| /******************************************************************************* |
| * Copyright (c) 2006, 2007 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.core.databinding.observable.map; |
| |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import org.eclipse.core.databinding.observable.Realm; |
| |
| /** |
| * |
| * <p> |
| * This class is thread safe. All state accessing methods must be invoked from |
| * the {@link Realm#isCurrent() current realm}. Methods for adding and removing |
| * listeners may be invoked from any thread. |
| * </p> |
| * @since 1.0 |
| * |
| */ |
| public class BidirectionalMap extends ObservableMap { |
| |
| private Map valueToElements = new HashMap(); |
| |
| private IMapChangeListener mapListener = new IMapChangeListener() { |
| |
| public void handleMapChange(MapChangeEvent event) { |
| MapDiff diff = event.diff; |
| for (Iterator it = diff.getAddedKeys().iterator(); it.hasNext();) { |
| Object addedKey = it.next(); |
| addMapping(addedKey, diff.getNewValue(addedKey)); |
| } |
| for (Iterator it = diff.getChangedKeys().iterator(); it.hasNext();) { |
| Object changedKey = it.next(); |
| removeMapping(changedKey, diff.getOldValue(changedKey)); |
| addMapping(changedKey, diff.getNewValue(changedKey)); |
| } |
| for (Iterator it = diff.getRemovedKeys().iterator(); it.hasNext();) { |
| Object removedKey = it.next(); |
| removeMapping(removedKey, diff.getOldValue(removedKey)); |
| } |
| fireMapChange(diff); |
| } |
| }; |
| |
| /** |
| * @param wrappedMap |
| */ |
| public BidirectionalMap(IObservableMap wrappedMap) { |
| super(wrappedMap.getRealm(), wrappedMap); |
| wrappedMap.addMapChangeListener(mapListener); |
| for (Iterator it = wrappedMap.entrySet().iterator(); it.hasNext();) { |
| Map.Entry entry = (Entry) it.next(); |
| addMapping(entry.getKey(), entry.getValue()); |
| } |
| } |
| |
| /** |
| * @param key |
| * @param value |
| */ |
| private void addMapping(Object key, Object value) { |
| Object elementOrSet = valueToElements.get(value); |
| if (elementOrSet == null) { |
| valueToElements.put(value, key); |
| return; |
| } |
| if (!(elementOrSet instanceof Set)) { |
| elementOrSet = new HashSet(Collections.singleton(elementOrSet)); |
| valueToElements.put(value, elementOrSet); |
| } |
| Set set = (Set) elementOrSet; |
| set.add(key); |
| } |
| |
| /** |
| * @param functionValue |
| * @param element |
| */ |
| private void removeMapping(Object functionValue, Object element) { |
| Object elementOrSet = valueToElements.get(functionValue); |
| if (elementOrSet instanceof Set) { |
| Set set = (Set) elementOrSet; |
| set.remove(element); |
| if (set.size() == 0) { |
| valueToElements.remove(functionValue); |
| } |
| } else { |
| valueToElements.remove(functionValue); |
| } |
| } |
| |
| } |