1 /*

     2 * Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of the License "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description: 

    15 *

    16 */

    17 package com.nokia.carbide.internal.cpp.epoc.engine.model;

    18 

    19 import java.util.AbstractMap;

    20 import java.util.IdentityHashMap;

    21 import java.util.Iterator;

    22 import java.util.LinkedList;

    23 import java.util.Map;

    24 import java.util.Set;

    25 

    26 public class OrderedObjectMap<K,V> extends AbstractMap<K,V> {

    27 

    28 	IdentityHashMap<K, V> identityMap;

    29 	LinkedList<K> ordering;

    30 	

    31 	public OrderedObjectMap() {

    32 		this.identityMap = new IdentityHashMap<K, V>();

    33 		this.ordering = new LinkedList<K>();

    34 	}

    35 	

    36 	@Override

    37 	public Set entrySet() {

    38 		return identityMap.entrySet();

    39 	}

    40 

    41 	@Override

    42 	public V put(K key, V value) {

    43 		V orig = identityMap.put(key, value);

    44 		if (orig == null) {

    45 			ordering.add(key);

    46 		}

    47 		return orig;

    48 	}

    49 	

    50 	@Override

    51 	public V remove(Object key) {

    52 		ordering.remove(key);

    53 		return super.remove(key);

    54 	}

    55 	

    56 	/**

    57 	 * This method returns an iterator over the entries in

    58 	 * insertion order.

    59 	 * @return

    60 	 */

    61 	public Iterator<Map.Entry<K, V>> orderedIterator() {

    62 		return new Iterator<Entry<K,V>>() {

    63 			Iterator<K> listIterator = ordering.iterator();

    64 			K lastKey = null;

    65 			public boolean hasNext() {

    66 				return listIterator.hasNext();

    67 			}

    68 

    69 			public java.util.Map.Entry<K, V> next() {

    70 				lastKey = listIterator.next();

    71 				Entry<K,V> entry = new Entry<K,V>() {

    72 

    73 					public K getKey() {

    74 						return lastKey;

    75 					}

    76 

    77 					public V getValue() {

    78 						return identityMap.get(lastKey);

    79 					}

    80 

    81 					public V setValue(V value) {

    82 						return identityMap.put(lastKey, value);

    83 					}

    84 					

    85 				};

    86 				return entry;

    87 			}

    88 

    89 			public void remove() {

    90 				listIterator.remove();

    91 				identityMap.remove(lastKey);

    92 			}

    93 			

    94 		};

    95 	}

    96 

    97 	public Iterator<K> orderedKeyIterator() {

    98 		return ordering.iterator();

    99 	}

   100 }