001/* ActionMap.java --
002   Copyright (C) 2002, 2004, 2006, Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038package javax.swing;
039
040import java.io.Serializable;
041import java.util.Arrays;
042import java.util.HashMap;
043import java.util.HashSet;
044import java.util.Map;
045import java.util.Set;
046
047
048/**
049 * Maps arbitrary keys (usually Strings) to {@link Action} instances. This
050 * is used in combination with {@link InputMap}s.
051 *
052 * If a component receives an input event, this is looked up in
053 * the component's <code>InputMap</code>. The result is an object which
054 * serves as a key to the components <code>ActionMap</code>. Finally
055 * the <code>Action</code> that is stored is executed.
056 *
057 * @author Andrew Selkirk
058 * @author Michael Koch
059 */
060public class ActionMap
061  implements Serializable
062{
063  private static final long serialVersionUID = -6277518704513986346L;
064
065  /**
066   * actionMap
067   */
068  private Map actionMap = new HashMap();
069
070  /**
071   * parent
072   */
073  private ActionMap parent;
074
075  /**
076   * Creates a new <code>ActionMap</code> instance.
077   */
078  public ActionMap()
079  {
080    // Nothing to do here.
081  }
082
083  /**
084   * Returns an action associated with an object.
085   *
086   * @param key the key of the enty
087   *
088   * @return the action associated with key, may be null
089   */
090  public Action get(Object key)
091  {
092    Object result = actionMap.get(key);
093
094    if (result == null && parent != null)
095      result = parent.get(key);
096
097    return (Action) result;
098  }
099
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}