libjava/classpath/javax/swing/ActionMap.java

   1 /* ActionMap.java --
   2    Copyright (C) 2002, 2004, 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 package javax.swing;
  39
  40 import java.io.Serializable;
  41 import java.util.Arrays;
  42 import java.util.HashMap;
  43 import java.util.HashSet;
  44 import java.util.Map;
  45 import java.util.Set;
  46
  47
  48 /**
  49  * Maps arbitrary keys (usually Strings) to {@link Action} instances. This
  50  * is used in combination with {@link InputMap}s.
  51  *
  52  * If a component receives an input event, this is looked up in
  53  * the component's <code>InputMap</code>. The result is an object which
  54  * serves as a key to the components <code>ActionMap</code>. Finally
  55  * the <code>Action</code> that is stored is executed.
  56  *
  57  * @author Andrew Selkirk
  58  * @author Michael Koch
  59  */
  60 public class ActionMap
  61   implements Serializable
  62 {
  63   private static final long serialVersionUID = -6277518704513986346L;
  64
  65   /**
  66    * actionMap
  67    */
  68   private Map actionMap = new HashMap();
  69
  70   /**
  71    * parent
  72    */
  73   private ActionMap parent;
  74
  75   /**
  76    * Creates a new <code>ActionMap</code> instance.
  77    */
  78   public ActionMap()
  79   {
  80     // Nothing to do here.
  81   }
  82
  83   /**
  84    * Returns an action associated with an object.
  85    *
  86    * @param key the key of the enty
  87    *
  88    * @return the action associated with key, may be null
  89    */
  90   public Action get(Object key)
  91   {
  92     Object result = actionMap.get(key);
  93
  94     if (result == null && parent != null)
  95       result = parent.get(key);
  96
  97     return (Action) result;
  98   }
  99
 100   /**
 101    * Puts a new <code>Action</code> into the <code>ActionMap</code>.
 102    * If action is null an existing entry will be removed.
 103    *
 104    * @param key the key for the entry
 105    * @param action the action.
 106    */
 107   public void put(Object key, Action action)
 108   {
 109     if (action == null)
 110       actionMap.remove(key);
 111     else
 112       actionMap.put(key, action);
 113   }
 114
 115   /**
 116    * Remove an entry from the <code>ActionMap</code>.
 117    *
 118    * @param key the key of the entry to remove
 119    */
 120   public void remove(Object key)
 121   {
 122     actionMap.remove(key);
 123   }
 124
 125   /**
 126    * Returns the parent of this <code>ActionMap</code>.
 127    *
 128    * @return the parent, may be null.
 129    */
 130   public ActionMap getParent()
 131   {
 132     return parent;
 133   }
 134
 135   /**
 136    * Sets a parent for this <code>ActionMap</code>.
 137    *
 138    * @param parentMap the new parent
 139    */
 140   public void setParent(ActionMap parentMap)
 141   {
 142     if (parentMap != this)
 143       parent = parentMap;
 144   }
 145
 146   /**
 147    * Returns the number of entries in this <code>ActionMap</code>.
 148    *
 149    * @return the number of entries
 150    */
 151   public int size()
 152   {
 153     return actionMap.size();
 154   }
 155
 156   /**
 157    * Clears the <code>ActionMap</code>.
 158    */
 159   public void clear()
 160   {
 161     actionMap.clear();
 162   }
 163
 164   /**
 165    * Returns all keys of entries in this <code>ActionMap</code>.
 166    *
 167    * @return an array of keys
 168    */
 169   public Object[] keys()
 170   {
 171     if (size() != 0)
 172       return actionMap.keySet().toArray();
 173     return null;
 174   }
 175
 176   /**
 177    * Returns all keys of entries in this <code>ActionMap</code>
 178    * and all its parents.
 179    *
 180    * @return an array of keys
 181    */
 182   public Object[] allKeys()
 183   {
 184     Set set = new HashSet();
 185
 186     if (parent != null)
 187       set.addAll(Arrays.asList(parent.allKeys()));
 188
 189     set.addAll(actionMap.keySet());
 190     if (set.size() != 0)
 191       return set.toArray();
 192     return null;
 193   }
 194
 195 }