173 ** return the other type or not. I would presume not. 174 ** 175 ** @param iconType the type of icon to get (see the 176 ** ICON_* constants in this class). 177 ** @return the icon, or null if that type of icon is 178 ** unsupported by this Bean. 179 **/ 180 java.awt.Image getIcon(int iconType); 181 }