Source for java.beans.BeanInfo

   1: /* java.beans.BeanInfo
   2:    Copyright (C) 1998 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package java.beans;
  40: 
  41: /**
  42:  ** BeanInfo can be implemented in order to provide explicit information to the Introspector.
  43:  **
  44:  ** When you write a BeanInfo class, you implement this interface
  45:  ** and provide explicit information by returning a non-null
  46:  ** value from the appropriate method.  If you wish the
  47:  ** Introspector to determine certain information in the normal
  48:  ** way, just return null (or in the case of int methods, return
  49:  ** -1).  There is a class called SimpleBeanInfo which returns
  50:  ** null from all methods, which you may extend and only
  51:  ** override the methods you wish to override.<P>
  52:  **
  53:  ** When you have written the class, give it the name
  54:  ** <CODE>&lt;Bean Class Name&gt;BeanInfo</CODE> and place it in
  55:  ** the same package as the Bean, or in the bean info search path
  56:  ** (see Introspector for information on search paths).<P>
  57:  **
  58:  ** A simple note about the way the Introspector interacts with
  59:  ** BeanInfo.  Introspectors look at a Bean class and determine
  60:  ** if there is a BeanInfo class with it.  If there is not a
  61:  ** BeanInfo class, it will behave as if the BeanInfo class
  62:  ** provided was a SimpleBeanInfo class (i.e. it will determine
  63:  ** all information automatically).<P>If there is a BeanInfo
  64:  ** class, then any methods that do *not* return null are
  65:  ** regarded as providing definitive information about the class
  66:  ** and all of its superclasses for those information types.
  67:  ** Even if a parent BeanInfo class explicitly returns that
  68:  ** information, it will not be used.
  69:  **
  70:  ** @author John Keiser
  71:  ** @since JDK1.1
  72:  ** @version 1.1.0, 28 Jul 1998
  73:  **/
  74: 
  75: public interface BeanInfo {
  76:         /** Use this as a parameter for the getIcon() command to retrieve a certain type of icon. **/
  77:         int ICON_COLOR_16x16 = 1;
  78:         /** Use this as a parameter for the getIcon() command to retrieve a certain type of icon. **/
  79:         int ICON_COLOR_32x32 = 2;
  80:         /** Use this as a parameter for the getIcon() command to retrieve a certain type of icon. **/
  81:         int ICON_MONO_16x16 = 3;
  82:         /** Use this as a parameter for the getIcon() command to retrieve a certain type of icon. **/
  83:         int ICON_MONO_32x32 = 4;
  84: 
  85:         /** Get the general description of this Bean type.
  86:          ** @return the BeanDescriptor for the Bean, or null if
  87:          **         the BeanDescriptor should be obtained by
  88:          **         Introspection.
  89:          **/
  90:         BeanDescriptor getBeanDescriptor();
  91: 
  92:         /** Get the events this Bean type fires.
  93:          ** @return the EventDescriptors representing events this
  94:          **         Bean fires.  Returns <CODE>null</CODE> if the
  95:          **         events are to be acquired by Introspection.
  96:          **/
  97:         EventSetDescriptor[] getEventSetDescriptors();
  98: 
  99:         /** 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: }