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    1   /*
    2    * Copyright (c) 1999, 2008, 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</code> provides mappings from
   36    * <code>Object</code>s
   37    * (called <em>keys</em> or <em><code>Action</code> names</em>)
   38    * to <code>Action</code>s.
   39    * An <code>ActionMap</code> is usually used with an <code>InputMap</code>
   40    * to locate a particular action
   41    * when a key is pressed. As with <code>InputMap</code>,
   42    * an <code>ActionMap</code> can have a parent
   43    * that is searched for keys not defined in the <code>ActionMap</code>.
   44    * <p>As with <code>InputMap</code> 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   public class ActionMap implements Serializable {
   59       /** Handles the mapping between Action name and Action. */
   60       private transient ArrayTable     arrayTable;
   61       /** Parent that handles any bindings we don't contain. */
   62       private ActionMap                               parent;
   63   
   64   
   65       /**
   66        * Creates an <code>ActionMap</code> with no parent and no mappings.
   67        */
   68       public ActionMap() {
   69       }
   70   
   71       /**
   72        * Sets this <code>ActionMap</code>'s parent.
   73        *
   74        * @param map  the <code>ActionMap</code> that is the parent of this one
   75        */
   76       public void setParent(ActionMap map) {
   77           this.parent = map;
   78       }
   79   
   80       /**
   81        * Returns this <code>ActionMap</code>'s parent.
   82        *
   83        * @return the <code>ActionMap</code> that is the parent of this one,
   84        *         or null if this <code>ActionMap</code> has no parent
   85        */
   86       public ActionMap getParent() {
   87           return parent;
   88       }
   89   
   90       /**
   91        * Adds a binding for <code>key</code> to <code>action</code>.
   92        * If <code>action</code> is null, this removes the current binding
   93        * for <code>key</code>.
   94        * <p>In most instances, <code>key</code> will be
   95        * <code>action.getValue(NAME)</code>.
   96        */
   97       public void put(Object key, Action action) {
   98           if (key == null) {
   99               return;
  100           }
  101           if (action == null) {
  102               remove(key);
  103           }
  104           else {
  105               if (arrayTable == null) {
  106                   arrayTable = new ArrayTable();
  107               }
  108               arrayTable.put(key, action);
  109           }
  110       }
  111   
  112       /**
  113        * Returns the binding for <code>key</code>, messaging the
  114        * parent <code>ActionMap</code> if the binding is not locally defined.
  115        */
  116       public Action get(Object key) {
  117           Action value = (arrayTable == null) ? null :
  118                          (Action)arrayTable.get(key);
  119   
  120           if (value == null) {
  121               ActionMap    parent = getParent();
  122   
  123               if (parent != null) {
  124                   return parent.get(key);
  125               }
  126           }
  127           return value;
  128       }
  129   
  130       /**
  131        * Removes the binding for <code>key</code> from this <code>ActionMap</code>.
  132        */
  133       public void remove(Object key) {
  134           if (arrayTable != null) {
  135               arrayTable.remove(key);
  136           }
  137       }
  138   
  139       /**
  140        * Removes all the mappings from this <code>ActionMap</code>.
  141        */
  142       public void clear() {
  143           if (arrayTable != null) {
  144               arrayTable.clear();
  145           }
  146       }
  147   
  148       /**
  149        * Returns the <code>Action</code> names that are bound in this <code>ActionMap</code>.
  150        */
  151       public Object[] keys() {
  152           if (arrayTable == null) {
  153               return null;
  154           }
  155           return arrayTable.getKeys(null);
  156       }
  157   
  158       /**
  159        * Returns the number of bindings in this {@code ActionMap}.
  160        *
  161        * @return the number of bindings in this {@code ActionMap}
  162        */
  163       public int size() {
  164           if (arrayTable == null) {
  165               return 0;
  166           }
  167           return arrayTable.size();
  168       }
  169   
  170       /**
  171        * Returns an array of the keys defined in this <code>ActionMap</code> and
  172        * its parent. This method differs from <code>keys()</code> in that
  173        * this method includes the keys defined in the parent.
  174        */
  175       public Object[] allKeys() {
  176           int           count = size();
  177           ActionMap     parent = getParent();
  178   
  179           if (count == 0) {
  180               if (parent != null) {
  181                   return parent.allKeys();
  182               }
  183               return keys();
  184           }
  185           if (parent == null) {
  186               return keys();
  187           }
  188           Object[]    keys = keys();
  189           Object[]    pKeys =  parent.allKeys();
  190   
  191           if (pKeys == null) {
  192               return keys;
  193           }
  194           if (keys == null) {
  195               // Should only happen if size() != keys.length, which should only
  196               // happen if mutated from multiple threads (or a bogus subclass).
  197               return pKeys;
  198           }
  199   
  200           HashMap<Object, Object> keyMap = new HashMap<Object, Object>();
  201           int            counter;
  202   
  203           for (counter = keys.length - 1; counter >= 0; counter--) {
  204               keyMap.put(keys[counter], keys[counter]);
  205           }
  206           for (counter = pKeys.length - 1; counter >= 0; counter--) {
  207               keyMap.put(pKeys[counter], pKeys[counter]);
  208           }
  209           return keyMap.keySet().toArray();
  210       }
  211   
  212       private void writeObject(ObjectOutputStream s) throws IOException {
  213           s.defaultWriteObject();
  214   
  215           ArrayTable.writeArrayTable(s, arrayTable);
  216       }
  217   
  218       private void readObject(ObjectInputStream s) throws ClassNotFoundException,
  219                                                    IOException {
  220           s.defaultReadObject();
  221           for (int counter = s.readInt() - 1; counter >= 0; counter--) {
  222               put(s.readObject(), (Action)s.readObject());
  223           }
  224       }
  225   }

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