libjava/java/beans/PropertyEditorManager.java

   1 /* java.beans.PropertyEditorManager
   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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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 gnu.java.lang.ClassHelper;
  42 import gnu.java.beans.editors.ColorEditor;
  43 import gnu.java.beans.editors.FontEditor;
  44 import gnu.java.beans.editors.NativeBooleanEditor;
  45 import gnu.java.beans.editors.NativeByteEditor;
  46 import gnu.java.beans.editors.NativeDoubleEditor;
  47 import gnu.java.beans.editors.NativeFloatEditor;
  48 import gnu.java.beans.editors.NativeIntEditor;
  49 import gnu.java.beans.editors.NativeLongEditor;
  50 import gnu.java.beans.editors.NativeShortEditor;
  51 import gnu.java.beans.editors.StringEditor;
  52 import java.awt.Color;
  53 import java.awt.Font;
  54
  55 /**
  56  * PropertyEditorManager is used to find property editors
  57  * for various types (not necessarily Beans).<P>
  58  *
  59  * It first checks to see if the property editor is
  60  * already registered; if it is, that property editor is
  61  * used.  Next it takes the type's classname and appends
  62  * "Editor" to it, and searches first in the class's
  63  * package and then in the property editor search path.<P>
  64  *
  65  * Default property editors are provided for:<P>
  66  * <OL>
  67  * <LI>boolean, byte, short, int, long, float, and double</LI>
  68  * <LI>java.lang.String</LI>
  69  * <LI>java.awt.Color</LI>
  70  * <LI>java.awt.Font</LI>
  71  * <OL>
  72  *
  73  * <STRONG>Spec Suggestion:</STRONG> Perhaps an editor for
  74  * Filename or something like it should be provided.  As well
  75  * as char.
  76  *
  77  * @author John Keiser
  78  * @since 1.1
  79  * @version 1.1.0, 29 Jul 1998
  80  */
  81
  82 public class PropertyEditorManager
  83 {
  84   static java.util.Hashtable editors = new java.util.Hashtable();
  85   static String[] editorSearchPath = { "gnu.java.beans.editors",
  86                                        "sun.beans.editors" };
  87
  88   static
  89     {
  90       registerEditor(Boolean.TYPE, NativeBooleanEditor.class);
  91       registerEditor(Byte.TYPE,    NativeByteEditor.class);
  92       registerEditor(Short.TYPE,   NativeShortEditor.class);
  93       registerEditor(Integer.TYPE, NativeIntEditor.class);
  94       registerEditor(Long.TYPE,    NativeLongEditor.class);
  95       registerEditor(Float.TYPE,   NativeFloatEditor.class);
  96       registerEditor(Double.TYPE,  NativeDoubleEditor.class);
  97       registerEditor(String.class, StringEditor.class);
  98       registerEditor(Color.class,  ColorEditor.class);
  99       registerEditor(Font.class,   FontEditor.class);
 100     }
 101
 102   /**
 103    * Beats me why this class can be instantiated, but there
 104    * you have it.
 105    */
 106   public PropertyEditorManager()
 107   {
 108     // Do nothing here
 109   }
 110
 111   /**
 112    * Register an editor for a class.  Replaces old editor
 113    * if there was one registered before.
 114    *
 115    * @param editedClass the class that the property editor
 116    *        will edit.
 117    * @param editorClass the PropertyEditor class.
 118    */
 119   public static void registerEditor(Class editedClass, Class editorClass)
 120   {
 121     editors.put(editedClass, editorClass);
 122   }
 123
 124   /**
 125    * Returns a new instance of the property editor for the
 126    * specified class.
 127    *
 128    * @param editedClass the class that the property editor
 129    *        will edit.
 130    * @return a PropertyEditor instance that can edit the
 131    *         specified class.
 132    */
 133   public static PropertyEditor findEditor(Class editedClass)
 134   {
 135     try
 136       {
 137         Class found = (Class)editors.get(editedClass);
 138         if(found != null)
 139           {
 140             return (PropertyEditor)found.newInstance();
 141           }
 142
 143         ClassLoader contextClassLoader
 144                 = Thread.currentThread().getContextClassLoader();
 145
 146         try
 147           {
 148             found = Class.forName(editedClass.getName()+"Editor", true,
 149                                   contextClassLoader);
 150             registerEditor(editedClass,found);
 151             return (PropertyEditor)found.newInstance();
 152           }
 153         catch(ClassNotFoundException E)
 154           {
 155           }
 156
 157         String appendName
 158                 = "."
 159                 + ClassHelper.getTruncatedClassName(editedClass)
 160                 + "Editor";
 161         synchronized(editorSearchPath)
 162           {
 163             for(int i=0;i<editorSearchPath.length;i++)
 164               {
 165                 try
 166                   {
 167                     found = Class.forName(editorSearchPath[i] + appendName,
 168                                           true, contextClassLoader);
 169                     registerEditor(editedClass,found);
 170                     return (PropertyEditor)found.newInstance();
 171                   }
 172                 catch(ClassNotFoundException E)
 173                   {
 174                   }
 175               }
 176           }
 177       }
 178     catch(InstantiationException E)
 179       {
 180       }
 181     catch(IllegalAccessException E)
 182       {
 183       }
 184
 185     return null;
 186   }
 187
 188   /**
 189    * Get the editor search path.
 190    * As a minor departure from the spec, the default value
 191    * for the editor search path is "gnu.java.beans.editors",
 192    * "sun.beans.editors".
 193    *
 194    * @return the editor search path.
 195    */
 196   public static String[] getEditorSearchPath()
 197   {
 198     return editorSearchPath;
 199   }
 200
 201   /**
 202    * Set the editor search path.
 203    *
 204    * @param editorSearchPath the new value for the editor search path.
 205    */
 206   public static void setEditorSearchPath(String[] editorSearchPath)
 207   {
 208     synchronized(editorSearchPath)
 209       {
 210         PropertyEditorManager.editorSearchPath = editorSearchPath;
 211       }
 212   }
 213 }