1 /*
   2  * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package javax.swing;
  26 
  27 import java.io.IOException;
  28 import java.io.ObjectInputStream;
  29 import java.io.ObjectOutputStream;
  30 import java.io.Serializable;
  31 import java.util.HashMap;
  32 import java.util.Set;
  33 
  34 /**
  35  * {@code ActionMap} provides mappings from
  36  * {@code Object}s
  37  * (called <em>keys</em> or <em>{@code Action} names</em>)
  38  * to {@code Action}s.
  39  * An {@code ActionMap} is usually used with an {@code InputMap}
  40  * to locate a particular action
  41  * when a key is pressed. As with {@code InputMap},
  42  * an {@code ActionMap} can have a parent
  43  * that is searched for keys not defined in the {@code ActionMap}.
  44  * <p>As with {@code InputMap} if you create a cycle, eg:
  45  * <pre>
  46  *   ActionMap am = new ActionMap();
  47  *   ActionMap bm = new ActionMap():
  48  *   am.setParent(bm);
  49  *   bm.setParent(am);
  50  * </pre>
  51  * some of the methods will cause a StackOverflowError to be thrown.
  52  *
  53  * @see InputMap
  54  *
  55  * @author Scott Violet
  56  * @since 1.3
  57  */
  58 @SuppressWarnings("serial")
  59 public class ActionMap implements Serializable {
  60     /** Handles the mapping between Action name and Action. */
  61     private transient ArrayTable     arrayTable;
  62     /** Parent that handles any bindings we don't contain. */
  63     private ActionMap                               parent;
  64 
  65 
  66     /**
  67      * Creates an {@code ActionMap} with no parent and no mappings.
  68      */
  69     public ActionMap() {
  70     }
  71 
  72     /**
  73      * Sets this {@code ActionMap}'s parent.
  74      *
  75      * @param map  the {@code ActionMap} that is the parent of this one
  76      */
  77     public void setParent(ActionMap map) {
  78         this.parent = map;
  79     }
  80 
  81     /**
  82      * Returns this {@code ActionMap}'s parent.
  83      *
  84      * @return the {@code ActionMap} that is the parent of this one,
  85      *         or null if this {@code ActionMap} has no parent
  86      */
  87     public ActionMap getParent() {
  88         return parent;
  89     }
  90 
  91     /**
  92      * Adds a binding for {@code key} to {@code action}.
  93      * If {@code action} is null, this removes the current binding
  94      * for {@code key}.
  95      * <p>In most instances, {@code key} will be
  96      * {@code action.getValue(NAME)}.
  97      *
  98      * @param key a key
  99      * @param action a binding for {@code key}
 100      */
 101     public void put(Object key, Action action) {
 102         if (key == null) {
 103             return;
 104         }
 105         if (action == null) {
 106             remove(key);
 107         }
 108         else {
 109             if (arrayTable == null) {
 110                 arrayTable = new ArrayTable();
 111             }
 112             arrayTable.put(key, action);
 113         }
 114     }
 115 
 116     /**
 117      * Returns the binding for {@code key}, messaging the
 118      * parent {@code ActionMap} if the binding is not locally defined.
 119      *
 120      * @param key a key
 121      * @return the binding for {@code key}
 122      */
 123     public Action get(Object key) {
 124         Action value = (arrayTable == null) ? null :
 125                        (Action)arrayTable.get(key);
 126 
 127         if (value == null) {
 128             ActionMap    parent = getParent();
 129 
 130             if (parent != null) {
 131                 return parent.get(key);
 132             }
 133         }
 134         return value;
 135     }
 136 
 137     /**
 138      * Removes the binding for {@code key} from this {@code ActionMap}.
 139      *
 140      * @param key a key
 141      */
 142     public void remove(Object key) {
 143         if (arrayTable != null) {
 144             arrayTable.remove(key);
 145         }
 146     }
 147 
 148     /**
 149      * Removes all the mappings from this {@code ActionMap}.
 150      */
 151     public void clear() {
 152         if (arrayTable != null) {
 153             arrayTable.clear();
 154         }
 155     }
 156 
 157     /**
 158      * Returns the {@code Action} names that are bound in this {@code ActionMap}.
 159      *
 160      * @return an array of the keys
 161      */
 162     public Object[] keys() {
 163         if (arrayTable == null) {
 164             return null;
 165         }
 166         return arrayTable.getKeys(null);
 167     }
 168 
 169     /**
 170      * Returns the number of bindings in this {@code ActionMap}.
 171      *
 172      * @return the number of bindings in this {@code ActionMap}
 173      */
 174     public int size() {
 175         if (arrayTable == null) {
 176             return 0;
 177         }
 178         return arrayTable.size();
 179     }
 180 
 181     /**
 182      * Returns an array of the keys defined in this {@code ActionMap} and
 183      * its parent. This method differs from {@code keys()} in that
 184      * this method includes the keys defined in the parent.
 185      *
 186      * @return an array of the keys
 187      */
 188     public Object[] allKeys() {
 189         int           count = size();
 190         ActionMap     parent = getParent();
 191 
 192         if (count == 0) {
 193             if (parent != null) {
 194                 return parent.allKeys();
 195             }
 196             return keys();
 197         }
 198         if (parent == null) {
 199             return keys();
 200         }
 201         Object[]    keys = keys();
 202         Object[]    pKeys =  parent.allKeys();
 203 
 204         if (pKeys == null) {
 205             return keys;
 206         }
 207         if (keys == null) {
 208             // Should only happen if size() != keys.length, which should only
 209             // happen if mutated from multiple threads (or a bogus subclass).
 210             return pKeys;
 211         }
 212 
 213         HashMap<Object, Object> keyMap = new HashMap<Object, Object>();
 214         int            counter;
 215 
 216         for (counter = keys.length - 1; counter >= 0; counter--) {
 217             keyMap.put(keys[counter], keys[counter]);
 218         }
 219         for (counter = pKeys.length - 1; counter >= 0; counter--) {
 220             keyMap.put(pKeys[counter], pKeys[counter]);
 221         }
 222         return keyMap.keySet().toArray();
 223     }
 224 
 225     private void writeObject(ObjectOutputStream s) throws IOException {
 226         s.defaultWriteObject();
 227 
 228         ArrayTable.writeArrayTable(s, arrayTable);
 229     }
 230 
 231     private void readObject(ObjectInputStream s) throws ClassNotFoundException,
 232                                                  IOException {
 233         s.defaultReadObject();
 234         for (int counter = s.readInt() - 1; counter >= 0; counter--) {
 235             put(s.readObject(), (Action)s.readObject());
 236         }
 237     }
 238 }