Source for javax.swing.ActionMap

   1: /* ActionMap.java --
   2:    Copyright (C) 2002, 2004 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: package javax.swing;
  39: 
  40: import java.io.IOException;
  41: import java.io.ObjectInputStream;
  42: import java.io.ObjectOutputStream;
  43: import java.io.Serializable;
  44: import java.util.Arrays;
  45: import java.util.HashMap;
  46: import java.util.HashSet;
  47: import java.util.Map;
  48: import java.util.Set;
  49: 
  50: 
  51: /**
  52:  * Maps arbitrary keys (usually Strings) to {@link Action} instances. This
  53:  * is used in combination with {@link InputMap}s.
  54:  *
  55:  * If a component receives an input event, this is looked up in
  56:  * the component's <code>InputMap</code>. The result is an object which
  57:  * serves as a key to the components <code>ActionMap</code>. Finally
  58:  * the <code>Action</code> that is stored is executed.
  59:  *
  60:  * @author Andrew Selkirk
  61:  * @author Michael Koch
  62:  */
  63: public class ActionMap
  64:   implements Serializable
  65: {
  66:   private static final long serialVersionUID = -6277518704513986346L;
  67: 
  68:   /**
  69:    * actionMap
  70:    */
  71:   private Map actionMap = new HashMap();
  72: 
  73:   /**
  74:    * parent
  75:    */
  76:   private ActionMap parent;
  77: 
  78:   /**
  79:    * Creates a new <code>ActionMap</code> instance.
  80:    */
  81:   public ActionMap()
  82:   {
  83:     // Nothing to do here.
  84:   }
  85: 
  86:   /**
  87:    * Returns an action associated with an object.
  88:    *
  89:    * @param key the key of the enty
  90:    *
  91:    * @return the action associated with key, may be null
  92:    */
  93:   public Action get(Object key)
  94:   {
  95:     Object result = actionMap.get(key);
  96: 
  97:     if (result == null && parent != null)
  98:       result = parent.get(key);
  99: 
 100:     return (Action) result;
 101:   }
 102: 
 103:   /**
 104:    * Puts a new <code>Action</code> into the <code>ActionMap</code>.
 105:    * If action is null an existing entry will be removed.
 106:    *
 107:    * @param key the key for the entry
 108:    * @param action the action.
 109:    */
 110:   public void put(Object key, Action action)
 111:   {
 112:     if (action == null)
 113:       actionMap.remove(key);
 114:     else
 115:       actionMap.put(key, action);
 116:   }
 117: 
 118:   /**
 119:    * Remove an entry from the <code>ActionMap</code>.
 120:    *
 121:    * @param key the key of the entry to remove
 122:    */
 123:   public void remove(Object key)
 124:   {
 125:     actionMap.remove(key);
 126:   }
 127: 
 128:   /**
 129:    * Returns the parent of this <code>ActionMap</code>.
 130:    *
 131:    * @return the parent, may be null.
 132:    */
 133:   public ActionMap getParent()
 134:   {
 135:     return parent;
 136:   }
 137: 
 138:   /**
 139:    * Sets a parent for this <code>ActionMap</code>.
 140:    *
 141:    * @param parentMap the new parent
 142:    */
 143:   public void setParent(ActionMap parentMap)
 144:   {
 145:     if (parentMap != this)
 146:       parent = parentMap;
 147:   }
 148: 
 149:   /**
 150:    * Returns the number of entries in this <code>ActionMap</code>.
 151:    *
 152:    * @return the number of entries
 153:    */
 154:   public int size()
 155:   {
 156:     return actionMap.size();
 157:   }
 158: 
 159:   /**
 160:    * Clears the <code>ActionMap</code>.
 161:    */
 162:   public void clear()
 163:   {
 164:     actionMap.clear();
 165:   }
 166: 
 167:   /**
 168:    * Returns all keys of entries in this <code>ActionMap</code>.
 169:    *
 170:    * @return an array of keys
 171:    */
 172:   public Object[] keys()
 173:   {
 174:     if (size() != 0)
 175:       return actionMap.keySet().toArray();
 176:     return null;
 177:   }
 178: 
 179:   /**
 180:    * Returns all keys of entries in this <code>ActionMap</code>
 181:    * and all its parents.
 182:    *
 183:    * @return an array of keys
 184:    */
 185:   public Object[] allKeys()
 186:   {
 187:     Set set = new HashSet();
 188: 
 189:     if (parent != null)
 190:       set.addAll(Arrays.asList(parent.allKeys()));
 191: 
 192:     set.addAll(actionMap.keySet());
 193:     if (set.size() != 0)
 194:       return set.toArray();
 195:     return null;
 196:   }
 197: 
 198:   /**
 199:    * writeObject
 200:    *
 201:    * @param stream the stream to write to
 202:    *
 203:    * @exception IOException If an error occurs
 204:    */
 205:   private void writeObject(ObjectOutputStream stream)
 206:     throws IOException
 207:   {
 208:     // TODO
 209:   }
 210: 
 211:   /**
 212:    * readObject
 213:    *
 214:    * @param stream the stream to read from
 215:    *
 216:    * @exception ClassNotFoundException If the serialized class cannot be found
 217:    * @exception IOException If an error occurs
 218:    */
 219:   private void readObject(ObjectInputStream stream)
 220:     throws ClassNotFoundException, IOException
 221:   {
 222:     // TODO
 223:   }
 224: }