libjava/classpath/java/beans/SimpleBeanInfo.java

   1 /* java.beans.SimpleBeanInfo
   2    Copyright (C) 1998, 2006, 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 import java.awt.Image;
  42 import java.awt.Toolkit;
  43 import java.net.URL;
  44
  45 /**
  46  ** SimpleBeanInfo is a class you may extend to more easily
  47  ** provide select information to the Introspector.  It
  48  ** implements all of the methods in BeanInfo by returning
  49  ** null and forces the Introspector to behave exactly as
  50  ** if there were no BeanInfo class at all (Introspecting
  51  ** everything).<P>
  52  **
  53  ** Overriding one or two of these functions
  54  ** to give explicit information on only those things you
  55  ** wish to give explicit information is perfectly safe,
  56  ** and even desirable.<P>
  57  **
  58  ** See the BeanInfo class for information on what the
  59  ** various methods actually do.
  60  **
  61  ** @author John Keiser
  62  ** @since JDK1.1
  63  ** @version 1.1.0, 29 Jul 1998
  64  ** @see java.beans.BeanInfo
  65  **/
  66
  67 public class SimpleBeanInfo implements BeanInfo {
  68         /** Force Introspection of the general bean info.
  69          ** @return <CODE>null</CODE>.
  70          **/
  71         public BeanDescriptor getBeanDescriptor() {
  72                 return null;
  73         }
  74
  75         /** Force Introspection of the events this Bean type
  76          ** fires.
  77          ** @return <CODE>null</CODE>
  78          **/
  79         public EventSetDescriptor[] getEventSetDescriptors() {
  80                 return null;
  81         }
  82
  83         /** Say that there is no "default" event set.
  84          ** @return <CODE>-1</CODE>.
  85          **/
  86         public int getDefaultEventIndex() {
  87                 return -1;
  88         }
  89
  90         /** Force Introspection of the Bean properties.
  91          ** @return <CODE>null</CODE>.
  92          **/
  93         public PropertyDescriptor[] getPropertyDescriptors() {
  94                 return null;
  95         }
  96
  97         /** Say that there is no "default" property.
  98          ** @return <CODE>-1</CODE>.
  99          **/
 100         public int getDefaultPropertyIndex() {
 101                 return -1;
 102         }
 103
 104         /** Force Introspection of the Bean's methods.
 105          ** @return <CODE>null</CODE>.
 106          **/
 107         public MethodDescriptor[] getMethodDescriptors() {
 108                 return null;
 109         }
 110
 111         /** Tell the Introspector to go look for other BeanInfo
 112          ** itself.
 113          ** @return <CODE>null</CODE>.
 114          **/
 115         public BeanInfo[] getAdditionalBeanInfo() {
 116                 return null;
 117         }
 118
 119         /** Say that this Bean has no icons.
 120          ** @param iconType the type of icon
 121          ** @return <CODE>null</CODE>.
 122          **/
 123         public Image getIcon(int iconType) {
 124                 return null;
 125         }
 126
 127         /** Helper method to load an image using the Bean class
 128          ** getResource() method on the BeanInfo class (using
 129          ** getClass(), since you'll extend this class to get
 130          ** the BeanInfo).  Basically it's assumed that the Bean
 131          ** and its BeanInfo are both loaded by the same
 132          ** ClassLoader, generally a reasonable assumption.
 133          ** @param location the URL relative
 134          ** @return the Image in question (possibly <code>null</code>).
 135          **/
 136         public Image loadImage(String location)
 137     {
 138       if (location == null)
 139         return null;
 140       URL url = getClass().getResource(location);
 141       if (url == null)
 142         return null;
 143       return Toolkit.getDefaultToolkit().getImage(url);
 144         }
 145 }